1 #ifndef USE_LIBSQLITE3
2 /*
3 ** 2001-09-15
4 **
5 ** The author disclaims copyright to this source code. In place of
6 ** a legal notice, here is a blessing:
7 **
8 ** May you do good and not evil.
9 ** May you find forgiveness for yourself and forgive others.
10 ** May you share freely, never taking more than you give.
11 **
12 *************************************************************************
13 ** This header file defines the interface that the SQLite library
14 ** presents to client programs. If a C-function, structure, datatype,
15 ** or constant definition does not appear in this file, then it is
16 ** not a published API of SQLite, is subject to change without
17 ** notice, and should not be referenced by programs that use SQLite.
18 **
19 ** Some of the definitions that are in this file are marked as
20 ** "experimental". Experimental interfaces are normally new
21 ** features recently added to SQLite. We do not anticipate changes
22 ** to experimental interfaces but reserve the right to make minor changes
23 ** if experience from use "in the wild" suggest such changes are prudent.
24 **
25 ** The official C-language API documentation for SQLite is derived
26 ** from comments in this file. This file is the authoritative source
27 ** on how SQLite interfaces are supposed to operate.
28 **
29 ** The name of this file under configuration management is "sqlite.h.in".
30 ** The makefile makes some minor changes to this file (such as inserting
31 ** the version number) and changes its name to "sqlite3.h" as
32 ** part of the build process.
33 */
34 #ifndef SQLITE3_H
35 #define SQLITE3_H
36 #include <stdarg.h> /* Needed for the definition of va_list */
37 38 /*
39 ** Make sure we can call this stuff from C++.
40 */
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44 45 46 /*
47 ** Facilitate override of interface linkage and calling conventions.
48 ** Be aware that these macros may not be used within this particular
49 ** translation of the amalgamation and its associated header file.
50 **
51 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
52 ** compiler that the target identifier should have external linkage.
53 **
54 ** The SQLITE_CDECL macro is used to set the calling convention for
55 ** public functions that accept a variable number of arguments.
56 **
57 ** The SQLITE_APICALL macro is used to set the calling convention for
58 ** public functions that accept a fixed number of arguments.
59 **
60 ** The SQLITE_STDCALL macro is no longer used and is now deprecated.
61 **
62 ** The SQLITE_CALLBACK macro is used to set the calling convention for
63 ** function pointers.
64 **
65 ** The SQLITE_SYSAPI macro is used to set the calling convention for
66 ** functions provided by the operating system.
67 **
68 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
69 ** SQLITE_SYSAPI macros are used only when building for environments
70 ** that require non-default calling conventions.
71 */
72 #ifndef SQLITE_EXTERN
73 # define SQLITE_EXTERN extern
74 #endif
75 #ifndef SQLITE_API
76 # define SQLITE_API
77 #endif
78 #ifndef SQLITE_CDECL
79 # define SQLITE_CDECL
80 #endif
81 #ifndef SQLITE_APICALL
82 # define SQLITE_APICALL
83 #endif
84 #ifndef SQLITE_STDCALL
85 # define SQLITE_STDCALL SQLITE_APICALL
86 #endif
87 #ifndef SQLITE_CALLBACK
88 # define SQLITE_CALLBACK
89 #endif
90 #ifndef SQLITE_SYSAPI
91 # define SQLITE_SYSAPI
92 #endif
93 94 /*
95 ** These no-op macros are used in front of interfaces to mark those
96 ** interfaces as either deprecated or experimental. New applications
97 ** should not use deprecated interfaces - they are supported for backwards
98 ** compatibility only. Application writers should be aware that
99 ** experimental interfaces are subject to change in point releases.
100 **
101 ** These macros used to resolve to various kinds of compiler magic that
102 ** would generate warning messages when they were used. But that
103 ** compiler magic ended up generating such a flurry of bug reports
104 ** that we have taken it all out and gone back to using simple
105 ** noop macros.
106 */
107 #define SQLITE_DEPRECATED
108 #define SQLITE_EXPERIMENTAL
109 110 /*
111 ** Ensure these symbols were not defined by some previous header file.
112 */
113 #ifdef SQLITE_VERSION
114 # undef SQLITE_VERSION
115 #endif
116 #ifdef SQLITE_VERSION_NUMBER
117 # undef SQLITE_VERSION_NUMBER
118 #endif
119 120 /*
121 ** CAPI3REF: Compile-Time Library Version Numbers
122 **
123 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
124 ** evaluates to a string literal that is the SQLite version in the
125 ** format "X.Y.Z" where X is the major version number (always 3 for
126 ** SQLite3) and Y is the minor version number and Z is the release number.)^
127 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
128 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
129 ** numbers used in [SQLITE_VERSION].)^
130 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
131 ** be larger than the release from which it is derived. Either Y will
132 ** be held constant and Z will be incremented or else Y will be incremented
133 ** and Z will be reset to zero.
134 **
135 ** Since [version 3.6.18] ([dateof:3.6.18]),
136 ** SQLite source code has been stored in the
137 ** <a href="http://fossil-scm.org/">Fossil configuration management
138 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
139 ** a string which identifies a particular check-in of SQLite
140 ** within its configuration management system. ^The SQLITE_SOURCE_ID
141 ** string contains the date and time of the check-in (UTC) and a SHA1
142 ** or SHA3-256 hash of the entire source tree. If the source code has
143 ** been edited in any way since it was last checked in, then the last
144 ** four hexadecimal digits of the hash may be modified.
145 **
146 ** See also: [sqlite3_libversion()],
147 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
148 ** [sqlite_version()] and [sqlite_source_id()].
149 */
150 #define SQLITE_VERSION "3.50.4"
151 #define SQLITE_VERSION_NUMBER 3050004
152 #define SQLITE_SOURCE_ID "2025-07-30 19:33:53 4d8adfb30e03f9cf27f800a2c1ba3c48fb4ca1b08b0f5ed59a4d5ecbf45e20a3"
153 154 /*
155 ** CAPI3REF: Run-Time Library Version Numbers
156 ** KEYWORDS: sqlite3_version sqlite3_sourceid
157 **
158 ** These interfaces provide the same information as the [SQLITE_VERSION],
159 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
160 ** but are associated with the library instead of the header file. ^(Cautious
161 ** programmers might include assert() statements in their application to
162 ** verify that values returned by these interfaces match the macros in
163 ** the header, and thus ensure that the application is
164 ** compiled with matching library and header files.
165 **
166 ** <blockquote><pre>
167 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
168 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
169 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
170 ** </pre></blockquote>)^
171 **
172 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
173 ** macro. ^The sqlite3_libversion() function returns a pointer to the
174 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
175 ** function is provided for use in DLLs since DLL users usually do not have
176 ** direct access to string constants within the DLL. ^The
177 ** sqlite3_libversion_number() function returns an integer equal to
178 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
179 ** a pointer to a string constant whose value is the same as the
180 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
181 ** using an edited copy of [the amalgamation], then the last four characters
182 ** of the hash might be different from [SQLITE_SOURCE_ID].)^
183 **
184 ** See also: [sqlite_version()] and [sqlite_source_id()].
185 */
186 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
187 SQLITE_API const char *sqlite3_libversion(void);
188 SQLITE_API const char *sqlite3_sourceid(void);
189 SQLITE_API int sqlite3_libversion_number(void);
190 191 /*
192 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
193 **
194 ** ^The sqlite3_compileoption_used() function returns 0 or 1
195 ** indicating whether the specified option was defined at
196 ** compile time. ^The SQLITE_ prefix may be omitted from the
197 ** option name passed to sqlite3_compileoption_used().
198 **
199 ** ^The sqlite3_compileoption_get() function allows iterating
200 ** over the list of options that were defined at compile time by
201 ** returning the N-th compile time option string. ^If N is out of range,
202 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
203 ** prefix is omitted from any strings returned by
204 ** sqlite3_compileoption_get().
205 **
206 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
207 ** and sqlite3_compileoption_get() may be omitted by specifying the
208 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
209 **
210 ** See also: SQL functions [sqlite_compileoption_used()] and
211 ** [sqlite_compileoption_get()] and the [compile_options pragma].
212 */
213 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
214 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
215 SQLITE_API const char *sqlite3_compileoption_get(int N);
216 #else
217 # define sqlite3_compileoption_used(X) 0
218 # define sqlite3_compileoption_get(X) ((void*)0)
219 #endif
220 221 /*
222 ** CAPI3REF: Test To See If The Library Is Threadsafe
223 **
224 ** ^The sqlite3_threadsafe() function returns zero if and only if
225 ** SQLite was compiled with mutexing code omitted due to the
226 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
227 **
228 ** SQLite can be compiled with or without mutexes. When
229 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
230 ** are enabled and SQLite is threadsafe. When the
231 ** [SQLITE_THREADSAFE] macro is 0,
232 ** the mutexes are omitted. Without the mutexes, it is not safe
233 ** to use SQLite concurrently from more than one thread.
234 **
235 ** Enabling mutexes incurs a measurable performance penalty.
236 ** So if speed is of utmost importance, it makes sense to disable
237 ** the mutexes. But for maximum safety, mutexes should be enabled.
238 ** ^The default behavior is for mutexes to be enabled.
239 **
240 ** This interface can be used by an application to make sure that the
241 ** version of SQLite that it is linking against was compiled with
242 ** the desired setting of the [SQLITE_THREADSAFE] macro.
243 **
244 ** This interface only reports on the compile-time mutex setting
245 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
246 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
247 ** can be fully or partially disabled using a call to [sqlite3_config()]
248 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
249 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
250 ** sqlite3_threadsafe() function shows only the compile-time setting of
251 ** thread safety, not any run-time changes to that setting made by
252 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
253 ** is unchanged by calls to sqlite3_config().)^
254 **
255 ** See the [threading mode] documentation for additional information.
256 */
257 SQLITE_API int sqlite3_threadsafe(void);
258 259 /*
260 ** CAPI3REF: Database Connection Handle
261 ** KEYWORDS: {database connection} {database connections}
262 **
263 ** Each open SQLite database is represented by a pointer to an instance of
264 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
265 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
266 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
267 ** and [sqlite3_close_v2()] are its destructors. There are many other
268 ** interfaces (such as
269 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
270 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
271 ** sqlite3 object.
272 */
273 typedef struct sqlite3 sqlite3;
274 275 /*
276 ** CAPI3REF: 64-Bit Integer Types
277 ** KEYWORDS: sqlite_int64 sqlite_uint64
278 **
279 ** Because there is no cross-platform way to specify 64-bit integer types
280 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
281 **
282 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
283 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
284 ** compatibility only.
285 **
286 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
287 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
288 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
289 ** between 0 and +18446744073709551615 inclusive.
290 */
291 #ifdef SQLITE_INT64_TYPE
292 typedef SQLITE_INT64_TYPE sqlite_int64;
293 # ifdef SQLITE_UINT64_TYPE
294 typedef SQLITE_UINT64_TYPE sqlite_uint64;
295 # else
296 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
297 # endif
298 #elif defined(_MSC_VER) || defined(__BORLANDC__)
299 typedef __int64 sqlite_int64;
300 typedef unsigned __int64 sqlite_uint64;
301 #else
302 typedef long long int sqlite_int64;
303 typedef unsigned long long int sqlite_uint64;
304 #endif
305 typedef sqlite_int64 sqlite3_int64;
306 typedef sqlite_uint64 sqlite3_uint64;
307 308 /*
309 ** If compiling for a processor that lacks floating point support,
310 ** substitute integer for floating-point.
311 */
312 #ifdef SQLITE_OMIT_FLOATING_POINT
313 # define double sqlite3_int64
314 #endif
315 316 /*
317 ** CAPI3REF: Closing A Database Connection
318 ** DESTRUCTOR: sqlite3
319 **
320 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
321 ** for the [sqlite3] object.
322 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
323 ** the [sqlite3] object is successfully destroyed and all associated
324 ** resources are deallocated.
325 **
326 ** Ideally, applications should [sqlite3_finalize | finalize] all
327 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
328 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
329 ** with the [sqlite3] object prior to attempting to close the object.
330 ** ^If the database connection is associated with unfinalized prepared
331 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
332 ** sqlite3_close() will leave the database connection open and return
333 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
334 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
335 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database
336 ** connection immediately, it marks the database connection as an unusable
337 ** "zombie" and makes arrangements to automatically deallocate the database
338 ** connection after all prepared statements are finalized, all BLOB handles
339 ** are closed, and all backups have finished. The sqlite3_close_v2() interface
340 ** is intended for use with host languages that are garbage collected, and
341 ** where the order in which destructors are called is arbitrary.
342 **
343 ** ^If an [sqlite3] object is destroyed while a transaction is open,
344 ** the transaction is automatically rolled back.
345 **
346 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
347 ** must be either a NULL
348 ** pointer or an [sqlite3] object pointer obtained
349 ** from [sqlite3_open()], [sqlite3_open16()], or
350 ** [sqlite3_open_v2()], and not previously closed.
351 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
352 ** argument is a harmless no-op.
353 */
354 SQLITE_API int sqlite3_close(sqlite3*);
355 SQLITE_API int sqlite3_close_v2(sqlite3*);
356 357 /*
358 ** The type for a callback function.
359 ** This is legacy and deprecated. It is included for historical
360 ** compatibility and is not documented.
361 */
362 typedef int (*sqlite3_callback)(void*,int,char**, char**);
363 364 /*
365 ** CAPI3REF: One-Step Query Execution Interface
366 ** METHOD: sqlite3
367 **
368 ** The sqlite3_exec() interface is a convenience wrapper around
369 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
370 ** that allows an application to run multiple statements of SQL
371 ** without having to use a lot of C code.
372 **
373 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
374 ** semicolon-separate SQL statements passed into its 2nd argument,
375 ** in the context of the [database connection] passed in as its 1st
376 ** argument. ^If the callback function of the 3rd argument to
377 ** sqlite3_exec() is not NULL, then it is invoked for each result row
378 ** coming out of the evaluated SQL statements. ^The 4th argument to
379 ** sqlite3_exec() is relayed through to the 1st argument of each
380 ** callback invocation. ^If the callback pointer to sqlite3_exec()
381 ** is NULL, then no callback is ever invoked and result rows are
382 ** ignored.
383 **
384 ** ^If an error occurs while evaluating the SQL statements passed into
385 ** sqlite3_exec(), then execution of the current statement stops and
386 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
387 ** is not NULL then any error message is written into memory obtained
388 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
389 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
390 ** on error message strings returned through the 5th parameter of
391 ** sqlite3_exec() after the error message string is no longer needed.
392 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
393 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
394 ** NULL before returning.
395 **
396 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
397 ** routine returns SQLITE_ABORT without invoking the callback again and
398 ** without running any subsequent SQL statements.
399 **
400 ** ^The 2nd argument to the sqlite3_exec() callback function is the
401 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
402 ** callback is an array of pointers to strings obtained as if from
403 ** [sqlite3_column_text()], one for each column. ^If an element of a
404 ** result row is NULL then the corresponding string pointer for the
405 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
406 ** sqlite3_exec() callback is an array of pointers to strings where each
407 ** entry represents the name of corresponding result column as obtained
408 ** from [sqlite3_column_name()].
409 **
410 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
411 ** to an empty string, or a pointer that contains only whitespace and/or
412 ** SQL comments, then no SQL statements are evaluated and the database
413 ** is not changed.
414 **
415 ** Restrictions:
416 **
417 ** <ul>
418 ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
419 ** is a valid and open [database connection].
420 ** <li> The application must not close the [database connection] specified by
421 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
422 ** <li> The application must not modify the SQL statement text passed into
423 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
424 ** <li> The application must not dereference the arrays or string pointers
425 ** passed as the 3rd and 4th callback parameters after it returns.
426 ** </ul>
427 */
428 SQLITE_API int sqlite3_exec(
429 sqlite3*, /* An open database */
430 const char *sql, /* SQL to be evaluated */
431 int (*callback)(void*,int,char**,char**), /* Callback function */
432 void *, /* 1st argument to callback */
433 char **errmsg /* Error msg written here */
434 );
435 436 /*
437 ** CAPI3REF: Result Codes
438 ** KEYWORDS: {result code definitions}
439 **
440 ** Many SQLite functions return an integer result code from the set shown
441 ** here in order to indicate success or failure.
442 **
443 ** New error codes may be added in future versions of SQLite.
444 **
445 ** See also: [extended result code definitions]
446 */
447 #define SQLITE_OK 0 /* Successful result */
448 /* beginning-of-error-codes */
449 #define SQLITE_ERROR 1 /* Generic error */
450 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
451 #define SQLITE_PERM 3 /* Access permission denied */
452 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
453 #define SQLITE_BUSY 5 /* The database file is locked */
454 #define SQLITE_LOCKED 6 /* A table in the database is locked */
455 #define SQLITE_NOMEM 7 /* A malloc() failed */
456 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
457 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
458 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
459 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
460 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
461 #define SQLITE_FULL 13 /* Insertion failed because database is full */
462 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
463 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
464 #define SQLITE_EMPTY 16 /* Internal use only */
465 #define SQLITE_SCHEMA 17 /* The database schema changed */
466 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
467 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
468 #define SQLITE_MISMATCH 20 /* Data type mismatch */
469 #define SQLITE_MISUSE 21 /* Library used incorrectly */
470 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
471 #define SQLITE_AUTH 23 /* Authorization denied */
472 #define SQLITE_FORMAT 24 /* Not used */
473 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
474 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
475 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
476 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
477 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
478 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
479 /* end-of-error-codes */
480 481 /*
482 ** CAPI3REF: Extended Result Codes
483 ** KEYWORDS: {extended result code definitions}
484 **
485 ** In its default configuration, SQLite API routines return one of 30 integer
486 ** [result codes]. However, experience has shown that many of
487 ** these result codes are too coarse-grained. They do not provide as
488 ** much information about problems as programmers might like. In an effort to
489 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
490 ** and later) include
491 ** support for additional result codes that provide more detailed information
492 ** about errors. These [extended result codes] are enabled or disabled
493 ** on a per database connection basis using the
494 ** [sqlite3_extended_result_codes()] API. Or, the extended code for
495 ** the most recent error can be obtained using
496 ** [sqlite3_extended_errcode()].
497 */
498 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
499 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
500 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
501 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
502 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
503 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
504 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
505 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
506 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
507 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
508 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
509 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
510 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
511 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
512 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
513 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
514 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
515 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
516 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
517 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
518 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
519 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
520 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
521 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
522 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
523 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
524 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
525 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
526 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
527 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
528 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
529 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
530 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
531 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
532 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
533 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
534 #define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
535 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
536 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
537 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
538 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
539 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
540 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
541 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
542 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
543 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
544 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
545 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
546 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
547 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
548 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
549 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
550 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
551 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
552 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
553 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
554 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
555 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
556 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
557 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
558 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
559 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
560 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
561 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
562 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
563 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
564 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
565 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
566 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
567 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
568 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
569 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
570 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
571 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
572 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
573 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
574 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
575 576 /*
577 ** CAPI3REF: Flags For File Open Operations
578 **
579 ** These bit values are intended for use in the
580 ** 3rd parameter to the [sqlite3_open_v2()] interface and
581 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
582 **
583 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be
584 ** used as the third argument to the [sqlite3_open_v2()] interface.
585 ** The other flags have historically been ignored by sqlite3_open_v2(),
586 ** though future versions of SQLite might change so that an error is
587 ** raised if any of the disallowed bits are passed into sqlite3_open_v2().
588 ** Applications should not depend on the historical behavior.
589 **
590 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
591 ** [sqlite3_open_v2()] does *not* cause the underlying database file
592 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
593 ** [sqlite3_open_v2()] has historically be a no-op and might become an
594 ** error in future versions of SQLite.
595 */
596 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
597 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
598 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
599 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
600 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
601 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
602 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
603 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
604 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
605 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
606 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
607 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
608 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
609 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
610 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
611 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
612 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
613 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
614 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
615 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
616 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
617 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
618 619 /* Reserved: 0x00F00000 */
620 /* Legacy compatibility: */
621 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
622 623 624 /*
625 ** CAPI3REF: Device Characteristics
626 **
627 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
628 ** object returns an integer which is a vector of these
629 ** bit values expressing I/O characteristics of the mass storage
630 ** device that holds the file that the [sqlite3_io_methods]
631 ** refers to.
632 **
633 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
634 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
635 ** mean that writes of blocks that are nnn bytes in size and
636 ** are aligned to an address which is an integer multiple of
637 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
638 ** that when data is appended to a file, the data is appended
639 ** first then the size of the file is extended, never the other
640 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
641 ** information is written to disk in the same order as calls
642 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
643 ** after reboot following a crash or power loss, the only bytes in a
644 ** file that were written at the application level might have changed
645 ** and that adjacent bytes, even bytes within the same sector are
646 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
647 ** flag indicates that a file cannot be deleted when open. The
648 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
649 ** read-only media and cannot be changed even by processes with
650 ** elevated privileges.
651 **
652 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
653 ** filesystem supports doing multiple write operations atomically when those
654 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
655 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
656 **
657 ** The SQLITE_IOCAP_SUBPAGE_READ property means that it is ok to read
658 ** from the database file in amounts that are not a multiple of the
659 ** page size and that do not begin at a page boundary. Without this
660 ** property, SQLite is careful to only do full-page reads and write
661 ** on aligned pages, with the one exception that it will do a sub-page
662 ** read of the first page to access the database header.
663 */
664 #define SQLITE_IOCAP_ATOMIC 0x00000001
665 #define SQLITE_IOCAP_ATOMIC512 0x00000002
666 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
667 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
668 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
669 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
670 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
671 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
672 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
673 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
674 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
675 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
676 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
677 #define SQLITE_IOCAP_IMMUTABLE 0x00002000
678 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
679 #define SQLITE_IOCAP_SUBPAGE_READ 0x00008000
680 681 /*
682 ** CAPI3REF: File Locking Levels
683 **
684 ** SQLite uses one of these integer values as the second
685 ** argument to calls it makes to the xLock() and xUnlock() methods
686 ** of an [sqlite3_io_methods] object. These values are ordered from
687 ** lest restrictive to most restrictive.
688 **
689 ** The argument to xLock() is always SHARED or higher. The argument to
690 ** xUnlock is either SHARED or NONE.
691 */
692 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */
693 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
694 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */
695 #define SQLITE_LOCK_PENDING 3 /* xLock() only */
696 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
697 698 /*
699 ** CAPI3REF: Synchronization Type Flags
700 **
701 ** When SQLite invokes the xSync() method of an
702 ** [sqlite3_io_methods] object it uses a combination of
703 ** these integer values as the second argument.
704 **
705 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
706 ** sync operation only needs to flush data to mass storage. Inode
707 ** information need not be flushed. If the lower four bits of the flag
708 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
709 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
710 ** to use Mac OS X style fullsync instead of fsync().
711 **
712 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
713 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
714 ** settings. The [synchronous pragma] determines when calls to the
715 ** xSync VFS method occur and applies uniformly across all platforms.
716 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
717 ** energetic or rigorous or forceful the sync operations are and
718 ** only make a difference on Mac OSX for the default SQLite code.
719 ** (Third-party VFS implementations might also make the distinction
720 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
721 ** operating systems natively supported by SQLite, only Mac OSX
722 ** cares about the difference.)
723 */
724 #define SQLITE_SYNC_NORMAL 0x00002
725 #define SQLITE_SYNC_FULL 0x00003
726 #define SQLITE_SYNC_DATAONLY 0x00010
727 728 /*
729 ** CAPI3REF: OS Interface Open File Handle
730 **
731 ** An [sqlite3_file] object represents an open file in the
732 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
733 ** implementations will
734 ** want to subclass this object by appending additional fields
735 ** for their own use. The pMethods entry is a pointer to an
736 ** [sqlite3_io_methods] object that defines methods for performing
737 ** I/O operations on the open file.
738 */
739 typedef struct sqlite3_file sqlite3_file;
740 struct sqlite3_file {
741 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
742 };
743 744 /*
745 ** CAPI3REF: OS Interface File Virtual Methods Object
746 **
747 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
748 ** [sqlite3_file] object (or, more commonly, a subclass of the
749 ** [sqlite3_file] object) with a pointer to an instance of this object.
750 ** This object defines the methods used to perform various operations
751 ** against the open file represented by the [sqlite3_file] object.
752 **
753 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
754 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
755 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
756 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
757 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
758 ** to NULL.
759 **
760 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
761 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
762 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
763 ** flag may be ORed in to indicate that only the data of the file
764 ** and not its inode needs to be synced.
765 **
766 ** The integer values to xLock() and xUnlock() are one of
767 ** <ul>
768 ** <li> [SQLITE_LOCK_NONE],
769 ** <li> [SQLITE_LOCK_SHARED],
770 ** <li> [SQLITE_LOCK_RESERVED],
771 ** <li> [SQLITE_LOCK_PENDING], or
772 ** <li> [SQLITE_LOCK_EXCLUSIVE].
773 ** </ul>
774 ** xLock() upgrades the database file lock. In other words, xLock() moves the
775 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to
776 ** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
777 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the
778 ** requested lock, then the call to xLock() is a no-op.
779 ** xUnlock() downgrades the database file lock to either SHARED or NONE.
780 ** If the lock is already at or below the requested lock state, then the call
781 ** to xUnlock() is a no-op.
782 ** The xCheckReservedLock() method checks whether any database connection,
783 ** either in this process or in some other process, is holding a RESERVED,
784 ** PENDING, or EXCLUSIVE lock on the file. It returns, via its output
785 ** pointer parameter, true if such a lock exists and false otherwise.
786 **
787 ** The xFileControl() method is a generic interface that allows custom
788 ** VFS implementations to directly control an open file using the
789 ** [sqlite3_file_control()] interface. The second "op" argument is an
790 ** integer opcode. The third argument is a generic pointer intended to
791 ** point to a structure that may contain arguments or space in which to
792 ** write return values. Potential uses for xFileControl() might be
793 ** functions to enable blocking locks with timeouts, to change the
794 ** locking strategy (for example to use dot-file locks), to inquire
795 ** about the status of a lock, or to break stale locks. The SQLite
796 ** core reserves all opcodes less than 100 for its own use.
797 ** A [file control opcodes | list of opcodes] less than 100 is available.
798 ** Applications that define a custom xFileControl method should use opcodes
799 ** greater than 100 to avoid conflicts. VFS implementations should
800 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
801 ** recognize.
802 **
803 ** The xSectorSize() method returns the sector size of the
804 ** device that underlies the file. The sector size is the
805 ** minimum write that can be performed without disturbing
806 ** other bytes in the file. The xDeviceCharacteristics()
807 ** method returns a bit vector describing behaviors of the
808 ** underlying device:
809 **
810 ** <ul>
811 ** <li> [SQLITE_IOCAP_ATOMIC]
812 ** <li> [SQLITE_IOCAP_ATOMIC512]
813 ** <li> [SQLITE_IOCAP_ATOMIC1K]
814 ** <li> [SQLITE_IOCAP_ATOMIC2K]
815 ** <li> [SQLITE_IOCAP_ATOMIC4K]
816 ** <li> [SQLITE_IOCAP_ATOMIC8K]
817 ** <li> [SQLITE_IOCAP_ATOMIC16K]
818 ** <li> [SQLITE_IOCAP_ATOMIC32K]
819 ** <li> [SQLITE_IOCAP_ATOMIC64K]
820 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
821 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
822 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
823 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
824 ** <li> [SQLITE_IOCAP_IMMUTABLE]
825 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
826 ** <li> [SQLITE_IOCAP_SUBPAGE_READ]
827 ** </ul>
828 **
829 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
830 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
831 ** mean that writes of blocks that are nnn bytes in size and
832 ** are aligned to an address which is an integer multiple of
833 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
834 ** that when data is appended to a file, the data is appended
835 ** first then the size of the file is extended, never the other
836 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
837 ** information is written to disk in the same order as calls
838 ** to xWrite().
839 **
840 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
841 ** in the unread portions of the buffer with zeros. A VFS that
842 ** fails to zero-fill short reads might seem to work. However,
843 ** failure to zero-fill short reads will eventually lead to
844 ** database corruption.
845 */
846 typedef struct sqlite3_io_methods sqlite3_io_methods;
847 struct sqlite3_io_methods {
848 int iVersion;
849 int (*xClose)(sqlite3_file*);
850 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
851 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
852 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
853 int (*xSync)(sqlite3_file*, int flags);
854 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
855 int (*xLock)(sqlite3_file*, int);
856 int (*xUnlock)(sqlite3_file*, int);
857 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
858 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
859 int (*xSectorSize)(sqlite3_file*);
860 int (*xDeviceCharacteristics)(sqlite3_file*);
861 /* Methods above are valid for version 1 */
862 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
863 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
864 void (*xShmBarrier)(sqlite3_file*);
865 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
866 /* Methods above are valid for version 2 */
867 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
868 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
869 /* Methods above are valid for version 3 */
870 /* Additional methods may be added in future releases */
871 };
872 873 /*
874 ** CAPI3REF: Standard File Control Opcodes
875 ** KEYWORDS: {file control opcodes} {file control opcode}
876 **
877 ** These integer constants are opcodes for the xFileControl method
878 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
879 ** interface.
880 **
881 ** <ul>
882 ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
883 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
884 ** opcode causes the xFileControl method to write the current state of
885 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
886 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
887 ** into an integer that the pArg argument points to.
888 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
889 **
890 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
891 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
892 ** layer a hint of how large the database file will grow to be during the
893 ** current transaction. This hint is not guaranteed to be accurate but it
894 ** is often close. The underlying VFS might choose to preallocate database
895 ** file space based on this hint in order to help writes to the database
896 ** file run faster.
897 **
898 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
899 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
900 ** implements [sqlite3_deserialize()] to set an upper bound on the size
901 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
902 ** If the integer pointed to is negative, then it is filled in with the
903 ** current limit. Otherwise the limit is set to the larger of the value
904 ** of the integer pointed to and the current database size. The integer
905 ** pointed to is set to the new limit.
906 **
907 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
908 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
909 ** extends and truncates the database file in chunks of a size specified
910 ** by the user. The fourth argument to [sqlite3_file_control()] should
911 ** point to an integer (type int) containing the new chunk-size to use
912 ** for the nominated database. Allocating database file space in large
913 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
914 ** improve performance on some systems.
915 **
916 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
917 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
918 ** to the [sqlite3_file] object associated with a particular database
919 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
920 **
921 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
922 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
923 ** to the [sqlite3_file] object associated with the journal file (either
924 ** the [rollback journal] or the [write-ahead log]) for a particular database
925 ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
926 **
927 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
928 ** No longer in use.
929 **
930 ** <li>[[SQLITE_FCNTL_SYNC]]
931 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
932 ** sent to the VFS immediately before the xSync method is invoked on a
933 ** database file descriptor. Or, if the xSync method is not invoked
934 ** because the user has configured SQLite with
935 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
936 ** of the xSync method. In most cases, the pointer argument passed with
937 ** this file-control is NULL. However, if the database file is being synced
938 ** as part of a multi-database commit, the argument points to a nul-terminated
939 ** string containing the transactions super-journal file name. VFSes that
940 ** do not need this signal should silently ignore this opcode. Applications
941 ** should not call [sqlite3_file_control()] with this opcode as doing so may
942 ** disrupt the operation of the specialized VFSes that do require it.
943 **
944 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
945 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
946 ** and sent to the VFS after a transaction has been committed immediately
947 ** but before the database is unlocked. VFSes that do not need this signal
948 ** should silently ignore this opcode. Applications should not call
949 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
950 ** operation of the specialized VFSes that do require it.
951 **
952 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
953 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
954 ** retry counts and intervals for certain disk I/O operations for the
955 ** windows [VFS] in order to provide robustness in the presence of
956 ** anti-virus programs. By default, the windows VFS will retry file read,
957 ** file write, and file delete operations up to 10 times, with a delay
958 ** of 25 milliseconds before the first retry and with the delay increasing
959 ** by an additional 25 milliseconds with each subsequent retry. This
960 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
961 ** to be adjusted. The values are changed for all database connections
962 ** within the same process. The argument is a pointer to an array of two
963 ** integers where the first integer is the new retry count and the second
964 ** integer is the delay. If either integer is negative, then the setting
965 ** is not changed but instead the prior value of that setting is written
966 ** into the array entry, allowing the current retry settings to be
967 ** interrogated. The zDbName parameter is ignored.
968 **
969 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
970 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
971 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
972 ** write ahead log ([WAL file]) and shared memory
973 ** files used for transaction control
974 ** are automatically deleted when the latest connection to the database
975 ** closes. Setting persistent WAL mode causes those files to persist after
976 ** close. Persisting the files is useful when other processes that do not
977 ** have write permission on the directory containing the database file want
978 ** to read the database file, as the WAL and shared memory files must exist
979 ** in order for the database to be readable. The fourth parameter to
980 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
981 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
982 ** WAL mode. If the integer is -1, then it is overwritten with the current
983 ** WAL persistence setting.
984 **
985 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
986 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
987 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
988 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
989 ** xDeviceCharacteristics methods. The fourth parameter to
990 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
991 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
992 ** mode. If the integer is -1, then it is overwritten with the current
993 ** zero-damage mode setting.
994 **
995 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
996 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
997 ** a write transaction to indicate that, unless it is rolled back for some
998 ** reason, the entire database file will be overwritten by the current
999 ** transaction. This is used by VACUUM operations.
1000 **
1001 ** <li>[[SQLITE_FCNTL_VFSNAME]]
1002 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
1003 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
1004 ** final bottom-level VFS are written into memory obtained from
1005 ** [sqlite3_malloc()] and the result is stored in the char* variable
1006 ** that the fourth parameter of [sqlite3_file_control()] points to.
1007 ** The caller is responsible for freeing the memory when done. As with
1008 ** all file-control actions, there is no guarantee that this will actually
1009 ** do anything. Callers should initialize the char* variable to a NULL
1010 ** pointer in case this file-control is not implemented. This file-control
1011 ** is intended for diagnostic use only.
1012 **
1013 ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1014 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1015 ** [VFSes] currently in use. ^(The argument X in
1016 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1017 ** of type "[sqlite3_vfs] **". This opcodes will set *X
1018 ** to a pointer to the top-level VFS.)^
1019 ** ^When there are multiple VFS shims in the stack, this opcode finds the
1020 ** upper-most shim only.
1021 **
1022 ** <li>[[SQLITE_FCNTL_PRAGMA]]
1023 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1024 ** file control is sent to the open [sqlite3_file] object corresponding
1025 ** to the database file to which the pragma statement refers. ^The argument
1026 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1027 ** pointers to strings (char**) in which the second element of the array
1028 ** is the name of the pragma and the third element is the argument to the
1029 ** pragma or NULL if the pragma has no argument. ^The handler for an
1030 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1031 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1032 ** or the equivalent and that string will become the result of the pragma or
1033 ** the error message if the pragma fails. ^If the
1034 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1035 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1036 ** file control returns [SQLITE_OK], then the parser assumes that the
1037 ** VFS has handled the PRAGMA itself and the parser generates a no-op
1038 ** prepared statement if result string is NULL, or that returns a copy
1039 ** of the result string if the string is non-NULL.
1040 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1041 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1042 ** that the VFS encountered an error while handling the [PRAGMA] and the
1043 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1044 ** file control occurs at the beginning of pragma statement analysis and so
1045 ** it is able to override built-in [PRAGMA] statements.
1046 **
1047 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1048 ** ^The [SQLITE_FCNTL_BUSYHANDLER]
1049 ** file-control may be invoked by SQLite on the database file handle
1050 ** shortly after it is opened in order to provide a custom VFS with access
1051 ** to the connection's busy-handler callback. The argument is of type (void**)
1052 ** - an array of two (void *) values. The first (void *) actually points
1053 ** to a function of type (int (*)(void *)). In order to invoke the connection's
1054 ** busy-handler, this function should be invoked with the second (void *) in
1055 ** the array as the only argument. If it returns non-zero, then the operation
1056 ** should be retried. If it returns zero, the custom VFS should abandon the
1057 ** current operation.
1058 **
1059 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1060 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1061 ** to have SQLite generate a
1062 ** temporary filename using the same algorithm that is followed to generate
1063 ** temporary filenames for TEMP tables and other internal uses. The
1064 ** argument should be a char** which will be filled with the filename
1065 ** written into memory obtained from [sqlite3_malloc()]. The caller should
1066 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
1067 **
1068 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1069 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1070 ** maximum number of bytes that will be used for memory-mapped I/O.
1071 ** The argument is a pointer to a value of type sqlite3_int64 that
1072 ** is an advisory maximum number of bytes in the file to memory map. The
1073 ** pointer is overwritten with the old value. The limit is not changed if
1074 ** the value originally pointed to is negative, and so the current limit
1075 ** can be queried by passing in a pointer to a negative number. This
1076 ** file-control is used internally to implement [PRAGMA mmap_size].
1077 **
1078 ** <li>[[SQLITE_FCNTL_TRACE]]
1079 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1080 ** to the VFS about what the higher layers of the SQLite stack are doing.
1081 ** This file control is used by some VFS activity tracing [shims].
1082 ** The argument is a zero-terminated string. Higher layers in the
1083 ** SQLite stack may generate instances of this file control if
1084 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1085 **
1086 ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1087 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1088 ** pointer to an integer and it writes a boolean into that integer depending
1089 ** on whether or not the file has been renamed, moved, or deleted since it
1090 ** was first opened.
1091 **
1092 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1093 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1094 ** underlying native file handle associated with a file handle. This file
1095 ** control interprets its argument as a pointer to a native file handle and
1096 ** writes the resulting value there.
1097 **
1098 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1099 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1100 ** opcode causes the xFileControl method to swap the file handle with the one
1101 ** pointed to by the pArg argument. This capability is used during testing
1102 ** and only needs to be supported when SQLITE_TEST is defined.
1103 **
1104 ** <li>[[SQLITE_FCNTL_NULL_IO]]
1105 ** The [SQLITE_FCNTL_NULL_IO] opcode sets the low-level file descriptor
1106 ** or file handle for the [sqlite3_file] object such that it will no longer
1107 ** read or write to the database file.
1108 **
1109 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1110 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1111 ** be advantageous to block on the next WAL lock if the lock is not immediately
1112 ** available. The WAL subsystem issues this signal during rare
1113 ** circumstances in order to fix a problem with priority inversion.
1114 ** Applications should <em>not</em> use this file-control.
1115 **
1116 ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1117 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1118 ** VFS should return SQLITE_NOTFOUND for this opcode.
1119 **
1120 ** <li>[[SQLITE_FCNTL_RBU]]
1121 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1122 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1123 ** this opcode.
1124 **
1125 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1126 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1127 ** the file descriptor is placed in "batch write mode", which
1128 ** means all subsequent write operations will be deferred and done
1129 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1130 ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1131 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1132 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1133 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1134 ** no VFS interface calls on the same [sqlite3_file] file descriptor
1135 ** except for calls to the xWrite method and the xFileControl method
1136 ** with [SQLITE_FCNTL_SIZE_HINT].
1137 **
1138 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1139 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1140 ** operations since the previous successful call to
1141 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1142 ** This file control returns [SQLITE_OK] if and only if the writes were
1143 ** all performed successfully and have been committed to persistent storage.
1144 ** ^Regardless of whether or not it is successful, this file control takes
1145 ** the file descriptor out of batch write mode so that all subsequent
1146 ** write operations are independent.
1147 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1148 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1149 **
1150 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1151 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1152 ** operations since the previous successful call to
1153 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1154 ** ^This file control takes the file descriptor out of batch write mode
1155 ** so that all subsequent write operations are independent.
1156 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1157 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1158 **
1159 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1160 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1161 ** to block for up to M milliseconds before failing when attempting to
1162 ** obtain a file lock using the xLock or xShmLock methods of the VFS.
1163 ** The parameter is a pointer to a 32-bit signed integer that contains
1164 ** the value that M is to be set to. Before returning, the 32-bit signed
1165 ** integer is overwritten with the previous value of M.
1166 **
1167 ** <li>[[SQLITE_FCNTL_BLOCK_ON_CONNECT]]
1168 ** The [SQLITE_FCNTL_BLOCK_ON_CONNECT] opcode is used to configure the
1169 ** VFS to block when taking a SHARED lock to connect to a wal mode database.
1170 ** This is used to implement the functionality associated with
1171 ** SQLITE_SETLK_BLOCK_ON_CONNECT.
1172 **
1173 ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1174 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1175 ** a database file. The argument is a pointer to a 32-bit unsigned integer.
1176 ** The "data version" for the pager is written into the pointer. The
1177 ** "data version" changes whenever any change occurs to the corresponding
1178 ** database file, either through SQL statements on the same database
1179 ** connection or through transactions committed by separate database
1180 ** connections possibly in other processes. The [sqlite3_total_changes()]
1181 ** interface can be used to find if any database on the connection has changed,
1182 ** but that interface responds to changes on TEMP as well as MAIN and does
1183 ** not provide a mechanism to detect changes to MAIN only. Also, the
1184 ** [sqlite3_total_changes()] interface responds to internal changes only and
1185 ** omits changes made by other database connections. The
1186 ** [PRAGMA data_version] command provides a mechanism to detect changes to
1187 ** a single attached database that occur due to other database connections,
1188 ** but omits changes implemented by the database connection on which it is
1189 ** called. This file control is the only mechanism to detect changes that
1190 ** happen either internally or externally and that are associated with
1191 ** a particular attached database.
1192 **
1193 ** <li>[[SQLITE_FCNTL_CKPT_START]]
1194 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1195 ** in wal mode before the client starts to copy pages from the wal
1196 ** file to the database file.
1197 **
1198 ** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1199 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1200 ** in wal mode after the client has finished copying pages from the wal
1201 ** file to the database file, but before the *-shm file is updated to
1202 ** record the fact that the pages have been checkpointed.
1203 **
1204 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1205 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1206 ** whether or not there is a database client in another process with a wal-mode
1207 ** transaction open on the database or not. It is only available on unix.The
1208 ** (void*) argument passed with this file-control should be a pointer to a
1209 ** value of type (int). The integer value is set to 1 if the database is a wal
1210 ** mode database and there exists at least one client in another process that
1211 ** currently has an SQL transaction open on the database. It is set to 0 if
1212 ** the database is not a wal-mode db, or if there is no such connection in any
1213 ** other process. This opcode cannot be used to detect transactions opened
1214 ** by clients within the current process, only within other processes.
1215 **
1216 ** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1217 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1218 ** [checksum VFS shim] only.
1219 **
1220 ** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1221 ** If there is currently no transaction open on the database, and the
1222 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1223 ** purges the contents of the in-memory page cache. If there is an open
1224 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1225 ** </ul>
1226 */
1227 #define SQLITE_FCNTL_LOCKSTATE 1
1228 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1229 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1230 #define SQLITE_FCNTL_LAST_ERRNO 4
1231 #define SQLITE_FCNTL_SIZE_HINT 5
1232 #define SQLITE_FCNTL_CHUNK_SIZE 6
1233 #define SQLITE_FCNTL_FILE_POINTER 7
1234 #define SQLITE_FCNTL_SYNC_OMITTED 8
1235 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1236 #define SQLITE_FCNTL_PERSIST_WAL 10
1237 #define SQLITE_FCNTL_OVERWRITE 11
1238 #define SQLITE_FCNTL_VFSNAME 12
1239 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1240 #define SQLITE_FCNTL_PRAGMA 14
1241 #define SQLITE_FCNTL_BUSYHANDLER 15
1242 #define SQLITE_FCNTL_TEMPFILENAME 16
1243 #define SQLITE_FCNTL_MMAP_SIZE 18
1244 #define SQLITE_FCNTL_TRACE 19
1245 #define SQLITE_FCNTL_HAS_MOVED 20
1246 #define SQLITE_FCNTL_SYNC 21
1247 #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1248 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1249 #define SQLITE_FCNTL_WAL_BLOCK 24
1250 #define SQLITE_FCNTL_ZIPVFS 25
1251 #define SQLITE_FCNTL_RBU 26
1252 #define SQLITE_FCNTL_VFS_POINTER 27
1253 #define SQLITE_FCNTL_JOURNAL_POINTER 28
1254 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1255 #define SQLITE_FCNTL_PDB 30
1256 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1257 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1258 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1259 #define SQLITE_FCNTL_LOCK_TIMEOUT 34
1260 #define SQLITE_FCNTL_DATA_VERSION 35
1261 #define SQLITE_FCNTL_SIZE_LIMIT 36
1262 #define SQLITE_FCNTL_CKPT_DONE 37
1263 #define SQLITE_FCNTL_RESERVE_BYTES 38
1264 #define SQLITE_FCNTL_CKPT_START 39
1265 #define SQLITE_FCNTL_EXTERNAL_READER 40
1266 #define SQLITE_FCNTL_CKSM_FILE 41
1267 #define SQLITE_FCNTL_RESET_CACHE 42
1268 #define SQLITE_FCNTL_NULL_IO 43
1269 #define SQLITE_FCNTL_BLOCK_ON_CONNECT 44
1270 1271 /* deprecated names */
1272 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1273 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1274 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1275 1276 1277 /*
1278 ** CAPI3REF: Mutex Handle
1279 **
1280 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1281 ** abstract type for a mutex object. The SQLite core never looks
1282 ** at the internal representation of an [sqlite3_mutex]. It only
1283 ** deals with pointers to the [sqlite3_mutex] object.
1284 **
1285 ** Mutexes are created using [sqlite3_mutex_alloc()].
1286 */
1287 typedef struct sqlite3_mutex sqlite3_mutex;
1288 1289 /*
1290 ** CAPI3REF: Loadable Extension Thunk
1291 **
1292 ** A pointer to the opaque sqlite3_api_routines structure is passed as
1293 ** the third parameter to entry points of [loadable extensions]. This
1294 ** structure must be typedefed in order to work around compiler warnings
1295 ** on some platforms.
1296 */
1297 typedef struct sqlite3_api_routines sqlite3_api_routines;
1298 1299 /*
1300 ** CAPI3REF: File Name
1301 **
1302 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1303 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1304 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1305 ** may also be passed to special APIs such as:
1306 **
1307 ** <ul>
1308 ** <li> sqlite3_filename_database()
1309 ** <li> sqlite3_filename_journal()
1310 ** <li> sqlite3_filename_wal()
1311 ** <li> sqlite3_uri_parameter()
1312 ** <li> sqlite3_uri_boolean()
1313 ** <li> sqlite3_uri_int64()
1314 ** <li> sqlite3_uri_key()
1315 ** </ul>
1316 */
1317 typedef const char *sqlite3_filename;
1318 1319 /*
1320 ** CAPI3REF: OS Interface Object
1321 **
1322 ** An instance of the sqlite3_vfs object defines the interface between
1323 ** the SQLite core and the underlying operating system. The "vfs"
1324 ** in the name of the object stands for "virtual file system". See
1325 ** the [VFS | VFS documentation] for further information.
1326 **
1327 ** The VFS interface is sometimes extended by adding new methods onto
1328 ** the end. Each time such an extension occurs, the iVersion field
1329 ** is incremented. The iVersion value started out as 1 in
1330 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1331 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1332 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1333 ** may be appended to the sqlite3_vfs object and the iVersion value
1334 ** may increase again in future versions of SQLite.
1335 ** Note that due to an oversight, the structure
1336 ** of the sqlite3_vfs object changed in the transition from
1337 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1338 ** and yet the iVersion field was not increased.
1339 **
1340 ** The szOsFile field is the size of the subclassed [sqlite3_file]
1341 ** structure used by this VFS. mxPathname is the maximum length of
1342 ** a pathname in this VFS.
1343 **
1344 ** Registered sqlite3_vfs objects are kept on a linked list formed by
1345 ** the pNext pointer. The [sqlite3_vfs_register()]
1346 ** and [sqlite3_vfs_unregister()] interfaces manage this list
1347 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1348 ** searches the list. Neither the application code nor the VFS
1349 ** implementation should use the pNext pointer.
1350 **
1351 ** The pNext field is the only field in the sqlite3_vfs
1352 ** structure that SQLite will ever modify. SQLite will only access
1353 ** or modify this field while holding a particular static mutex.
1354 ** The application should never modify anything within the sqlite3_vfs
1355 ** object once the object has been registered.
1356 **
1357 ** The zName field holds the name of the VFS module. The name must
1358 ** be unique across all VFS modules.
1359 **
1360 ** [[sqlite3_vfs.xOpen]]
1361 ** ^SQLite guarantees that the zFilename parameter to xOpen
1362 ** is either a NULL pointer or string obtained
1363 ** from xFullPathname() with an optional suffix added.
1364 ** ^If a suffix is added to the zFilename parameter, it will
1365 ** consist of a single "-" character followed by no more than
1366 ** 11 alphanumeric and/or "-" characters.
1367 ** ^SQLite further guarantees that
1368 ** the string will be valid and unchanged until xClose() is
1369 ** called. Because of the previous sentence,
1370 ** the [sqlite3_file] can safely store a pointer to the
1371 ** filename if it needs to remember the filename for some reason.
1372 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1373 ** must invent its own temporary name for the file. ^Whenever the
1374 ** xFilename parameter is NULL it will also be the case that the
1375 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1376 **
1377 ** The flags argument to xOpen() includes all bits set in
1378 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1379 ** or [sqlite3_open16()] is used, then flags includes at least
1380 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1381 ** If xOpen() opens a file read-only then it sets *pOutFlags to
1382 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1383 **
1384 ** ^(SQLite will also add one of the following flags to the xOpen()
1385 ** call, depending on the object being opened:
1386 **
1387 ** <ul>
1388 ** <li> [SQLITE_OPEN_MAIN_DB]
1389 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1390 ** <li> [SQLITE_OPEN_TEMP_DB]
1391 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1392 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1393 ** <li> [SQLITE_OPEN_SUBJOURNAL]
1394 ** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1395 ** <li> [SQLITE_OPEN_WAL]
1396 ** </ul>)^
1397 **
1398 ** The file I/O implementation can use the object type flags to
1399 ** change the way it deals with files. For example, an application
1400 ** that does not care about crash recovery or rollback might make
1401 ** the open of a journal file a no-op. Writes to this journal would
1402 ** also be no-ops, and any attempt to read the journal would return
1403 ** SQLITE_IOERR. Or the implementation might recognize that a database
1404 ** file will be doing page-aligned sector reads and writes in a random
1405 ** order and set up its I/O subsystem accordingly.
1406 **
1407 ** SQLite might also add one of the following flags to the xOpen method:
1408 **
1409 ** <ul>
1410 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1411 ** <li> [SQLITE_OPEN_EXCLUSIVE]
1412 ** </ul>
1413 **
1414 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1415 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1416 ** will be set for TEMP databases and their journals, transient
1417 ** databases, and subjournals.
1418 **
1419 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1420 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1421 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1422 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1423 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1424 ** be created, and that it is an error if it already exists.
1425 ** It is <i>not</i> used to indicate the file should be opened
1426 ** for exclusive access.
1427 **
1428 ** ^At least szOsFile bytes of memory are allocated by SQLite
1429 ** to hold the [sqlite3_file] structure passed as the third
1430 ** argument to xOpen. The xOpen method does not have to
1431 ** allocate the structure; it should just fill it in. Note that
1432 ** the xOpen method must set the sqlite3_file.pMethods to either
1433 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1434 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1435 ** element will be valid after xOpen returns regardless of the success
1436 ** or failure of the xOpen call.
1437 **
1438 ** [[sqlite3_vfs.xAccess]]
1439 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1440 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1441 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1442 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1443 ** flag is never actually used and is not implemented in the built-in
1444 ** VFSes of SQLite. The file is named by the second argument and can be a
1445 ** directory. The xAccess method returns [SQLITE_OK] on success or some
1446 ** non-zero error code if there is an I/O error or if the name of
1447 ** the file given in the second argument is illegal. If SQLITE_OK
1448 ** is returned, then non-zero or zero is written into *pResOut to indicate
1449 ** whether or not the file is accessible.
1450 **
1451 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1452 ** output buffer xFullPathname. The exact size of the output buffer
1453 ** is also passed as a parameter to both methods. If the output buffer
1454 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1455 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1456 ** to prevent this by setting mxPathname to a sufficiently large value.
1457 **
1458 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1459 ** interfaces are not strictly a part of the filesystem, but they are
1460 ** included in the VFS structure for completeness.
1461 ** The xRandomness() function attempts to return nBytes bytes
1462 ** of good-quality randomness into zOut. The return value is
1463 ** the actual number of bytes of randomness obtained.
1464 ** The xSleep() method causes the calling thread to sleep for at
1465 ** least the number of microseconds given. ^The xCurrentTime()
1466 ** method returns a Julian Day Number for the current date and time as
1467 ** a floating point value.
1468 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1469 ** Day Number multiplied by 86400000 (the number of milliseconds in
1470 ** a 24-hour day).
1471 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1472 ** date and time if that method is available (if iVersion is 2 or
1473 ** greater and the function pointer is not NULL) and will fall back
1474 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1475 **
1476 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1477 ** are not used by the SQLite core. These optional interfaces are provided
1478 ** by some VFSes to facilitate testing of the VFS code. By overriding
1479 ** system calls with functions under its control, a test program can
1480 ** simulate faults and error conditions that would otherwise be difficult
1481 ** or impossible to induce. The set of system calls that can be overridden
1482 ** varies from one VFS to another, and from one version of the same VFS to the
1483 ** next. Applications that use these interfaces must be prepared for any
1484 ** or all of these interfaces to be NULL or for their behavior to change
1485 ** from one release to the next. Applications must not attempt to access
1486 ** any of these methods if the iVersion of the VFS is less than 3.
1487 */
1488 typedef struct sqlite3_vfs sqlite3_vfs;
1489 typedef void (*sqlite3_syscall_ptr)(void);
1490 struct sqlite3_vfs {
1491 int iVersion; /* Structure version number (currently 3) */
1492 int szOsFile; /* Size of subclassed sqlite3_file */
1493 int mxPathname; /* Maximum file pathname length */
1494 sqlite3_vfs *pNext; /* Next registered VFS */
1495 const char *zName; /* Name of this virtual file system */
1496 void *pAppData; /* Pointer to application-specific data */
1497 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1498 int flags, int *pOutFlags);
1499 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1500 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1501 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1502 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1503 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1504 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1505 void (*xDlClose)(sqlite3_vfs*, void*);
1506 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1507 int (*xSleep)(sqlite3_vfs*, int microseconds);
1508 int (*xCurrentTime)(sqlite3_vfs*, double*);
1509 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1510 /*
1511 ** The methods above are in version 1 of the sqlite_vfs object
1512 ** definition. Those that follow are added in version 2 or later
1513 */
1514 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1515 /*
1516 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1517 ** Those below are for version 3 and greater.
1518 */
1519 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1520 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1521 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1522 /*
1523 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1524 ** New fields may be appended in future versions. The iVersion
1525 ** value will increment whenever this happens.
1526 */
1527 };
1528 1529 /*
1530 ** CAPI3REF: Flags for the xAccess VFS method
1531 **
1532 ** These integer constants can be used as the third parameter to
1533 ** the xAccess method of an [sqlite3_vfs] object. They determine
1534 ** what kind of permissions the xAccess method is looking for.
1535 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1536 ** simply checks whether the file exists.
1537 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1538 ** checks whether the named directory is both readable and writable
1539 ** (in other words, if files can be added, removed, and renamed within
1540 ** the directory).
1541 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1542 ** [temp_store_directory pragma], though this could change in a future
1543 ** release of SQLite.
1544 ** With SQLITE_ACCESS_READ, the xAccess method
1545 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1546 ** currently unused, though it might be used in a future release of
1547 ** SQLite.
1548 */
1549 #define SQLITE_ACCESS_EXISTS 0
1550 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1551 #define SQLITE_ACCESS_READ 2 /* Unused */
1552 1553 /*
1554 ** CAPI3REF: Flags for the xShmLock VFS method
1555 **
1556 ** These integer constants define the various locking operations
1557 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1558 ** following are the only legal combinations of flags to the
1559 ** xShmLock method:
1560 **
1561 ** <ul>
1562 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1563 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1564 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1565 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1566 ** </ul>
1567 **
1568 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1569 ** was given on the corresponding lock.
1570 **
1571 ** The xShmLock method can transition between unlocked and SHARED or
1572 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1573 ** and EXCLUSIVE.
1574 */
1575 #define SQLITE_SHM_UNLOCK 1
1576 #define SQLITE_SHM_LOCK 2
1577 #define SQLITE_SHM_SHARED 4
1578 #define SQLITE_SHM_EXCLUSIVE 8
1579 1580 /*
1581 ** CAPI3REF: Maximum xShmLock index
1582 **
1583 ** The xShmLock method on [sqlite3_io_methods] may use values
1584 ** between 0 and this upper bound as its "offset" argument.
1585 ** The SQLite core will never attempt to acquire or release a
1586 ** lock outside of this range
1587 */
1588 #define SQLITE_SHM_NLOCK 8
1589 1590 1591 /*
1592 ** CAPI3REF: Initialize The SQLite Library
1593 **
1594 ** ^The sqlite3_initialize() routine initializes the
1595 ** SQLite library. ^The sqlite3_shutdown() routine
1596 ** deallocates any resources that were allocated by sqlite3_initialize().
1597 ** These routines are designed to aid in process initialization and
1598 ** shutdown on embedded systems. Workstation applications using
1599 ** SQLite normally do not need to invoke either of these routines.
1600 **
1601 ** A call to sqlite3_initialize() is an "effective" call if it is
1602 ** the first time sqlite3_initialize() is invoked during the lifetime of
1603 ** the process, or if it is the first time sqlite3_initialize() is invoked
1604 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1605 ** of sqlite3_initialize() does any initialization. All other calls
1606 ** are harmless no-ops.)^
1607 **
1608 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1609 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1610 ** an effective call to sqlite3_shutdown() does any deinitialization.
1611 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1612 **
1613 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1614 ** is not. The sqlite3_shutdown() interface must only be called from a
1615 ** single thread. All open [database connections] must be closed and all
1616 ** other SQLite resources must be deallocated prior to invoking
1617 ** sqlite3_shutdown().
1618 **
1619 ** Among other things, ^sqlite3_initialize() will invoke
1620 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1621 ** will invoke sqlite3_os_end().
1622 **
1623 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1624 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1625 ** the library (perhaps it is unable to allocate a needed resource such
1626 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1627 **
1628 ** ^The sqlite3_initialize() routine is called internally by many other
1629 ** SQLite interfaces so that an application usually does not need to
1630 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1631 ** calls sqlite3_initialize() so the SQLite library will be automatically
1632 ** initialized when [sqlite3_open()] is called if it has not be initialized
1633 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1634 ** compile-time option, then the automatic calls to sqlite3_initialize()
1635 ** are omitted and the application must call sqlite3_initialize() directly
1636 ** prior to using any other SQLite interface. For maximum portability,
1637 ** it is recommended that applications always invoke sqlite3_initialize()
1638 ** directly prior to using any other SQLite interface. Future releases
1639 ** of SQLite may require this. In other words, the behavior exhibited
1640 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1641 ** default behavior in some future release of SQLite.
1642 **
1643 ** The sqlite3_os_init() routine does operating-system specific
1644 ** initialization of the SQLite library. The sqlite3_os_end()
1645 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1646 ** performed by these routines include allocation or deallocation
1647 ** of static resources, initialization of global variables,
1648 ** setting up a default [sqlite3_vfs] module, or setting up
1649 ** a default configuration using [sqlite3_config()].
1650 **
1651 ** The application should never invoke either sqlite3_os_init()
1652 ** or sqlite3_os_end() directly. The application should only invoke
1653 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1654 ** interface is called automatically by sqlite3_initialize() and
1655 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1656 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1657 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1658 ** When [custom builds | built for other platforms]
1659 ** (using the [SQLITE_OS_OTHER=1] compile-time
1660 ** option) the application must supply a suitable implementation for
1661 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1662 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1663 ** must return [SQLITE_OK] on success and some other [error code] upon
1664 ** failure.
1665 */
1666 SQLITE_API int sqlite3_initialize(void);
1667 SQLITE_API int sqlite3_shutdown(void);
1668 SQLITE_API int sqlite3_os_init(void);
1669 SQLITE_API int sqlite3_os_end(void);
1670 1671 /*
1672 ** CAPI3REF: Configuring The SQLite Library
1673 **
1674 ** The sqlite3_config() interface is used to make global configuration
1675 ** changes to SQLite in order to tune SQLite to the specific needs of
1676 ** the application. The default configuration is recommended for most
1677 ** applications and so this routine is usually not necessary. It is
1678 ** provided to support rare applications with unusual needs.
1679 **
1680 ** <b>The sqlite3_config() interface is not threadsafe. The application
1681 ** must ensure that no other SQLite interfaces are invoked by other
1682 ** threads while sqlite3_config() is running.</b>
1683 **
1684 ** The first argument to sqlite3_config() is an integer
1685 ** [configuration option] that determines
1686 ** what property of SQLite is to be configured. Subsequent arguments
1687 ** vary depending on the [configuration option]
1688 ** in the first argument.
1689 **
1690 ** For most configuration options, the sqlite3_config() interface
1691 ** may only be invoked prior to library initialization using
1692 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1693 ** The exceptional configuration options that may be invoked at any time
1694 ** are called "anytime configuration options".
1695 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1696 ** [sqlite3_shutdown()] with a first argument that is not an anytime
1697 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1698 ** Note, however, that ^sqlite3_config() can be called as part of the
1699 ** implementation of an application-defined [sqlite3_os_init()].
1700 **
1701 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1702 ** ^If the option is unknown or SQLite is unable to set the option
1703 ** then this routine returns a non-zero [error code].
1704 */
1705 SQLITE_API int sqlite3_config(int, ...);
1706 1707 /*
1708 ** CAPI3REF: Configure database connections
1709 ** METHOD: sqlite3
1710 **
1711 ** The sqlite3_db_config() interface is used to make configuration
1712 ** changes to a [database connection]. The interface is similar to
1713 ** [sqlite3_config()] except that the changes apply to a single
1714 ** [database connection] (specified in the first argument).
1715 **
1716 ** The second argument to sqlite3_db_config(D,V,...) is the
1717 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1718 ** that indicates what aspect of the [database connection] is being configured.
1719 ** Subsequent arguments vary depending on the configuration verb.
1720 **
1721 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1722 ** the call is considered successful.
1723 */
1724 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1725 1726 /*
1727 ** CAPI3REF: Memory Allocation Routines
1728 **
1729 ** An instance of this object defines the interface between SQLite
1730 ** and low-level memory allocation routines.
1731 **
1732 ** This object is used in only one place in the SQLite interface.
1733 ** A pointer to an instance of this object is the argument to
1734 ** [sqlite3_config()] when the configuration option is
1735 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1736 ** By creating an instance of this object
1737 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1738 ** during configuration, an application can specify an alternative
1739 ** memory allocation subsystem for SQLite to use for all of its
1740 ** dynamic memory needs.
1741 **
1742 ** Note that SQLite comes with several [built-in memory allocators]
1743 ** that are perfectly adequate for the overwhelming majority of applications
1744 ** and that this object is only useful to a tiny minority of applications
1745 ** with specialized memory allocation requirements. This object is
1746 ** also used during testing of SQLite in order to specify an alternative
1747 ** memory allocator that simulates memory out-of-memory conditions in
1748 ** order to verify that SQLite recovers gracefully from such
1749 ** conditions.
1750 **
1751 ** The xMalloc, xRealloc, and xFree methods must work like the
1752 ** malloc(), realloc() and free() functions from the standard C library.
1753 ** ^SQLite guarantees that the second argument to
1754 ** xRealloc is always a value returned by a prior call to xRoundup.
1755 **
1756 ** xSize should return the allocated size of a memory allocation
1757 ** previously obtained from xMalloc or xRealloc. The allocated size
1758 ** is always at least as big as the requested size but may be larger.
1759 **
1760 ** The xRoundup method returns what would be the allocated size of
1761 ** a memory allocation given a particular requested size. Most memory
1762 ** allocators round up memory allocations at least to the next multiple
1763 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1764 ** Every memory allocation request coming in through [sqlite3_malloc()]
1765 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1766 ** that causes the corresponding memory allocation to fail.
1767 **
1768 ** The xInit method initializes the memory allocator. For example,
1769 ** it might allocate any required mutexes or initialize internal data
1770 ** structures. The xShutdown method is invoked (indirectly) by
1771 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1772 ** by xInit. The pAppData pointer is used as the only parameter to
1773 ** xInit and xShutdown.
1774 **
1775 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1776 ** the xInit method, so the xInit method need not be threadsafe. The
1777 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1778 ** not need to be threadsafe either. For all other methods, SQLite
1779 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1780 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1781 ** it is by default) and so the methods are automatically serialized.
1782 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1783 ** methods must be threadsafe or else make their own arrangements for
1784 ** serialization.
1785 **
1786 ** SQLite will never invoke xInit() more than once without an intervening
1787 ** call to xShutdown().
1788 */
1789 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1790 struct sqlite3_mem_methods {
1791 void *(*xMalloc)(int); /* Memory allocation function */
1792 void (*xFree)(void*); /* Free a prior allocation */
1793 void *(*xRealloc)(void*,int); /* Resize an allocation */
1794 int (*xSize)(void*); /* Return the size of an allocation */
1795 int (*xRoundup)(int); /* Round up request size to allocation size */
1796 int (*xInit)(void*); /* Initialize the memory allocator */
1797 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1798 void *pAppData; /* Argument to xInit() and xShutdown() */
1799 };
1800 1801 /*
1802 ** CAPI3REF: Configuration Options
1803 ** KEYWORDS: {configuration option}
1804 **
1805 ** These constants are the available integer configuration options that
1806 ** can be passed as the first argument to the [sqlite3_config()] interface.
1807 **
1808 ** Most of the configuration options for sqlite3_config()
1809 ** will only work if invoked prior to [sqlite3_initialize()] or after
1810 ** [sqlite3_shutdown()]. The few exceptions to this rule are called
1811 ** "anytime configuration options".
1812 ** ^Calling [sqlite3_config()] with a first argument that is not an
1813 ** anytime configuration option in between calls to [sqlite3_initialize()] and
1814 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1815 **
1816 ** The set of anytime configuration options can change (by insertions
1817 ** and/or deletions) from one release of SQLite to the next.
1818 ** As of SQLite version 3.42.0, the complete set of anytime configuration
1819 ** options is:
1820 ** <ul>
1821 ** <li> SQLITE_CONFIG_LOG
1822 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1823 ** </ul>
1824 **
1825 ** New configuration options may be added in future releases of SQLite.
1826 ** Existing configuration options might be discontinued. Applications
1827 ** should check the return code from [sqlite3_config()] to make sure that
1828 ** the call worked. The [sqlite3_config()] interface will return a
1829 ** non-zero [error code] if a discontinued or unsupported configuration option
1830 ** is invoked.
1831 **
1832 ** <dl>
1833 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1834 ** <dd>There are no arguments to this option. ^This option sets the
1835 ** [threading mode] to Single-thread. In other words, it disables
1836 ** all mutexing and puts SQLite into a mode where it can only be used
1837 ** by a single thread. ^If SQLite is compiled with
1838 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1839 ** it is not possible to change the [threading mode] from its default
1840 ** value of Single-thread and so [sqlite3_config()] will return
1841 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1842 ** configuration option.</dd>
1843 **
1844 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1845 ** <dd>There are no arguments to this option. ^This option sets the
1846 ** [threading mode] to Multi-thread. In other words, it disables
1847 ** mutexing on [database connection] and [prepared statement] objects.
1848 ** The application is responsible for serializing access to
1849 ** [database connections] and [prepared statements]. But other mutexes
1850 ** are enabled so that SQLite will be safe to use in a multi-threaded
1851 ** environment as long as no two threads attempt to use the same
1852 ** [database connection] at the same time. ^If SQLite is compiled with
1853 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1854 ** it is not possible to set the Multi-thread [threading mode] and
1855 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1856 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1857 **
1858 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1859 ** <dd>There are no arguments to this option. ^This option sets the
1860 ** [threading mode] to Serialized. In other words, this option enables
1861 ** all mutexes including the recursive
1862 ** mutexes on [database connection] and [prepared statement] objects.
1863 ** In this mode (which is the default when SQLite is compiled with
1864 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1865 ** to [database connections] and [prepared statements] so that the
1866 ** application is free to use the same [database connection] or the
1867 ** same [prepared statement] in different threads at the same time.
1868 ** ^If SQLite is compiled with
1869 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1870 ** it is not possible to set the Serialized [threading mode] and
1871 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1872 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1873 **
1874 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1875 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1876 ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1877 ** The argument specifies
1878 ** alternative low-level memory allocation routines to be used in place of
1879 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1880 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1881 ** before the [sqlite3_config()] call returns.</dd>
1882 **
1883 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1884 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1885 ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1886 ** The [sqlite3_mem_methods]
1887 ** structure is filled with the currently defined memory allocation routines.)^
1888 ** This option can be used to overload the default memory allocation
1889 ** routines with a wrapper that simulations memory allocation failure or
1890 ** tracks memory usage, for example. </dd>
1891 **
1892 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1893 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1894 ** type int, interpreted as a boolean, which if true provides a hint to
1895 ** SQLite that it should avoid large memory allocations if possible.
1896 ** SQLite will run faster if it is free to make large memory allocations,
1897 ** but some application might prefer to run slower in exchange for
1898 ** guarantees about memory fragmentation that are possible if large
1899 ** allocations are avoided. This hint is normally off.
1900 ** </dd>
1901 **
1902 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1903 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1904 ** interpreted as a boolean, which enables or disables the collection of
1905 ** memory allocation statistics. ^(When memory allocation statistics are
1906 ** disabled, the following SQLite interfaces become non-operational:
1907 ** <ul>
1908 ** <li> [sqlite3_hard_heap_limit64()]
1909 ** <li> [sqlite3_memory_used()]
1910 ** <li> [sqlite3_memory_highwater()]
1911 ** <li> [sqlite3_soft_heap_limit64()]
1912 ** <li> [sqlite3_status64()]
1913 ** </ul>)^
1914 ** ^Memory allocation statistics are enabled by default unless SQLite is
1915 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1916 ** allocation statistics are disabled by default.
1917 ** </dd>
1918 **
1919 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1920 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1921 ** </dd>
1922 **
1923 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1924 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1925 ** that SQLite can use for the database page cache with the default page
1926 ** cache implementation.
1927 ** This configuration option is a no-op if an application-defined page
1928 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1929 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1930 ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1931 ** and the number of cache lines (N).
1932 ** The sz argument should be the size of the largest database page
1933 ** (a power of two between 512 and 65536) plus some extra bytes for each
1934 ** page header. ^The number of extra bytes needed by the page header
1935 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1936 ** ^It is harmless, apart from the wasted memory,
1937 ** for the sz parameter to be larger than necessary. The pMem
1938 ** argument must be either a NULL pointer or a pointer to an 8-byte
1939 ** aligned block of memory of at least sz*N bytes, otherwise
1940 ** subsequent behavior is undefined.
1941 ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1942 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1943 ** a page cache line is larger than sz bytes or if all of the pMem buffer
1944 ** is exhausted.
1945 ** ^If pMem is NULL and N is non-zero, then each database connection
1946 ** does an initial bulk allocation for page cache memory
1947 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1948 ** of -1024*N bytes if N is negative, . ^If additional
1949 ** page cache memory is needed beyond what is provided by the initial
1950 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1951 ** additional cache line. </dd>
1952 **
1953 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1954 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1955 ** that SQLite will use for all of its dynamic memory allocation needs
1956 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1957 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1958 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1959 ** [SQLITE_ERROR] if invoked otherwise.
1960 ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1961 ** An 8-byte aligned pointer to the memory,
1962 ** the number of bytes in the memory buffer, and the minimum allocation size.
1963 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1964 ** to using its default memory allocator (the system malloc() implementation),
1965 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1966 ** memory pointer is not NULL then the alternative memory
1967 ** allocator is engaged to handle all of SQLites memory allocation needs.
1968 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1969 ** boundary or subsequent behavior of SQLite will be undefined.
1970 ** The minimum allocation size is capped at 2**12. Reasonable values
1971 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1972 **
1973 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1974 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1975 ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1976 ** The argument specifies alternative low-level mutex routines to be used
1977 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1978 ** the content of the [sqlite3_mutex_methods] structure before the call to
1979 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1980 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1981 ** the entire mutexing subsystem is omitted from the build and hence calls to
1982 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1983 ** return [SQLITE_ERROR].</dd>
1984 **
1985 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1986 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1987 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1988 ** [sqlite3_mutex_methods]
1989 ** structure is filled with the currently defined mutex routines.)^
1990 ** This option can be used to overload the default mutex allocation
1991 ** routines with a wrapper used to track mutex usage for performance
1992 ** profiling or testing, for example. ^If SQLite is compiled with
1993 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1994 ** the entire mutexing subsystem is omitted from the build and hence calls to
1995 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1996 ** return [SQLITE_ERROR].</dd>
1997 **
1998 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1999 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
2000 ** the default size of [lookaside memory] on each [database connection].
2001 ** The first argument is the
2002 ** size of each lookaside buffer slot ("sz") and the second is the number of
2003 ** slots allocated to each database connection ("cnt").)^
2004 ** ^(SQLITE_CONFIG_LOOKASIDE sets the <i>default</i> lookaside size.
2005 ** The [SQLITE_DBCONFIG_LOOKASIDE] option to [sqlite3_db_config()] can
2006 ** be used to change the lookaside configuration on individual connections.)^
2007 ** The [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to change the
2008 ** default lookaside configuration at compile-time.
2009 ** </dd>
2010 **
2011 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
2012 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
2013 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
2014 ** the interface to a custom page cache implementation.)^
2015 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
2016 **
2017 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
2018 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
2019 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
2020 ** the current page cache implementation into that object.)^ </dd>
2021 **
2022 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
2023 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
2024 ** global [error log].
2025 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
2026 ** function with a call signature of void(*)(void*,int,const char*),
2027 ** and a pointer to void. ^If the function pointer is not NULL, it is
2028 ** invoked by [sqlite3_log()] to process each logging event. ^If the
2029 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2030 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2031 ** passed through as the first parameter to the application-defined logger
2032 ** function whenever that function is invoked. ^The second parameter to
2033 ** the logger function is a copy of the first parameter to the corresponding
2034 ** [sqlite3_log()] call and is intended to be a [result code] or an
2035 ** [extended result code]. ^The third parameter passed to the logger is
2036 ** log message after formatting via [sqlite3_snprintf()].
2037 ** The SQLite logging interface is not reentrant; the logger function
2038 ** supplied by the application must not invoke any SQLite interface.
2039 ** In a multi-threaded application, the application-defined logger
2040 ** function must be threadsafe. </dd>
2041 **
2042 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2043 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2044 ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2045 ** then URI handling is globally disabled.)^ ^If URI handling is globally
2046 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2047 ** [sqlite3_open16()] or
2048 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2049 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2050 ** connection is opened. ^If it is globally disabled, filenames are
2051 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2052 ** database connection is opened. ^(By default, URI handling is globally
2053 ** disabled. The default value may be changed by compiling with the
2054 ** [SQLITE_USE_URI] symbol defined.)^
2055 **
2056 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2057 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2058 ** argument which is interpreted as a boolean in order to enable or disable
2059 ** the use of covering indices for full table scans in the query optimizer.
2060 ** ^The default setting is determined
2061 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2062 ** if that compile-time option is omitted.
2063 ** The ability to disable the use of covering indices for full table scans
2064 ** is because some incorrectly coded legacy applications might malfunction
2065 ** when the optimization is enabled. Providing the ability to
2066 ** disable the optimization allows the older, buggy application code to work
2067 ** without change even with newer versions of SQLite.
2068 **
2069 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2070 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2071 ** <dd> These options are obsolete and should not be used by new code.
2072 ** They are retained for backwards compatibility but are now no-ops.
2073 ** </dd>
2074 **
2075 ** [[SQLITE_CONFIG_SQLLOG]]
2076 ** <dt>SQLITE_CONFIG_SQLLOG
2077 ** <dd>This option is only available if sqlite is compiled with the
2078 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2079 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2080 ** The second should be of type (void*). The callback is invoked by the library
2081 ** in three separate circumstances, identified by the value passed as the
2082 ** fourth parameter. If the fourth parameter is 0, then the database connection
2083 ** passed as the second argument has just been opened. The third argument
2084 ** points to a buffer containing the name of the main database file. If the
2085 ** fourth parameter is 1, then the SQL statement that the third parameter
2086 ** points to has just been executed. Or, if the fourth parameter is 2, then
2087 ** the connection being passed as the second parameter is being closed. The
2088 ** third parameter is passed NULL In this case. An example of using this
2089 ** configuration option can be seen in the "test_sqllog.c" source file in
2090 ** the canonical SQLite source tree.</dd>
2091 **
2092 ** [[SQLITE_CONFIG_MMAP_SIZE]]
2093 ** <dt>SQLITE_CONFIG_MMAP_SIZE
2094 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2095 ** that are the default mmap size limit (the default setting for
2096 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2097 ** ^The default setting can be overridden by each database connection using
2098 ** either the [PRAGMA mmap_size] command, or by using the
2099 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2100 ** will be silently truncated if necessary so that it does not exceed the
2101 ** compile-time maximum mmap size set by the
2102 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2103 ** ^If either argument to this option is negative, then that argument is
2104 ** changed to its compile-time default.
2105 **
2106 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2107 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2108 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2109 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2110 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2111 ** that specifies the maximum size of the created heap.
2112 **
2113 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2114 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2115 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2116 ** is a pointer to an integer and writes into that integer the number of extra
2117 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2118 ** The amount of extra space required can change depending on the compiler,
2119 ** target platform, and SQLite version.
2120 **
2121 ** [[SQLITE_CONFIG_PMASZ]]
2122 ** <dt>SQLITE_CONFIG_PMASZ
2123 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2124 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2125 ** sorter to that integer. The default minimum PMA Size is set by the
2126 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2127 ** to help with sort operations when multithreaded sorting
2128 ** is enabled (using the [PRAGMA threads] command) and the amount of content
2129 ** to be sorted exceeds the page size times the minimum of the
2130 ** [PRAGMA cache_size] setting and this value.
2131 **
2132 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2133 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2134 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2135 ** becomes the [statement journal] spill-to-disk threshold.
2136 ** [Statement journals] are held in memory until their size (in bytes)
2137 ** exceeds this threshold, at which point they are written to disk.
2138 ** Or if the threshold is -1, statement journals are always held
2139 ** exclusively in memory.
2140 ** Since many statement journals never become large, setting the spill
2141 ** threshold to a value such as 64KiB can greatly reduce the amount of
2142 ** I/O required to support statement rollback.
2143 ** The default value for this setting is controlled by the
2144 ** [SQLITE_STMTJRNL_SPILL] compile-time option.
2145 **
2146 ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2147 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2148 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2149 ** of type (int) - the new value of the sorter-reference size threshold.
2150 ** Usually, when SQLite uses an external sort to order records according
2151 ** to an ORDER BY clause, all fields required by the caller are present in the
2152 ** sorted records. However, if SQLite determines based on the declared type
2153 ** of a table column that its values are likely to be very large - larger
2154 ** than the configured sorter-reference size threshold - then a reference
2155 ** is stored in each sorted record and the required column values loaded
2156 ** from the database as records are returned in sorted order. The default
2157 ** value for this option is to never use this optimization. Specifying a
2158 ** negative value for this option restores the default behavior.
2159 ** This option is only available if SQLite is compiled with the
2160 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2161 **
2162 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2163 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2164 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2165 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2166 ** database created using [sqlite3_deserialize()]. This default maximum
2167 ** size can be adjusted up or down for individual databases using the
2168 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2169 ** configuration setting is never used, then the default maximum is determined
2170 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2171 ** compile-time option is not set, then the default maximum is 1073741824.
2172 **
2173 ** [[SQLITE_CONFIG_ROWID_IN_VIEW]]
2174 ** <dt>SQLITE_CONFIG_ROWID_IN_VIEW
2175 ** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability
2176 ** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is
2177 ** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability
2178 ** defaults to on. This configuration option queries the current setting or
2179 ** changes the setting to off or on. The argument is a pointer to an integer.
2180 ** If that integer initially holds a value of 1, then the ability for VIEWs to
2181 ** have ROWIDs is activated. If the integer initially holds zero, then the
2182 ** ability is deactivated. Any other initial value for the integer leaves the
2183 ** setting unchanged. After changes, if any, the integer is written with
2184 ** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite
2185 ** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and
2186 ** recommended case) then the integer is always filled with zero, regardless
2187 ** if its initial value.
2188 ** </dl>
2189 */
2190 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2191 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2192 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2193 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2194 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2195 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2196 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2197 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2198 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2199 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2200 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2201 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2202 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2203 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
2204 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2205 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2206 #define SQLITE_CONFIG_URI 17 /* int */
2207 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2208 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2209 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2210 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2211 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2212 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2213 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2214 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2215 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2216 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2217 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2218 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2219 #define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */
2220 2221 /*
2222 ** CAPI3REF: Database Connection Configuration Options
2223 **
2224 ** These constants are the available integer configuration options that
2225 ** can be passed as the second parameter to the [sqlite3_db_config()] interface.
2226 **
2227 ** The [sqlite3_db_config()] interface is a var-args functions. It takes a
2228 ** variable number of parameters, though always at least two. The number of
2229 ** parameters passed into sqlite3_db_config() depends on which of these
2230 ** constants is given as the second parameter. This documentation page
2231 ** refers to parameters beyond the second as "arguments". Thus, when this
2232 ** page says "the N-th argument" it means "the N-th parameter past the
2233 ** configuration option" or "the (N+2)-th parameter to sqlite3_db_config()".
2234 **
2235 ** New configuration options may be added in future releases of SQLite.
2236 ** Existing configuration options might be discontinued. Applications
2237 ** should check the return code from [sqlite3_db_config()] to make sure that
2238 ** the call worked. ^The [sqlite3_db_config()] interface will return a
2239 ** non-zero [error code] if a discontinued or unsupported configuration option
2240 ** is invoked.
2241 **
2242 ** <dl>
2243 ** [[SQLITE_DBCONFIG_LOOKASIDE]]
2244 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2245 ** <dd> The SQLITE_DBCONFIG_LOOKASIDE option is used to adjust the
2246 ** configuration of the [lookaside memory allocator] within a database
2247 ** connection.
2248 ** The arguments to the SQLITE_DBCONFIG_LOOKASIDE option are <i>not</i>
2249 ** in the [DBCONFIG arguments|usual format].
2250 ** The SQLITE_DBCONFIG_LOOKASIDE option takes three arguments, not two,
2251 ** so that a call to [sqlite3_db_config()] that uses SQLITE_DBCONFIG_LOOKASIDE
2252 ** should have a total of five parameters.
2253 ** <ol>
2254 ** <li><p>The first argument ("buf") is a
2255 ** pointer to a memory buffer to use for lookaside memory.
2256 ** The first argument may be NULL in which case SQLite will allocate the
2257 ** lookaside buffer itself using [sqlite3_malloc()].
2258 ** <li><P>The second argument ("sz") is the
2259 ** size of each lookaside buffer slot. Lookaside is disabled if "sz"
2260 ** is less than 8. The "sz" argument should be a multiple of 8 less than
2261 ** 65536. If "sz" does not meet this constraint, it is reduced in size until
2262 ** it does.
2263 ** <li><p>The third argument ("cnt") is the number of slots. Lookaside is disabled
2264 ** if "cnt"is less than 1. The "cnt" value will be reduced, if necessary, so
2265 ** that the product of "sz" and "cnt" does not exceed 2,147,418,112. The "cnt"
2266 ** parameter is usually chosen so that the product of "sz" and "cnt" is less
2267 ** than 1,000,000.
2268 ** </ol>
2269 ** <p>If the "buf" argument is not NULL, then it must
2270 ** point to a memory buffer with a size that is greater than
2271 ** or equal to the product of "sz" and "cnt".
2272 ** The buffer must be aligned to an 8-byte boundary.
2273 ** The lookaside memory
2274 ** configuration for a database connection can only be changed when that
2275 ** connection is not currently using lookaside memory, or in other words
2276 ** when the value returned by [SQLITE_DBSTATUS_LOOKASIDE_USED] is zero.
2277 ** Any attempt to change the lookaside memory configuration when lookaside
2278 ** memory is in use leaves the configuration unchanged and returns
2279 ** [SQLITE_BUSY].
2280 ** If the "buf" argument is NULL and an attempt
2281 ** to allocate memory based on "sz" and "cnt" fails, then
2282 ** lookaside is silently disabled.
2283 ** <p>
2284 ** The [SQLITE_CONFIG_LOOKASIDE] configuration option can be used to set the
2285 ** default lookaside configuration at initialization. The
2286 ** [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to set the default lookaside
2287 ** configuration at compile-time. Typical values for lookaside are 1200 for
2288 ** "sz" and 40 to 100 for "cnt".
2289 ** </dd>
2290 **
2291 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2292 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2293 ** <dd> ^This option is used to enable or disable the enforcement of
2294 ** [foreign key constraints]. This is the same setting that is
2295 ** enabled or disabled by the [PRAGMA foreign_keys] statement.
2296 ** The first argument is an integer which is 0 to disable FK enforcement,
2297 ** positive to enable FK enforcement or negative to leave FK enforcement
2298 ** unchanged. The second parameter is a pointer to an integer into which
2299 ** is written 0 or 1 to indicate whether FK enforcement is off or on
2300 ** following this call. The second parameter may be a NULL pointer, in
2301 ** which case the FK enforcement setting is not reported back. </dd>
2302 **
2303 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2304 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2305 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2306 ** There should be two additional arguments.
2307 ** The first argument is an integer which is 0 to disable triggers,
2308 ** positive to enable triggers or negative to leave the setting unchanged.
2309 ** The second parameter is a pointer to an integer into which
2310 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
2311 ** following this call. The second parameter may be a NULL pointer, in
2312 ** which case the trigger setting is not reported back.
2313 **
2314 ** <p>Originally this option disabled all triggers. ^(However, since
2315 ** SQLite version 3.35.0, TEMP triggers are still allowed even if
2316 ** this option is off. So, in other words, this option now only disables
2317 ** triggers in the main database schema or in the schemas of [ATTACH]-ed
2318 ** databases.)^ </dd>
2319 **
2320 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2321 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2322 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2323 ** There must be two additional arguments.
2324 ** The first argument is an integer which is 0 to disable views,
2325 ** positive to enable views or negative to leave the setting unchanged.
2326 ** The second parameter is a pointer to an integer into which
2327 ** is written 0 or 1 to indicate whether views are disabled or enabled
2328 ** following this call. The second parameter may be a NULL pointer, in
2329 ** which case the view setting is not reported back.
2330 **
2331 ** <p>Originally this option disabled all views. ^(However, since
2332 ** SQLite version 3.35.0, TEMP views are still allowed even if
2333 ** this option is off. So, in other words, this option now only disables
2334 ** views in the main database schema or in the schemas of ATTACH-ed
2335 ** databases.)^ </dd>
2336 **
2337 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2338 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2339 ** <dd> ^This option is used to enable or disable the
2340 ** [fts3_tokenizer()] function which is part of the
2341 ** [FTS3] full-text search engine extension.
2342 ** There must be two additional arguments.
2343 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2344 ** positive to enable fts3_tokenizer() or negative to leave the setting
2345 ** unchanged.
2346 ** The second parameter is a pointer to an integer into which
2347 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2348 ** following this call. The second parameter may be a NULL pointer, in
2349 ** which case the new setting is not reported back. </dd>
2350 **
2351 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2352 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2353 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2354 ** interface independently of the [load_extension()] SQL function.
2355 ** The [sqlite3_enable_load_extension()] API enables or disables both the
2356 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2357 ** There must be two additional arguments.
2358 ** When the first argument to this interface is 1, then only the C-API is
2359 ** enabled and the SQL function remains disabled. If the first argument to
2360 ** this interface is 0, then both the C-API and the SQL function are disabled.
2361 ** If the first argument is -1, then no changes are made to state of either the
2362 ** C-API or the SQL function.
2363 ** The second parameter is a pointer to an integer into which
2364 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2365 ** is disabled or enabled following this call. The second parameter may
2366 ** be a NULL pointer, in which case the new setting is not reported back.
2367 ** </dd>
2368 **
2369 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2370 ** <dd> ^This option is used to change the name of the "main" database
2371 ** schema. This option does not follow the
2372 ** [DBCONFIG arguments|usual SQLITE_DBCONFIG argument format].
2373 ** This option takes exactly one additional argument so that the
2374 ** [sqlite3_db_config()] call has a total of three parameters. The
2375 ** extra argument must be a pointer to a constant UTF8 string which
2376 ** will become the new schema name in place of "main". ^SQLite does
2377 ** not make a copy of the new main schema name string, so the application
2378 ** must ensure that the argument passed into SQLITE_DBCONFIG MAINDBNAME
2379 ** is unchanged until after the database connection closes.
2380 ** </dd>
2381 **
2382 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2383 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2384 ** <dd> Usually, when a database in [WAL mode] is closed or detached from a
2385 ** database handle, SQLite checks if if there are other connections to the
2386 ** same database, and if there are no other database connection (if the
2387 ** connection being closed is the last open connection to the database),
2388 ** then SQLite performs a [checkpoint] before closing the connection and
2389 ** deletes the WAL file. The SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE option can
2390 ** be used to override that behavior. The first argument passed to this
2391 ** operation (the third parameter to [sqlite3_db_config()]) is an integer
2392 ** which is positive to disable checkpoints-on-close, or zero (the default)
2393 ** to enable them, and negative to leave the setting unchanged.
2394 ** The second argument (the fourth parameter) is a pointer to an integer
2395 ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2396 ** have been disabled - 0 if they are not disabled, 1 if they are.
2397 ** </dd>
2398 **
2399 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2400 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2401 ** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2402 ** a single SQL query statement will always use the same algorithm regardless
2403 ** of values of [bound parameters].)^ The QPSG disables some query optimizations
2404 ** that look at the values of bound parameters, which can make some queries
2405 ** slower. But the QPSG has the advantage of more predictable behavior. With
2406 ** the QPSG active, SQLite will always use the same query plan in the field as
2407 ** was used during testing in the lab.
2408 ** The first argument to this setting is an integer which is 0 to disable
2409 ** the QPSG, positive to enable QPSG, or negative to leave the setting
2410 ** unchanged. The second parameter is a pointer to an integer into which
2411 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2412 ** following this call.
2413 ** </dd>
2414 **
2415 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2416 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2417 ** include output for any operations performed by trigger programs. This
2418 ** option is used to set or clear (the default) a flag that governs this
2419 ** behavior. The first parameter passed to this operation is an integer -
2420 ** positive to enable output for trigger programs, or zero to disable it,
2421 ** or negative to leave the setting unchanged.
2422 ** The second parameter is a pointer to an integer into which is written
2423 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2424 ** it is not disabled, 1 if it is.
2425 ** </dd>
2426 **
2427 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2428 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2429 ** [VACUUM] in order to reset a database back to an empty database
2430 ** with no schema and no content. The following process works even for
2431 ** a badly corrupted database file:
2432 ** <ol>
2433 ** <li> If the database connection is newly opened, make sure it has read the
2434 ** database schema by preparing then discarding some query against the
2435 ** database, or calling sqlite3_table_column_metadata(), ignoring any
2436 ** errors. This step is only necessary if the application desires to keep
2437 ** the database in WAL mode after the reset if it was in WAL mode before
2438 ** the reset.
2439 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2440 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2441 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2442 ** </ol>
2443 ** Because resetting a database is destructive and irreversible, the
2444 ** process requires the use of this obscure API and multiple steps to
2445 ** help ensure that it does not happen by accident. Because this
2446 ** feature must be capable of resetting corrupt databases, and
2447 ** shutting down virtual tables may require access to that corrupt
2448 ** storage, the library must abandon any installed virtual tables
2449 ** without calling their xDestroy() methods.
2450 **
2451 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2452 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2453 ** "defensive" flag for a database connection. When the defensive
2454 ** flag is enabled, language features that allow ordinary SQL to
2455 ** deliberately corrupt the database file are disabled. The disabled
2456 ** features include but are not limited to the following:
2457 ** <ul>
2458 ** <li> The [PRAGMA writable_schema=ON] statement.
2459 ** <li> The [PRAGMA journal_mode=OFF] statement.
2460 ** <li> The [PRAGMA schema_version=N] statement.
2461 ** <li> Writes to the [sqlite_dbpage] virtual table.
2462 ** <li> Direct writes to [shadow tables].
2463 ** </ul>
2464 ** </dd>
2465 **
2466 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2467 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2468 ** "writable_schema" flag. This has the same effect and is logically equivalent
2469 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2470 ** The first argument to this setting is an integer which is 0 to disable
2471 ** the writable_schema, positive to enable writable_schema, or negative to
2472 ** leave the setting unchanged. The second parameter is a pointer to an
2473 ** integer into which is written 0 or 1 to indicate whether the writable_schema
2474 ** is enabled or disabled following this call.
2475 ** </dd>
2476 **
2477 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2478 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2479 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2480 ** the legacy behavior of the [ALTER TABLE RENAME] command such it
2481 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2482 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2483 ** additional information. This feature can also be turned on and off
2484 ** using the [PRAGMA legacy_alter_table] statement.
2485 ** </dd>
2486 **
2487 ** [[SQLITE_DBCONFIG_DQS_DML]]
2488 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2489 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2490 ** the legacy [double-quoted string literal] misfeature for DML statements
2491 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2492 ** default value of this setting is determined by the [-DSQLITE_DQS]
2493 ** compile-time option.
2494 ** </dd>
2495 **
2496 ** [[SQLITE_DBCONFIG_DQS_DDL]]
2497 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2498 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2499 ** the legacy [double-quoted string literal] misfeature for DDL statements,
2500 ** such as CREATE TABLE and CREATE INDEX. The
2501 ** default value of this setting is determined by the [-DSQLITE_DQS]
2502 ** compile-time option.
2503 ** </dd>
2504 **
2505 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2506 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2507 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2508 ** assume that database schemas are untainted by malicious content.
2509 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2510 ** takes additional defensive steps to protect the application from harm
2511 ** including:
2512 ** <ul>
2513 ** <li> Prohibit the use of SQL functions inside triggers, views,
2514 ** CHECK constraints, DEFAULT clauses, expression indexes,
2515 ** partial indexes, or generated columns
2516 ** unless those functions are tagged with [SQLITE_INNOCUOUS].
2517 ** <li> Prohibit the use of virtual tables inside of triggers or views
2518 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2519 ** </ul>
2520 ** This setting defaults to "on" for legacy compatibility, however
2521 ** all applications are advised to turn it off if possible. This setting
2522 ** can also be controlled using the [PRAGMA trusted_schema] statement.
2523 ** </dd>
2524 **
2525 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2526 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2527 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2528 ** the legacy file format flag. When activated, this flag causes all newly
2529 ** created database file to have a schema format version number (the 4-byte
2530 ** integer found at offset 44 into the database header) of 1. This in turn
2531 ** means that the resulting database file will be readable and writable by
2532 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2533 ** newly created databases are generally not understandable by SQLite versions
2534 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2535 ** is now scarcely any need to generate database files that are compatible
2536 ** all the way back to version 3.0.0, and so this setting is of little
2537 ** practical use, but is provided so that SQLite can continue to claim the
2538 ** ability to generate new database files that are compatible with version
2539 ** 3.0.0.
2540 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2541 ** the [VACUUM] command will fail with an obscure error when attempting to
2542 ** process a table with generated columns and a descending index. This is
2543 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2544 ** either generated columns or descending indexes.
2545 ** </dd>
2546 **
2547 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2548 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2549 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2550 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2551 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2552 ** statistics. For statistics to be collected, the flag must be set on
2553 ** the database handle both when the SQL statement is prepared and when it
2554 ** is stepped. The flag is set (collection of statistics is enabled)
2555 ** by default. <p>This option takes two arguments: an integer and a pointer to
2556 ** an integer.. The first argument is 1, 0, or -1 to enable, disable, or
2557 ** leave unchanged the statement scanstatus option. If the second argument
2558 ** is not NULL, then the value of the statement scanstatus setting after
2559 ** processing the first argument is written into the integer that the second
2560 ** argument points to.
2561 ** </dd>
2562 **
2563 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2564 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2565 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2566 ** in which tables and indexes are scanned so that the scans start at the end
2567 ** and work toward the beginning rather than starting at the beginning and
2568 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2569 ** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes
2570 ** two arguments which are an integer and a pointer to an integer. The first
2571 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2572 ** reverse scan order flag, respectively. If the second argument is not NULL,
2573 ** then 0 or 1 is written into the integer that the second argument points to
2574 ** depending on if the reverse scan order flag is set after processing the
2575 ** first argument.
2576 ** </dd>
2577 **
2578 ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]]
2579 ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt>
2580 ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables
2581 ** the ability of the [ATTACH DATABASE] SQL command to create a new database
2582 ** file if the database filed named in the ATTACH command does not already
2583 ** exist. This ability of ATTACH to create a new database is enabled by
2584 ** default. Applications can disable or reenable the ability for ATTACH to
2585 ** create new database files using this DBCONFIG option.<p>
2586 ** This option takes two arguments which are an integer and a pointer
2587 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2588 ** leave unchanged the attach-create flag, respectively. If the second
2589 ** argument is not NULL, then 0 or 1 is written into the integer that the
2590 ** second argument points to depending on if the attach-create flag is set
2591 ** after processing the first argument.
2592 ** </dd>
2593 **
2594 ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]]
2595 ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt>
2596 ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the
2597 ** ability of the [ATTACH DATABASE] SQL command to open a database for writing.
2598 ** This capability is enabled by default. Applications can disable or
2599 ** reenable this capability using the current DBCONFIG option. If the
2600 ** the this capability is disabled, the [ATTACH] command will still work,
2601 ** but the database will be opened read-only. If this option is disabled,
2602 ** then the ability to create a new database using [ATTACH] is also disabled,
2603 ** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]
2604 ** option.<p>
2605 ** This option takes two arguments which are an integer and a pointer
2606 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2607 ** leave unchanged the ability to ATTACH another database for writing,
2608 ** respectively. If the second argument is not NULL, then 0 or 1 is written
2609 ** into the integer to which the second argument points, depending on whether
2610 ** the ability to ATTACH a read/write database is enabled or disabled
2611 ** after processing the first argument.
2612 ** </dd>
2613 **
2614 ** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]]
2615 ** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt>
2616 ** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the
2617 ** ability to include comments in SQL text. Comments are enabled by default.
2618 ** An application can disable or reenable comments in SQL text using this
2619 ** DBCONFIG option.<p>
2620 ** This option takes two arguments which are an integer and a pointer
2621 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2622 ** leave unchanged the ability to use comments in SQL text,
2623 ** respectively. If the second argument is not NULL, then 0 or 1 is written
2624 ** into the integer that the second argument points to depending on if
2625 ** comments are allowed in SQL text after processing the first argument.
2626 ** </dd>
2627 **
2628 ** </dl>
2629 **
2630 ** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3>
2631 **
2632 ** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the
2633 ** overall call to [sqlite3_db_config()] has a total of four parameters.
2634 ** The first argument (the third parameter to sqlite3_db_config()) is a integer.
2635 ** The second argument is a pointer to an integer. If the first argument is 1,
2636 ** then the option becomes enabled. If the first integer argument is 0, then the
2637 ** option is disabled. If the first argument is -1, then the option setting
2638 ** is unchanged. The second argument, the pointer to an integer, may be NULL.
2639 ** If the second argument is not NULL, then a value of 0 or 1 is written into
2640 ** the integer to which the second argument points, depending on whether the
2641 ** setting is disabled or enabled after applying any changes specified by
2642 ** the first argument.
2643 **
2644 ** <p>While most SQLITE_DBCONFIG options use the argument format
2645 ** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME]
2646 ** and [SQLITE_DBCONFIG_LOOKASIDE] options are different. See the
2647 ** documentation of those exceptional options for details.
2648 */
2649 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2650 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2651 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2652 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2653 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2654 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2655 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2656 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2657 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2658 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2659 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2660 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2661 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2662 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2663 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2664 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2665 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2666 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2667 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2668 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2669 #define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE 1020 /* int int* */
2670 #define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE 1021 /* int int* */
2671 #define SQLITE_DBCONFIG_ENABLE_COMMENTS 1022 /* int int* */
2672 #define SQLITE_DBCONFIG_MAX 1022 /* Largest DBCONFIG */
2673 2674 /*
2675 ** CAPI3REF: Enable Or Disable Extended Result Codes
2676 ** METHOD: sqlite3
2677 **
2678 ** ^The sqlite3_extended_result_codes() routine enables or disables the
2679 ** [extended result codes] feature of SQLite. ^The extended result
2680 ** codes are disabled by default for historical compatibility.
2681 */
2682 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2683 2684 /*
2685 ** CAPI3REF: Last Insert Rowid
2686 ** METHOD: sqlite3
2687 **
2688 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2689 ** has a unique 64-bit signed
2690 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2691 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2692 ** names are not also used by explicitly declared columns. ^If
2693 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2694 ** is another alias for the rowid.
2695 **
2696 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2697 ** the most recent successful [INSERT] into a rowid table or [virtual table]
2698 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2699 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2700 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2701 ** zero.
2702 **
2703 ** As well as being set automatically as rows are inserted into database
2704 ** tables, the value returned by this function may be set explicitly by
2705 ** [sqlite3_set_last_insert_rowid()]
2706 **
2707 ** Some virtual table implementations may INSERT rows into rowid tables as
2708 ** part of committing a transaction (e.g. to flush data accumulated in memory
2709 ** to disk). In this case subsequent calls to this function return the rowid
2710 ** associated with these internal INSERT operations, which leads to
2711 ** unintuitive results. Virtual table implementations that do write to rowid
2712 ** tables in this way can avoid this problem by restoring the original
2713 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2714 ** control to the user.
2715 **
2716 ** ^(If an [INSERT] occurs within a trigger then this routine will
2717 ** return the [rowid] of the inserted row as long as the trigger is
2718 ** running. Once the trigger program ends, the value returned
2719 ** by this routine reverts to what it was before the trigger was fired.)^
2720 **
2721 ** ^An [INSERT] that fails due to a constraint violation is not a
2722 ** successful [INSERT] and does not change the value returned by this
2723 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2724 ** and INSERT OR ABORT make no changes to the return value of this
2725 ** routine when their insertion fails. ^(When INSERT OR REPLACE
2726 ** encounters a constraint violation, it does not fail. The
2727 ** INSERT continues to completion after deleting rows that caused
2728 ** the constraint problem so INSERT OR REPLACE will always change
2729 ** the return value of this interface.)^
2730 **
2731 ** ^For the purposes of this routine, an [INSERT] is considered to
2732 ** be successful even if it is subsequently rolled back.
2733 **
2734 ** This function is accessible to SQL statements via the
2735 ** [last_insert_rowid() SQL function].
2736 **
2737 ** If a separate thread performs a new [INSERT] on the same
2738 ** database connection while the [sqlite3_last_insert_rowid()]
2739 ** function is running and thus changes the last insert [rowid],
2740 ** then the value returned by [sqlite3_last_insert_rowid()] is
2741 ** unpredictable and might not equal either the old or the new
2742 ** last insert [rowid].
2743 */
2744 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2745 2746 /*
2747 ** CAPI3REF: Set the Last Insert Rowid value.
2748 ** METHOD: sqlite3
2749 **
2750 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2751 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2752 ** without inserting a row into the database.
2753 */
2754 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2755 2756 /*
2757 ** CAPI3REF: Count The Number Of Rows Modified
2758 ** METHOD: sqlite3
2759 **
2760 ** ^These functions return the number of rows modified, inserted or
2761 ** deleted by the most recently completed INSERT, UPDATE or DELETE
2762 ** statement on the database connection specified by the only parameter.
2763 ** The two functions are identical except for the type of the return value
2764 ** and that if the number of rows modified by the most recent INSERT, UPDATE,
2765 ** or DELETE is greater than the maximum value supported by type "int", then
2766 ** the return value of sqlite3_changes() is undefined. ^Executing any other
2767 ** type of SQL statement does not modify the value returned by these functions.
2768 ** For the purposes of this interface, a CREATE TABLE AS SELECT statement
2769 ** does not count as an INSERT, UPDATE or DELETE statement and hence the rows
2770 ** added to the new table by the CREATE TABLE AS SELECT statement are not
2771 ** counted.
2772 **
2773 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2774 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2775 ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2776 **
2777 ** Changes to a view that are intercepted by
2778 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2779 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2780 ** DELETE statement run on a view is always zero. Only changes made to real
2781 ** tables are counted.
2782 **
2783 ** Things are more complicated if the sqlite3_changes() function is
2784 ** executed while a trigger program is running. This may happen if the
2785 ** program uses the [changes() SQL function], or if some other callback
2786 ** function invokes sqlite3_changes() directly. Essentially:
2787 **
2788 ** <ul>
2789 ** <li> ^(Before entering a trigger program the value returned by
2790 ** sqlite3_changes() function is saved. After the trigger program
2791 ** has finished, the original value is restored.)^
2792 **
2793 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2794 ** statement sets the value returned by sqlite3_changes()
2795 ** upon completion as normal. Of course, this value will not include
2796 ** any changes performed by sub-triggers, as the sqlite3_changes()
2797 ** value will be saved and restored after each sub-trigger has run.)^
2798 ** </ul>
2799 **
2800 ** ^This means that if the changes() SQL function (or similar) is used
2801 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2802 ** returns the value as set when the calling statement began executing.
2803 ** ^If it is used by the second or subsequent such statement within a trigger
2804 ** program, the value returned reflects the number of rows modified by the
2805 ** previous INSERT, UPDATE or DELETE statement within the same trigger.
2806 **
2807 ** If a separate thread makes changes on the same database connection
2808 ** while [sqlite3_changes()] is running then the value returned
2809 ** is unpredictable and not meaningful.
2810 **
2811 ** See also:
2812 ** <ul>
2813 ** <li> the [sqlite3_total_changes()] interface
2814 ** <li> the [count_changes pragma]
2815 ** <li> the [changes() SQL function]
2816 ** <li> the [data_version pragma]
2817 ** </ul>
2818 */
2819 SQLITE_API int sqlite3_changes(sqlite3*);
2820 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2821 2822 /*
2823 ** CAPI3REF: Total Number Of Rows Modified
2824 ** METHOD: sqlite3
2825 **
2826 ** ^These functions return the total number of rows inserted, modified or
2827 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2828 ** since the database connection was opened, including those executed as
2829 ** part of trigger programs. The two functions are identical except for the
2830 ** type of the return value and that if the number of rows modified by the
2831 ** connection exceeds the maximum value supported by type "int", then
2832 ** the return value of sqlite3_total_changes() is undefined. ^Executing
2833 ** any other type of SQL statement does not affect the value returned by
2834 ** sqlite3_total_changes().
2835 **
2836 ** ^Changes made as part of [foreign key actions] are included in the
2837 ** count, but those made as part of REPLACE constraint resolution are
2838 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2839 ** are not counted.
2840 **
2841 ** The [sqlite3_total_changes(D)] interface only reports the number
2842 ** of rows that changed due to SQL statement run against database
2843 ** connection D. Any changes by other database connections are ignored.
2844 ** To detect changes against a database file from other database
2845 ** connections use the [PRAGMA data_version] command or the
2846 ** [SQLITE_FCNTL_DATA_VERSION] [file control].
2847 **
2848 ** If a separate thread makes changes on the same database connection
2849 ** while [sqlite3_total_changes()] is running then the value
2850 ** returned is unpredictable and not meaningful.
2851 **
2852 ** See also:
2853 ** <ul>
2854 ** <li> the [sqlite3_changes()] interface
2855 ** <li> the [count_changes pragma]
2856 ** <li> the [changes() SQL function]
2857 ** <li> the [data_version pragma]
2858 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2859 ** </ul>
2860 */
2861 SQLITE_API int sqlite3_total_changes(sqlite3*);
2862 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2863 2864 /*
2865 ** CAPI3REF: Interrupt A Long-Running Query
2866 ** METHOD: sqlite3
2867 **
2868 ** ^This function causes any pending database operation to abort and
2869 ** return at its earliest opportunity. This routine is typically
2870 ** called in response to a user action such as pressing "Cancel"
2871 ** or Ctrl-C where the user wants a long query operation to halt
2872 ** immediately.
2873 **
2874 ** ^It is safe to call this routine from a thread different from the
2875 ** thread that is currently running the database operation. But it
2876 ** is not safe to call this routine with a [database connection] that
2877 ** is closed or might close before sqlite3_interrupt() returns.
2878 **
2879 ** ^If an SQL operation is very nearly finished at the time when
2880 ** sqlite3_interrupt() is called, then it might not have an opportunity
2881 ** to be interrupted and might continue to completion.
2882 **
2883 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2884 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2885 ** that is inside an explicit transaction, then the entire transaction
2886 ** will be rolled back automatically.
2887 **
2888 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2889 ** SQL statements on [database connection] D complete. ^Any new SQL statements
2890 ** that are started after the sqlite3_interrupt() call and before the
2891 ** running statement count reaches zero are interrupted as if they had been
2892 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2893 ** that are started after the running statement count reaches zero are
2894 ** not effected by the sqlite3_interrupt().
2895 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2896 ** SQL statements is a no-op and has no effect on SQL statements
2897 ** that are started after the sqlite3_interrupt() call returns.
2898 **
2899 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2900 ** or not an interrupt is currently in effect for [database connection] D.
2901 ** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2902 */
2903 SQLITE_API void sqlite3_interrupt(sqlite3*);
2904 SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2905 2906 /*
2907 ** CAPI3REF: Determine If An SQL Statement Is Complete
2908 **
2909 ** These routines are useful during command-line input to determine if the
2910 ** currently entered text seems to form a complete SQL statement or
2911 ** if additional input is needed before sending the text into
2912 ** SQLite for parsing. ^These routines return 1 if the input string
2913 ** appears to be a complete SQL statement. ^A statement is judged to be
2914 ** complete if it ends with a semicolon token and is not a prefix of a
2915 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2916 ** string literals or quoted identifier names or comments are not
2917 ** independent tokens (they are part of the token in which they are
2918 ** embedded) and thus do not count as a statement terminator. ^Whitespace
2919 ** and comments that follow the final semicolon are ignored.
2920 **
2921 ** ^These routines return 0 if the statement is incomplete. ^If a
2922 ** memory allocation fails, then SQLITE_NOMEM is returned.
2923 **
2924 ** ^These routines do not parse the SQL statements thus
2925 ** will not detect syntactically incorrect SQL.
2926 **
2927 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2928 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2929 ** automatically by sqlite3_complete16(). If that initialization fails,
2930 ** then the return value from sqlite3_complete16() will be non-zero
2931 ** regardless of whether or not the input SQL is complete.)^
2932 **
2933 ** The input to [sqlite3_complete()] must be a zero-terminated
2934 ** UTF-8 string.
2935 **
2936 ** The input to [sqlite3_complete16()] must be a zero-terminated
2937 ** UTF-16 string in native byte order.
2938 */
2939 SQLITE_API int sqlite3_complete(const char *sql);
2940 SQLITE_API int sqlite3_complete16(const void *sql);
2941 2942 /*
2943 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2944 ** KEYWORDS: {busy-handler callback} {busy handler}
2945 ** METHOD: sqlite3
2946 **
2947 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2948 ** that might be invoked with argument P whenever
2949 ** an attempt is made to access a database table associated with
2950 ** [database connection] D when another thread
2951 ** or process has the table locked.
2952 ** The sqlite3_busy_handler() interface is used to implement
2953 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2954 **
2955 ** ^If the busy callback is NULL, then [SQLITE_BUSY]
2956 ** is returned immediately upon encountering the lock. ^If the busy callback
2957 ** is not NULL, then the callback might be invoked with two arguments.
2958 **
2959 ** ^The first argument to the busy handler is a copy of the void* pointer which
2960 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2961 ** the busy handler callback is the number of times that the busy handler has
2962 ** been invoked previously for the same locking event. ^If the
2963 ** busy callback returns 0, then no additional attempts are made to
2964 ** access the database and [SQLITE_BUSY] is returned
2965 ** to the application.
2966 ** ^If the callback returns non-zero, then another attempt
2967 ** is made to access the database and the cycle repeats.
2968 **
2969 ** The presence of a busy handler does not guarantee that it will be invoked
2970 ** when there is lock contention. ^If SQLite determines that invoking the busy
2971 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2972 ** to the application instead of invoking the
2973 ** busy handler.
2974 ** Consider a scenario where one process is holding a read lock that
2975 ** it is trying to promote to a reserved lock and
2976 ** a second process is holding a reserved lock that it is trying
2977 ** to promote to an exclusive lock. The first process cannot proceed
2978 ** because it is blocked by the second and the second process cannot
2979 ** proceed because it is blocked by the first. If both processes
2980 ** invoke the busy handlers, neither will make any progress. Therefore,
2981 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2982 ** will induce the first process to release its read lock and allow
2983 ** the second process to proceed.
2984 **
2985 ** ^The default busy callback is NULL.
2986 **
2987 ** ^(There can only be a single busy handler defined for each
2988 ** [database connection]. Setting a new busy handler clears any
2989 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2990 ** or evaluating [PRAGMA busy_timeout=N] will change the
2991 ** busy handler and thus clear any previously set busy handler.
2992 **
2993 ** The busy callback should not take any actions which modify the
2994 ** database connection that invoked the busy handler. In other words,
2995 ** the busy handler is not reentrant. Any such actions
2996 ** result in undefined behavior.
2997 **
2998 ** A busy handler must not close the database connection
2999 ** or [prepared statement] that invoked the busy handler.
3000 */
3001 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
3002 3003 /*
3004 ** CAPI3REF: Set A Busy Timeout
3005 ** METHOD: sqlite3
3006 **
3007 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
3008 ** for a specified amount of time when a table is locked. ^The handler
3009 ** will sleep multiple times until at least "ms" milliseconds of sleeping
3010 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
3011 ** the handler returns 0 which causes [sqlite3_step()] to return
3012 ** [SQLITE_BUSY].
3013 **
3014 ** ^Calling this routine with an argument less than or equal to zero
3015 ** turns off all busy handlers.
3016 **
3017 ** ^(There can only be a single busy handler for a particular
3018 ** [database connection] at any given moment. If another busy handler
3019 ** was defined (using [sqlite3_busy_handler()]) prior to calling
3020 ** this routine, that other busy handler is cleared.)^
3021 **
3022 ** See also: [PRAGMA busy_timeout]
3023 */
3024 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
3025 3026 /*
3027 ** CAPI3REF: Set the Setlk Timeout
3028 ** METHOD: sqlite3
3029 **
3030 ** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If
3031 ** the VFS supports blocking locks, it sets the timeout in ms used by
3032 ** eligible locks taken on wal mode databases by the specified database
3033 ** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does
3034 ** not support blocking locks, this function is a no-op.
3035 **
3036 ** Passing 0 to this function disables blocking locks altogether. Passing
3037 ** -1 to this function requests that the VFS blocks for a long time -
3038 ** indefinitely if possible. The results of passing any other negative value
3039 ** are undefined.
3040 **
3041 ** Internally, each SQLite database handle store two timeout values - the
3042 ** busy-timeout (used for rollback mode databases, or if the VFS does not
3043 ** support blocking locks) and the setlk-timeout (used for blocking locks
3044 ** on wal-mode databases). The sqlite3_busy_timeout() method sets both
3045 ** values, this function sets only the setlk-timeout value. Therefore,
3046 ** to configure separate busy-timeout and setlk-timeout values for a single
3047 ** database handle, call sqlite3_busy_timeout() followed by this function.
3048 **
3049 ** Whenever the number of connections to a wal mode database falls from
3050 ** 1 to 0, the last connection takes an exclusive lock on the database,
3051 ** then checkpoints and deletes the wal file. While it is doing this, any
3052 ** new connection that tries to read from the database fails with an
3053 ** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is
3054 ** passed to this API, the new connection blocks until the exclusive lock
3055 ** has been released.
3056 */
3057 SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags);
3058 3059 /*
3060 ** CAPI3REF: Flags for sqlite3_setlk_timeout()
3061 */
3062 #define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01
3063 3064 /*
3065 ** CAPI3REF: Convenience Routines For Running Queries
3066 ** METHOD: sqlite3
3067 **
3068 ** This is a legacy interface that is preserved for backwards compatibility.
3069 ** Use of this interface is not recommended.
3070 **
3071 ** Definition: A <b>result table</b> is memory data structure created by the
3072 ** [sqlite3_get_table()] interface. A result table records the
3073 ** complete query results from one or more queries.
3074 **
3075 ** The table conceptually has a number of rows and columns. But
3076 ** these numbers are not part of the result table itself. These
3077 ** numbers are obtained separately. Let N be the number of rows
3078 ** and M be the number of columns.
3079 **
3080 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
3081 ** There are (N+1)*M elements in the array. The first M pointers point
3082 ** to zero-terminated strings that contain the names of the columns.
3083 ** The remaining entries all point to query results. NULL values result
3084 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
3085 ** string representation as returned by [sqlite3_column_text()].
3086 **
3087 ** A result table might consist of one or more memory allocations.
3088 ** It is not safe to pass a result table directly to [sqlite3_free()].
3089 ** A result table should be deallocated using [sqlite3_free_table()].
3090 **
3091 ** ^(As an example of the result table format, suppose a query result
3092 ** is as follows:
3093 **
3094 ** <blockquote><pre>
3095 ** Name | Age
3096 ** -----------------------
3097 ** Alice | 43
3098 ** Bob | 28
3099 ** Cindy | 21
3100 ** </pre></blockquote>
3101 **
3102 ** There are two columns (M==2) and three rows (N==3). Thus the
3103 ** result table has 8 entries. Suppose the result table is stored
3104 ** in an array named azResult. Then azResult holds this content:
3105 **
3106 ** <blockquote><pre>
3107 ** azResult[0] = "Name";
3108 ** azResult[1] = "Age";
3109 ** azResult[2] = "Alice";
3110 ** azResult[3] = "43";
3111 ** azResult[4] = "Bob";
3112 ** azResult[5] = "28";
3113 ** azResult[6] = "Cindy";
3114 ** azResult[7] = "21";
3115 ** </pre></blockquote>)^
3116 **
3117 ** ^The sqlite3_get_table() function evaluates one or more
3118 ** semicolon-separated SQL statements in the zero-terminated UTF-8
3119 ** string of its 2nd parameter and returns a result table to the
3120 ** pointer given in its 3rd parameter.
3121 **
3122 ** After the application has finished with the result from sqlite3_get_table(),
3123 ** it must pass the result table pointer to sqlite3_free_table() in order to
3124 ** release the memory that was malloced. Because of the way the
3125 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
3126 ** function must not try to call [sqlite3_free()] directly. Only
3127 ** [sqlite3_free_table()] is able to release the memory properly and safely.
3128 **
3129 ** The sqlite3_get_table() interface is implemented as a wrapper around
3130 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
3131 ** to any internal data structures of SQLite. It uses only the public
3132 ** interface defined here. As a consequence, errors that occur in the
3133 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
3134 ** reflected in subsequent calls to [sqlite3_errcode()] or
3135 ** [sqlite3_errmsg()].
3136 */
3137 SQLITE_API int sqlite3_get_table(
3138 sqlite3 *db, /* An open database */
3139 const char *zSql, /* SQL to be evaluated */
3140 char ***pazResult, /* Results of the query */
3141 int *pnRow, /* Number of result rows written here */
3142 int *pnColumn, /* Number of result columns written here */
3143 char **pzErrmsg /* Error msg written here */
3144 );
3145 SQLITE_API void sqlite3_free_table(char **result);
3146 3147 /*
3148 ** CAPI3REF: Formatted String Printing Functions
3149 **
3150 ** These routines are work-alikes of the "printf()" family of functions
3151 ** from the standard C library.
3152 ** These routines understand most of the common formatting options from
3153 ** the standard library printf()
3154 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
3155 ** See the [built-in printf()] documentation for details.
3156 **
3157 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
3158 ** results into memory obtained from [sqlite3_malloc64()].
3159 ** The strings returned by these two routines should be
3160 ** released by [sqlite3_free()]. ^Both routines return a
3161 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
3162 ** memory to hold the resulting string.
3163 **
3164 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
3165 ** the standard C library. The result is written into the
3166 ** buffer supplied as the second parameter whose size is given by
3167 ** the first parameter. Note that the order of the
3168 ** first two parameters is reversed from snprintf().)^ This is an
3169 ** historical accident that cannot be fixed without breaking
3170 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
3171 ** returns a pointer to its buffer instead of the number of
3172 ** characters actually written into the buffer.)^ We admit that
3173 ** the number of characters written would be a more useful return
3174 ** value but we cannot change the implementation of sqlite3_snprintf()
3175 ** now without breaking compatibility.
3176 **
3177 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
3178 ** guarantees that the buffer is always zero-terminated. ^The first
3179 ** parameter "n" is the total size of the buffer, including space for
3180 ** the zero terminator. So the longest string that can be completely
3181 ** written will be n-1 characters.
3182 **
3183 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
3184 **
3185 ** See also: [built-in printf()], [printf() SQL function]
3186 */
3187 SQLITE_API char *sqlite3_mprintf(const char*,...);
3188 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
3189 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
3190 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
3191 3192 /*
3193 ** CAPI3REF: Memory Allocation Subsystem
3194 **
3195 ** The SQLite core uses these three routines for all of its own
3196 ** internal memory allocation needs. "Core" in the previous sentence
3197 ** does not include operating-system specific [VFS] implementation. The
3198 ** Windows VFS uses native malloc() and free() for some operations.
3199 **
3200 ** ^The sqlite3_malloc() routine returns a pointer to a block
3201 ** of memory at least N bytes in length, where N is the parameter.
3202 ** ^If sqlite3_malloc() is unable to obtain sufficient free
3203 ** memory, it returns a NULL pointer. ^If the parameter N to
3204 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3205 ** a NULL pointer.
3206 **
3207 ** ^The sqlite3_malloc64(N) routine works just like
3208 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3209 ** of a signed 32-bit integer.
3210 **
3211 ** ^Calling sqlite3_free() with a pointer previously returned
3212 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3213 ** that it might be reused. ^The sqlite3_free() routine is
3214 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
3215 ** to sqlite3_free() is harmless. After being freed, memory
3216 ** should neither be read nor written. Even reading previously freed
3217 ** memory might result in a segmentation fault or other severe error.
3218 ** Memory corruption, a segmentation fault, or other severe error
3219 ** might result if sqlite3_free() is called with a non-NULL pointer that
3220 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3221 **
3222 ** ^The sqlite3_realloc(X,N) interface attempts to resize a
3223 ** prior memory allocation X to be at least N bytes.
3224 ** ^If the X parameter to sqlite3_realloc(X,N)
3225 ** is a NULL pointer then its behavior is identical to calling
3226 ** sqlite3_malloc(N).
3227 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3228 ** negative then the behavior is exactly the same as calling
3229 ** sqlite3_free(X).
3230 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3231 ** of at least N bytes in size or NULL if insufficient memory is available.
3232 ** ^If M is the size of the prior allocation, then min(N,M) bytes
3233 ** of the prior allocation are copied into the beginning of buffer returned
3234 ** by sqlite3_realloc(X,N) and the prior allocation is freed.
3235 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3236 ** prior allocation is not freed.
3237 **
3238 ** ^The sqlite3_realloc64(X,N) interfaces works the same as
3239 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3240 ** of a 32-bit signed integer.
3241 **
3242 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3243 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3244 ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3245 ** ^The value returned by sqlite3_msize(X) might be larger than the number
3246 ** of bytes requested when X was allocated. ^If X is a NULL pointer then
3247 ** sqlite3_msize(X) returns zero. If X points to something that is not
3248 ** the beginning of memory allocation, or if it points to a formerly
3249 ** valid memory allocation that has now been freed, then the behavior
3250 ** of sqlite3_msize(X) is undefined and possibly harmful.
3251 **
3252 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3253 ** sqlite3_malloc64(), and sqlite3_realloc64()
3254 ** is always aligned to at least an 8 byte boundary, or to a
3255 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3256 ** option is used.
3257 **
3258 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3259 ** must be either NULL or else pointers obtained from a prior
3260 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3261 ** not yet been released.
3262 **
3263 ** The application must not read or write any part of
3264 ** a block of memory after it has been released using
3265 ** [sqlite3_free()] or [sqlite3_realloc()].
3266 */
3267 SQLITE_API void *sqlite3_malloc(int);
3268 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3269 SQLITE_API void *sqlite3_realloc(void*, int);
3270 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3271 SQLITE_API void sqlite3_free(void*);
3272 SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3273 3274 /*
3275 ** CAPI3REF: Memory Allocator Statistics
3276 **
3277 ** SQLite provides these two interfaces for reporting on the status
3278 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3279 ** routines, which form the built-in memory allocation subsystem.
3280 **
3281 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
3282 ** of memory currently outstanding (malloced but not freed).
3283 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
3284 ** value of [sqlite3_memory_used()] since the high-water mark
3285 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
3286 ** [sqlite3_memory_highwater()] include any overhead
3287 ** added by SQLite in its implementation of [sqlite3_malloc()],
3288 ** but not overhead added by the any underlying system library
3289 ** routines that [sqlite3_malloc()] may call.
3290 **
3291 ** ^The memory high-water mark is reset to the current value of
3292 ** [sqlite3_memory_used()] if and only if the parameter to
3293 ** [sqlite3_memory_highwater()] is true. ^The value returned
3294 ** by [sqlite3_memory_highwater(1)] is the high-water mark
3295 ** prior to the reset.
3296 */
3297 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3298 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3299 3300 /*
3301 ** CAPI3REF: Pseudo-Random Number Generator
3302 **
3303 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3304 ** select random [ROWID | ROWIDs] when inserting new records into a table that
3305 ** already uses the largest possible [ROWID]. The PRNG is also used for
3306 ** the built-in random() and randomblob() SQL functions. This interface allows
3307 ** applications to access the same PRNG for other purposes.
3308 **
3309 ** ^A call to this routine stores N bytes of randomness into buffer P.
3310 ** ^The P parameter can be a NULL pointer.
3311 **
3312 ** ^If this routine has not been previously called or if the previous
3313 ** call had N less than one or a NULL pointer for P, then the PRNG is
3314 ** seeded using randomness obtained from the xRandomness method of
3315 ** the default [sqlite3_vfs] object.
3316 ** ^If the previous call to this routine had an N of 1 or more and a
3317 ** non-NULL P then the pseudo-randomness is generated
3318 ** internally and without recourse to the [sqlite3_vfs] xRandomness
3319 ** method.
3320 */
3321 SQLITE_API void sqlite3_randomness(int N, void *P);
3322 3323 /*
3324 ** CAPI3REF: Compile-Time Authorization Callbacks
3325 ** METHOD: sqlite3
3326 ** KEYWORDS: {authorizer callback}
3327 **
3328 ** ^This routine registers an authorizer callback with a particular
3329 ** [database connection], supplied in the first argument.
3330 ** ^The authorizer callback is invoked as SQL statements are being compiled
3331 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3332 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3333 ** and [sqlite3_prepare16_v3()]. ^At various
3334 ** points during the compilation process, as logic is being created
3335 ** to perform various actions, the authorizer callback is invoked to
3336 ** see if those actions are allowed. ^The authorizer callback should
3337 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3338 ** specific action but allow the SQL statement to continue to be
3339 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3340 ** rejected with an error. ^If the authorizer callback returns
3341 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3342 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3343 ** the authorizer will fail with an error message.
3344 **
3345 ** When the callback returns [SQLITE_OK], that means the operation
3346 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
3347 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
3348 ** authorizer will fail with an error message explaining that
3349 ** access is denied.
3350 **
3351 ** ^The first parameter to the authorizer callback is a copy of the third
3352 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3353 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
3354 ** the particular action to be authorized. ^The third through sixth parameters
3355 ** to the callback are either NULL pointers or zero-terminated strings
3356 ** that contain additional details about the action to be authorized.
3357 ** Applications must always be prepared to encounter a NULL pointer in any
3358 ** of the third through the sixth parameters of the authorization callback.
3359 **
3360 ** ^If the action code is [SQLITE_READ]
3361 ** and the callback returns [SQLITE_IGNORE] then the
3362 ** [prepared statement] statement is constructed to substitute
3363 ** a NULL value in place of the table column that would have
3364 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3365 ** return can be used to deny an untrusted user access to individual
3366 ** columns of a table.
3367 ** ^When a table is referenced by a [SELECT] but no column values are
3368 ** extracted from that table (for example in a query like
3369 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3370 ** is invoked once for that table with a column name that is an empty string.
3371 ** ^If the action code is [SQLITE_DELETE] and the callback returns
3372 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3373 ** [truncate optimization] is disabled and all rows are deleted individually.
3374 **
3375 ** An authorizer is used when [sqlite3_prepare | preparing]
3376 ** SQL statements from an untrusted source, to ensure that the SQL statements
3377 ** do not try to access data they are not allowed to see, or that they do not
3378 ** try to execute malicious statements that damage the database. For
3379 ** example, an application may allow a user to enter arbitrary
3380 ** SQL queries for evaluation by a database. But the application does
3381 ** not want the user to be able to make arbitrary changes to the
3382 ** database. An authorizer could then be put in place while the
3383 ** user-entered SQL is being [sqlite3_prepare | prepared] that
3384 ** disallows everything except [SELECT] statements.
3385 **
3386 ** Applications that need to process SQL from untrusted sources
3387 ** might also consider lowering resource limits using [sqlite3_limit()]
3388 ** and limiting database size using the [max_page_count] [PRAGMA]
3389 ** in addition to using an authorizer.
3390 **
3391 ** ^(Only a single authorizer can be in place on a database connection
3392 ** at a time. Each call to sqlite3_set_authorizer overrides the
3393 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3394 ** The authorizer is disabled by default.
3395 **
3396 ** The authorizer callback must not do anything that will modify
3397 ** the database connection that invoked the authorizer callback.
3398 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3399 ** database connections for the meaning of "modify" in this paragraph.
3400 **
3401 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3402 ** statement might be re-prepared during [sqlite3_step()] due to a
3403 ** schema change. Hence, the application should ensure that the
3404 ** correct authorizer callback remains in place during the [sqlite3_step()].
3405 **
3406 ** ^Note that the authorizer callback is invoked only during
3407 ** [sqlite3_prepare()] or its variants. Authorization is not
3408 ** performed during statement evaluation in [sqlite3_step()], unless
3409 ** as stated in the previous paragraph, sqlite3_step() invokes
3410 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3411 */
3412 SQLITE_API int sqlite3_set_authorizer(
3413 sqlite3*,
3414 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3415 void *pUserData
3416 );
3417 3418 /*
3419 ** CAPI3REF: Authorizer Return Codes
3420 **
3421 ** The [sqlite3_set_authorizer | authorizer callback function] must
3422 ** return either [SQLITE_OK] or one of these two constants in order
3423 ** to signal SQLite whether or not the action is permitted. See the
3424 ** [sqlite3_set_authorizer | authorizer documentation] for additional
3425 ** information.
3426 **
3427 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3428 ** returned from the [sqlite3_vtab_on_conflict()] interface.
3429 */
3430 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3431 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3432 3433 /*
3434 ** CAPI3REF: Authorizer Action Codes
3435 **
3436 ** The [sqlite3_set_authorizer()] interface registers a callback function
3437 ** that is invoked to authorize certain SQL statement actions. The
3438 ** second parameter to the callback is an integer code that specifies
3439 ** what action is being authorized. These are the integer action codes that
3440 ** the authorizer callback may be passed.
3441 **
3442 ** These action code values signify what kind of operation is to be
3443 ** authorized. The 3rd and 4th parameters to the authorization
3444 ** callback function will be parameters or NULL depending on which of these
3445 ** codes is used as the second parameter. ^(The 5th parameter to the
3446 ** authorizer callback is the name of the database ("main", "temp",
3447 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3448 ** is the name of the inner-most trigger or view that is responsible for
3449 ** the access attempt or NULL if this access attempt is directly from
3450 ** top-level SQL code.
3451 */
3452 /******************************************* 3rd ************ 4th ***********/
3453 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3454 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3455 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3456 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3457 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3458 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3459 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3460 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3461 #define SQLITE_DELETE 9 /* Table Name NULL */
3462 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3463 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3464 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3465 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3466 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3467 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3468 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3469 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
3470 #define SQLITE_INSERT 18 /* Table Name NULL */
3471 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3472 #define SQLITE_READ 20 /* Table Name Column Name */
3473 #define SQLITE_SELECT 21 /* NULL NULL */
3474 #define SQLITE_TRANSACTION 22 /* Operation NULL */
3475 #define SQLITE_UPDATE 23 /* Table Name Column Name */
3476 #define SQLITE_ATTACH 24 /* Filename NULL */
3477 #define SQLITE_DETACH 25 /* Database Name NULL */
3478 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3479 #define SQLITE_REINDEX 27 /* Index Name NULL */
3480 #define SQLITE_ANALYZE 28 /* Table Name NULL */
3481 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3482 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3483 #define SQLITE_FUNCTION 31 /* NULL Function Name */
3484 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3485 #define SQLITE_COPY 0 /* No longer used */
3486 #define SQLITE_RECURSIVE 33 /* NULL NULL */
3487 3488 /*
3489 ** CAPI3REF: Deprecated Tracing And Profiling Functions
3490 ** DEPRECATED
3491 **
3492 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3493 ** instead of the routines described here.
3494 **
3495 ** These routines register callback functions that can be used for
3496 ** tracing and profiling the execution of SQL statements.
3497 **
3498 ** ^The callback function registered by sqlite3_trace() is invoked at
3499 ** various times when an SQL statement is being run by [sqlite3_step()].
3500 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3501 ** SQL statement text as the statement first begins executing.
3502 ** ^(Additional sqlite3_trace() callbacks might occur
3503 ** as each triggered subprogram is entered. The callbacks for triggers
3504 ** contain a UTF-8 SQL comment that identifies the trigger.)^
3505 **
3506 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3507 ** the length of [bound parameter] expansion in the output of sqlite3_trace().
3508 **
3509 ** ^The callback function registered by sqlite3_profile() is invoked
3510 ** as each SQL statement finishes. ^The profile callback contains
3511 ** the original statement text and an estimate of wall-clock time
3512 ** of how long that statement took to run. ^The profile callback
3513 ** time is in units of nanoseconds, however the current implementation
3514 ** is only capable of millisecond resolution so the six least significant
3515 ** digits in the time are meaningless. Future versions of SQLite
3516 ** might provide greater resolution on the profiler callback. Invoking
3517 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3518 ** profile callback.
3519 */
3520 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3521 void(*xTrace)(void*,const char*), void*);
3522 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3523 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3524 3525 /*
3526 ** CAPI3REF: SQL Trace Event Codes
3527 ** KEYWORDS: SQLITE_TRACE
3528 **
3529 ** These constants identify classes of events that can be monitored
3530 ** using the [sqlite3_trace_v2()] tracing logic. The M argument
3531 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3532 ** the following constants. ^The first argument to the trace callback
3533 ** is one of the following constants.
3534 **
3535 ** New tracing constants may be added in future releases.
3536 **
3537 ** ^A trace callback has four arguments: xCallback(T,C,P,X).
3538 ** ^The T argument is one of the integer type codes above.
3539 ** ^The C argument is a copy of the context pointer passed in as the
3540 ** fourth argument to [sqlite3_trace_v2()].
3541 ** The P and X arguments are pointers whose meanings depend on T.
3542 **
3543 ** <dl>
3544 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3545 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3546 ** first begins running and possibly at other times during the
3547 ** execution of the prepared statement, such as at the start of each
3548 ** trigger subprogram. ^The P argument is a pointer to the
3549 ** [prepared statement]. ^The X argument is a pointer to a string which
3550 ** is the unexpanded SQL text of the prepared statement or an SQL comment
3551 ** that indicates the invocation of a trigger. ^The callback can compute
3552 ** the same text that would have been returned by the legacy [sqlite3_trace()]
3553 ** interface by using the X argument when X begins with "--" and invoking
3554 ** [sqlite3_expanded_sql(P)] otherwise.
3555 **
3556 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3557 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3558 ** information as is provided by the [sqlite3_profile()] callback.
3559 ** ^The P argument is a pointer to the [prepared statement] and the
3560 ** X argument points to a 64-bit integer which is approximately
3561 ** the number of nanoseconds that the prepared statement took to run.
3562 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3563 **
3564 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3565 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3566 ** statement generates a single row of result.
3567 ** ^The P argument is a pointer to the [prepared statement] and the
3568 ** X argument is unused.
3569 **
3570 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3571 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3572 ** connection closes.
3573 ** ^The P argument is a pointer to the [database connection] object
3574 ** and the X argument is unused.
3575 ** </dl>
3576 */
3577 #define SQLITE_TRACE_STMT 0x01
3578 #define SQLITE_TRACE_PROFILE 0x02
3579 #define SQLITE_TRACE_ROW 0x04
3580 #define SQLITE_TRACE_CLOSE 0x08
3581 3582 /*
3583 ** CAPI3REF: SQL Trace Hook
3584 ** METHOD: sqlite3
3585 **
3586 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3587 ** function X against [database connection] D, using property mask M
3588 ** and context pointer P. ^If the X callback is
3589 ** NULL or if the M mask is zero, then tracing is disabled. The
3590 ** M argument should be the bitwise OR-ed combination of
3591 ** zero or more [SQLITE_TRACE] constants.
3592 **
3593 ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3594 ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3595 ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3596 ** database connection may have at most one trace callback.
3597 **
3598 ** ^The X callback is invoked whenever any of the events identified by
3599 ** mask M occur. ^The integer return value from the callback is currently
3600 ** ignored, though this may change in future releases. Callback
3601 ** implementations should return zero to ensure future compatibility.
3602 **
3603 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3604 ** ^The T argument is one of the [SQLITE_TRACE]
3605 ** constants to indicate why the callback was invoked.
3606 ** ^The C argument is a copy of the context pointer.
3607 ** The P and X arguments are pointers whose meanings depend on T.
3608 **
3609 ** The sqlite3_trace_v2() interface is intended to replace the legacy
3610 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3611 ** are deprecated.
3612 */
3613 SQLITE_API int sqlite3_trace_v2(
3614 sqlite3*,
3615 unsigned uMask,
3616 int(*xCallback)(unsigned,void*,void*,void*),
3617 void *pCtx
3618 );
3619 3620 /*
3621 ** CAPI3REF: Query Progress Callbacks
3622 ** METHOD: sqlite3
3623 **
3624 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3625 ** function X to be invoked periodically during long running calls to
3626 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3627 ** database connection D. An example use for this
3628 ** interface is to keep a GUI updated during a large query.
3629 **
3630 ** ^The parameter P is passed through as the only parameter to the
3631 ** callback function X. ^The parameter N is the approximate number of
3632 ** [virtual machine instructions] that are evaluated between successive
3633 ** invocations of the callback X. ^If N is less than one then the progress
3634 ** handler is disabled.
3635 **
3636 ** ^Only a single progress handler may be defined at one time per
3637 ** [database connection]; setting a new progress handler cancels the
3638 ** old one. ^Setting parameter X to NULL disables the progress handler.
3639 ** ^The progress handler is also disabled by setting N to a value less
3640 ** than 1.
3641 **
3642 ** ^If the progress callback returns non-zero, the operation is
3643 ** interrupted. This feature can be used to implement a
3644 ** "Cancel" button on a GUI progress dialog box.
3645 **
3646 ** The progress handler callback must not do anything that will modify
3647 ** the database connection that invoked the progress handler.
3648 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3649 ** database connections for the meaning of "modify" in this paragraph.
3650 **
3651 ** The progress handler callback would originally only be invoked from the
3652 ** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3653 ** and similar because those routines might force a reparse of the schema
3654 ** which involves running the bytecode engine. However, beginning with
3655 ** SQLite version 3.41.0, the progress handler callback might also be
3656 ** invoked directly from [sqlite3_prepare()] while analyzing and generating
3657 ** code for complex queries.
3658 */
3659 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3660 3661 /*
3662 ** CAPI3REF: Opening A New Database Connection
3663 ** CONSTRUCTOR: sqlite3
3664 **
3665 ** ^These routines open an SQLite database file as specified by the
3666 ** filename argument. ^The filename argument is interpreted as UTF-8 for
3667 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3668 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
3669 ** returned in *ppDb, even if an error occurs. The only exception is that
3670 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3671 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3672 ** object.)^ ^(If the database is opened (and/or created) successfully, then
3673 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3674 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3675 ** an English language description of the error following a failure of any
3676 ** of the sqlite3_open() routines.
3677 **
3678 ** ^The default encoding will be UTF-8 for databases created using
3679 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3680 ** created using sqlite3_open16() will be UTF-16 in the native byte order.
3681 **
3682 ** Whether or not an error occurs when it is opened, resources
3683 ** associated with the [database connection] handle should be released by
3684 ** passing it to [sqlite3_close()] when it is no longer required.
3685 **
3686 ** The sqlite3_open_v2() interface works like sqlite3_open()
3687 ** except that it accepts two additional parameters for additional control
3688 ** over the new database connection. ^(The flags parameter to
3689 ** sqlite3_open_v2() must include, at a minimum, one of the following
3690 ** three flag combinations:)^
3691 **
3692 ** <dl>
3693 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3694 ** <dd>The database is opened in read-only mode. If the database does
3695 ** not already exist, an error is returned.</dd>)^
3696 **
3697 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3698 ** <dd>The database is opened for reading and writing if possible, or
3699 ** reading only if the file is write protected by the operating
3700 ** system. In either case the database must already exist, otherwise
3701 ** an error is returned. For historical reasons, if opening in
3702 ** read-write mode fails due to OS-level permissions, an attempt is
3703 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3704 ** used to determine whether the database is actually
3705 ** read-write.</dd>)^
3706 **
3707 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3708 ** <dd>The database is opened for reading and writing, and is created if
3709 ** it does not already exist. This is the behavior that is always used for
3710 ** sqlite3_open() and sqlite3_open16().</dd>)^
3711 ** </dl>
3712 **
3713 ** In addition to the required flags, the following optional flags are
3714 ** also supported:
3715 **
3716 ** <dl>
3717 ** ^(<dt>[SQLITE_OPEN_URI]</dt>
3718 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3719 **
3720 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3721 ** <dd>The database will be opened as an in-memory database. The database
3722 ** is named by the "filename" argument for the purposes of cache-sharing,
3723 ** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3724 ** </dd>)^
3725 **
3726 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3727 ** <dd>The new database connection will use the "multi-thread"
3728 ** [threading mode].)^ This means that separate threads are allowed
3729 ** to use SQLite at the same time, as long as each thread is using
3730 ** a different [database connection].
3731 **
3732 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3733 ** <dd>The new database connection will use the "serialized"
3734 ** [threading mode].)^ This means the multiple threads can safely
3735 ** attempt to use the same database connection at the same time.
3736 ** (Mutexes will block any actual concurrency, but in this mode
3737 ** there is no harm in trying.)
3738 **
3739 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3740 ** <dd>The database is opened [shared cache] enabled, overriding
3741 ** the default shared cache setting provided by
3742 ** [sqlite3_enable_shared_cache()].)^
3743 ** The [use of shared cache mode is discouraged] and hence shared cache
3744 ** capabilities may be omitted from many builds of SQLite. In such cases,
3745 ** this option is a no-op.
3746 **
3747 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3748 ** <dd>The database is opened [shared cache] disabled, overriding
3749 ** the default shared cache setting provided by
3750 ** [sqlite3_enable_shared_cache()].)^
3751 **
3752 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3753 ** <dd>The database connection comes up in "extended result code mode".
3754 ** In other words, the database behaves as if
3755 ** [sqlite3_extended_result_codes(db,1)] were called on the database
3756 ** connection as soon as the connection is created. In addition to setting
3757 ** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3758 ** to return an extended result code.</dd>
3759 **
3760 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3761 ** <dd>The database filename is not allowed to contain a symbolic link</dd>
3762 ** </dl>)^
3763 **
3764 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
3765 ** required combinations shown above optionally combined with other
3766 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3767 ** then the behavior is undefined. Historic versions of SQLite
3768 ** have silently ignored surplus bits in the flags parameter to
3769 ** sqlite3_open_v2(), however that behavior might not be carried through
3770 ** into future versions of SQLite and so applications should not rely
3771 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3772 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3773 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3774 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3775 ** by sqlite3_open_v2().
3776 **
3777 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3778 ** [sqlite3_vfs] object that defines the operating system interface that
3779 ** the new database connection should use. ^If the fourth parameter is
3780 ** a NULL pointer then the default [sqlite3_vfs] object is used.
3781 **
3782 ** ^If the filename is ":memory:", then a private, temporary in-memory database
3783 ** is created for the connection. ^This in-memory database will vanish when
3784 ** the database connection is closed. Future versions of SQLite might
3785 ** make use of additional special filenames that begin with the ":" character.
3786 ** It is recommended that when a database filename actually does begin with
3787 ** a ":" character you should prefix the filename with a pathname such as
3788 ** "./" to avoid ambiguity.
3789 **
3790 ** ^If the filename is an empty string, then a private, temporary
3791 ** on-disk database will be created. ^This private database will be
3792 ** automatically deleted as soon as the database connection is closed.
3793 **
3794 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3795 **
3796 ** ^If [URI filename] interpretation is enabled, and the filename argument
3797 ** begins with "file:", then the filename is interpreted as a URI. ^URI
3798 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3799 ** set in the third argument to sqlite3_open_v2(), or if it has
3800 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3801 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3802 ** URI filename interpretation is turned off
3803 ** by default, but future releases of SQLite might enable URI filename
3804 ** interpretation by default. See "[URI filenames]" for additional
3805 ** information.
3806 **
3807 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3808 ** authority, then it must be either an empty string or the string
3809 ** "localhost". ^If the authority is not an empty string or "localhost", an
3810 ** error is returned to the caller. ^The fragment component of a URI, if
3811 ** present, is ignored.
3812 **
3813 ** ^SQLite uses the path component of the URI as the name of the disk file
3814 ** which contains the database. ^If the path begins with a '/' character,
3815 ** then it is interpreted as an absolute path. ^If the path does not begin
3816 ** with a '/' (meaning that the authority section is omitted from the URI)
3817 ** then the path is interpreted as a relative path.
3818 ** ^(On windows, the first component of an absolute path
3819 ** is a drive specification (e.g. "C:").)^
3820 **
3821 ** [[core URI query parameters]]
3822 ** The query component of a URI may contain parameters that are interpreted
3823 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
3824 ** SQLite and its built-in [VFSes] interpret the
3825 ** following query parameters:
3826 **
3827 ** <ul>
3828 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3829 ** a VFS object that provides the operating system interface that should
3830 ** be used to access the database file on disk. ^If this option is set to
3831 ** an empty string the default VFS object is used. ^Specifying an unknown
3832 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3833 ** present, then the VFS specified by the option takes precedence over
3834 ** the value passed as the fourth parameter to sqlite3_open_v2().
3835 **
3836 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3837 ** "rwc", or "memory". Attempting to set it to any other value is
3838 ** an error)^.
3839 ** ^If "ro" is specified, then the database is opened for read-only
3840 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3841 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3842 ** "rw", then the database is opened for read-write (but not create)
3843 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3844 ** been set. ^Value "rwc" is equivalent to setting both
3845 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3846 ** set to "memory" then a pure [in-memory database] that never reads
3847 ** or writes from disk is used. ^It is an error to specify a value for
3848 ** the mode parameter that is less restrictive than that specified by
3849 ** the flags passed in the third parameter to sqlite3_open_v2().
3850 **
3851 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3852 ** "private". ^Setting it to "shared" is equivalent to setting the
3853 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3854 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3855 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3856 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3857 ** a URI filename, its value overrides any behavior requested by setting
3858 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3859 **
3860 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3861 ** [powersafe overwrite] property does or does not apply to the
3862 ** storage media on which the database file resides.
3863 **
3864 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3865 ** which if set disables file locking in rollback journal modes. This
3866 ** is useful for accessing a database on a filesystem that does not
3867 ** support locking. Caution: Database corruption might result if two
3868 ** or more processes write to the same database and any one of those
3869 ** processes uses nolock=1.
3870 **
3871 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3872 ** parameter that indicates that the database file is stored on
3873 ** read-only media. ^When immutable is set, SQLite assumes that the
3874 ** database file cannot be changed, even by a process with higher
3875 ** privilege, and so the database is opened read-only and all locking
3876 ** and change detection is disabled. Caution: Setting the immutable
3877 ** property on a database file that does in fact change can result
3878 ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3879 ** See also: [SQLITE_IOCAP_IMMUTABLE].
3880 **
3881 ** </ul>
3882 **
3883 ** ^Specifying an unknown parameter in the query component of a URI is not an
3884 ** error. Future versions of SQLite might understand additional query
3885 ** parameters. See "[query parameters with special meaning to SQLite]" for
3886 ** additional information.
3887 **
3888 ** [[URI filename examples]] <h3>URI filename examples</h3>
3889 **
3890 ** <table border="1" align=center cellpadding=5>
3891 ** <tr><th> URI filenames <th> Results
3892 ** <tr><td> file:data.db <td>
3893 ** Open the file "data.db" in the current directory.
3894 ** <tr><td> file:/home/fred/data.db<br>
3895 ** file:///home/fred/data.db <br>
3896 ** file://localhost/home/fred/data.db <br> <td>
3897 ** Open the database file "/home/fred/data.db".
3898 ** <tr><td> file://darkstar/home/fred/data.db <td>
3899 ** An error. "darkstar" is not a recognized authority.
3900 ** <tr><td style="white-space:nowrap">
3901 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3902 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3903 ** C:. Note that the %20 escaping in this example is not strictly
3904 ** necessary - space characters can be used literally
3905 ** in URI filenames.
3906 ** <tr><td> file:data.db?mode=ro&cache=private <td>
3907 ** Open file "data.db" in the current directory for read-only access.
3908 ** Regardless of whether or not shared-cache mode is enabled by
3909 ** default, use a private cache.
3910 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3911 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3912 ** that uses dot-files in place of posix advisory locking.
3913 ** <tr><td> file:data.db?mode=readonly <td>
3914 ** An error. "readonly" is not a valid option for the "mode" parameter.
3915 ** Use "ro" instead: "file:data.db?mode=ro".
3916 ** </table>
3917 **
3918 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3919 ** query components of a URI. A hexadecimal escape sequence consists of a
3920 ** percent sign - "%" - followed by exactly two hexadecimal digits
3921 ** specifying an octet value. ^Before the path or query components of a
3922 ** URI filename are interpreted, they are encoded using UTF-8 and all
3923 ** hexadecimal escape sequences replaced by a single byte containing the
3924 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3925 ** the results are undefined.
3926 **
3927 ** <b>Note to Windows users:</b> The encoding used for the filename argument
3928 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3929 ** codepage is currently defined. Filenames containing international
3930 ** characters must be converted to UTF-8 prior to passing them into
3931 ** sqlite3_open() or sqlite3_open_v2().
3932 **
3933 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3934 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3935 ** features that require the use of temporary files may fail.
3936 **
3937 ** See also: [sqlite3_temp_directory]
3938 */
3939 SQLITE_API int sqlite3_open(
3940 const char *filename, /* Database filename (UTF-8) */
3941 sqlite3 **ppDb /* OUT: SQLite db handle */
3942 );
3943 SQLITE_API int sqlite3_open16(
3944 const void *filename, /* Database filename (UTF-16) */
3945 sqlite3 **ppDb /* OUT: SQLite db handle */
3946 );
3947 SQLITE_API int sqlite3_open_v2(
3948 const char *filename, /* Database filename (UTF-8) */
3949 sqlite3 **ppDb, /* OUT: SQLite db handle */
3950 int flags, /* Flags */
3951 const char *zVfs /* Name of VFS module to use */
3952 );
3953 3954 /*
3955 ** CAPI3REF: Obtain Values For URI Parameters
3956 **
3957 ** These are utility routines, useful to [VFS|custom VFS implementations],
3958 ** that check if a database file was a URI that contained a specific query
3959 ** parameter, and if so obtains the value of that query parameter.
3960 **
3961 ** The first parameter to these interfaces (hereafter referred to
3962 ** as F) must be one of:
3963 ** <ul>
3964 ** <li> A database filename pointer created by the SQLite core and
3965 ** passed into the xOpen() method of a VFS implementation, or
3966 ** <li> A filename obtained from [sqlite3_db_filename()], or
3967 ** <li> A new filename constructed using [sqlite3_create_filename()].
3968 ** </ul>
3969 ** If the F parameter is not one of the above, then the behavior is
3970 ** undefined and probably undesirable. Older versions of SQLite were
3971 ** more tolerant of invalid F parameters than newer versions.
3972 **
3973 ** If F is a suitable filename (as described in the previous paragraph)
3974 ** and if P is the name of the query parameter, then
3975 ** sqlite3_uri_parameter(F,P) returns the value of the P
3976 ** parameter if it exists or a NULL pointer if P does not appear as a
3977 ** query parameter on F. If P is a query parameter of F and it
3978 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3979 ** a pointer to an empty string.
3980 **
3981 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3982 ** parameter and returns true (1) or false (0) according to the value
3983 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3984 ** value of query parameter P is one of "yes", "true", or "on" in any
3985 ** case or if the value begins with a non-zero number. The
3986 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3987 ** query parameter P is one of "no", "false", or "off" in any case or
3988 ** if the value begins with a numeric zero. If P is not a query
3989 ** parameter on F or if the value of P does not match any of the
3990 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3991 **
3992 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3993 ** 64-bit signed integer and returns that integer, or D if P does not
3994 ** exist. If the value of P is something other than an integer, then
3995 ** zero is returned.
3996 **
3997 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3998 ** the value) of the N-th query parameter for filename F, or a NULL
3999 ** pointer if N is less than zero or greater than the number of query
4000 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain
4001 ** the name of the first query parameter, 1 for the second parameter, and
4002 ** so forth.
4003 **
4004 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
4005 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
4006 ** is not a database file pathname pointer that the SQLite core passed
4007 ** into the xOpen VFS method, then the behavior of this routine is undefined
4008 ** and probably undesirable.
4009 **
4010 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
4011 ** parameter can also be the name of a rollback journal file or WAL file
4012 ** in addition to the main database file. Prior to version 3.31.0, these
4013 ** routines would only work if F was the name of the main database file.
4014 ** When the F parameter is the name of the rollback journal or WAL file,
4015 ** it has access to all the same query parameters as were found on the
4016 ** main database file.
4017 **
4018 ** See the [URI filename] documentation for additional information.
4019 */
4020 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
4021 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
4022 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
4023 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
4024 4025 /*
4026 ** CAPI3REF: Translate filenames
4027 **
4028 ** These routines are available to [VFS|custom VFS implementations] for
4029 ** translating filenames between the main database file, the journal file,
4030 ** and the WAL file.
4031 **
4032 ** If F is the name of an sqlite database file, journal file, or WAL file
4033 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
4034 ** returns the name of the corresponding database file.
4035 **
4036 ** If F is the name of an sqlite database file, journal file, or WAL file
4037 ** passed by the SQLite core into the VFS, or if F is a database filename
4038 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
4039 ** returns the name of the corresponding rollback journal file.
4040 **
4041 ** If F is the name of an sqlite database file, journal file, or WAL file
4042 ** that was passed by the SQLite core into the VFS, or if F is a database
4043 ** filename obtained from [sqlite3_db_filename()], then
4044 ** sqlite3_filename_wal(F) returns the name of the corresponding
4045 ** WAL file.
4046 **
4047 ** In all of the above, if F is not the name of a database, journal or WAL
4048 ** filename passed into the VFS from the SQLite core and F is not the
4049 ** return value from [sqlite3_db_filename()], then the result is
4050 ** undefined and is likely a memory access violation.
4051 */
4052 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
4053 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
4054 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
4055 4056 /*
4057 ** CAPI3REF: Database File Corresponding To A Journal
4058 **
4059 ** ^If X is the name of a rollback or WAL-mode journal file that is
4060 ** passed into the xOpen method of [sqlite3_vfs], then
4061 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
4062 ** object that represents the main database file.
4063 **
4064 ** This routine is intended for use in custom [VFS] implementations
4065 ** only. It is not a general-purpose interface.
4066 ** The argument sqlite3_file_object(X) must be a filename pointer that
4067 ** has been passed into [sqlite3_vfs].xOpen method where the
4068 ** flags parameter to xOpen contains one of the bits
4069 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
4070 ** of this routine results in undefined and probably undesirable
4071 ** behavior.
4072 */
4073 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
4074 4075 /*
4076 ** CAPI3REF: Create and Destroy VFS Filenames
4077 **
4078 ** These interfaces are provided for use by [VFS shim] implementations and
4079 ** are not useful outside of that context.
4080 **
4081 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
4082 ** database filename D with corresponding journal file J and WAL file W and
4083 ** an array P of N URI Key/Value pairs. The result from
4084 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
4085 ** is safe to pass to routines like:
4086 ** <ul>
4087 ** <li> [sqlite3_uri_parameter()],
4088 ** <li> [sqlite3_uri_boolean()],
4089 ** <li> [sqlite3_uri_int64()],
4090 ** <li> [sqlite3_uri_key()],
4091 ** <li> [sqlite3_filename_database()],
4092 ** <li> [sqlite3_filename_journal()], or
4093 ** <li> [sqlite3_filename_wal()].
4094 ** </ul>
4095 ** If a memory allocation error occurs, sqlite3_create_filename() might
4096 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
4097 ** must be released by a corresponding call to sqlite3_free_filename(Y).
4098 **
4099 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
4100 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds
4101 ** to a key and value for a query parameter. The P parameter may be a NULL
4102 ** pointer if N is zero. None of the 2*N pointers in the P array may be
4103 ** NULL pointers and key pointers should not be empty strings.
4104 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
4105 ** be NULL pointers, though they can be empty strings.
4106 **
4107 ** The sqlite3_free_filename(Y) routine releases a memory allocation
4108 ** previously obtained from sqlite3_create_filename(). Invoking
4109 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
4110 **
4111 ** If the Y parameter to sqlite3_free_filename(Y) is anything other
4112 ** than a NULL pointer or a pointer previously acquired from
4113 ** sqlite3_create_filename(), then bad things such as heap
4114 ** corruption or segfaults may occur. The value Y should not be
4115 ** used again after sqlite3_free_filename(Y) has been called. This means
4116 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
4117 ** then the corresponding [sqlite3_module.xClose() method should also be
4118 ** invoked prior to calling sqlite3_free_filename(Y).
4119 */
4120 SQLITE_API sqlite3_filename sqlite3_create_filename(
4121 const char *zDatabase,
4122 const char *zJournal,
4123 const char *zWal,
4124 int nParam,
4125 const char **azParam
4126 );
4127 SQLITE_API void sqlite3_free_filename(sqlite3_filename);
4128 4129 /*
4130 ** CAPI3REF: Error Codes And Messages
4131 ** METHOD: sqlite3
4132 **
4133 ** ^If the most recent sqlite3_* API call associated with
4134 ** [database connection] D failed, then the sqlite3_errcode(D) interface
4135 ** returns the numeric [result code] or [extended result code] for that
4136 ** API call.
4137 ** ^The sqlite3_extended_errcode()
4138 ** interface is the same except that it always returns the
4139 ** [extended result code] even when extended result codes are
4140 ** disabled.
4141 **
4142 ** The values returned by sqlite3_errcode() and/or
4143 ** sqlite3_extended_errcode() might change with each API call.
4144 ** Except, there are some interfaces that are guaranteed to never
4145 ** change the value of the error code. The error-code preserving
4146 ** interfaces include the following:
4147 **
4148 ** <ul>
4149 ** <li> sqlite3_errcode()
4150 ** <li> sqlite3_extended_errcode()
4151 ** <li> sqlite3_errmsg()
4152 ** <li> sqlite3_errmsg16()
4153 ** <li> sqlite3_error_offset()
4154 ** </ul>
4155 **
4156 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
4157 ** text that describes the error, as either UTF-8 or UTF-16 respectively,
4158 ** or NULL if no error message is available.
4159 ** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
4160 ** ^(Memory to hold the error message string is managed internally.
4161 ** The application does not need to worry about freeing the result.
4162 ** However, the error string might be overwritten or deallocated by
4163 ** subsequent calls to other SQLite interface functions.)^
4164 **
4165 ** ^The sqlite3_errstr(E) interface returns the English-language text
4166 ** that describes the [result code] E, as UTF-8, or NULL if E is not an
4167 ** result code for which a text error message is available.
4168 ** ^(Memory to hold the error message string is managed internally
4169 ** and must not be freed by the application)^.
4170 **
4171 ** ^If the most recent error references a specific token in the input
4172 ** SQL, the sqlite3_error_offset() interface returns the byte offset
4173 ** of the start of that token. ^The byte offset returned by
4174 ** sqlite3_error_offset() assumes that the input SQL is UTF8.
4175 ** ^If the most recent error does not reference a specific token in the input
4176 ** SQL, then the sqlite3_error_offset() function returns -1.
4177 **
4178 ** When the serialized [threading mode] is in use, it might be the
4179 ** case that a second error occurs on a separate thread in between
4180 ** the time of the first error and the call to these interfaces.
4181 ** When that happens, the second error will be reported since these
4182 ** interfaces always report the most recent result. To avoid
4183 ** this, each thread can obtain exclusive use of the [database connection] D
4184 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
4185 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
4186 ** all calls to the interfaces listed here are completed.
4187 **
4188 ** If an interface fails with SQLITE_MISUSE, that means the interface
4189 ** was invoked incorrectly by the application. In that case, the
4190 ** error code and message may or may not be set.
4191 */
4192 SQLITE_API int sqlite3_errcode(sqlite3 *db);
4193 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
4194 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
4195 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
4196 SQLITE_API const char *sqlite3_errstr(int);
4197 SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4198 4199 /*
4200 ** CAPI3REF: Prepared Statement Object
4201 ** KEYWORDS: {prepared statement} {prepared statements}
4202 **
4203 ** An instance of this object represents a single SQL statement that
4204 ** has been compiled into binary form and is ready to be evaluated.
4205 **
4206 ** Think of each SQL statement as a separate computer program. The
4207 ** original SQL text is source code. A prepared statement object
4208 ** is the compiled object code. All SQL must be converted into a
4209 ** prepared statement before it can be run.
4210 **
4211 ** The life-cycle of a prepared statement object usually goes like this:
4212 **
4213 ** <ol>
4214 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4215 ** <li> Bind values to [parameters] using the sqlite3_bind_*()
4216 ** interfaces.
4217 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4218 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4219 ** to step 2. Do this zero or more times.
4220 ** <li> Destroy the object using [sqlite3_finalize()].
4221 ** </ol>
4222 */
4223 typedef struct sqlite3_stmt sqlite3_stmt;
4224 4225 /*
4226 ** CAPI3REF: Run-time Limits
4227 ** METHOD: sqlite3
4228 **
4229 ** ^(This interface allows the size of various constructs to be limited
4230 ** on a connection by connection basis. The first parameter is the
4231 ** [database connection] whose limit is to be set or queried. The
4232 ** second parameter is one of the [limit categories] that define a
4233 ** class of constructs to be size limited. The third parameter is the
4234 ** new limit for that construct.)^
4235 **
4236 ** ^If the new limit is a negative number, the limit is unchanged.
4237 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4238 ** [limits | hard upper bound]
4239 ** set at compile-time by a C preprocessor macro called
4240 ** [limits | SQLITE_MAX_<i>NAME</i>].
4241 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4242 ** ^Attempts to increase a limit above its hard upper bound are
4243 ** silently truncated to the hard upper bound.
4244 **
4245 ** ^Regardless of whether or not the limit was changed, the
4246 ** [sqlite3_limit()] interface returns the prior value of the limit.
4247 ** ^Hence, to find the current value of a limit without changing it,
4248 ** simply invoke this interface with the third parameter set to -1.
4249 **
4250 ** Run-time limits are intended for use in applications that manage
4251 ** both their own internal database and also databases that are controlled
4252 ** by untrusted external sources. An example application might be a
4253 ** web browser that has its own databases for storing history and
4254 ** separate databases controlled by JavaScript applications downloaded
4255 ** off the Internet. The internal databases can be given the
4256 ** large, default limits. Databases managed by external sources can
4257 ** be given much smaller limits designed to prevent a denial of service
4258 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4259 ** interface to further control untrusted SQL. The size of the database
4260 ** created by an untrusted script can be contained using the
4261 ** [max_page_count] [PRAGMA].
4262 **
4263 ** New run-time limit categories may be added in future releases.
4264 */
4265 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4266 4267 /*
4268 ** CAPI3REF: Run-Time Limit Categories
4269 ** KEYWORDS: {limit category} {*limit categories}
4270 **
4271 ** These constants define various performance limits
4272 ** that can be lowered at run-time using [sqlite3_limit()].
4273 ** The synopsis of the meanings of the various limits is shown below.
4274 ** Additional information is available at [limits | Limits in SQLite].
4275 **
4276 ** <dl>
4277 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4278 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4279 **
4280 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4281 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4282 **
4283 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4284 ** <dd>The maximum number of columns in a table definition or in the
4285 ** result set of a [SELECT] or the maximum number of columns in an index
4286 ** or in an ORDER BY or GROUP BY clause.</dd>)^
4287 **
4288 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4289 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4290 **
4291 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4292 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4293 **
4294 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4295 ** <dd>The maximum number of instructions in a virtual machine program
4296 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4297 ** the equivalent tries to allocate space for more than this many opcodes
4298 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4299 **
4300 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4301 ** <dd>The maximum number of arguments on a function.</dd>)^
4302 **
4303 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4304 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4305 **
4306 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4307 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4308 ** <dd>The maximum length of the pattern argument to the [LIKE] or
4309 ** [GLOB] operators.</dd>)^
4310 **
4311 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4312 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4313 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4314 **
4315 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4316 ** <dd>The maximum depth of recursion for triggers.</dd>)^
4317 **
4318 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4319 ** <dd>The maximum number of auxiliary worker threads that a single
4320 ** [prepared statement] may start.</dd>)^
4321 ** </dl>
4322 */
4323 #define SQLITE_LIMIT_LENGTH 0
4324 #define SQLITE_LIMIT_SQL_LENGTH 1
4325 #define SQLITE_LIMIT_COLUMN 2
4326 #define SQLITE_LIMIT_EXPR_DEPTH 3
4327 #define SQLITE_LIMIT_COMPOUND_SELECT 4
4328 #define SQLITE_LIMIT_VDBE_OP 5
4329 #define SQLITE_LIMIT_FUNCTION_ARG 6
4330 #define SQLITE_LIMIT_ATTACHED 7
4331 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4332 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
4333 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
4334 #define SQLITE_LIMIT_WORKER_THREADS 11
4335 4336 /*
4337 ** CAPI3REF: Prepare Flags
4338 **
4339 ** These constants define various flags that can be passed into
4340 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4341 ** [sqlite3_prepare16_v3()] interfaces.
4342 **
4343 ** New flags may be added in future releases of SQLite.
4344 **
4345 ** <dl>
4346 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4347 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4348 ** that the prepared statement will be retained for a long time and
4349 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4350 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4351 ** be used just once or at most a few times and then destroyed using
4352 ** [sqlite3_finalize()] relatively soon. The current implementation acts
4353 ** on this hint by avoiding the use of [lookaside memory] so as not to
4354 ** deplete the limited store of lookaside memory. Future versions of
4355 ** SQLite may act on this hint differently.
4356 **
4357 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4358 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4359 ** to be required for any prepared statement that wanted to use the
4360 ** [sqlite3_normalized_sql()] interface. However, the
4361 ** [sqlite3_normalized_sql()] interface is now available to all
4362 ** prepared statements, regardless of whether or not they use this
4363 ** flag.
4364 **
4365 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4366 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4367 ** to return an error (error code SQLITE_ERROR) if the statement uses
4368 ** any virtual tables.
4369 **
4370 ** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt>
4371 ** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler
4372 ** errors from being sent to the error log defined by
4373 ** [SQLITE_CONFIG_LOG]. This can be used, for example, to do test
4374 ** compiles to see if some SQL syntax is well-formed, without generating
4375 ** messages on the global error log when it is not. If the test compile
4376 ** fails, the sqlite3_prepare_v3() call returns the same error indications
4377 ** with or without this flag; it just omits the call to [sqlite3_log()] that
4378 ** logs the error.
4379 ** </dl>
4380 */
4381 #define SQLITE_PREPARE_PERSISTENT 0x01
4382 #define SQLITE_PREPARE_NORMALIZE 0x02
4383 #define SQLITE_PREPARE_NO_VTAB 0x04
4384 #define SQLITE_PREPARE_DONT_LOG 0x10
4385 4386 /*
4387 ** CAPI3REF: Compiling An SQL Statement
4388 ** KEYWORDS: {SQL statement compiler}
4389 ** METHOD: sqlite3
4390 ** CONSTRUCTOR: sqlite3_stmt
4391 **
4392 ** To execute an SQL statement, it must first be compiled into a byte-code
4393 ** program using one of these routines. Or, in other words, these routines
4394 ** are constructors for the [prepared statement] object.
4395 **
4396 ** The preferred routine to use is [sqlite3_prepare_v2()]. The
4397 ** [sqlite3_prepare()] interface is legacy and should be avoided.
4398 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4399 ** for special purposes.
4400 **
4401 ** The use of the UTF-8 interfaces is preferred, as SQLite currently
4402 ** does all parsing using UTF-8. The UTF-16 interfaces are provided
4403 ** as a convenience. The UTF-16 interfaces work by converting the
4404 ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4405 **
4406 ** The first argument, "db", is a [database connection] obtained from a
4407 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4408 ** [sqlite3_open16()]. The database connection must not have been closed.
4409 **
4410 ** The second argument, "zSql", is the statement to be compiled, encoded
4411 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4412 ** and sqlite3_prepare_v3()
4413 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4414 ** and sqlite3_prepare16_v3() use UTF-16.
4415 **
4416 ** ^If the nByte argument is negative, then zSql is read up to the
4417 ** first zero terminator. ^If nByte is positive, then it is the maximum
4418 ** number of bytes read from zSql. When nByte is positive, zSql is read
4419 ** up to the first zero terminator or until the nByte bytes have been read,
4420 ** whichever comes first. ^If nByte is zero, then no prepared
4421 ** statement is generated.
4422 ** If the caller knows that the supplied string is nul-terminated, then
4423 ** there is a small performance advantage to passing an nByte parameter that
4424 ** is the number of bytes in the input string <i>including</i>
4425 ** the nul-terminator.
4426 ** Note that nByte measure the length of the input in bytes, not
4427 ** characters, even for the UTF-16 interfaces.
4428 **
4429 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4430 ** past the end of the first SQL statement in zSql. These routines only
4431 ** compile the first statement in zSql, so *pzTail is left pointing to
4432 ** what remains uncompiled.
4433 **
4434 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4435 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4436 ** to NULL. ^If the input text contains no SQL (if the input is an empty
4437 ** string or a comment) then *ppStmt is set to NULL.
4438 ** The calling procedure is responsible for deleting the compiled
4439 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
4440 ** ppStmt may not be NULL.
4441 **
4442 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4443 ** otherwise an [error code] is returned.
4444 **
4445 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4446 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4447 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4448 ** are retained for backwards compatibility, but their use is discouraged.
4449 ** ^In the "vX" interfaces, the prepared statement
4450 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
4451 ** original SQL text. This causes the [sqlite3_step()] interface to
4452 ** behave differently in three ways:
4453 **
4454 ** <ol>
4455 ** <li>
4456 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4457 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
4458 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4459 ** retries will occur before sqlite3_step() gives up and returns an error.
4460 ** </li>
4461 **
4462 ** <li>
4463 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4464 ** [error codes] or [extended error codes]. ^The legacy behavior was that
4465 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4466 ** and the application would have to make a second call to [sqlite3_reset()]
4467 ** in order to find the underlying cause of the problem. With the "v2" prepare
4468 ** interfaces, the underlying reason for the error is returned immediately.
4469 ** </li>
4470 **
4471 ** <li>
4472 ** ^If the specific value bound to a [parameter | host parameter] in the
4473 ** WHERE clause might influence the choice of query plan for a statement,
4474 ** then the statement will be automatically recompiled, as if there had been
4475 ** a schema change, on the first [sqlite3_step()] call following any change
4476 ** to the [sqlite3_bind_text | bindings] of that [parameter].
4477 ** ^The specific value of a WHERE-clause [parameter] might influence the
4478 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
4479 ** or [GLOB] operator or if the parameter is compared to an indexed column
4480 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4481 ** </li>
4482 ** </ol>
4483 **
4484 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4485 ** the extra prepFlags parameter, which is a bit array consisting of zero or
4486 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4487 ** sqlite3_prepare_v2() interface works exactly the same as
4488 ** sqlite3_prepare_v3() with a zero prepFlags parameter.
4489 */
4490 SQLITE_API int sqlite3_prepare(
4491 sqlite3 *db, /* Database handle */
4492 const char *zSql, /* SQL statement, UTF-8 encoded */
4493 int nByte, /* Maximum length of zSql in bytes. */
4494 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4495 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4496 );
4497 SQLITE_API int sqlite3_prepare_v2(
4498 sqlite3 *db, /* Database handle */
4499 const char *zSql, /* SQL statement, UTF-8 encoded */
4500 int nByte, /* Maximum length of zSql in bytes. */
4501 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4502 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4503 );
4504 SQLITE_API int sqlite3_prepare_v3(
4505 sqlite3 *db, /* Database handle */
4506 const char *zSql, /* SQL statement, UTF-8 encoded */
4507 int nByte, /* Maximum length of zSql in bytes. */
4508 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4509 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4510 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4511 );
4512 SQLITE_API int sqlite3_prepare16(
4513 sqlite3 *db, /* Database handle */
4514 const void *zSql, /* SQL statement, UTF-16 encoded */
4515 int nByte, /* Maximum length of zSql in bytes. */
4516 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4517 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4518 );
4519 SQLITE_API int sqlite3_prepare16_v2(
4520 sqlite3 *db, /* Database handle */
4521 const void *zSql, /* SQL statement, UTF-16 encoded */
4522 int nByte, /* Maximum length of zSql in bytes. */
4523 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4524 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4525 );
4526 SQLITE_API int sqlite3_prepare16_v3(
4527 sqlite3 *db, /* Database handle */
4528 const void *zSql, /* SQL statement, UTF-16 encoded */
4529 int nByte, /* Maximum length of zSql in bytes. */
4530 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4531 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4532 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4533 );
4534 4535 /*
4536 ** CAPI3REF: Retrieving Statement SQL
4537 ** METHOD: sqlite3_stmt
4538 **
4539 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4540 ** SQL text used to create [prepared statement] P if P was
4541 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4542 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4543 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4544 ** string containing the SQL text of prepared statement P with
4545 ** [bound parameters] expanded.
4546 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4547 ** string containing the normalized SQL text of prepared statement P. The
4548 ** semantics used to normalize a SQL statement are unspecified and subject
4549 ** to change. At a minimum, literal values will be replaced with suitable
4550 ** placeholders.
4551 **
4552 ** ^(For example, if a prepared statement is created using the SQL
4553 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4554 ** and parameter :xyz is unbound, then sqlite3_sql() will return
4555 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4556 ** will return "SELECT 2345,NULL".)^
4557 **
4558 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4559 ** is available to hold the result, or if the result would exceed the
4560 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4561 **
4562 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4563 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4564 ** option causes sqlite3_expanded_sql() to always return NULL.
4565 **
4566 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4567 ** are managed by SQLite and are automatically freed when the prepared
4568 ** statement is finalized.
4569 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4570 ** is obtained from [sqlite3_malloc()] and must be freed by the application
4571 ** by passing it to [sqlite3_free()].
4572 **
4573 ** ^The sqlite3_normalized_sql() interface is only available if
4574 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4575 */
4576 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4577 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4578 #ifdef SQLITE_ENABLE_NORMALIZE
4579 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4580 #endif
4581 4582 /*
4583 ** CAPI3REF: Determine If An SQL Statement Writes The Database
4584 ** METHOD: sqlite3_stmt
4585 **
4586 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4587 ** and only if the [prepared statement] X makes no direct changes to
4588 ** the content of the database file.
4589 **
4590 ** Note that [application-defined SQL functions] or
4591 ** [virtual tables] might change the database indirectly as a side effect.
4592 ** ^(For example, if an application defines a function "eval()" that
4593 ** calls [sqlite3_exec()], then the following SQL statement would
4594 ** change the database file through side-effects:
4595 **
4596 ** <blockquote><pre>
4597 ** SELECT eval('DELETE FROM t1') FROM t2;
4598 ** </pre></blockquote>
4599 **
4600 ** But because the [SELECT] statement does not change the database file
4601 ** directly, sqlite3_stmt_readonly() would still return true.)^
4602 **
4603 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4604 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4605 ** since the statements themselves do not actually modify the database but
4606 ** rather they control the timing of when other statements modify the
4607 ** database. ^The [ATTACH] and [DETACH] statements also cause
4608 ** sqlite3_stmt_readonly() to return true since, while those statements
4609 ** change the configuration of a database connection, they do not make
4610 ** changes to the content of the database files on disk.
4611 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4612 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4613 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4614 ** sqlite3_stmt_readonly() returns false for those commands.
4615 **
4616 ** ^This routine returns false if there is any possibility that the
4617 ** statement might change the database file. ^A false return does
4618 ** not guarantee that the statement will change the database file.
4619 ** ^For example, an UPDATE statement might have a WHERE clause that
4620 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4621 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4622 ** read-only no-op if the table already exists, but
4623 ** sqlite3_stmt_readonly() still returns false for such a statement.
4624 **
4625 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4626 ** statement, then sqlite3_stmt_readonly(X) returns the same value as
4627 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4628 */
4629 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4630 4631 /*
4632 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4633 ** METHOD: sqlite3_stmt
4634 **
4635 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4636 ** prepared statement S is an EXPLAIN statement, or 2 if the
4637 ** statement S is an EXPLAIN QUERY PLAN.
4638 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4639 ** an ordinary statement or a NULL pointer.
4640 */
4641 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4642 4643 /*
4644 ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4645 ** METHOD: sqlite3_stmt
4646 **
4647 ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4648 ** setting for [prepared statement] S. If E is zero, then S becomes
4649 ** a normal prepared statement. If E is 1, then S behaves as if
4650 ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4651 ** its SQL text began with "[EXPLAIN QUERY PLAN]".
4652 **
4653 ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4654 ** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4655 ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4656 **
4657 ** Because of the potential need to reprepare, a call to
4658 ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4659 ** reprepared because it was created using [sqlite3_prepare()] instead of
4660 ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4661 ** hence has no saved SQL text with which to reprepare.
4662 **
4663 ** Changing the explain setting for a prepared statement does not change
4664 ** the original SQL text for the statement. Hence, if the SQL text originally
4665 ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4666 ** is called to convert the statement into an ordinary statement, the EXPLAIN
4667 ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4668 ** output, even though the statement now acts like a normal SQL statement.
4669 **
4670 ** This routine returns SQLITE_OK if the explain mode is successfully
4671 ** changed, or an error code if the explain mode could not be changed.
4672 ** The explain mode cannot be changed while a statement is active.
4673 ** Hence, it is good practice to call [sqlite3_reset(S)]
4674 ** immediately prior to calling sqlite3_stmt_explain(S,E).
4675 */
4676 SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4677 4678 /*
4679 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4680 ** METHOD: sqlite3_stmt
4681 **
4682 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4683 ** [prepared statement] S has been stepped at least once using
4684 ** [sqlite3_step(S)] but has neither run to completion (returned
4685 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4686 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4687 ** interface returns false if S is a NULL pointer. If S is not a
4688 ** NULL pointer and is not a pointer to a valid [prepared statement]
4689 ** object, then the behavior is undefined and probably undesirable.
4690 **
4691 ** This interface can be used in combination [sqlite3_next_stmt()]
4692 ** to locate all prepared statements associated with a database
4693 ** connection that are in need of being reset. This can be used,
4694 ** for example, in diagnostic routines to search for prepared
4695 ** statements that are holding a transaction open.
4696 */
4697 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4698 4699 /*
4700 ** CAPI3REF: Dynamically Typed Value Object
4701 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4702 **
4703 ** SQLite uses the sqlite3_value object to represent all values
4704 ** that can be stored in a database table. SQLite uses dynamic typing
4705 ** for the values it stores. ^Values stored in sqlite3_value objects
4706 ** can be integers, floating point values, strings, BLOBs, or NULL.
4707 **
4708 ** An sqlite3_value object may be either "protected" or "unprotected".
4709 ** Some interfaces require a protected sqlite3_value. Other interfaces
4710 ** will accept either a protected or an unprotected sqlite3_value.
4711 ** Every interface that accepts sqlite3_value arguments specifies
4712 ** whether or not it requires a protected sqlite3_value. The
4713 ** [sqlite3_value_dup()] interface can be used to construct a new
4714 ** protected sqlite3_value from an unprotected sqlite3_value.
4715 **
4716 ** The terms "protected" and "unprotected" refer to whether or not
4717 ** a mutex is held. An internal mutex is held for a protected
4718 ** sqlite3_value object but no mutex is held for an unprotected
4719 ** sqlite3_value object. If SQLite is compiled to be single-threaded
4720 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4721 ** or if SQLite is run in one of reduced mutex modes
4722 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4723 ** then there is no distinction between protected and unprotected
4724 ** sqlite3_value objects and they can be used interchangeably. However,
4725 ** for maximum code portability it is recommended that applications
4726 ** still make the distinction between protected and unprotected
4727 ** sqlite3_value objects even when not strictly required.
4728 **
4729 ** ^The sqlite3_value objects that are passed as parameters into the
4730 ** implementation of [application-defined SQL functions] are protected.
4731 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4732 ** are protected.
4733 ** ^The sqlite3_value object returned by
4734 ** [sqlite3_column_value()] is unprotected.
4735 ** Unprotected sqlite3_value objects may only be used as arguments
4736 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4737 ** [sqlite3_value_dup()].
4738 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
4739 ** interfaces require protected sqlite3_value objects.
4740 */
4741 typedef struct sqlite3_value sqlite3_value;
4742 4743 /*
4744 ** CAPI3REF: SQL Function Context Object
4745 **
4746 ** The context in which an SQL function executes is stored in an
4747 ** sqlite3_context object. ^A pointer to an sqlite3_context object
4748 ** is always first parameter to [application-defined SQL functions].
4749 ** The application-defined SQL function implementation will pass this
4750 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4751 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4752 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4753 ** and/or [sqlite3_set_auxdata()].
4754 */
4755 typedef struct sqlite3_context sqlite3_context;
4756 4757 /*
4758 ** CAPI3REF: Binding Values To Prepared Statements
4759 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4760 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4761 ** METHOD: sqlite3_stmt
4762 **
4763 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4764 ** literals may be replaced by a [parameter] that matches one of the following
4765 ** templates:
4766 **
4767 ** <ul>
4768 ** <li> ?
4769 ** <li> ?NNN
4770 ** <li> :VVV
4771 ** <li> @VVV
4772 ** <li> $VVV
4773 ** </ul>
4774 **
4775 ** In the templates above, NNN represents an integer literal,
4776 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
4777 ** parameters (also called "host parameter names" or "SQL parameters")
4778 ** can be set using the sqlite3_bind_*() routines defined here.
4779 **
4780 ** ^The first argument to the sqlite3_bind_*() routines is always
4781 ** a pointer to the [sqlite3_stmt] object returned from
4782 ** [sqlite3_prepare_v2()] or its variants.
4783 **
4784 ** ^The second argument is the index of the SQL parameter to be set.
4785 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
4786 ** SQL parameter is used more than once, second and subsequent
4787 ** occurrences have the same index as the first occurrence.
4788 ** ^The index for named parameters can be looked up using the
4789 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
4790 ** for "?NNN" parameters is the value of NNN.
4791 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
4792 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4793 **
4794 ** ^The third argument is the value to bind to the parameter.
4795 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4796 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4797 ** is ignored and the end result is the same as sqlite3_bind_null().
4798 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4799 ** it should be a pointer to well-formed UTF8 text.
4800 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4801 ** it should be a pointer to well-formed UTF16 text.
4802 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4803 ** it should be a pointer to a well-formed unicode string that is
4804 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4805 ** otherwise.
4806 **
4807 ** [[byte-order determination rules]] ^The byte-order of
4808 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4809 ** found in the first character, which is removed, or in the absence of a BOM
4810 ** the byte order is the native byte order of the host
4811 ** machine for sqlite3_bind_text16() or the byte order specified in
4812 ** the 6th parameter for sqlite3_bind_text64().)^
4813 ** ^If UTF16 input text contains invalid unicode
4814 ** characters, then SQLite might change those invalid characters
4815 ** into the unicode replacement character: U+FFFD.
4816 **
4817 ** ^(In those routines that have a fourth argument, its value is the
4818 ** number of bytes in the parameter. To be clear: the value is the
4819 ** number of <u>bytes</u> in the value, not the number of characters.)^
4820 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4821 ** is negative, then the length of the string is
4822 ** the number of bytes up to the first zero terminator.
4823 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
4824 ** the behavior is undefined.
4825 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4826 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4827 ** that parameter must be the byte offset
4828 ** where the NUL terminator would occur assuming the string were NUL
4829 ** terminated. If any NUL characters occur at byte offsets less than
4830 ** the value of the fourth parameter then the resulting string value will
4831 ** contain embedded NULs. The result of expressions involving strings
4832 ** with embedded NULs is undefined.
4833 **
4834 ** ^The fifth argument to the BLOB and string binding interfaces controls
4835 ** or indicates the lifetime of the object referenced by the third parameter.
4836 ** These three options exist:
4837 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4838 ** with it may be passed. ^It is called to dispose of the BLOB or string even
4839 ** if the call to the bind API fails, except the destructor is not called if
4840 ** the third parameter is a NULL pointer or the fourth parameter is negative.
4841 ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4842 ** the application remains responsible for disposing of the object. ^In this
4843 ** case, the object and the provided pointer to it must remain valid until
4844 ** either the prepared statement is finalized or the same SQL parameter is
4845 ** bound to something else, whichever occurs sooner.
4846 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4847 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4848 ** object and pointer to it must remain valid until then. ^SQLite will then
4849 ** manage the lifetime of its private copy.
4850 **
4851 ** ^The sixth argument to sqlite3_bind_text64() must be one of
4852 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4853 ** to specify the encoding of the text in the third parameter. If
4854 ** the sixth argument to sqlite3_bind_text64() is not one of the
4855 ** allowed values shown above, or if the text encoding is different
4856 ** from the encoding specified by the sixth parameter, then the behavior
4857 ** is undefined.
4858 **
4859 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4860 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4861 ** (just an integer to hold its size) while it is being processed.
4862 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
4863 ** content is later written using
4864 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
4865 ** ^A negative value for the zeroblob results in a zero-length BLOB.
4866 **
4867 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4868 ** [prepared statement] S to have an SQL value of NULL, but to also be
4869 ** associated with the pointer P of type T. ^D is either a NULL pointer or
4870 ** a pointer to a destructor function for P. ^SQLite will invoke the
4871 ** destructor D with a single argument of P when it is finished using
4872 ** P. The T parameter should be a static string, preferably a string
4873 ** literal. The sqlite3_bind_pointer() routine is part of the
4874 ** [pointer passing interface] added for SQLite 3.20.0.
4875 **
4876 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4877 ** for the [prepared statement] or with a prepared statement for which
4878 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4879 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4880 ** routine is passed a [prepared statement] that has been finalized, the
4881 ** result is undefined and probably harmful.
4882 **
4883 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4884 ** ^Unbound parameters are interpreted as NULL.
4885 **
4886 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4887 ** [error code] if anything goes wrong.
4888 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4889 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4890 ** [SQLITE_MAX_LENGTH].
4891 ** ^[SQLITE_RANGE] is returned if the parameter
4892 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4893 **
4894 ** See also: [sqlite3_bind_parameter_count()],
4895 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4896 */
4897 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4898 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4899 void(*)(void*));
4900 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4901 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4902 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4903 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4904 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4905 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4906 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4907 void(*)(void*), unsigned char encoding);
4908 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4909 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4910 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4911 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4912 4913 /*
4914 ** CAPI3REF: Number Of SQL Parameters
4915 ** METHOD: sqlite3_stmt
4916 **
4917 ** ^This routine can be used to find the number of [SQL parameters]
4918 ** in a [prepared statement]. SQL parameters are tokens of the
4919 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4920 ** placeholders for values that are [sqlite3_bind_blob | bound]
4921 ** to the parameters at a later time.
4922 **
4923 ** ^(This routine actually returns the index of the largest (rightmost)
4924 ** parameter. For all forms except ?NNN, this will correspond to the
4925 ** number of unique parameters. If parameters of the ?NNN form are used,
4926 ** there may be gaps in the list.)^
4927 **
4928 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4929 ** [sqlite3_bind_parameter_name()], and
4930 ** [sqlite3_bind_parameter_index()].
4931 */
4932 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4933 4934 /*
4935 ** CAPI3REF: Name Of A Host Parameter
4936 ** METHOD: sqlite3_stmt
4937 **
4938 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
4939 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
4940 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4941 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4942 ** respectively.
4943 ** In other words, the initial ":" or "$" or "@" or "?"
4944 ** is included as part of the name.)^
4945 ** ^Parameters of the form "?" without a following integer have no name
4946 ** and are referred to as "nameless" or "anonymous parameters".
4947 **
4948 ** ^The first host parameter has an index of 1, not 0.
4949 **
4950 ** ^If the value N is out of range or if the N-th parameter is
4951 ** nameless, then NULL is returned. ^The returned string is
4952 ** always in UTF-8 encoding even if the named parameter was
4953 ** originally specified as UTF-16 in [sqlite3_prepare16()],
4954 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4955 **
4956 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4957 ** [sqlite3_bind_parameter_count()], and
4958 ** [sqlite3_bind_parameter_index()].
4959 */
4960 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4961 4962 /*
4963 ** CAPI3REF: Index Of A Parameter With A Given Name
4964 ** METHOD: sqlite3_stmt
4965 **
4966 ** ^Return the index of an SQL parameter given its name. ^The
4967 ** index value returned is suitable for use as the second
4968 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4969 ** is returned if no matching parameter is found. ^The parameter
4970 ** name must be given in UTF-8 even if the original statement
4971 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4972 ** [sqlite3_prepare16_v3()].
4973 **
4974 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4975 ** [sqlite3_bind_parameter_count()], and
4976 ** [sqlite3_bind_parameter_name()].
4977 */
4978 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4979 4980 /*
4981 ** CAPI3REF: Reset All Bindings On A Prepared Statement
4982 ** METHOD: sqlite3_stmt
4983 **
4984 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4985 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4986 ** ^Use this routine to reset all host parameters to NULL.
4987 */
4988 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4989 4990 /*
4991 ** CAPI3REF: Number Of Columns In A Result Set
4992 ** METHOD: sqlite3_stmt
4993 **
4994 ** ^Return the number of columns in the result set returned by the
4995 ** [prepared statement]. ^If this routine returns 0, that means the
4996 ** [prepared statement] returns no data (for example an [UPDATE]).
4997 ** ^However, just because this routine returns a positive number does not
4998 ** mean that one or more rows of data will be returned. ^A SELECT statement
4999 ** will always have a positive sqlite3_column_count() but depending on the
5000 ** WHERE clause constraints and the table content, it might return no rows.
5001 **
5002 ** See also: [sqlite3_data_count()]
5003 */
5004 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
5005 5006 /*
5007 ** CAPI3REF: Column Names In A Result Set
5008 ** METHOD: sqlite3_stmt
5009 **
5010 ** ^These routines return the name assigned to a particular column
5011 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
5012 ** interface returns a pointer to a zero-terminated UTF-8 string
5013 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
5014 ** UTF-16 string. ^The first parameter is the [prepared statement]
5015 ** that implements the [SELECT] statement. ^The second parameter is the
5016 ** column number. ^The leftmost column is number 0.
5017 **
5018 ** ^The returned string pointer is valid until either the [prepared statement]
5019 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
5020 ** reprepared by the first call to [sqlite3_step()] for a particular run
5021 ** or until the next call to
5022 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
5023 **
5024 ** ^If sqlite3_malloc() fails during the processing of either routine
5025 ** (for example during a conversion from UTF-8 to UTF-16) then a
5026 ** NULL pointer is returned.
5027 **
5028 ** ^The name of a result column is the value of the "AS" clause for
5029 ** that column, if there is an AS clause. If there is no AS clause
5030 ** then the name of the column is unspecified and may change from
5031 ** one release of SQLite to the next.
5032 */
5033 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
5034 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
5035 5036 /*
5037 ** CAPI3REF: Source Of Data In A Query Result
5038 ** METHOD: sqlite3_stmt
5039 **
5040 ** ^These routines provide a means to determine the database, table, and
5041 ** table column that is the origin of a particular result column in a
5042 ** [SELECT] statement.
5043 ** ^The name of the database or table or column can be returned as
5044 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
5045 ** the database name, the _table_ routines return the table name, and
5046 ** the origin_ routines return the column name.
5047 ** ^The returned string is valid until the [prepared statement] is destroyed
5048 ** using [sqlite3_finalize()] or until the statement is automatically
5049 ** reprepared by the first call to [sqlite3_step()] for a particular run
5050 ** or until the same information is requested
5051 ** again in a different encoding.
5052 **
5053 ** ^The names returned are the original un-aliased names of the
5054 ** database, table, and column.
5055 **
5056 ** ^The first argument to these interfaces is a [prepared statement].
5057 ** ^These functions return information about the Nth result column returned by
5058 ** the statement, where N is the second function argument.
5059 ** ^The left-most column is column 0 for these routines.
5060 **
5061 ** ^If the Nth column returned by the statement is an expression or
5062 ** subquery and is not a column value, then all of these functions return
5063 ** NULL. ^These routines might also return NULL if a memory allocation error
5064 ** occurs. ^Otherwise, they return the name of the attached database, table,
5065 ** or column that query result column was extracted from.
5066 **
5067 ** ^As with all other SQLite APIs, those whose names end with "16" return
5068 ** UTF-16 encoded strings and the other functions return UTF-8.
5069 **
5070 ** ^These APIs are only available if the library was compiled with the
5071 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
5072 **
5073 ** If two or more threads call one or more
5074 ** [sqlite3_column_database_name | column metadata interfaces]
5075 ** for the same [prepared statement] and result column
5076 ** at the same time then the results are undefined.
5077 */
5078 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
5079 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
5080 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
5081 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
5082 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
5083 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
5084 5085 /*
5086 ** CAPI3REF: Declared Datatype Of A Query Result
5087 ** METHOD: sqlite3_stmt
5088 **
5089 ** ^(The first parameter is a [prepared statement].
5090 ** If this statement is a [SELECT] statement and the Nth column of the
5091 ** returned result set of that [SELECT] is a table column (not an
5092 ** expression or subquery) then the declared type of the table
5093 ** column is returned.)^ ^If the Nth column of the result set is an
5094 ** expression or subquery, then a NULL pointer is returned.
5095 ** ^The returned string is always UTF-8 encoded.
5096 **
5097 ** ^(For example, given the database schema:
5098 **
5099 ** CREATE TABLE t1(c1 VARIANT);
5100 **
5101 ** and the following statement to be compiled:
5102 **
5103 ** SELECT c1 + 1, c1 FROM t1;
5104 **
5105 ** this routine would return the string "VARIANT" for the second result
5106 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
5107 **
5108 ** ^SQLite uses dynamic run-time typing. ^So just because a column
5109 ** is declared to contain a particular type does not mean that the
5110 ** data stored in that column is of the declared type. SQLite is
5111 ** strongly typed, but the typing is dynamic not static. ^Type
5112 ** is associated with individual values, not with the containers
5113 ** used to hold those values.
5114 */
5115 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
5116 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
5117 5118 /*
5119 ** CAPI3REF: Evaluate An SQL Statement
5120 ** METHOD: sqlite3_stmt
5121 **
5122 ** After a [prepared statement] has been prepared using any of
5123 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
5124 ** or [sqlite3_prepare16_v3()] or one of the legacy
5125 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
5126 ** must be called one or more times to evaluate the statement.
5127 **
5128 ** The details of the behavior of the sqlite3_step() interface depend
5129 ** on whether the statement was prepared using the newer "vX" interfaces
5130 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
5131 ** [sqlite3_prepare16_v2()] or the older legacy
5132 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
5133 ** new "vX" interface is recommended for new applications but the legacy
5134 ** interface will continue to be supported.
5135 **
5136 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
5137 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
5138 ** ^With the "v2" interface, any of the other [result codes] or
5139 ** [extended result codes] might be returned as well.
5140 **
5141 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
5142 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
5143 ** or occurs outside of an explicit transaction, then you can retry the
5144 ** statement. If the statement is not a [COMMIT] and occurs within an
5145 ** explicit transaction then you should rollback the transaction before
5146 ** continuing.
5147 **
5148 ** ^[SQLITE_DONE] means that the statement has finished executing
5149 ** successfully. sqlite3_step() should not be called again on this virtual
5150 ** machine without first calling [sqlite3_reset()] to reset the virtual
5151 ** machine back to its initial state.
5152 **
5153 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
5154 ** is returned each time a new row of data is ready for processing by the
5155 ** caller. The values may be accessed using the [column access functions].
5156 ** sqlite3_step() is called again to retrieve the next row of data.
5157 **
5158 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
5159 ** violation) has occurred. sqlite3_step() should not be called again on
5160 ** the VM. More information may be found by calling [sqlite3_errmsg()].
5161 ** ^With the legacy interface, a more specific error code (for example,
5162 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
5163 ** can be obtained by calling [sqlite3_reset()] on the
5164 ** [prepared statement]. ^In the "v2" interface,
5165 ** the more specific error code is returned directly by sqlite3_step().
5166 **
5167 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
5168 ** Perhaps it was called on a [prepared statement] that has
5169 ** already been [sqlite3_finalize | finalized] or on one that had
5170 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
5171 ** be the case that the same database connection is being used by two or
5172 ** more threads at the same moment in time.
5173 **
5174 ** For all versions of SQLite up to and including 3.6.23.1, a call to
5175 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
5176 ** other than [SQLITE_ROW] before any subsequent invocation of
5177 ** sqlite3_step(). Failure to reset the prepared statement using
5178 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
5179 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1]),
5180 ** sqlite3_step() began
5181 ** calling [sqlite3_reset()] automatically in this circumstance rather
5182 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
5183 ** break because any application that ever receives an SQLITE_MISUSE error
5184 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
5185 ** can be used to restore the legacy behavior.
5186 **
5187 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
5188 ** API always returns a generic error code, [SQLITE_ERROR], following any
5189 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
5190 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
5191 ** specific [error codes] that better describes the error.
5192 ** We admit that this is a goofy design. The problem has been fixed
5193 ** with the "v2" interface. If you prepare all of your SQL statements
5194 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
5195 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
5196 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
5197 ** then the more specific [error codes] are returned directly
5198 ** by sqlite3_step(). The use of the "vX" interfaces is recommended.
5199 */
5200 SQLITE_API int sqlite3_step(sqlite3_stmt*);
5201 5202 /*
5203 ** CAPI3REF: Number of columns in a result set
5204 ** METHOD: sqlite3_stmt
5205 **
5206 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
5207 ** current row of the result set of [prepared statement] P.
5208 ** ^If prepared statement P does not have results ready to return
5209 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
5210 ** interfaces) then sqlite3_data_count(P) returns 0.
5211 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
5212 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
5213 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
5214 ** will return non-zero if previous call to [sqlite3_step](P) returned
5215 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
5216 ** where it always returns zero since each step of that multi-step
5217 ** pragma returns 0 columns of data.
5218 **
5219 ** See also: [sqlite3_column_count()]
5220 */
5221 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5222 5223 /*
5224 ** CAPI3REF: Fundamental Datatypes
5225 ** KEYWORDS: SQLITE_TEXT
5226 **
5227 ** ^(Every value in SQLite has one of five fundamental datatypes:
5228 **
5229 ** <ul>
5230 ** <li> 64-bit signed integer
5231 ** <li> 64-bit IEEE floating point number
5232 ** <li> string
5233 ** <li> BLOB
5234 ** <li> NULL
5235 ** </ul>)^
5236 **
5237 ** These constants are codes for each of those types.
5238 **
5239 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5240 ** for a completely different meaning. Software that links against both
5241 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5242 ** SQLITE_TEXT.
5243 */
5244 #define SQLITE_INTEGER 1
5245 #define SQLITE_FLOAT 2
5246 #define SQLITE_BLOB 4
5247 #define SQLITE_NULL 5
5248 #ifdef SQLITE_TEXT
5249 # undef SQLITE_TEXT
5250 #else
5251 # define SQLITE_TEXT 3
5252 #endif
5253 #define SQLITE3_TEXT 3
5254 5255 /*
5256 ** CAPI3REF: Result Values From A Query
5257 ** KEYWORDS: {column access functions}
5258 ** METHOD: sqlite3_stmt
5259 **
5260 ** <b>Summary:</b>
5261 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5262 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result
5263 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result
5264 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result
5265 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result
5266 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result
5267 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result
5268 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an
5269 ** [sqlite3_value|unprotected sqlite3_value] object.
5270 ** <tr><td> <td> <td>
5271 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB
5272 ** or a UTF-8 TEXT result in bytes
5273 ** <tr><td><b>sqlite3_column_bytes16 </b>
5274 ** <td>→ <td>Size of UTF-16
5275 ** TEXT in bytes
5276 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default
5277 ** datatype of the result
5278 ** </table></blockquote>
5279 **
5280 ** <b>Details:</b>
5281 **
5282 ** ^These routines return information about a single column of the current
5283 ** result row of a query. ^In every case the first argument is a pointer
5284 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5285 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5286 ** and the second argument is the index of the column for which information
5287 ** should be returned. ^The leftmost column of the result set has the index 0.
5288 ** ^The number of columns in the result can be determined using
5289 ** [sqlite3_column_count()].
5290 **
5291 ** If the SQL statement does not currently point to a valid row, or if the
5292 ** column index is out of range, the result is undefined.
5293 ** These routines may only be called when the most recent call to
5294 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5295 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5296 ** If any of these routines are called after [sqlite3_reset()] or
5297 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5298 ** something other than [SQLITE_ROW], the results are undefined.
5299 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5300 ** are called from a different thread while any of these routines
5301 ** are pending, then the results are undefined.
5302 **
5303 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5304 ** each return the value of a result column in a specific data format. If
5305 ** the result column is not initially in the requested format (for example,
5306 ** if the query returns an integer but the sqlite3_column_text() interface
5307 ** is used to extract the value) then an automatic type conversion is performed.
5308 **
5309 ** ^The sqlite3_column_type() routine returns the
5310 ** [SQLITE_INTEGER | datatype code] for the initial data type
5311 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5312 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5313 ** The return value of sqlite3_column_type() can be used to decide which
5314 ** of the first six interface should be used to extract the column value.
5315 ** The value returned by sqlite3_column_type() is only meaningful if no
5316 ** automatic type conversions have occurred for the value in question.
5317 ** After a type conversion, the result of calling sqlite3_column_type()
5318 ** is undefined, though harmless. Future
5319 ** versions of SQLite may change the behavior of sqlite3_column_type()
5320 ** following a type conversion.
5321 **
5322 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5323 ** or sqlite3_column_bytes16() interfaces can be used to determine the size
5324 ** of that BLOB or string.
5325 **
5326 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5327 ** routine returns the number of bytes in that BLOB or string.
5328 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5329 ** the string to UTF-8 and then returns the number of bytes.
5330 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
5331 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5332 ** the number of bytes in that string.
5333 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5334 **
5335 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5336 ** routine returns the number of bytes in that BLOB or string.
5337 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5338 ** the string to UTF-16 and then returns the number of bytes.
5339 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5340 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5341 ** the number of bytes in that string.
5342 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5343 **
5344 ** ^The values returned by [sqlite3_column_bytes()] and
5345 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5346 ** of the string. ^For clarity: the values returned by
5347 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5348 ** bytes in the string, not the number of characters.
5349 **
5350 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5351 ** even empty strings, are always zero-terminated. ^The return
5352 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5353 **
5354 ** ^Strings returned by sqlite3_column_text16() always have the endianness
5355 ** which is native to the platform, regardless of the text encoding set
5356 ** for the database.
5357 **
5358 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5359 ** [unprotected sqlite3_value] object. In a multithreaded environment,
5360 ** an unprotected sqlite3_value object may only be used safely with
5361 ** [sqlite3_bind_value()] and [sqlite3_result_value()].
5362 ** If the [unprotected sqlite3_value] object returned by
5363 ** [sqlite3_column_value()] is used in any other way, including calls
5364 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5365 ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5366 ** Hence, the sqlite3_column_value() interface
5367 ** is normally only useful within the implementation of
5368 ** [application-defined SQL functions] or [virtual tables], not within
5369 ** top-level application code.
5370 **
5371 ** These routines may attempt to convert the datatype of the result.
5372 ** ^For example, if the internal representation is FLOAT and a text result
5373 ** is requested, [sqlite3_snprintf()] is used internally to perform the
5374 ** conversion automatically. ^(The following table details the conversions
5375 ** that are applied:
5376 **
5377 ** <blockquote>
5378 ** <table border="1">
5379 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5380 **
5381 ** <tr><td> NULL <td> INTEGER <td> Result is 0
5382 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5383 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5384 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5385 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5386 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5387 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5388 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5389 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5390 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5391 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5392 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5393 ** <tr><td> TEXT <td> BLOB <td> No change
5394 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5395 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5396 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5397 ** </table>
5398 ** </blockquote>)^
5399 **
5400 ** Note that when type conversions occur, pointers returned by prior
5401 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5402 ** sqlite3_column_text16() may be invalidated.
5403 ** Type conversions and pointer invalidations might occur
5404 ** in the following cases:
5405 **
5406 ** <ul>
5407 ** <li> The initial content is a BLOB and sqlite3_column_text() or
5408 ** sqlite3_column_text16() is called. A zero-terminator might
5409 ** need to be added to the string.</li>
5410 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5411 ** sqlite3_column_text16() is called. The content must be converted
5412 ** to UTF-16.</li>
5413 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5414 ** sqlite3_column_text() is called. The content must be converted
5415 ** to UTF-8.</li>
5416 ** </ul>
5417 **
5418 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5419 ** not invalidate a prior pointer, though of course the content of the buffer
5420 ** that the prior pointer references will have been modified. Other kinds
5421 ** of conversion are done in place when it is possible, but sometimes they
5422 ** are not possible and in those cases prior pointers are invalidated.
5423 **
5424 ** The safest policy is to invoke these routines
5425 ** in one of the following ways:
5426 **
5427 ** <ul>
5428 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5429 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5430 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5431 ** </ul>
5432 **
5433 ** In other words, you should call sqlite3_column_text(),
5434 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5435 ** into the desired format, then invoke sqlite3_column_bytes() or
5436 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5437 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5438 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5439 ** with calls to sqlite3_column_bytes().
5440 **
5441 ** ^The pointers returned are valid until a type conversion occurs as
5442 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5443 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5444 ** and BLOBs is freed automatically. Do not pass the pointers returned
5445 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5446 ** [sqlite3_free()].
5447 **
5448 ** As long as the input parameters are correct, these routines will only
5449 ** fail if an out-of-memory error occurs during a format conversion.
5450 ** Only the following subset of interfaces are subject to out-of-memory
5451 ** errors:
5452 **
5453 ** <ul>
5454 ** <li> sqlite3_column_blob()
5455 ** <li> sqlite3_column_text()
5456 ** <li> sqlite3_column_text16()
5457 ** <li> sqlite3_column_bytes()
5458 ** <li> sqlite3_column_bytes16()
5459 ** </ul>
5460 **
5461 ** If an out-of-memory error occurs, then the return value from these
5462 ** routines is the same as if the column had contained an SQL NULL value.
5463 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5464 ** by invoking the [sqlite3_errcode()] immediately after the suspect
5465 ** return value is obtained and before any
5466 ** other SQLite interface is called on the same [database connection].
5467 */
5468 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5469 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5470 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5471 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5472 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5473 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5474 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5475 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5476 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5477 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5478 5479 /*
5480 ** CAPI3REF: Destroy A Prepared Statement Object
5481 ** DESTRUCTOR: sqlite3_stmt
5482 **
5483 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5484 ** ^If the most recent evaluation of the statement encountered no errors
5485 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
5486 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5487 ** sqlite3_finalize(S) returns the appropriate [error code] or
5488 ** [extended error code].
5489 **
5490 ** ^The sqlite3_finalize(S) routine can be called at any point during
5491 ** the life cycle of [prepared statement] S:
5492 ** before statement S is ever evaluated, after
5493 ** one or more calls to [sqlite3_reset()], or after any call
5494 ** to [sqlite3_step()] regardless of whether or not the statement has
5495 ** completed execution.
5496 **
5497 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5498 **
5499 ** The application must finalize every [prepared statement] in order to avoid
5500 ** resource leaks. It is a grievous error for the application to try to use
5501 ** a prepared statement after it has been finalized. Any use of a prepared
5502 ** statement after it has been finalized can result in undefined and
5503 ** undesirable behavior such as segfaults and heap corruption.
5504 */
5505 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5506 5507 /*
5508 ** CAPI3REF: Reset A Prepared Statement Object
5509 ** METHOD: sqlite3_stmt
5510 **
5511 ** The sqlite3_reset() function is called to reset a [prepared statement]
5512 ** object back to its initial state, ready to be re-executed.
5513 ** ^Any SQL statement variables that had values bound to them using
5514 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5515 ** Use [sqlite3_clear_bindings()] to reset the bindings.
5516 **
5517 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5518 ** back to the beginning of its program.
5519 **
5520 ** ^The return code from [sqlite3_reset(S)] indicates whether or not
5521 ** the previous evaluation of prepared statement S completed successfully.
5522 ** ^If [sqlite3_step(S)] has never before been called on S or if
5523 ** [sqlite3_step(S)] has not been called since the previous call
5524 ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5525 ** [SQLITE_OK].
5526 **
5527 ** ^If the most recent call to [sqlite3_step(S)] for the
5528 ** [prepared statement] S indicated an error, then
5529 ** [sqlite3_reset(S)] returns an appropriate [error code].
5530 ** ^The [sqlite3_reset(S)] interface might also return an [error code]
5531 ** if there were no prior errors but the process of resetting
5532 ** the prepared statement caused a new error. ^For example, if an
5533 ** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5534 ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5535 ** the overall statement might still fail and the [sqlite3_reset(S)] call
5536 ** might return SQLITE_BUSY if locking constraints prevent the
5537 ** database change from committing. Therefore, it is important that
5538 ** applications check the return code from [sqlite3_reset(S)] even if
5539 ** no prior call to [sqlite3_step(S)] indicated a problem.
5540 **
5541 ** ^The [sqlite3_reset(S)] interface does not change the values
5542 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5543 */
5544 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5545 5546 5547 /*
5548 ** CAPI3REF: Create Or Redefine SQL Functions
5549 ** KEYWORDS: {function creation routines}
5550 ** METHOD: sqlite3
5551 **
5552 ** ^These functions (collectively known as "function creation routines")
5553 ** are used to add SQL functions or aggregates or to redefine the behavior
5554 ** of existing SQL functions or aggregates. The only differences between
5555 ** the three "sqlite3_create_function*" routines are the text encoding
5556 ** expected for the second parameter (the name of the function being
5557 ** created) and the presence or absence of a destructor callback for
5558 ** the application data pointer. Function sqlite3_create_window_function()
5559 ** is similar, but allows the user to supply the extra callback functions
5560 ** needed by [aggregate window functions].
5561 **
5562 ** ^The first parameter is the [database connection] to which the SQL
5563 ** function is to be added. ^If an application uses more than one database
5564 ** connection then application-defined SQL functions must be added
5565 ** to each database connection separately.
5566 **
5567 ** ^The second parameter is the name of the SQL function to be created or
5568 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5569 ** representation, exclusive of the zero-terminator. ^Note that the name
5570 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5571 ** ^Any attempt to create a function with a longer name
5572 ** will result in [SQLITE_MISUSE] being returned.
5573 **
5574 ** ^The third parameter (nArg)
5575 ** is the number of arguments that the SQL function or
5576 ** aggregate takes. ^If this parameter is -1, then the SQL function or
5577 ** aggregate may take any number of arguments between 0 and the limit
5578 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5579 ** parameter is less than -1 or greater than 127 then the behavior is
5580 ** undefined.
5581 **
5582 ** ^The fourth parameter, eTextRep, specifies what
5583 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5584 ** its parameters. The application should set this parameter to
5585 ** [SQLITE_UTF16LE] if the function implementation invokes
5586 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5587 ** implementation invokes [sqlite3_value_text16be()] on an input, or
5588 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5589 ** otherwise. ^The same SQL function may be registered multiple times using
5590 ** different preferred text encodings, with different implementations for
5591 ** each encoding.
5592 ** ^When multiple implementations of the same function are available, SQLite
5593 ** will pick the one that involves the least amount of data conversion.
5594 **
5595 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5596 ** to signal that the function will always return the same result given
5597 ** the same inputs within a single SQL statement. Most SQL functions are
5598 ** deterministic. The built-in [random()] SQL function is an example of a
5599 ** function that is not deterministic. The SQLite query planner is able to
5600 ** perform additional optimizations on deterministic functions, so use
5601 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5602 **
5603 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5604 ** flag, which if present prevents the function from being invoked from
5605 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5606 ** index expressions, or the WHERE clause of partial indexes.
5607 **
5608 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5609 ** all application-defined SQL functions that do not need to be
5610 ** used inside of triggers, views, CHECK constraints, or other elements of
5611 ** the database schema. This flag is especially recommended for SQL
5612 ** functions that have side effects or reveal internal application state.
5613 ** Without this flag, an attacker might be able to modify the schema of
5614 ** a database file to include invocations of the function with parameters
5615 ** chosen by the attacker, which the application will then execute when
5616 ** the database file is opened and read.
5617 **
5618 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5619 ** function can gain access to this pointer using [sqlite3_user_data()].)^
5620 **
5621 ** ^The sixth, seventh and eighth parameters passed to the three
5622 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5623 ** pointers to C-language functions that implement the SQL function or
5624 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5625 ** callback only; NULL pointers must be passed as the xStep and xFinal
5626 ** parameters. ^An aggregate SQL function requires an implementation of xStep
5627 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5628 ** SQL function or aggregate, pass NULL pointers for all three function
5629 ** callbacks.
5630 **
5631 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5632 ** and xInverse) passed to sqlite3_create_window_function are pointers to
5633 ** C-language callbacks that implement the new function. xStep and xFinal
5634 ** must both be non-NULL. xValue and xInverse may either both be NULL, in
5635 ** which case a regular aggregate function is created, or must both be
5636 ** non-NULL, in which case the new function may be used as either an aggregate
5637 ** or aggregate window function. More details regarding the implementation
5638 ** of aggregate window functions are
5639 ** [user-defined window functions|available here].
5640 **
5641 ** ^(If the final parameter to sqlite3_create_function_v2() or
5642 ** sqlite3_create_window_function() is not NULL, then it is the destructor for
5643 ** the application data pointer. The destructor is invoked when the function
5644 ** is deleted, either by being overloaded or when the database connection
5645 ** closes.)^ ^The destructor is also invoked if the call to
5646 ** sqlite3_create_function_v2() fails. ^When the destructor callback is
5647 ** invoked, it is passed a single argument which is a copy of the application
5648 ** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5649 **
5650 ** ^It is permitted to register multiple implementations of the same
5651 ** functions with the same name but with either differing numbers of
5652 ** arguments or differing preferred text encodings. ^SQLite will use
5653 ** the implementation that most closely matches the way in which the
5654 ** SQL function is used. ^A function implementation with a non-negative
5655 ** nArg parameter is a better match than a function implementation with
5656 ** a negative nArg. ^A function where the preferred text encoding
5657 ** matches the database encoding is a better
5658 ** match than a function where the encoding is different.
5659 ** ^A function where the encoding difference is between UTF16le and UTF16be
5660 ** is a closer match than a function where the encoding difference is
5661 ** between UTF8 and UTF16.
5662 **
5663 ** ^Built-in functions may be overloaded by new application-defined functions.
5664 **
5665 ** ^An application-defined function is permitted to call other
5666 ** SQLite interfaces. However, such calls must not
5667 ** close the database connection nor finalize or reset the prepared
5668 ** statement in which the function is running.
5669 */
5670 SQLITE_API int sqlite3_create_function(
5671 sqlite3 *db,
5672 const char *zFunctionName,
5673 int nArg,
5674 int eTextRep,
5675 void *pApp,
5676 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5677 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5678 void (*xFinal)(sqlite3_context*)
5679 );
5680 SQLITE_API int sqlite3_create_function16(
5681 sqlite3 *db,
5682 const void *zFunctionName,
5683 int nArg,
5684 int eTextRep,
5685 void *pApp,
5686 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5687 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5688 void (*xFinal)(sqlite3_context*)
5689 );
5690 SQLITE_API int sqlite3_create_function_v2(
5691 sqlite3 *db,
5692 const char *zFunctionName,
5693 int nArg,
5694 int eTextRep,
5695 void *pApp,
5696 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5697 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5698 void (*xFinal)(sqlite3_context*),
5699 void(*xDestroy)(void*)
5700 );
5701 SQLITE_API int sqlite3_create_window_function(
5702 sqlite3 *db,
5703 const char *zFunctionName,
5704 int nArg,
5705 int eTextRep,
5706 void *pApp,
5707 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5708 void (*xFinal)(sqlite3_context*),
5709 void (*xValue)(sqlite3_context*),
5710 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5711 void(*xDestroy)(void*)
5712 );
5713 5714 /*
5715 ** CAPI3REF: Text Encodings
5716 **
5717 ** These constant define integer codes that represent the various
5718 ** text encodings supported by SQLite.
5719 */
5720 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5721 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5722 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5723 #define SQLITE_UTF16 4 /* Use native byte order */
5724 #define SQLITE_ANY 5 /* Deprecated */
5725 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5726 5727 /*
5728 ** CAPI3REF: Function Flags
5729 **
5730 ** These constants may be ORed together with the
5731 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5732 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5733 ** [sqlite3_create_function_v2()].
5734 **
5735 ** <dl>
5736 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5737 ** The SQLITE_DETERMINISTIC flag means that the new function always gives
5738 ** the same output when the input parameters are the same.
5739 ** The [abs|abs() function] is deterministic, for example, but
5740 ** [randomblob|randomblob()] is not. Functions must
5741 ** be deterministic in order to be used in certain contexts such as
5742 ** with the WHERE clause of [partial indexes] or in [generated columns].
5743 ** SQLite might also optimize deterministic functions by factoring them
5744 ** out of inner loops.
5745 ** </dd>
5746 **
5747 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5748 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5749 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5750 ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5751 ** [expression indexes], [partial indexes], or [generated columns].
5752 ** <p>
5753 ** The SQLITE_DIRECTONLY flag is recommended for any
5754 ** [application-defined SQL function]
5755 ** that has side-effects or that could potentially leak sensitive information.
5756 ** This will prevent attacks in which an application is tricked
5757 ** into using a database file that has had its schema surreptitiously
5758 ** modified to invoke the application-defined function in ways that are
5759 ** harmful.
5760 ** <p>
5761 ** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5762 ** [application-defined SQL functions], regardless of whether or not they
5763 ** are security sensitive, as doing so prevents those functions from being used
5764 ** inside of the database schema, and thus ensures that the database
5765 ** can be inspected and modified using generic tools (such as the [CLI])
5766 ** that do not have access to the application-defined functions.
5767 ** </dd>
5768 **
5769 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5770 ** The SQLITE_INNOCUOUS flag means that the function is unlikely
5771 ** to cause problems even if misused. An innocuous function should have
5772 ** no side effects and should not depend on any values other than its
5773 ** input parameters. The [abs|abs() function] is an example of an
5774 ** innocuous function.
5775 ** The [load_extension() SQL function] is not innocuous because of its
5776 ** side effects.
5777 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5778 ** exactly the same. The [random|random() function] is an example of a
5779 ** function that is innocuous but not deterministic.
5780 ** <p>Some heightened security settings
5781 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5782 ** disable the use of SQL functions inside views and triggers and in
5783 ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5784 ** [expression indexes], [partial indexes], and [generated columns] unless
5785 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5786 ** are innocuous. Developers are advised to avoid using the
5787 ** SQLITE_INNOCUOUS flag for application-defined functions unless the
5788 ** function has been carefully audited and found to be free of potentially
5789 ** security-adverse side-effects and information-leaks.
5790 ** </dd>
5791 **
5792 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5793 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
5794 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5795 ** This flag instructs SQLite to omit some corner-case optimizations that
5796 ** might disrupt the operation of the [sqlite3_value_subtype()] function,
5797 ** causing it to return zero rather than the correct subtype().
5798 ** All SQL functions that invoke [sqlite3_value_subtype()] should have this
5799 ** property. If the SQLITE_SUBTYPE property is omitted, then the return
5800 ** value from [sqlite3_value_subtype()] might sometimes be zero even though
5801 ** a non-zero subtype was specified by the function argument expression.
5802 **
5803 ** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
5804 ** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
5805 ** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
5806 ** result.
5807 ** Every function that invokes [sqlite3_result_subtype()] should have this
5808 ** property. If it does not, then the call to [sqlite3_result_subtype()]
5809 ** might become a no-op if the function is used as term in an
5810 ** [expression index]. On the other hand, SQL functions that never invoke
5811 ** [sqlite3_result_subtype()] should avoid setting this property, as the
5812 ** purpose of this property is to disable certain optimizations that are
5813 ** incompatible with subtypes.
5814 **
5815 ** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd>
5816 ** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate
5817 ** that internally orders the values provided to the first argument. The
5818 ** ordered-set aggregate SQL notation with a single ORDER BY term can be
5819 ** used to invoke this function. If the ordered-set aggregate notation is
5820 ** used on a function that lacks this flag, then an error is raised. Note
5821 ** that the ordered-set aggregate syntax is only available if SQLite is
5822 ** built using the -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES compile-time option.
5823 ** </dd>
5824 ** </dl>
5825 */
5826 #define SQLITE_DETERMINISTIC 0x000000800
5827 #define SQLITE_DIRECTONLY 0x000080000
5828 #define SQLITE_SUBTYPE 0x000100000
5829 #define SQLITE_INNOCUOUS 0x000200000
5830 #define SQLITE_RESULT_SUBTYPE 0x001000000
5831 #define SQLITE_SELFORDER1 0x002000000
5832 5833 /*
5834 ** CAPI3REF: Deprecated Functions
5835 ** DEPRECATED
5836 **
5837 ** These functions are [deprecated]. In order to maintain
5838 ** backwards compatibility with older code, these functions continue
5839 ** to be supported. However, new applications should avoid
5840 ** the use of these functions. To encourage programmers to avoid
5841 ** these functions, we will not explain what they do.
5842 */
5843 #ifndef SQLITE_OMIT_DEPRECATED
5844 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5845 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5846 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5847 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5848 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5849 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5850 void*,sqlite3_int64);
5851 #endif
5852 5853 /*
5854 ** CAPI3REF: Obtaining SQL Values
5855 ** METHOD: sqlite3_value
5856 **
5857 ** <b>Summary:</b>
5858 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5859 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value
5860 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value
5861 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value
5862 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value
5863 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value
5864 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value
5865 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in
5866 ** the native byteorder
5867 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value
5868 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value
5869 ** <tr><td> <td> <td>
5870 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB
5871 ** or a UTF-8 TEXT in bytes
5872 ** <tr><td><b>sqlite3_value_bytes16 </b>
5873 ** <td>→ <td>Size of UTF-16
5874 ** TEXT in bytes
5875 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default
5876 ** datatype of the value
5877 ** <tr><td><b>sqlite3_value_numeric_type </b>
5878 ** <td>→ <td>Best numeric datatype of the value
5879 ** <tr><td><b>sqlite3_value_nochange </b>
5880 ** <td>→ <td>True if the column is unchanged in an UPDATE
5881 ** against a virtual table.
5882 ** <tr><td><b>sqlite3_value_frombind </b>
5883 ** <td>→ <td>True if value originated from a [bound parameter]
5884 ** </table></blockquote>
5885 **
5886 ** <b>Details:</b>
5887 **
5888 ** These routines extract type, size, and content information from
5889 ** [protected sqlite3_value] objects. Protected sqlite3_value objects
5890 ** are used to pass parameter information into the functions that
5891 ** implement [application-defined SQL functions] and [virtual tables].
5892 **
5893 ** These routines work only with [protected sqlite3_value] objects.
5894 ** Any attempt to use these routines on an [unprotected sqlite3_value]
5895 ** is not threadsafe.
5896 **
5897 ** ^These routines work just like the corresponding [column access functions]
5898 ** except that these routines take a single [protected sqlite3_value] object
5899 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5900 **
5901 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5902 ** in the native byte-order of the host machine. ^The
5903 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5904 ** extract UTF-16 strings as big-endian and little-endian respectively.
5905 **
5906 ** ^If [sqlite3_value] object V was initialized
5907 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5908 ** and if X and Y are strings that compare equal according to strcmp(X,Y),
5909 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5910 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5911 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5912 **
5913 ** ^(The sqlite3_value_type(V) interface returns the
5914 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5915 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5916 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5917 ** Other interfaces might change the datatype for an sqlite3_value object.
5918 ** For example, if the datatype is initially SQLITE_INTEGER and
5919 ** sqlite3_value_text(V) is called to extract a text value for that
5920 ** integer, then subsequent calls to sqlite3_value_type(V) might return
5921 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5922 ** occurs is undefined and may change from one release of SQLite to the next.
5923 **
5924 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
5925 ** numeric affinity to the value. This means that an attempt is
5926 ** made to convert the value to an integer or floating point. If
5927 ** such a conversion is possible without loss of information (in other
5928 ** words, if the value is a string that looks like a number)
5929 ** then the conversion is performed. Otherwise no conversion occurs.
5930 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5931 **
5932 ** ^Within the [xUpdate] method of a [virtual table], the
5933 ** sqlite3_value_nochange(X) interface returns true if and only if
5934 ** the column corresponding to X is unchanged by the UPDATE operation
5935 ** that the xUpdate method call was invoked to implement and if
5936 ** and the prior [xColumn] method call that was invoked to extracted
5937 ** the value for that column returned without setting a result (probably
5938 ** because it queried [sqlite3_vtab_nochange()] and found that the column
5939 ** was unchanging). ^Within an [xUpdate] method, any value for which
5940 ** sqlite3_value_nochange(X) is true will in all other respects appear
5941 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5942 ** than within an [xUpdate] method call for an UPDATE statement, then
5943 ** the return value is arbitrary and meaningless.
5944 **
5945 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5946 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5947 ** interfaces. ^If X comes from an SQL literal value, or a table column,
5948 ** or an expression, then sqlite3_value_frombind(X) returns zero.
5949 **
5950 ** Please pay particular attention to the fact that the pointer returned
5951 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5952 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5953 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5954 ** or [sqlite3_value_text16()].
5955 **
5956 ** These routines must be called from the same thread as
5957 ** the SQL function that supplied the [sqlite3_value*] parameters.
5958 **
5959 ** As long as the input parameter is correct, these routines can only
5960 ** fail if an out-of-memory error occurs during a format conversion.
5961 ** Only the following subset of interfaces are subject to out-of-memory
5962 ** errors:
5963 **
5964 ** <ul>
5965 ** <li> sqlite3_value_blob()
5966 ** <li> sqlite3_value_text()
5967 ** <li> sqlite3_value_text16()
5968 ** <li> sqlite3_value_text16le()
5969 ** <li> sqlite3_value_text16be()
5970 ** <li> sqlite3_value_bytes()
5971 ** <li> sqlite3_value_bytes16()
5972 ** </ul>
5973 **
5974 ** If an out-of-memory error occurs, then the return value from these
5975 ** routines is the same as if the column had contained an SQL NULL value.
5976 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5977 ** by invoking the [sqlite3_errcode()] immediately after the suspect
5978 ** return value is obtained and before any
5979 ** other SQLite interface is called on the same [database connection].
5980 */
5981 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5982 SQLITE_API double sqlite3_value_double(sqlite3_value*);
5983 SQLITE_API int sqlite3_value_int(sqlite3_value*);
5984 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5985 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5986 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5987 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5988 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5989 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5990 SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5991 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5992 SQLITE_API int sqlite3_value_type(sqlite3_value*);
5993 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5994 SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5995 SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5996 5997 /*
5998 ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
5999 ** METHOD: sqlite3_value
6000 **
6001 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
6002 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
6003 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
6004 ** returns something other than SQLITE_TEXT, then the return value from
6005 ** sqlite3_value_encoding(X) is meaningless. ^Calls to
6006 ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
6007 ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
6008 ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
6009 ** thus change the return from subsequent calls to sqlite3_value_encoding(X).
6010 **
6011 ** This routine is intended for used by applications that test and validate
6012 ** the SQLite implementation. This routine is inquiring about the opaque
6013 ** internal state of an [sqlite3_value] object. Ordinary applications should
6014 ** not need to know what the internal state of an sqlite3_value object is and
6015 ** hence should not need to use this interface.
6016 */
6017 SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
6018 6019 /*
6020 ** CAPI3REF: Finding The Subtype Of SQL Values
6021 ** METHOD: sqlite3_value
6022 **
6023 ** The sqlite3_value_subtype(V) function returns the subtype for
6024 ** an [application-defined SQL function] argument V. The subtype
6025 ** information can be used to pass a limited amount of context from
6026 ** one SQL function to another. Use the [sqlite3_result_subtype()]
6027 ** routine to set the subtype for the return value of an SQL function.
6028 **
6029 ** Every [application-defined SQL function] that invokes this interface
6030 ** should include the [SQLITE_SUBTYPE] property in the text
6031 ** encoding argument when the function is [sqlite3_create_function|registered].
6032 ** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
6033 ** might return zero instead of the upstream subtype in some corner cases.
6034 */
6035 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
6036 6037 /*
6038 ** CAPI3REF: Copy And Free SQL Values
6039 ** METHOD: sqlite3_value
6040 **
6041 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
6042 ** object V and returns a pointer to that copy. ^The [sqlite3_value] returned
6043 ** is a [protected sqlite3_value] object even if the input is not.
6044 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
6045 ** memory allocation fails. ^If V is a [pointer value], then the result
6046 ** of sqlite3_value_dup(V) is a NULL value.
6047 **
6048 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
6049 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
6050 ** then sqlite3_value_free(V) is a harmless no-op.
6051 */
6052 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
6053 SQLITE_API void sqlite3_value_free(sqlite3_value*);
6054 6055 /*
6056 ** CAPI3REF: Obtain Aggregate Function Context
6057 ** METHOD: sqlite3_context
6058 **
6059 ** Implementations of aggregate SQL functions use this
6060 ** routine to allocate memory for storing their state.
6061 **
6062 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
6063 ** for a particular aggregate function, SQLite allocates
6064 ** N bytes of memory, zeroes out that memory, and returns a pointer
6065 ** to the new memory. ^On second and subsequent calls to
6066 ** sqlite3_aggregate_context() for the same aggregate function instance,
6067 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
6068 ** called once for each invocation of the xStep callback and then one
6069 ** last time when the xFinal callback is invoked. ^(When no rows match
6070 ** an aggregate query, the xStep() callback of the aggregate function
6071 ** implementation is never called and xFinal() is called exactly once.
6072 ** In those cases, sqlite3_aggregate_context() might be called for the
6073 ** first time from within xFinal().)^
6074 **
6075 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
6076 ** when first called if N is less than or equal to zero or if a memory
6077 ** allocation error occurs.
6078 **
6079 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
6080 ** determined by the N parameter on the first successful call. Changing the
6081 ** value of N in any subsequent call to sqlite3_aggregate_context() within
6082 ** the same aggregate function instance will not resize the memory
6083 ** allocation.)^ Within the xFinal callback, it is customary to set
6084 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
6085 ** pointless memory allocations occur.
6086 **
6087 ** ^SQLite automatically frees the memory allocated by
6088 ** sqlite3_aggregate_context() when the aggregate query concludes.
6089 **
6090 ** The first parameter must be a copy of the
6091 ** [sqlite3_context | SQL function context] that is the first parameter
6092 ** to the xStep or xFinal callback routine that implements the aggregate
6093 ** function.
6094 **
6095 ** This routine must be called from the same thread in which
6096 ** the aggregate SQL function is running.
6097 */
6098 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
6099 6100 /*
6101 ** CAPI3REF: User Data For Functions
6102 ** METHOD: sqlite3_context
6103 **
6104 ** ^The sqlite3_user_data() interface returns a copy of
6105 ** the pointer that was the pUserData parameter (the 5th parameter)
6106 ** of the [sqlite3_create_function()]
6107 ** and [sqlite3_create_function16()] routines that originally
6108 ** registered the application defined function.
6109 **
6110 ** This routine must be called from the same thread in which
6111 ** the application-defined function is running.
6112 */
6113 SQLITE_API void *sqlite3_user_data(sqlite3_context*);
6114 6115 /*
6116 ** CAPI3REF: Database Connection For Functions
6117 ** METHOD: sqlite3_context
6118 **
6119 ** ^The sqlite3_context_db_handle() interface returns a copy of
6120 ** the pointer to the [database connection] (the 1st parameter)
6121 ** of the [sqlite3_create_function()]
6122 ** and [sqlite3_create_function16()] routines that originally
6123 ** registered the application defined function.
6124 */
6125 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
6126 6127 /*
6128 ** CAPI3REF: Function Auxiliary Data
6129 ** METHOD: sqlite3_context
6130 **
6131 ** These functions may be used by (non-aggregate) SQL functions to
6132 ** associate auxiliary data with argument values. If the same argument
6133 ** value is passed to multiple invocations of the same SQL function during
6134 ** query execution, under some circumstances the associated auxiliary data
6135 ** might be preserved. An example of where this might be useful is in a
6136 ** regular-expression matching function. The compiled version of the regular
6137 ** expression can be stored as auxiliary data associated with the pattern string.
6138 ** Then as long as the pattern string remains the same,
6139 ** the compiled regular expression can be reused on multiple
6140 ** invocations of the same function.
6141 **
6142 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data
6143 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
6144 ** value to the application-defined function. ^N is zero for the left-most
6145 ** function argument. ^If there is no auxiliary data
6146 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
6147 ** returns a NULL pointer.
6148 **
6149 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
6150 ** N-th argument of the application-defined function. ^Subsequent
6151 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
6152 ** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
6153 ** NULL if the auxiliary data has been discarded.
6154 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
6155 ** SQLite will invoke the destructor function X with parameter P exactly
6156 ** once, when the auxiliary data is discarded.
6157 ** SQLite is free to discard the auxiliary data at any time, including: <ul>
6158 ** <li> ^(when the corresponding function parameter changes)^, or
6159 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
6160 ** SQL statement)^, or
6161 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
6162 ** parameter)^, or
6163 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
6164 ** allocation error occurs.)^
6165 ** <li> ^(during the original sqlite3_set_auxdata() call if the function
6166 ** is evaluated during query planning instead of during query execution,
6167 ** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
6168 **
6169 ** Note the last two bullets in particular. The destructor X in
6170 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
6171 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
6172 ** should be called near the end of the function implementation and the
6173 ** function implementation should not make any use of P after
6174 ** sqlite3_set_auxdata() has been called. Furthermore, a call to
6175 ** sqlite3_get_auxdata() that occurs immediately after a corresponding call
6176 ** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
6177 ** condition occurred during the sqlite3_set_auxdata() call or if the
6178 ** function is being evaluated during query planning rather than during
6179 ** query execution.
6180 **
6181 ** ^(In practice, auxiliary data is preserved between function calls for
6182 ** function parameters that are compile-time constants, including literal
6183 ** values and [parameters] and expressions composed from the same.)^
6184 **
6185 ** The value of the N parameter to these interfaces should be non-negative.
6186 ** Future enhancements may make use of negative N values to define new
6187 ** kinds of function caching behavior.
6188 **
6189 ** These routines must be called from the same thread in which
6190 ** the SQL function is running.
6191 **
6192 ** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
6193 */
6194 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
6195 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
6196 6197 /*
6198 ** CAPI3REF: Database Connection Client Data
6199 ** METHOD: sqlite3
6200 **
6201 ** These functions are used to associate one or more named pointers
6202 ** with a [database connection].
6203 ** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
6204 ** to be attached to [database connection] D using name N. Subsequent
6205 ** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
6206 ** or a NULL pointer if there were no prior calls to
6207 ** sqlite3_set_clientdata() with the same values of D and N.
6208 ** Names are compared using strcmp() and are thus case sensitive.
6209 **
6210 ** If P and X are both non-NULL, then the destructor X is invoked with
6211 ** argument P on the first of the following occurrences:
6212 ** <ul>
6213 ** <li> An out-of-memory error occurs during the call to
6214 ** sqlite3_set_clientdata() which attempts to register pointer P.
6215 ** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
6216 ** with the same D and N parameters.
6217 ** <li> The database connection closes. SQLite does not make any guarantees
6218 ** about the order in which destructors are called, only that all
6219 ** destructors will be called exactly once at some point during the
6220 ** database connection closing process.
6221 ** </ul>
6222 **
6223 ** SQLite does not do anything with client data other than invoke
6224 ** destructors on the client data at the appropriate time. The intended
6225 ** use for client data is to provide a mechanism for wrapper libraries
6226 ** to store additional information about an SQLite database connection.
6227 **
6228 ** There is no limit (other than available memory) on the number of different
6229 ** client data pointers (with different names) that can be attached to a
6230 ** single database connection. However, the implementation is optimized
6231 ** for the case of having only one or two different client data names.
6232 ** Applications and wrapper libraries are discouraged from using more than
6233 ** one client data name each.
6234 **
6235 ** There is no way to enumerate the client data pointers
6236 ** associated with a database connection. The N parameter can be thought
6237 ** of as a secret key such that only code that knows the secret key is able
6238 ** to access the associated data.
6239 **
6240 ** Security Warning: These interfaces should not be exposed in scripting
6241 ** languages or in other circumstances where it might be possible for an
6242 ** attacker to invoke them. Any agent that can invoke these interfaces
6243 ** can probably also take control of the process.
6244 **
6245 ** Database connection client data is only available for SQLite
6246 ** version 3.44.0 ([dateof:3.44.0]) and later.
6247 **
6248 ** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
6249 */
6250 SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
6251 SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
6252 6253 /*
6254 ** CAPI3REF: Constants Defining Special Destructor Behavior
6255 **
6256 ** These are special values for the destructor that is passed in as the
6257 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
6258 ** argument is SQLITE_STATIC, it means that the content pointer is constant
6259 ** and will never change. It does not need to be destroyed. ^The
6260 ** SQLITE_TRANSIENT value means that the content will likely change in
6261 ** the near future and that SQLite should make its own private copy of
6262 ** the content before returning.
6263 **
6264 ** The typedef is necessary to work around problems in certain
6265 ** C++ compilers.
6266 */
6267 typedef void (*sqlite3_destructor_type)(void*);
6268 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
6269 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
6270 6271 /*
6272 ** CAPI3REF: Setting The Result Of An SQL Function
6273 ** METHOD: sqlite3_context
6274 **
6275 ** These routines are used by the xFunc or xFinal callbacks that
6276 ** implement SQL functions and aggregates. See
6277 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
6278 ** for additional information.
6279 **
6280 ** These functions work very much like the [parameter binding] family of
6281 ** functions used to bind values to host parameters in prepared statements.
6282 ** Refer to the [SQL parameter] documentation for additional information.
6283 **
6284 ** ^The sqlite3_result_blob() interface sets the result from
6285 ** an application-defined function to be the BLOB whose content is pointed
6286 ** to by the second parameter and which is N bytes long where N is the
6287 ** third parameter.
6288 **
6289 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
6290 ** interfaces set the result of the application-defined function to be
6291 ** a BLOB containing all zero bytes and N bytes in size.
6292 **
6293 ** ^The sqlite3_result_double() interface sets the result from
6294 ** an application-defined function to be a floating point value specified
6295 ** by its 2nd argument.
6296 **
6297 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
6298 ** cause the implemented SQL function to throw an exception.
6299 ** ^SQLite uses the string pointed to by the
6300 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
6301 ** as the text of an error message. ^SQLite interprets the error
6302 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
6303 ** interprets the string from sqlite3_result_error16() as UTF-16 using
6304 ** the same [byte-order determination rules] as [sqlite3_bind_text16()].
6305 ** ^If the third parameter to sqlite3_result_error()
6306 ** or sqlite3_result_error16() is negative then SQLite takes as the error
6307 ** message all text up through the first zero character.
6308 ** ^If the third parameter to sqlite3_result_error() or
6309 ** sqlite3_result_error16() is non-negative then SQLite takes that many
6310 ** bytes (not characters) from the 2nd parameter as the error message.
6311 ** ^The sqlite3_result_error() and sqlite3_result_error16()
6312 ** routines make a private copy of the error message text before
6313 ** they return. Hence, the calling function can deallocate or
6314 ** modify the text after they return without harm.
6315 ** ^The sqlite3_result_error_code() function changes the error code
6316 ** returned by SQLite as a result of an error in a function. ^By default,
6317 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6318 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6319 **
6320 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6321 ** error indicating that a string or BLOB is too long to represent.
6322 **
6323 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6324 ** error indicating that a memory allocation failed.
6325 **
6326 ** ^The sqlite3_result_int() interface sets the return value
6327 ** of the application-defined function to be the 32-bit signed integer
6328 ** value given in the 2nd argument.
6329 ** ^The sqlite3_result_int64() interface sets the return value
6330 ** of the application-defined function to be the 64-bit signed integer
6331 ** value given in the 2nd argument.
6332 **
6333 ** ^The sqlite3_result_null() interface sets the return value
6334 ** of the application-defined function to be NULL.
6335 **
6336 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
6337 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6338 ** set the return value of the application-defined function to be
6339 ** a text string which is represented as UTF-8, UTF-16 native byte order,
6340 ** UTF-16 little endian, or UTF-16 big endian, respectively.
6341 ** ^The sqlite3_result_text64() interface sets the return value of an
6342 ** application-defined function to be a text string in an encoding
6343 ** specified by the fifth (and last) parameter, which must be one
6344 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
6345 ** ^SQLite takes the text result from the application from
6346 ** the 2nd parameter of the sqlite3_result_text* interfaces.
6347 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6348 ** other than sqlite3_result_text64() is negative, then SQLite computes
6349 ** the string length itself by searching the 2nd parameter for the first
6350 ** zero character.
6351 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6352 ** is non-negative, then as many bytes (not characters) of the text
6353 ** pointed to by the 2nd parameter are taken as the application-defined
6354 ** function result. If the 3rd parameter is non-negative, then it
6355 ** must be the byte offset into the string where the NUL terminator would
6356 ** appear if the string were NUL terminated. If any NUL characters occur
6357 ** in the string at a byte offset that is less than the value of the 3rd
6358 ** parameter, then the resulting string will contain embedded NULs and the
6359 ** result of expressions operating on strings with embedded NULs is undefined.
6360 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
6361 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6362 ** function as the destructor on the text or BLOB result when it has
6363 ** finished using that result.
6364 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6365 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6366 ** assumes that the text or BLOB result is in constant space and does not
6367 ** copy the content of the parameter nor call a destructor on the content
6368 ** when it has finished using that result.
6369 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
6370 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6371 ** then SQLite makes a copy of the result into space obtained
6372 ** from [sqlite3_malloc()] before it returns.
6373 **
6374 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6375 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6376 ** when the encoding is not UTF8, if the input UTF16 begins with a
6377 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6378 ** string and the rest of the string is interpreted according to the
6379 ** byte-order specified by the BOM. ^The byte-order specified by
6380 ** the BOM at the beginning of the text overrides the byte-order
6381 ** specified by the interface procedure. ^So, for example, if
6382 ** sqlite3_result_text16le() is invoked with text that begins
6383 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6384 ** first two bytes of input are skipped and the remaining input
6385 ** is interpreted as UTF16BE text.
6386 **
6387 ** ^For UTF16 input text to the sqlite3_result_text16(),
6388 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6389 ** sqlite3_result_text64() routines, if the text contains invalid
6390 ** UTF16 characters, the invalid characters might be converted
6391 ** into the unicode replacement character, U+FFFD.
6392 **
6393 ** ^The sqlite3_result_value() interface sets the result of
6394 ** the application-defined function to be a copy of the
6395 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6396 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6397 ** so that the [sqlite3_value] specified in the parameter may change or
6398 ** be deallocated after sqlite3_result_value() returns without harm.
6399 ** ^A [protected sqlite3_value] object may always be used where an
6400 ** [unprotected sqlite3_value] object is required, so either
6401 ** kind of [sqlite3_value] object can be used with this interface.
6402 **
6403 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6404 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6405 ** also associates the host-language pointer P or type T with that
6406 ** NULL value such that the pointer can be retrieved within an
6407 ** [application-defined SQL function] using [sqlite3_value_pointer()].
6408 ** ^If the D parameter is not NULL, then it is a pointer to a destructor
6409 ** for the P parameter. ^SQLite invokes D with P as its only argument
6410 ** when SQLite is finished with P. The T parameter should be a static
6411 ** string and preferably a string literal. The sqlite3_result_pointer()
6412 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6413 **
6414 ** If these routines are called from within a different thread
6415 ** than the one containing the application-defined function that received
6416 ** the [sqlite3_context] pointer, the results are undefined.
6417 */
6418 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6419 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6420 sqlite3_uint64,void(*)(void*));
6421 SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6422 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6423 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6424 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6425 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6426 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6427 SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6428 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6429 SQLITE_API void sqlite3_result_null(sqlite3_context*);
6430 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6431 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
6432 void(*)(void*), unsigned char encoding);
6433 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6434 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6435 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6436 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6437 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6438 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6439 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6440 6441 6442 /*
6443 ** CAPI3REF: Setting The Subtype Of An SQL Function
6444 ** METHOD: sqlite3_context
6445 **
6446 ** The sqlite3_result_subtype(C,T) function causes the subtype of
6447 ** the result from the [application-defined SQL function] with
6448 ** [sqlite3_context] C to be the value T. Only the lower 8 bits
6449 ** of the subtype T are preserved in current versions of SQLite;
6450 ** higher order bits are discarded.
6451 ** The number of subtype bytes preserved by SQLite might increase
6452 ** in future releases of SQLite.
6453 **
6454 ** Every [application-defined SQL function] that invokes this interface
6455 ** should include the [SQLITE_RESULT_SUBTYPE] property in its
6456 ** text encoding argument when the SQL function is
6457 ** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE]
6458 ** property is omitted from the function that invokes sqlite3_result_subtype(),
6459 ** then in some cases the sqlite3_result_subtype() might fail to set
6460 ** the result subtype.
6461 **
6462 ** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
6463 ** SQL function that invokes the sqlite3_result_subtype() interface
6464 ** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
6465 ** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
6466 ** by default.
6467 */
6468 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6469 6470 /*
6471 ** CAPI3REF: Define New Collating Sequences
6472 ** METHOD: sqlite3
6473 **
6474 ** ^These functions add, remove, or modify a [collation] associated
6475 ** with the [database connection] specified as the first argument.
6476 **
6477 ** ^The name of the collation is a UTF-8 string
6478 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6479 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6480 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6481 ** considered to be the same name.
6482 **
6483 ** ^(The third argument (eTextRep) must be one of the constants:
6484 ** <ul>
6485 ** <li> [SQLITE_UTF8],
6486 ** <li> [SQLITE_UTF16LE],
6487 ** <li> [SQLITE_UTF16BE],
6488 ** <li> [SQLITE_UTF16], or
6489 ** <li> [SQLITE_UTF16_ALIGNED].
6490 ** </ul>)^
6491 ** ^The eTextRep argument determines the encoding of strings passed
6492 ** to the collating function callback, xCompare.
6493 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6494 ** force strings to be UTF16 with native byte order.
6495 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6496 ** on an even byte address.
6497 **
6498 ** ^The fourth argument, pArg, is an application data pointer that is passed
6499 ** through as the first argument to the collating function callback.
6500 **
6501 ** ^The fifth argument, xCompare, is a pointer to the collating function.
6502 ** ^Multiple collating functions can be registered using the same name but
6503 ** with different eTextRep parameters and SQLite will use whichever
6504 ** function requires the least amount of data transformation.
6505 ** ^If the xCompare argument is NULL then the collating function is
6506 ** deleted. ^When all collating functions having the same name are deleted,
6507 ** that collation is no longer usable.
6508 **
6509 ** ^The collating function callback is invoked with a copy of the pArg
6510 ** application data pointer and with two strings in the encoding specified
6511 ** by the eTextRep argument. The two integer parameters to the collating
6512 ** function callback are the length of the two strings, in bytes. The collating
6513 ** function must return an integer that is negative, zero, or positive
6514 ** if the first string is less than, equal to, or greater than the second,
6515 ** respectively. A collating function must always return the same answer
6516 ** given the same inputs. If two or more collating functions are registered
6517 ** to the same collation name (using different eTextRep values) then all
6518 ** must give an equivalent answer when invoked with equivalent strings.
6519 ** The collating function must obey the following properties for all
6520 ** strings A, B, and C:
6521 **
6522 ** <ol>
6523 ** <li> If A==B then B==A.
6524 ** <li> If A==B and B==C then A==C.
6525 ** <li> If A<B THEN B>A.
6526 ** <li> If A<B and B<C then A<C.
6527 ** </ol>
6528 **
6529 ** If a collating function fails any of the above constraints and that
6530 ** collating function is registered and used, then the behavior of SQLite
6531 ** is undefined.
6532 **
6533 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6534 ** with the addition that the xDestroy callback is invoked on pArg when
6535 ** the collating function is deleted.
6536 ** ^Collating functions are deleted when they are overridden by later
6537 ** calls to the collation creation functions or when the
6538 ** [database connection] is closed using [sqlite3_close()].
6539 **
6540 ** ^The xDestroy callback is <u>not</u> called if the
6541 ** sqlite3_create_collation_v2() function fails. Applications that invoke
6542 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6543 ** check the return code and dispose of the application data pointer
6544 ** themselves rather than expecting SQLite to deal with it for them.
6545 ** This is different from every other SQLite interface. The inconsistency
6546 ** is unfortunate but cannot be changed without breaking backwards
6547 ** compatibility.
6548 **
6549 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6550 */
6551 SQLITE_API int sqlite3_create_collation(
6552 sqlite3*,
6553 const char *zName,
6554 int eTextRep,
6555 void *pArg,
6556 int(*xCompare)(void*,int,const void*,int,const void*)
6557 );
6558 SQLITE_API int sqlite3_create_collation_v2(
6559 sqlite3*,
6560 const char *zName,
6561 int eTextRep,
6562 void *pArg,
6563 int(*xCompare)(void*,int,const void*,int,const void*),
6564 void(*xDestroy)(void*)
6565 );
6566 SQLITE_API int sqlite3_create_collation16(
6567 sqlite3*,
6568 const void *zName,
6569 int eTextRep,
6570 void *pArg,
6571 int(*xCompare)(void*,int,const void*,int,const void*)
6572 );
6573 6574 /*
6575 ** CAPI3REF: Collation Needed Callbacks
6576 ** METHOD: sqlite3
6577 **
6578 ** ^To avoid having to register all collation sequences before a database
6579 ** can be used, a single callback function may be registered with the
6580 ** [database connection] to be invoked whenever an undefined collation
6581 ** sequence is required.
6582 **
6583 ** ^If the function is registered using the sqlite3_collation_needed() API,
6584 ** then it is passed the names of undefined collation sequences as strings
6585 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6586 ** the names are passed as UTF-16 in machine native byte order.
6587 ** ^A call to either function replaces the existing collation-needed callback.
6588 **
6589 ** ^(When the callback is invoked, the first argument passed is a copy
6590 ** of the second argument to sqlite3_collation_needed() or
6591 ** sqlite3_collation_needed16(). The second argument is the database
6592 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6593 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6594 ** sequence function required. The fourth parameter is the name of the
6595 ** required collation sequence.)^
6596 **
6597 ** The callback function should register the desired collation using
6598 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6599 ** [sqlite3_create_collation_v2()].
6600 */
6601 SQLITE_API int sqlite3_collation_needed(
6602 sqlite3*,
6603 void*,
6604 void(*)(void*,sqlite3*,int eTextRep,const char*)
6605 );
6606 SQLITE_API int sqlite3_collation_needed16(
6607 sqlite3*,
6608 void*,
6609 void(*)(void*,sqlite3*,int eTextRep,const void*)
6610 );
6611 6612 #ifdef SQLITE_ENABLE_CEROD
6613 /*
6614 ** Specify the activation key for a CEROD database. Unless
6615 ** activated, none of the CEROD routines will work.
6616 */
6617 SQLITE_API void sqlite3_activate_cerod(
6618 const char *zPassPhrase /* Activation phrase */
6619 );
6620 #endif
6621 6622 /*
6623 ** CAPI3REF: Suspend Execution For A Short Time
6624 **
6625 ** The sqlite3_sleep() function causes the current thread to suspend execution
6626 ** for at least a number of milliseconds specified in its parameter.
6627 **
6628 ** If the operating system does not support sleep requests with
6629 ** millisecond time resolution, then the time will be rounded up to
6630 ** the nearest second. The number of milliseconds of sleep actually
6631 ** requested from the operating system is returned.
6632 **
6633 ** ^SQLite implements this interface by calling the xSleep()
6634 ** method of the default [sqlite3_vfs] object. If the xSleep() method
6635 ** of the default VFS is not implemented correctly, or not implemented at
6636 ** all, then the behavior of sqlite3_sleep() may deviate from the description
6637 ** in the previous paragraphs.
6638 **
6639 ** If a negative argument is passed to sqlite3_sleep() the results vary by
6640 ** VFS and operating system. Some system treat a negative argument as an
6641 ** instruction to sleep forever. Others understand it to mean do not sleep
6642 ** at all. ^In SQLite version 3.42.0 and later, a negative
6643 ** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6644 ** down into the xSleep method of the VFS.
6645 */
6646 SQLITE_API int sqlite3_sleep(int);
6647 6648 /*
6649 ** CAPI3REF: Name Of The Folder Holding Temporary Files
6650 **
6651 ** ^(If this global variable is made to point to a string which is
6652 ** the name of a folder (a.k.a. directory), then all temporary files
6653 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6654 ** will be placed in that directory.)^ ^If this variable
6655 ** is a NULL pointer, then SQLite performs a search for an appropriate
6656 ** temporary file directory.
6657 **
6658 ** Applications are strongly discouraged from using this global variable.
6659 ** It is required to set a temporary folder on Windows Runtime (WinRT).
6660 ** But for all other platforms, it is highly recommended that applications
6661 ** neither read nor write this variable. This global variable is a relic
6662 ** that exists for backwards compatibility of legacy applications and should
6663 ** be avoided in new projects.
6664 **
6665 ** It is not safe to read or modify this variable in more than one
6666 ** thread at a time. It is not safe to read or modify this variable
6667 ** if a [database connection] is being used at the same time in a separate
6668 ** thread.
6669 ** It is intended that this variable be set once
6670 ** as part of process initialization and before any SQLite interface
6671 ** routines have been called and that this variable remain unchanged
6672 ** thereafter.
6673 **
6674 ** ^The [temp_store_directory pragma] may modify this variable and cause
6675 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6676 ** the [temp_store_directory pragma] always assumes that any string
6677 ** that this variable points to is held in memory obtained from
6678 ** [sqlite3_malloc] and the pragma may attempt to free that memory
6679 ** using [sqlite3_free].
6680 ** Hence, if this variable is modified directly, either it should be
6681 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6682 ** or else the use of the [temp_store_directory pragma] should be avoided.
6683 ** Except when requested by the [temp_store_directory pragma], SQLite
6684 ** does not free the memory that sqlite3_temp_directory points to. If
6685 ** the application wants that memory to be freed, it must do
6686 ** so itself, taking care to only do so after all [database connection]
6687 ** objects have been destroyed.
6688 **
6689 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6690 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6691 ** features that require the use of temporary files may fail. Here is an
6692 ** example of how to do this using C++ with the Windows Runtime:
6693 **
6694 ** <blockquote><pre>
6695 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6696 ** TemporaryFolder->Path->Data();
6697 ** char zPathBuf[MAX_PATH + 1];
6698 ** memset(zPathBuf, 0, sizeof(zPathBuf));
6699 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6700 ** NULL, NULL);
6701 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6702 ** </pre></blockquote>
6703 */
6704 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6705 6706 /*
6707 ** CAPI3REF: Name Of The Folder Holding Database Files
6708 **
6709 ** ^(If this global variable is made to point to a string which is
6710 ** the name of a folder (a.k.a. directory), then all database files
6711 ** specified with a relative pathname and created or accessed by
6712 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6713 ** to be relative to that directory.)^ ^If this variable is a NULL
6714 ** pointer, then SQLite assumes that all database files specified
6715 ** with a relative pathname are relative to the current directory
6716 ** for the process. Only the windows VFS makes use of this global
6717 ** variable; it is ignored by the unix VFS.
6718 **
6719 ** Changing the value of this variable while a database connection is
6720 ** open can result in a corrupt database.
6721 **
6722 ** It is not safe to read or modify this variable in more than one
6723 ** thread at a time. It is not safe to read or modify this variable
6724 ** if a [database connection] is being used at the same time in a separate
6725 ** thread.
6726 ** It is intended that this variable be set once
6727 ** as part of process initialization and before any SQLite interface
6728 ** routines have been called and that this variable remain unchanged
6729 ** thereafter.
6730 **
6731 ** ^The [data_store_directory pragma] may modify this variable and cause
6732 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6733 ** the [data_store_directory pragma] always assumes that any string
6734 ** that this variable points to is held in memory obtained from
6735 ** [sqlite3_malloc] and the pragma may attempt to free that memory
6736 ** using [sqlite3_free].
6737 ** Hence, if this variable is modified directly, either it should be
6738 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6739 ** or else the use of the [data_store_directory pragma] should be avoided.
6740 */
6741 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6742 6743 /*
6744 ** CAPI3REF: Win32 Specific Interface
6745 **
6746 ** These interfaces are available only on Windows. The
6747 ** [sqlite3_win32_set_directory] interface is used to set the value associated
6748 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6749 ** zValue, depending on the value of the type parameter. The zValue parameter
6750 ** should be NULL to cause the previous value to be freed via [sqlite3_free];
6751 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6752 ** prior to being used. The [sqlite3_win32_set_directory] interface returns
6753 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6754 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6755 ** [sqlite3_data_directory] variable is intended to act as a replacement for
6756 ** the current directory on the sub-platforms of Win32 where that concept is
6757 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6758 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6759 ** sqlite3_win32_set_directory interface except the string parameter must be
6760 ** UTF-8 or UTF-16, respectively.
6761 */
6762 SQLITE_API int sqlite3_win32_set_directory(
6763 unsigned long type, /* Identifier for directory being set or reset */
6764 void *zValue /* New value for directory being set or reset */
6765 );
6766 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6767 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6768 6769 /*
6770 ** CAPI3REF: Win32 Directory Types
6771 **
6772 ** These macros are only available on Windows. They define the allowed values
6773 ** for the type argument to the [sqlite3_win32_set_directory] interface.
6774 */
6775 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6776 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6777 6778 /*
6779 ** CAPI3REF: Test For Auto-Commit Mode
6780 ** KEYWORDS: {autocommit mode}
6781 ** METHOD: sqlite3
6782 **
6783 ** ^The sqlite3_get_autocommit() interface returns non-zero or
6784 ** zero if the given database connection is or is not in autocommit mode,
6785 ** respectively. ^Autocommit mode is on by default.
6786 ** ^Autocommit mode is disabled by a [BEGIN] statement.
6787 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6788 **
6789 ** If certain kinds of errors occur on a statement within a multi-statement
6790 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6791 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6792 ** transaction might be rolled back automatically. The only way to
6793 ** find out whether SQLite automatically rolled back the transaction after
6794 ** an error is to use this function.
6795 **
6796 ** If another thread changes the autocommit status of the database
6797 ** connection while this routine is running, then the return value
6798 ** is undefined.
6799 */
6800 SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6801 6802 /*
6803 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
6804 ** METHOD: sqlite3_stmt
6805 **
6806 ** ^The sqlite3_db_handle interface returns the [database connection] handle
6807 ** to which a [prepared statement] belongs. ^The [database connection]
6808 ** returned by sqlite3_db_handle is the same [database connection]
6809 ** that was the first argument
6810 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6811 ** create the statement in the first place.
6812 */
6813 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6814 6815 /*
6816 ** CAPI3REF: Return The Schema Name For A Database Connection
6817 ** METHOD: sqlite3
6818 **
6819 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6820 ** for the N-th database on database connection D, or a NULL pointer if N is
6821 ** out of range. An N value of 0 means the main database file. An N of 1 is
6822 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6823 ** databases.
6824 **
6825 ** Space to hold the string that is returned by sqlite3_db_name() is managed
6826 ** by SQLite itself. The string might be deallocated by any operation that
6827 ** changes the schema, including [ATTACH] or [DETACH] or calls to
6828 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6829 ** occur on a different thread. Applications that need to
6830 ** remember the string long-term should make their own copy. Applications that
6831 ** are accessing the same database connection simultaneously on multiple
6832 ** threads should mutex-protect calls to this API and should make their own
6833 ** private copy of the result prior to releasing the mutex.
6834 */
6835 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6836 6837 /*
6838 ** CAPI3REF: Return The Filename For A Database Connection
6839 ** METHOD: sqlite3
6840 **
6841 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6842 ** associated with database N of connection D.
6843 ** ^If there is no attached database N on the database
6844 ** connection D, or if database N is a temporary or in-memory database, then
6845 ** this function will return either a NULL pointer or an empty string.
6846 **
6847 ** ^The string value returned by this routine is owned and managed by
6848 ** the database connection. ^The value will be valid until the database N
6849 ** is [DETACH]-ed or until the database connection closes.
6850 **
6851 ** ^The filename returned by this function is the output of the
6852 ** xFullPathname method of the [VFS]. ^In other words, the filename
6853 ** will be an absolute pathname, even if the filename used
6854 ** to open the database originally was a URI or relative pathname.
6855 **
6856 ** If the filename pointer returned by this routine is not NULL, then it
6857 ** can be used as the filename input parameter to these routines:
6858 ** <ul>
6859 ** <li> [sqlite3_uri_parameter()]
6860 ** <li> [sqlite3_uri_boolean()]
6861 ** <li> [sqlite3_uri_int64()]
6862 ** <li> [sqlite3_filename_database()]
6863 ** <li> [sqlite3_filename_journal()]
6864 ** <li> [sqlite3_filename_wal()]
6865 ** </ul>
6866 */
6867 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6868 6869 /*
6870 ** CAPI3REF: Determine if a database is read-only
6871 ** METHOD: sqlite3
6872 **
6873 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6874 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6875 ** the name of a database on connection D.
6876 */
6877 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6878 6879 /*
6880 ** CAPI3REF: Determine the transaction state of a database
6881 ** METHOD: sqlite3
6882 **
6883 ** ^The sqlite3_txn_state(D,S) interface returns the current
6884 ** [transaction state] of schema S in database connection D. ^If S is NULL,
6885 ** then the highest transaction state of any schema on database connection D
6886 ** is returned. Transaction states are (in order of lowest to highest):
6887 ** <ol>
6888 ** <li value="0"> SQLITE_TXN_NONE
6889 ** <li value="1"> SQLITE_TXN_READ
6890 ** <li value="2"> SQLITE_TXN_WRITE
6891 ** </ol>
6892 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6893 ** a valid schema, then -1 is returned.
6894 */
6895 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6896 6897 /*
6898 ** CAPI3REF: Allowed return values from sqlite3_txn_state()
6899 ** KEYWORDS: {transaction state}
6900 **
6901 ** These constants define the current transaction state of a database file.
6902 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6903 ** constants in order to describe the transaction state of schema S
6904 ** in [database connection] D.
6905 **
6906 ** <dl>
6907 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6908 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6909 ** pending.</dd>
6910 **
6911 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6912 ** <dd>The SQLITE_TXN_READ state means that the database is currently
6913 ** in a read transaction. Content has been read from the database file
6914 ** but nothing in the database file has changed. The transaction state
6915 ** will be advanced to SQLITE_TXN_WRITE if any changes occur and there are
6916 ** no other conflicting concurrent write transactions. The transaction
6917 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6918 ** [COMMIT].</dd>
6919 **
6920 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6921 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6922 ** in a write transaction. Content has been written to the database file
6923 ** but has not yet committed. The transaction state will change to
6924 ** SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6925 */
6926 #define SQLITE_TXN_NONE 0
6927 #define SQLITE_TXN_READ 1
6928 #define SQLITE_TXN_WRITE 2
6929 6930 /*
6931 ** CAPI3REF: Find the next prepared statement
6932 ** METHOD: sqlite3
6933 **
6934 ** ^This interface returns a pointer to the next [prepared statement] after
6935 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6936 ** then this interface returns a pointer to the first prepared statement
6937 ** associated with the database connection pDb. ^If no prepared statement
6938 ** satisfies the conditions of this routine, it returns NULL.
6939 **
6940 ** The [database connection] pointer D in a call to
6941 ** [sqlite3_next_stmt(D,S)] must refer to an open database
6942 ** connection and in particular must not be a NULL pointer.
6943 */
6944 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6945 6946 /*
6947 ** CAPI3REF: Commit And Rollback Notification Callbacks
6948 ** METHOD: sqlite3
6949 **
6950 ** ^The sqlite3_commit_hook() interface registers a callback
6951 ** function to be invoked whenever a transaction is [COMMIT | committed].
6952 ** ^Any callback set by a previous call to sqlite3_commit_hook()
6953 ** for the same database connection is overridden.
6954 ** ^The sqlite3_rollback_hook() interface registers a callback
6955 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6956 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
6957 ** for the same database connection is overridden.
6958 ** ^The pArg argument is passed through to the callback.
6959 ** ^If the callback on a commit hook function returns non-zero,
6960 ** then the commit is converted into a rollback.
6961 **
6962 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6963 ** return the P argument from the previous call of the same function
6964 ** on the same [database connection] D, or NULL for
6965 ** the first call for each function on D.
6966 **
6967 ** The commit and rollback hook callbacks are not reentrant.
6968 ** The callback implementation must not do anything that will modify
6969 ** the database connection that invoked the callback. Any actions
6970 ** to modify the database connection must be deferred until after the
6971 ** completion of the [sqlite3_step()] call that triggered the commit
6972 ** or rollback hook in the first place.
6973 ** Note that running any other SQL statements, including SELECT statements,
6974 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6975 ** the database connections for the meaning of "modify" in this paragraph.
6976 **
6977 ** ^Registering a NULL function disables the callback.
6978 **
6979 ** ^When the commit hook callback routine returns zero, the [COMMIT]
6980 ** operation is allowed to continue normally. ^If the commit hook
6981 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6982 ** ^The rollback hook is invoked on a rollback that results from a commit
6983 ** hook returning non-zero, just as it would be with any other rollback.
6984 **
6985 ** ^For the purposes of this API, a transaction is said to have been
6986 ** rolled back if an explicit "ROLLBACK" statement is executed, or
6987 ** an error or constraint causes an implicit rollback to occur.
6988 ** ^The rollback callback is not invoked if a transaction is
6989 ** automatically rolled back because the database connection is closed.
6990 **
6991 ** See also the [sqlite3_update_hook()] interface.
6992 */
6993 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6994 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6995 6996 /*
6997 ** CAPI3REF: Autovacuum Compaction Amount Callback
6998 ** METHOD: sqlite3
6999 **
7000 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
7001 ** function C that is invoked prior to each autovacuum of the database
7002 ** file. ^The callback is passed a copy of the generic data pointer (P),
7003 ** the schema-name of the attached database that is being autovacuumed,
7004 ** the size of the database file in pages, the number of free pages,
7005 ** and the number of bytes per page, respectively. The callback should
7006 ** return the number of free pages that should be removed by the
7007 ** autovacuum. ^If the callback returns zero, then no autovacuum happens.
7008 ** ^If the value returned is greater than or equal to the number of
7009 ** free pages, then a complete autovacuum happens.
7010 **
7011 ** <p>^If there are multiple ATTACH-ed database files that are being
7012 ** modified as part of a transaction commit, then the autovacuum pages
7013 ** callback is invoked separately for each file.
7014 **
7015 ** <p><b>The callback is not reentrant.</b> The callback function should
7016 ** not attempt to invoke any other SQLite interface. If it does, bad
7017 ** things may happen, including segmentation faults and corrupt database
7018 ** files. The callback function should be a simple function that
7019 ** does some arithmetic on its input parameters and returns a result.
7020 **
7021 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
7022 ** destructor for the P parameter. ^If X is not NULL, then X(P) is
7023 ** invoked whenever the database connection closes or when the callback
7024 ** is overwritten by another invocation of sqlite3_autovacuum_pages().
7025 **
7026 ** <p>^There is only one autovacuum pages callback per database connection.
7027 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
7028 ** previous invocations for that database connection. ^If the callback
7029 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
7030 ** then the autovacuum steps callback is canceled. The return value
7031 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
7032 ** be some other error code if something goes wrong. The current
7033 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
7034 ** return codes might be added in future releases.
7035 **
7036 ** <p>If no autovacuum pages callback is specified (the usual case) or
7037 ** a NULL pointer is provided for the callback,
7038 ** then the default behavior is to vacuum all free pages. So, in other
7039 ** words, the default behavior is the same as if the callback function
7040 ** were something like this:
7041 **
7042 ** <blockquote><pre>
7043 ** unsigned int demonstration_autovac_pages_callback(
7044 ** void *pClientData,
7045 ** const char *zSchema,
7046 ** unsigned int nDbPage,
7047 ** unsigned int nFreePage,
7048 ** unsigned int nBytePerPage
7049 ** ){
7050 ** return nFreePage;
7051 ** }
7052 ** </pre></blockquote>
7053 */
7054 SQLITE_API int sqlite3_autovacuum_pages(
7055 sqlite3 *db,
7056 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
7057 void*,
7058 void(*)(void*)
7059 );
7060 7061 7062 /*
7063 ** CAPI3REF: Data Change Notification Callbacks
7064 ** METHOD: sqlite3
7065 **
7066 ** ^The sqlite3_update_hook() interface registers a callback function
7067 ** with the [database connection] identified by the first argument
7068 ** to be invoked whenever a row is updated, inserted or deleted in
7069 ** a [rowid table].
7070 ** ^Any callback set by a previous call to this function
7071 ** for the same database connection is overridden.
7072 **
7073 ** ^The second argument is a pointer to the function to invoke when a
7074 ** row is updated, inserted or deleted in a rowid table.
7075 ** ^The update hook is disabled by invoking sqlite3_update_hook()
7076 ** with a NULL pointer as the second parameter.
7077 ** ^The first argument to the callback is a copy of the third argument
7078 ** to sqlite3_update_hook().
7079 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
7080 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
7081 ** to be invoked.
7082 ** ^The third and fourth arguments to the callback contain pointers to the
7083 ** database and table name containing the affected row.
7084 ** ^The final callback parameter is the [rowid] of the row.
7085 ** ^In the case of an update, this is the [rowid] after the update takes place.
7086 **
7087 ** ^(The update hook is not invoked when internal system tables are
7088 ** modified (i.e. sqlite_sequence).)^
7089 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
7090 **
7091 ** ^In the current implementation, the update hook
7092 ** is not invoked when conflicting rows are deleted because of an
7093 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
7094 ** invoked when rows are deleted using the [truncate optimization].
7095 ** The exceptions defined in this paragraph might change in a future
7096 ** release of SQLite.
7097 **
7098 ** Whether the update hook is invoked before or after the
7099 ** corresponding change is currently unspecified and may differ
7100 ** depending on the type of change. Do not rely on the order of the
7101 ** hook call with regards to the final result of the operation which
7102 ** triggers the hook.
7103 **
7104 ** The update hook implementation must not do anything that will modify
7105 ** the database connection that invoked the update hook. Any actions
7106 ** to modify the database connection must be deferred until after the
7107 ** completion of the [sqlite3_step()] call that triggered the update hook.
7108 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
7109 ** database connections for the meaning of "modify" in this paragraph.
7110 **
7111 ** ^The sqlite3_update_hook(D,C,P) function
7112 ** returns the P argument from the previous call
7113 ** on the same [database connection] D, or NULL for
7114 ** the first call on D.
7115 **
7116 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
7117 ** and [sqlite3_preupdate_hook()] interfaces.
7118 */
7119 SQLITE_API void *sqlite3_update_hook(
7120 sqlite3*,
7121 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
7122 void*
7123 );
7124 7125 /*
7126 ** CAPI3REF: Enable Or Disable Shared Pager Cache
7127 **
7128 ** ^(This routine enables or disables the sharing of the database cache
7129 ** and schema data structures between [database connection | connections]
7130 ** to the same database. Sharing is enabled if the argument is true
7131 ** and disabled if the argument is false.)^
7132 **
7133 ** This interface is omitted if SQLite is compiled with
7134 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
7135 ** compile-time option is recommended because the
7136 ** [use of shared cache mode is discouraged].
7137 **
7138 ** ^Cache sharing is enabled and disabled for an entire process.
7139 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
7140 ** In prior versions of SQLite,
7141 ** sharing was enabled or disabled for each thread separately.
7142 **
7143 ** ^(The cache sharing mode set by this interface effects all subsequent
7144 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
7145 ** Existing database connections continue to use the sharing mode
7146 ** that was in effect at the time they were opened.)^
7147 **
7148 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
7149 ** successfully. An [error code] is returned otherwise.)^
7150 **
7151 ** ^Shared cache is disabled by default. It is recommended that it stay
7152 ** that way. In other words, do not use this routine. This interface
7153 ** continues to be provided for historical compatibility, but its use is
7154 ** discouraged. Any use of shared cache is discouraged. If shared cache
7155 ** must be used, it is recommended that shared cache only be enabled for
7156 ** individual database connections using the [sqlite3_open_v2()] interface
7157 ** with the [SQLITE_OPEN_SHAREDCACHE] flag.
7158 **
7159 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
7160 ** and will always return SQLITE_MISUSE. On those systems,
7161 ** shared cache mode should be enabled per-database connection via
7162 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
7163 **
7164 ** This interface is threadsafe on processors where writing a
7165 ** 32-bit integer is atomic.
7166 **
7167 ** See Also: [SQLite Shared-Cache Mode]
7168 */
7169 SQLITE_API int sqlite3_enable_shared_cache(int);
7170 7171 /*
7172 ** CAPI3REF: Attempt To Free Heap Memory
7173 **
7174 ** ^The sqlite3_release_memory() interface attempts to free N bytes
7175 ** of heap memory by deallocating non-essential memory allocations
7176 ** held by the database library. Memory used to cache database
7177 ** pages to improve performance is an example of non-essential memory.
7178 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
7179 ** which might be more or less than the amount requested.
7180 ** ^The sqlite3_release_memory() routine is a no-op returning zero
7181 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
7182 **
7183 ** See also: [sqlite3_db_release_memory()]
7184 */
7185 SQLITE_API int sqlite3_release_memory(int);
7186 7187 /*
7188 ** CAPI3REF: Free Memory Used By A Database Connection
7189 ** METHOD: sqlite3
7190 **
7191 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
7192 ** memory as possible from database connection D. Unlike the
7193 ** [sqlite3_release_memory()] interface, this interface is in effect even
7194 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
7195 ** omitted.
7196 **
7197 ** See also: [sqlite3_release_memory()]
7198 */
7199 SQLITE_API int sqlite3_db_release_memory(sqlite3*);
7200 7201 /*
7202 ** CAPI3REF: Impose A Limit On Heap Size
7203 **
7204 ** These interfaces impose limits on the amount of heap memory that will be
7205 ** used by all database connections within a single process.
7206 **
7207 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
7208 ** soft limit on the amount of heap memory that may be allocated by SQLite.
7209 ** ^SQLite strives to keep heap memory utilization below the soft heap
7210 ** limit by reducing the number of pages held in the page cache
7211 ** as heap memory usages approaches the limit.
7212 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
7213 ** below the limit, it will exceed the limit rather than generate
7214 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
7215 ** is advisory only.
7216 **
7217 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
7218 ** N bytes on the amount of memory that will be allocated. ^The
7219 ** sqlite3_hard_heap_limit64(N) interface is similar to
7220 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
7221 ** when the hard heap limit is reached.
7222 **
7223 ** ^The return value from both sqlite3_soft_heap_limit64() and
7224 ** sqlite3_hard_heap_limit64() is the size of
7225 ** the heap limit prior to the call, or negative in the case of an
7226 ** error. ^If the argument N is negative
7227 ** then no change is made to the heap limit. Hence, the current
7228 ** size of heap limits can be determined by invoking
7229 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
7230 **
7231 ** ^Setting the heap limits to zero disables the heap limiter mechanism.
7232 **
7233 ** ^The soft heap limit may not be greater than the hard heap limit.
7234 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
7235 ** is invoked with a value of N that is greater than the hard heap limit,
7236 ** the soft heap limit is set to the value of the hard heap limit.
7237 ** ^The soft heap limit is automatically enabled whenever the hard heap
7238 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
7239 ** the soft heap limit is outside the range of 1..N, then the soft heap
7240 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
7241 ** hard heap limit is enabled makes the soft heap limit equal to the
7242 ** hard heap limit.
7243 **
7244 ** The memory allocation limits can also be adjusted using
7245 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
7246 **
7247 ** ^(The heap limits are not enforced in the current implementation
7248 ** if one or more of following conditions are true:
7249 **
7250 ** <ul>
7251 ** <li> The limit value is set to zero.
7252 ** <li> Memory accounting is disabled using a combination of the
7253 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
7254 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
7255 ** <li> An alternative page cache implementation is specified using
7256 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
7257 ** <li> The page cache allocates from its own memory pool supplied
7258 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
7259 ** from the heap.
7260 ** </ul>)^
7261 **
7262 ** The circumstances under which SQLite will enforce the heap limits may
7263 ** change in future releases of SQLite.
7264 */
7265 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
7266 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
7267 7268 /*
7269 ** CAPI3REF: Deprecated Soft Heap Limit Interface
7270 ** DEPRECATED
7271 **
7272 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
7273 ** interface. This routine is provided for historical compatibility
7274 ** only. All new applications should use the
7275 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
7276 */
7277 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
7278 7279 7280 /*
7281 ** CAPI3REF: Extract Metadata About A Column Of A Table
7282 ** METHOD: sqlite3
7283 **
7284 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
7285 ** information about column C of table T in database D
7286 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
7287 ** interface returns SQLITE_OK and fills in the non-NULL pointers in
7288 ** the final five arguments with appropriate values if the specified
7289 ** column exists. ^The sqlite3_table_column_metadata() interface returns
7290 ** SQLITE_ERROR if the specified column does not exist.
7291 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
7292 ** NULL pointer, then this routine simply checks for the existence of the
7293 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
7294 ** does not. If the table name parameter T in a call to
7295 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
7296 ** undefined behavior.
7297 **
7298 ** ^The column is identified by the second, third and fourth parameters to
7299 ** this function. ^(The second parameter is either the name of the database
7300 ** (i.e. "main", "temp", or an attached database) containing the specified
7301 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
7302 ** for the table using the same algorithm used by the database engine to
7303 ** resolve unqualified table references.
7304 **
7305 ** ^The third and fourth parameters to this function are the table and column
7306 ** name of the desired column, respectively.
7307 **
7308 ** ^Metadata is returned by writing to the memory locations passed as the 5th
7309 ** and subsequent parameters to this function. ^Any of these arguments may be
7310 ** NULL, in which case the corresponding element of metadata is omitted.
7311 **
7312 ** ^(<blockquote>
7313 ** <table border="1">
7314 ** <tr><th> Parameter <th> Output<br>Type <th> Description
7315 **
7316 ** <tr><td> 5th <td> const char* <td> Data type
7317 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
7318 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
7319 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
7320 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
7321 ** </table>
7322 ** </blockquote>)^
7323 **
7324 ** ^The memory pointed to by the character pointers returned for the
7325 ** declaration type and collation sequence is valid until the next
7326 ** call to any SQLite API function.
7327 **
7328 ** ^If the specified table is actually a view, an [error code] is returned.
7329 **
7330 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
7331 ** is not a [WITHOUT ROWID] table and an
7332 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
7333 ** parameters are set for the explicitly declared column. ^(If there is no
7334 ** [INTEGER PRIMARY KEY] column, then the outputs
7335 ** for the [rowid] are set as follows:
7336 **
7337 ** <pre>
7338 ** data type: "INTEGER"
7339 ** collation sequence: "BINARY"
7340 ** not null: 0
7341 ** primary key: 1
7342 ** auto increment: 0
7343 ** </pre>)^
7344 **
7345 ** ^This function causes all database schemas to be read from disk and
7346 ** parsed, if that has not already been done, and returns an error if
7347 ** any errors are encountered while loading the schema.
7348 */
7349 SQLITE_API int sqlite3_table_column_metadata(
7350 sqlite3 *db, /* Connection handle */
7351 const char *zDbName, /* Database name or NULL */
7352 const char *zTableName, /* Table name */
7353 const char *zColumnName, /* Column name */
7354 char const **pzDataType, /* OUTPUT: Declared data type */
7355 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7356 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7357 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7358 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7359 );
7360 7361 /*
7362 ** CAPI3REF: Load An Extension
7363 ** METHOD: sqlite3
7364 **
7365 ** ^This interface loads an SQLite extension library from the named file.
7366 **
7367 ** ^The sqlite3_load_extension() interface attempts to load an
7368 ** [SQLite extension] library contained in the file zFile. If
7369 ** the file cannot be loaded directly, attempts are made to load
7370 ** with various operating-system specific extensions added.
7371 ** So for example, if "samplelib" cannot be loaded, then names like
7372 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7373 ** be tried also.
7374 **
7375 ** ^The entry point is zProc.
7376 ** ^(zProc may be 0, in which case SQLite will try to come up with an
7377 ** entry point name on its own. It first tries "sqlite3_extension_init".
7378 ** If that does not work, it constructs a name "sqlite3_X_init" where
7379 ** X consists of the lower-case equivalent of all ASCII alphabetic
7380 ** characters in the filename from the last "/" to the first following
7381 ** "." and omitting any initial "lib".)^
7382 ** ^The sqlite3_load_extension() interface returns
7383 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7384 ** ^If an error occurs and pzErrMsg is not 0, then the
7385 ** [sqlite3_load_extension()] interface shall attempt to
7386 ** fill *pzErrMsg with error message text stored in memory
7387 ** obtained from [sqlite3_malloc()]. The calling function
7388 ** should free this memory by calling [sqlite3_free()].
7389 **
7390 ** ^Extension loading must be enabled using
7391 ** [sqlite3_enable_load_extension()] or
7392 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7393 ** prior to calling this API,
7394 ** otherwise an error will be returned.
7395 **
7396 ** <b>Security warning:</b> It is recommended that the
7397 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7398 ** interface. The use of the [sqlite3_enable_load_extension()] interface
7399 ** should be avoided. This will keep the SQL function [load_extension()]
7400 ** disabled and prevent SQL injections from giving attackers
7401 ** access to extension loading capabilities.
7402 **
7403 ** See also the [load_extension() SQL function].
7404 */
7405 SQLITE_API int sqlite3_load_extension(
7406 sqlite3 *db, /* Load the extension into this database connection */
7407 const char *zFile, /* Name of the shared library containing extension */
7408 const char *zProc, /* Entry point. Derived from zFile if 0 */
7409 char **pzErrMsg /* Put error message here if not 0 */
7410 );
7411 7412 /*
7413 ** CAPI3REF: Enable Or Disable Extension Loading
7414 ** METHOD: sqlite3
7415 **
7416 ** ^So as not to open security holes in older applications that are
7417 ** unprepared to deal with [extension loading], and as a means of disabling
7418 ** [extension loading] while evaluating user-entered SQL, the following API
7419 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7420 **
7421 ** ^Extension loading is off by default.
7422 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7423 ** to turn extension loading on and call it with onoff==0 to turn
7424 ** it back off again.
7425 **
7426 ** ^This interface enables or disables both the C-API
7427 ** [sqlite3_load_extension()] and the SQL function [load_extension()].
7428 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7429 ** to enable or disable only the C-API.)^
7430 **
7431 ** <b>Security warning:</b> It is recommended that extension loading
7432 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7433 ** rather than this interface, so the [load_extension()] SQL function
7434 ** remains disabled. This will prevent SQL injections from giving attackers
7435 ** access to extension loading capabilities.
7436 */
7437 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7438 7439 /*
7440 ** CAPI3REF: Automatically Load Statically Linked Extensions
7441 **
7442 ** ^This interface causes the xEntryPoint() function to be invoked for
7443 ** each new [database connection] that is created. The idea here is that
7444 ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7445 ** that is to be automatically loaded into all new database connections.
7446 **
7447 ** ^(Even though the function prototype shows that xEntryPoint() takes
7448 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
7449 ** arguments and expects an integer result as if the signature of the
7450 ** entry point were as follows:
7451 **
7452 ** <blockquote><pre>
7453 ** int xEntryPoint(
7454 ** sqlite3 *db,
7455 ** const char **pzErrMsg,
7456 ** const struct sqlite3_api_routines *pThunk
7457 ** );
7458 ** </pre></blockquote>)^
7459 **
7460 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7461 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7462 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7463 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7464 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7465 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7466 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7467 **
7468 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7469 ** on the list of automatic extensions is a harmless no-op. ^No entry point
7470 ** will be called more than once for each database connection that is opened.
7471 **
7472 ** See also: [sqlite3_reset_auto_extension()]
7473 ** and [sqlite3_cancel_auto_extension()]
7474 */
7475 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7476 7477 /*
7478 ** CAPI3REF: Cancel Automatic Extension Loading
7479 **
7480 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7481 ** initialization routine X that was registered using a prior call to
7482 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7483 ** routine returns 1 if initialization routine X was successfully
7484 ** unregistered and it returns 0 if X was not on the list of initialization
7485 ** routines.
7486 */
7487 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7488 7489 /*
7490 ** CAPI3REF: Reset Automatic Extension Loading
7491 **
7492 ** ^This interface disables all automatic extensions previously
7493 ** registered using [sqlite3_auto_extension()].
7494 */
7495 SQLITE_API void sqlite3_reset_auto_extension(void);
7496 7497 /*
7498 ** Structures used by the virtual table interface
7499 */
7500 typedef struct sqlite3_vtab sqlite3_vtab;
7501 typedef struct sqlite3_index_info sqlite3_index_info;
7502 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7503 typedef struct sqlite3_module sqlite3_module;
7504 7505 /*
7506 ** CAPI3REF: Virtual Table Object
7507 ** KEYWORDS: sqlite3_module {virtual table module}
7508 **
7509 ** This structure, sometimes called a "virtual table module",
7510 ** defines the implementation of a [virtual table].
7511 ** This structure consists mostly of methods for the module.
7512 **
7513 ** ^A virtual table module is created by filling in a persistent
7514 ** instance of this structure and passing a pointer to that instance
7515 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7516 ** ^The registration remains valid until it is replaced by a different
7517 ** module or until the [database connection] closes. The content
7518 ** of this structure must not change while it is registered with
7519 ** any database connection.
7520 */
7521 struct sqlite3_module {
7522 int iVersion;
7523 int (*xCreate)(sqlite3*, void *pAux,
7524 int argc, const char *const*argv,
7525 sqlite3_vtab **ppVTab, char**);
7526 int (*xConnect)(sqlite3*, void *pAux,
7527 int argc, const char *const*argv,
7528 sqlite3_vtab **ppVTab, char**);
7529 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7530 int (*xDisconnect)(sqlite3_vtab *pVTab);
7531 int (*xDestroy)(sqlite3_vtab *pVTab);
7532 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7533 int (*xClose)(sqlite3_vtab_cursor*);
7534 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7535 int argc, sqlite3_value **argv);
7536 int (*xNext)(sqlite3_vtab_cursor*);
7537 int (*xEof)(sqlite3_vtab_cursor*);
7538 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7539 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7540 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7541 int (*xBegin)(sqlite3_vtab *pVTab);
7542 int (*xSync)(sqlite3_vtab *pVTab);
7543 int (*xCommit)(sqlite3_vtab *pVTab);
7544 int (*xRollback)(sqlite3_vtab *pVTab);
7545 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7546 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7547 void **ppArg);
7548 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7549 /* The methods above are in version 1 of the sqlite_module object. Those
7550 ** below are for version 2 and greater. */
7551 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7552 int (*xRelease)(sqlite3_vtab *pVTab, int);
7553 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7554 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7555 ** Those below are for version 3 and greater. */
7556 int (*xShadowName)(const char*);
7557 /* The methods above are in versions 1 through 3 of the sqlite_module object.
7558 ** Those below are for version 4 and greater. */
7559 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
7560 const char *zTabName, int mFlags, char **pzErr);
7561 };
7562 7563 /*
7564 ** CAPI3REF: Virtual Table Indexing Information
7565 ** KEYWORDS: sqlite3_index_info
7566 **
7567 ** The sqlite3_index_info structure and its substructures is used as part
7568 ** of the [virtual table] interface to
7569 ** pass information into and receive the reply from the [xBestIndex]
7570 ** method of a [virtual table module]. The fields under **Inputs** are the
7571 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
7572 ** results into the **Outputs** fields.
7573 **
7574 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
7575 **
7576 ** <blockquote>column OP expr</blockquote>
7577 **
7578 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
7579 ** stored in aConstraint[].op using one of the
7580 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7581 ** ^(The index of the column is stored in
7582 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7583 ** expr on the right-hand side can be evaluated (and thus the constraint
7584 ** is usable) and false if it cannot.)^
7585 **
7586 ** ^The optimizer automatically inverts terms of the form "expr OP column"
7587 ** and makes other simplifications to the WHERE clause in an attempt to
7588 ** get as many WHERE clause terms into the form shown above as possible.
7589 ** ^The aConstraint[] array only reports WHERE clause terms that are
7590 ** relevant to the particular virtual table being queried.
7591 **
7592 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
7593 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
7594 **
7595 ** The colUsed field indicates which columns of the virtual table may be
7596 ** required by the current scan. Virtual table columns are numbered from
7597 ** zero in the order in which they appear within the CREATE TABLE statement
7598 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7599 ** the corresponding bit is set within the colUsed mask if the column may be
7600 ** required by SQLite. If the table has at least 64 columns and any column
7601 ** to the right of the first 63 is required, then bit 63 of colUsed is also
7602 ** set. In other words, column iCol may be required if the expression
7603 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7604 ** non-zero.
7605 **
7606 ** The [xBestIndex] method must fill aConstraintUsage[] with information
7607 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
7608 ** the right-hand side of the corresponding aConstraint[] is evaluated
7609 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7610 ** is true, then the constraint is assumed to be fully handled by the
7611 ** virtual table and might not be checked again by the byte code.)^ ^(The
7612 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7613 ** is left in its default setting of false, the constraint will always be
7614 ** checked separately in byte code. If the omit flag is changed to true, then
7615 ** the constraint may or may not be checked in byte code. In other words,
7616 ** when the omit flag is true there is no guarantee that the constraint will
7617 ** not be checked again using byte code.)^
7618 **
7619 ** ^The idxNum and idxStr values are recorded and passed into the
7620 ** [xFilter] method.
7621 ** ^[sqlite3_free()] is used to free idxStr if and only if
7622 ** needToFreeIdxStr is true.
7623 **
7624 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7625 ** the correct order to satisfy the ORDER BY clause so that no separate
7626 ** sorting step is required.
7627 **
7628 ** ^The estimatedCost value is an estimate of the cost of a particular
7629 ** strategy. A cost of N indicates that the cost of the strategy is similar
7630 ** to a linear scan of an SQLite table with N rows. A cost of log(N)
7631 ** indicates that the expense of the operation is similar to that of a
7632 ** binary search on a unique indexed field of an SQLite table with N rows.
7633 **
7634 ** ^The estimatedRows value is an estimate of the number of rows that
7635 ** will be returned by the strategy.
7636 **
7637 ** The xBestIndex method may optionally populate the idxFlags field with a
7638 ** mask of SQLITE_INDEX_SCAN_* flags. One such flag is
7639 ** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN]
7640 ** output to show the idxNum as hex instead of as decimal. Another flag is
7641 ** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will
7642 ** return at most one row.
7643 **
7644 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7645 ** SQLite also assumes that if a call to the xUpdate() method is made as
7646 ** part of the same statement to delete or update a virtual table row and the
7647 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7648 ** any database changes. In other words, if the xUpdate() returns
7649 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7650 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7651 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7652 ** the xUpdate method are automatically rolled back by SQLite.
7653 **
7654 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7655 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7656 ** If a virtual table extension is
7657 ** used with an SQLite version earlier than 3.8.2, the results of attempting
7658 ** to read or write the estimatedRows field are undefined (but are likely
7659 ** to include crashing the application). The estimatedRows field should
7660 ** therefore only be used if [sqlite3_libversion_number()] returns a
7661 ** value greater than or equal to 3008002. Similarly, the idxFlags field
7662 ** was added for [version 3.9.0] ([dateof:3.9.0]).
7663 ** It may therefore only be used if
7664 ** sqlite3_libversion_number() returns a value greater than or equal to
7665 ** 3009000.
7666 */
7667 struct sqlite3_index_info {
7668 /* Inputs */
7669 int nConstraint; /* Number of entries in aConstraint */
7670 struct sqlite3_index_constraint {
7671 int iColumn; /* Column constrained. -1 for ROWID */
7672 unsigned char op; /* Constraint operator */
7673 unsigned char usable; /* True if this constraint is usable */
7674 int iTermOffset; /* Used internally - xBestIndex should ignore */
7675 } *aConstraint; /* Table of WHERE clause constraints */
7676 int nOrderBy; /* Number of terms in the ORDER BY clause */
7677 struct sqlite3_index_orderby {
7678 int iColumn; /* Column number */
7679 unsigned char desc; /* True for DESC. False for ASC. */
7680 } *aOrderBy; /* The ORDER BY clause */
7681 /* Outputs */
7682 struct sqlite3_index_constraint_usage {
7683 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7684 unsigned char omit; /* Do not code a test for this constraint */
7685 } *aConstraintUsage;
7686 int idxNum; /* Number used to identify the index */
7687 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7688 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7689 int orderByConsumed; /* True if output is already ordered */
7690 double estimatedCost; /* Estimated cost of using this index */
7691 /* Fields below are only available in SQLite 3.8.2 and later */
7692 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7693 /* Fields below are only available in SQLite 3.9.0 and later */
7694 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7695 /* Fields below are only available in SQLite 3.10.0 and later */
7696 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7697 };
7698 7699 /*
7700 ** CAPI3REF: Virtual Table Scan Flags
7701 **
7702 ** Virtual table implementations are allowed to set the
7703 ** [sqlite3_index_info].idxFlags field to some combination of
7704 ** these bits.
7705 */
7706 #define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */
7707 #define SQLITE_INDEX_SCAN_HEX 0x00000002 /* Display idxNum as hex */
7708 /* in EXPLAIN QUERY PLAN */
7709 7710 /*
7711 ** CAPI3REF: Virtual Table Constraint Operator Codes
7712 **
7713 ** These macros define the allowed values for the
7714 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
7715 ** an operator that is part of a constraint term in the WHERE clause of
7716 ** a query that uses a [virtual table].
7717 **
7718 ** ^The left-hand operand of the operator is given by the corresponding
7719 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7720 ** operand is the rowid.
7721 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7722 ** operators have no left-hand operand, and so for those operators the
7723 ** corresponding aConstraint[].iColumn is meaningless and should not be
7724 ** used.
7725 **
7726 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7727 ** value 255 are reserved to represent functions that are overloaded
7728 ** by the [xFindFunction|xFindFunction method] of the virtual table
7729 ** implementation.
7730 **
7731 ** The right-hand operands for each constraint might be accessible using
7732 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7733 ** operand is only available if it appears as a single constant literal
7734 ** in the input SQL. If the right-hand operand is another column or an
7735 ** expression (even a constant expression) or a parameter, then the
7736 ** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7737 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7738 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7739 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7740 ** always return SQLITE_NOTFOUND.
7741 **
7742 ** The collating sequence to be used for comparison can be found using
7743 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7744 ** tables, the collating sequence of constraints does not matter (for example
7745 ** because the constraints are numeric) and so the sqlite3_vtab_collation()
7746 ** interface is not commonly needed.
7747 */
7748 #define SQLITE_INDEX_CONSTRAINT_EQ 2
7749 #define SQLITE_INDEX_CONSTRAINT_GT 4
7750 #define SQLITE_INDEX_CONSTRAINT_LE 8
7751 #define SQLITE_INDEX_CONSTRAINT_LT 16
7752 #define SQLITE_INDEX_CONSTRAINT_GE 32
7753 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
7754 #define SQLITE_INDEX_CONSTRAINT_LIKE 65
7755 #define SQLITE_INDEX_CONSTRAINT_GLOB 66
7756 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7757 #define SQLITE_INDEX_CONSTRAINT_NE 68
7758 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7759 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7760 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7761 #define SQLITE_INDEX_CONSTRAINT_IS 72
7762 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7763 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7764 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7765 7766 /*
7767 ** CAPI3REF: Register A Virtual Table Implementation
7768 ** METHOD: sqlite3
7769 **
7770 ** ^These routines are used to register a new [virtual table module] name.
7771 ** ^Module names must be registered before
7772 ** creating a new [virtual table] using the module and before using a
7773 ** preexisting [virtual table] for the module.
7774 **
7775 ** ^The module name is registered on the [database connection] specified
7776 ** by the first parameter. ^The name of the module is given by the
7777 ** second parameter. ^The third parameter is a pointer to
7778 ** the implementation of the [virtual table module]. ^The fourth
7779 ** parameter is an arbitrary client data pointer that is passed through
7780 ** into the [xCreate] and [xConnect] methods of the virtual table module
7781 ** when a new virtual table is being created or reinitialized.
7782 **
7783 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7784 ** is a pointer to a destructor for the pClientData. ^SQLite will
7785 ** invoke the destructor function (if it is not NULL) when SQLite
7786 ** no longer needs the pClientData pointer. ^The destructor will also
7787 ** be invoked if the call to sqlite3_create_module_v2() fails.
7788 ** ^The sqlite3_create_module()
7789 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
7790 ** destructor.
7791 **
7792 ** ^If the third parameter (the pointer to the sqlite3_module object) is
7793 ** NULL then no new module is created and any existing modules with the
7794 ** same name are dropped.
7795 **
7796 ** See also: [sqlite3_drop_modules()]
7797 */
7798 SQLITE_API int sqlite3_create_module(
7799 sqlite3 *db, /* SQLite connection to register module with */
7800 const char *zName, /* Name of the module */
7801 const sqlite3_module *p, /* Methods for the module */
7802 void *pClientData /* Client data for xCreate/xConnect */
7803 );
7804 SQLITE_API int sqlite3_create_module_v2(
7805 sqlite3 *db, /* SQLite connection to register module with */
7806 const char *zName, /* Name of the module */
7807 const sqlite3_module *p, /* Methods for the module */
7808 void *pClientData, /* Client data for xCreate/xConnect */
7809 void(*xDestroy)(void*) /* Module destructor function */
7810 );
7811 7812 /*
7813 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7814 ** METHOD: sqlite3
7815 **
7816 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7817 ** table modules from database connection D except those named on list L.
7818 ** The L parameter must be either NULL or a pointer to an array of pointers
7819 ** to strings where the array is terminated by a single NULL pointer.
7820 ** ^If the L parameter is NULL, then all virtual table modules are removed.
7821 **
7822 ** See also: [sqlite3_create_module()]
7823 */
7824 SQLITE_API int sqlite3_drop_modules(
7825 sqlite3 *db, /* Remove modules from this connection */
7826 const char **azKeep /* Except, do not remove the ones named here */
7827 );
7828 7829 /*
7830 ** CAPI3REF: Virtual Table Instance Object
7831 ** KEYWORDS: sqlite3_vtab
7832 **
7833 ** Every [virtual table module] implementation uses a subclass
7834 ** of this object to describe a particular instance
7835 ** of the [virtual table]. Each subclass will
7836 ** be tailored to the specific needs of the module implementation.
7837 ** The purpose of this superclass is to define certain fields that are
7838 ** common to all module implementations.
7839 **
7840 ** ^Virtual tables methods can set an error message by assigning a
7841 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7842 ** take care that any prior string is freed by a call to [sqlite3_free()]
7843 ** prior to assigning a new string to zErrMsg. ^After the error message
7844 ** is delivered up to the client application, the string will be automatically
7845 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7846 */
7847 struct sqlite3_vtab {
7848 const sqlite3_module *pModule; /* The module for this virtual table */
7849 int nRef; /* Number of open cursors */
7850 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7851 /* Virtual table implementations will typically add additional fields */
7852 };
7853 7854 /*
7855 ** CAPI3REF: Virtual Table Cursor Object
7856 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7857 **
7858 ** Every [virtual table module] implementation uses a subclass of the
7859 ** following structure to describe cursors that point into the
7860 ** [virtual table] and are used
7861 ** to loop through the virtual table. Cursors are created using the
7862 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7863 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7864 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7865 ** of the module. Each module implementation will define
7866 ** the content of a cursor structure to suit its own needs.
7867 **
7868 ** This superclass exists in order to define fields of the cursor that
7869 ** are common to all implementations.
7870 */
7871 struct sqlite3_vtab_cursor {
7872 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7873 /* Virtual table implementations will typically add additional fields */
7874 };
7875 7876 /*
7877 ** CAPI3REF: Declare The Schema Of A Virtual Table
7878 **
7879 ** ^The [xCreate] and [xConnect] methods of a
7880 ** [virtual table module] call this interface
7881 ** to declare the format (the names and datatypes of the columns) of
7882 ** the virtual tables they implement.
7883 */
7884 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7885 7886 /*
7887 ** CAPI3REF: Overload A Function For A Virtual Table
7888 ** METHOD: sqlite3
7889 **
7890 ** ^(Virtual tables can provide alternative implementations of functions
7891 ** using the [xFindFunction] method of the [virtual table module].
7892 ** But global versions of those functions
7893 ** must exist in order to be overloaded.)^
7894 **
7895 ** ^(This API makes sure a global version of a function with a particular
7896 ** name and number of parameters exists. If no such function exists
7897 ** before this API is called, a new function is created.)^ ^The implementation
7898 ** of the new function always causes an exception to be thrown. So
7899 ** the new function is not good for anything by itself. Its only
7900 ** purpose is to be a placeholder function that can be overloaded
7901 ** by a [virtual table].
7902 */
7903 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7904 7905 /*
7906 ** CAPI3REF: A Handle To An Open BLOB
7907 ** KEYWORDS: {BLOB handle} {BLOB handles}
7908 **
7909 ** An instance of this object represents an open BLOB on which
7910 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7911 ** ^Objects of this type are created by [sqlite3_blob_open()]
7912 ** and destroyed by [sqlite3_blob_close()].
7913 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7914 ** can be used to read or write small subsections of the BLOB.
7915 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7916 */
7917 typedef struct sqlite3_blob sqlite3_blob;
7918 7919 /*
7920 ** CAPI3REF: Open A BLOB For Incremental I/O
7921 ** METHOD: sqlite3
7922 ** CONSTRUCTOR: sqlite3_blob
7923 **
7924 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7925 ** in row iRow, column zColumn, table zTable in database zDb;
7926 ** in other words, the same BLOB that would be selected by:
7927 **
7928 ** <pre>
7929 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7930 ** </pre>)^
7931 **
7932 ** ^(Parameter zDb is not the filename that contains the database, but
7933 ** rather the symbolic name of the database. For attached databases, this is
7934 ** the name that appears after the AS keyword in the [ATTACH] statement.
7935 ** For the main database file, the database name is "main". For TEMP
7936 ** tables, the database name is "temp".)^
7937 **
7938 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
7939 ** and write access. ^If the flags parameter is zero, the BLOB is opened for
7940 ** read-only access.
7941 **
7942 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7943 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7944 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7945 ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7946 ** on *ppBlob after this function returns.
7947 **
7948 ** This function fails with SQLITE_ERROR if any of the following are true:
7949 ** <ul>
7950 ** <li> ^(Database zDb does not exist)^,
7951 ** <li> ^(Table zTable does not exist within database zDb)^,
7952 ** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7953 ** <li> ^(Column zColumn does not exist)^,
7954 ** <li> ^(Row iRow is not present in the table)^,
7955 ** <li> ^(The specified column of row iRow contains a value that is not
7956 ** a TEXT or BLOB value)^,
7957 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7958 ** constraint and the blob is being opened for read/write access)^,
7959 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7960 ** column zColumn is part of a [child key] definition and the blob is
7961 ** being opened for read/write access)^.
7962 ** </ul>
7963 **
7964 ** ^Unless it returns SQLITE_MISUSE, this function sets the
7965 ** [database connection] error code and message accessible via
7966 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7967 **
7968 ** A BLOB referenced by sqlite3_blob_open() may be read using the
7969 ** [sqlite3_blob_read()] interface and modified by using
7970 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7971 ** different row of the same table using the [sqlite3_blob_reopen()]
7972 ** interface. However, the column, table, or database of a [BLOB handle]
7973 ** cannot be changed after the [BLOB handle] is opened.
7974 **
7975 ** ^(If the row that a BLOB handle points to is modified by an
7976 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7977 ** then the BLOB handle is marked as "expired".
7978 ** This is true if any column of the row is changed, even a column
7979 ** other than the one the BLOB handle is open on.)^
7980 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7981 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7982 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
7983 ** rolled back by the expiration of the BLOB. Such changes will eventually
7984 ** commit if the transaction continues to completion.)^
7985 **
7986 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7987 ** the opened blob. ^The size of a blob may not be changed by this
7988 ** interface. Use the [UPDATE] SQL command to change the size of a
7989 ** blob.
7990 **
7991 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7992 ** and the built-in [zeroblob] SQL function may be used to create a
7993 ** zero-filled blob to read or write using the incremental-blob interface.
7994 **
7995 ** To avoid a resource leak, every open [BLOB handle] should eventually
7996 ** be released by a call to [sqlite3_blob_close()].
7997 **
7998 ** See also: [sqlite3_blob_close()],
7999 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
8000 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
8001 */
8002 SQLITE_API int sqlite3_blob_open(
8003 sqlite3*,
8004 const char *zDb,
8005 const char *zTable,
8006 const char *zColumn,
8007 sqlite3_int64 iRow,
8008 int flags,
8009 sqlite3_blob **ppBlob
8010 );
8011 8012 /*
8013 ** CAPI3REF: Move a BLOB Handle to a New Row
8014 ** METHOD: sqlite3_blob
8015 **
8016 ** ^This function is used to move an existing [BLOB handle] so that it points
8017 ** to a different row of the same database table. ^The new row is identified
8018 ** by the rowid value passed as the second argument. Only the row can be
8019 ** changed. ^The database, table and column on which the blob handle is open
8020 ** remain the same. Moving an existing [BLOB handle] to a new row is
8021 ** faster than closing the existing handle and opening a new one.
8022 **
8023 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
8024 ** it must exist and there must be either a blob or text value stored in
8025 ** the nominated column.)^ ^If the new row is not present in the table, or if
8026 ** it does not contain a blob or text value, or if another error occurs, an
8027 ** SQLite error code is returned and the blob handle is considered aborted.
8028 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
8029 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
8030 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
8031 ** always returns zero.
8032 **
8033 ** ^This function sets the database handle error code and message.
8034 */
8035 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
8036 8037 /*
8038 ** CAPI3REF: Close A BLOB Handle
8039 ** DESTRUCTOR: sqlite3_blob
8040 **
8041 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
8042 ** unconditionally. Even if this routine returns an error code, the
8043 ** handle is still closed.)^
8044 **
8045 ** ^If the blob handle being closed was opened for read-write access, and if
8046 ** the database is in auto-commit mode and there are no other open read-write
8047 ** blob handles or active write statements, the current transaction is
8048 ** committed. ^If an error occurs while committing the transaction, an error
8049 ** code is returned and the transaction rolled back.
8050 **
8051 ** Calling this function with an argument that is not a NULL pointer or an
8052 ** open blob handle results in undefined behavior. ^Calling this routine
8053 ** with a null pointer (such as would be returned by a failed call to
8054 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
8055 ** is passed a valid open blob handle, the values returned by the
8056 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
8057 */
8058 SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
8059 8060 /*
8061 ** CAPI3REF: Return The Size Of An Open BLOB
8062 ** METHOD: sqlite3_blob
8063 **
8064 ** ^Returns the size in bytes of the BLOB accessible via the
8065 ** successfully opened [BLOB handle] in its only argument. ^The
8066 ** incremental blob I/O routines can only read or overwrite existing
8067 ** blob content; they cannot change the size of a blob.
8068 **
8069 ** This routine only works on a [BLOB handle] which has been created
8070 ** by a prior successful call to [sqlite3_blob_open()] and which has not
8071 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8072 ** to this routine results in undefined and probably undesirable behavior.
8073 */
8074 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
8075 8076 /*
8077 ** CAPI3REF: Read Data From A BLOB Incrementally
8078 ** METHOD: sqlite3_blob
8079 **
8080 ** ^(This function is used to read data from an open [BLOB handle] into a
8081 ** caller-supplied buffer. N bytes of data are copied into buffer Z
8082 ** from the open BLOB, starting at offset iOffset.)^
8083 **
8084 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
8085 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
8086 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
8087 ** ^The size of the blob (and hence the maximum value of N+iOffset)
8088 ** can be determined using the [sqlite3_blob_bytes()] interface.
8089 **
8090 ** ^An attempt to read from an expired [BLOB handle] fails with an
8091 ** error code of [SQLITE_ABORT].
8092 **
8093 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
8094 ** Otherwise, an [error code] or an [extended error code] is returned.)^
8095 **
8096 ** This routine only works on a [BLOB handle] which has been created
8097 ** by a prior successful call to [sqlite3_blob_open()] and which has not
8098 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8099 ** to this routine results in undefined and probably undesirable behavior.
8100 **
8101 ** See also: [sqlite3_blob_write()].
8102 */
8103 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
8104 8105 /*
8106 ** CAPI3REF: Write Data Into A BLOB Incrementally
8107 ** METHOD: sqlite3_blob
8108 **
8109 ** ^(This function is used to write data into an open [BLOB handle] from a
8110 ** caller-supplied buffer. N bytes of data are copied from the buffer Z
8111 ** into the open BLOB, starting at offset iOffset.)^
8112 **
8113 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
8114 ** Otherwise, an [error code] or an [extended error code] is returned.)^
8115 ** ^Unless SQLITE_MISUSE is returned, this function sets the
8116 ** [database connection] error code and message accessible via
8117 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8118 **
8119 ** ^If the [BLOB handle] passed as the first argument was not opened for
8120 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
8121 ** this function returns [SQLITE_READONLY].
8122 **
8123 ** This function may only modify the contents of the BLOB; it is
8124 ** not possible to increase the size of a BLOB using this API.
8125 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
8126 ** [SQLITE_ERROR] is returned and no data is written. The size of the
8127 ** BLOB (and hence the maximum value of N+iOffset) can be determined
8128 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
8129 ** than zero [SQLITE_ERROR] is returned and no data is written.
8130 **
8131 ** ^An attempt to write to an expired [BLOB handle] fails with an
8132 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
8133 ** before the [BLOB handle] expired are not rolled back by the
8134 ** expiration of the handle, though of course those changes might
8135 ** have been overwritten by the statement that expired the BLOB handle
8136 ** or by other independent statements.
8137 **
8138 ** This routine only works on a [BLOB handle] which has been created
8139 ** by a prior successful call to [sqlite3_blob_open()] and which has not
8140 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8141 ** to this routine results in undefined and probably undesirable behavior.
8142 **
8143 ** See also: [sqlite3_blob_read()].
8144 */
8145 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
8146 8147 /*
8148 ** CAPI3REF: Virtual File System Objects
8149 **
8150 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
8151 ** that SQLite uses to interact
8152 ** with the underlying operating system. Most SQLite builds come with a
8153 ** single default VFS that is appropriate for the host computer.
8154 ** New VFSes can be registered and existing VFSes can be unregistered.
8155 ** The following interfaces are provided.
8156 **
8157 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
8158 ** ^Names are case sensitive.
8159 ** ^Names are zero-terminated UTF-8 strings.
8160 ** ^If there is no match, a NULL pointer is returned.
8161 ** ^If zVfsName is NULL then the default VFS is returned.
8162 **
8163 ** ^New VFSes are registered with sqlite3_vfs_register().
8164 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
8165 ** ^The same VFS can be registered multiple times without injury.
8166 ** ^To make an existing VFS into the default VFS, register it again
8167 ** with the makeDflt flag set. If two different VFSes with the
8168 ** same name are registered, the behavior is undefined. If a
8169 ** VFS is registered with a name that is NULL or an empty string,
8170 ** then the behavior is undefined.
8171 **
8172 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
8173 ** ^(If the default VFS is unregistered, another VFS is chosen as
8174 ** the default. The choice for the new VFS is arbitrary.)^
8175 */
8176 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
8177 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
8178 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
8179 8180 /*
8181 ** CAPI3REF: Mutexes
8182 **
8183 ** The SQLite core uses these routines for thread
8184 ** synchronization. Though they are intended for internal
8185 ** use by SQLite, code that links against SQLite is
8186 ** permitted to use any of these routines.
8187 **
8188 ** The SQLite source code contains multiple implementations
8189 ** of these mutex routines. An appropriate implementation
8190 ** is selected automatically at compile-time. The following
8191 ** implementations are available in the SQLite core:
8192 **
8193 ** <ul>
8194 ** <li> SQLITE_MUTEX_PTHREADS
8195 ** <li> SQLITE_MUTEX_W32
8196 ** <li> SQLITE_MUTEX_NOOP
8197 ** </ul>
8198 **
8199 ** The SQLITE_MUTEX_NOOP implementation is a set of routines
8200 ** that does no real locking and is appropriate for use in
8201 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
8202 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
8203 ** and Windows.
8204 **
8205 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
8206 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
8207 ** implementation is included with the library. In this case the
8208 ** application must supply a custom mutex implementation using the
8209 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
8210 ** before calling sqlite3_initialize() or any other public sqlite3_
8211 ** function that calls sqlite3_initialize().
8212 **
8213 ** ^The sqlite3_mutex_alloc() routine allocates a new
8214 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
8215 ** routine returns NULL if it is unable to allocate the requested
8216 ** mutex. The argument to sqlite3_mutex_alloc() must be one of these
8217 ** integer constants:
8218 **
8219 ** <ul>
8220 ** <li> SQLITE_MUTEX_FAST
8221 ** <li> SQLITE_MUTEX_RECURSIVE
8222 ** <li> SQLITE_MUTEX_STATIC_MAIN
8223 ** <li> SQLITE_MUTEX_STATIC_MEM
8224 ** <li> SQLITE_MUTEX_STATIC_OPEN
8225 ** <li> SQLITE_MUTEX_STATIC_PRNG
8226 ** <li> SQLITE_MUTEX_STATIC_LRU
8227 ** <li> SQLITE_MUTEX_STATIC_PMEM
8228 ** <li> SQLITE_MUTEX_STATIC_APP1
8229 ** <li> SQLITE_MUTEX_STATIC_APP2
8230 ** <li> SQLITE_MUTEX_STATIC_APP3
8231 ** <li> SQLITE_MUTEX_STATIC_VFS1
8232 ** <li> SQLITE_MUTEX_STATIC_VFS2
8233 ** <li> SQLITE_MUTEX_STATIC_VFS3
8234 ** </ul>
8235 **
8236 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
8237 ** cause sqlite3_mutex_alloc() to create
8238 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
8239 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
8240 ** The mutex implementation does not need to make a distinction
8241 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
8242 ** not want to. SQLite will only request a recursive mutex in
8243 ** cases where it really needs one. If a faster non-recursive mutex
8244 ** implementation is available on the host platform, the mutex subsystem
8245 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
8246 **
8247 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
8248 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
8249 ** a pointer to a static preexisting mutex. ^Nine static mutexes are
8250 ** used by the current version of SQLite. Future versions of SQLite
8251 ** may add additional static mutexes. Static mutexes are for internal
8252 ** use by SQLite only. Applications that use SQLite mutexes should
8253 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
8254 ** SQLITE_MUTEX_RECURSIVE.
8255 **
8256 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
8257 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
8258 ** returns a different mutex on every call. ^For the static
8259 ** mutex types, the same mutex is returned on every call that has
8260 ** the same type number.
8261 **
8262 ** ^The sqlite3_mutex_free() routine deallocates a previously
8263 ** allocated dynamic mutex. Attempting to deallocate a static
8264 ** mutex results in undefined behavior.
8265 **
8266 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
8267 ** to enter a mutex. ^If another thread is already within the mutex,
8268 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
8269 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
8270 ** upon successful entry. ^(Mutexes created using
8271 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
8272 ** In such cases, the
8273 ** mutex must be exited an equal number of times before another thread
8274 ** can enter.)^ If the same thread tries to enter any mutex other
8275 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
8276 **
8277 ** ^(Some systems (for example, Windows 95) do not support the operation
8278 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
8279 ** will always return SQLITE_BUSY. In most cases the SQLite core only uses
8280 ** sqlite3_mutex_try() as an optimization, so this is acceptable
8281 ** behavior. The exceptions are unix builds that set the
8282 ** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
8283 ** sqlite3_mutex_try() is required.)^
8284 **
8285 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
8286 ** previously entered by the same thread. The behavior
8287 ** is undefined if the mutex is not currently entered by the
8288 ** calling thread or is not currently allocated.
8289 **
8290 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
8291 ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
8292 ** then any of the four routines behaves as a no-op.
8293 **
8294 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
8295 */
8296 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
8297 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
8298 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
8299 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
8300 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
8301 8302 /*
8303 ** CAPI3REF: Mutex Methods Object
8304 **
8305 ** An instance of this structure defines the low-level routines
8306 ** used to allocate and use mutexes.
8307 **
8308 ** Usually, the default mutex implementations provided by SQLite are
8309 ** sufficient, however the application has the option of substituting a custom
8310 ** implementation for specialized deployments or systems for which SQLite
8311 ** does not provide a suitable implementation. In this case, the application
8312 ** creates and populates an instance of this structure to pass
8313 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
8314 ** Additionally, an instance of this structure can be used as an
8315 ** output variable when querying the system for the current mutex
8316 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
8317 **
8318 ** ^The xMutexInit method defined by this structure is invoked as
8319 ** part of system initialization by the sqlite3_initialize() function.
8320 ** ^The xMutexInit routine is called by SQLite exactly once for each
8321 ** effective call to [sqlite3_initialize()].
8322 **
8323 ** ^The xMutexEnd method defined by this structure is invoked as
8324 ** part of system shutdown by the sqlite3_shutdown() function. The
8325 ** implementation of this method is expected to release all outstanding
8326 ** resources obtained by the mutex methods implementation, especially
8327 ** those obtained by the xMutexInit method. ^The xMutexEnd()
8328 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
8329 **
8330 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
8331 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
8332 ** xMutexNotheld) implement the following interfaces (respectively):
8333 **
8334 ** <ul>
8335 ** <li> [sqlite3_mutex_alloc()] </li>
8336 ** <li> [sqlite3_mutex_free()] </li>
8337 ** <li> [sqlite3_mutex_enter()] </li>
8338 ** <li> [sqlite3_mutex_try()] </li>
8339 ** <li> [sqlite3_mutex_leave()] </li>
8340 ** <li> [sqlite3_mutex_held()] </li>
8341 ** <li> [sqlite3_mutex_notheld()] </li>
8342 ** </ul>)^
8343 **
8344 ** The only difference is that the public sqlite3_XXX functions enumerated
8345 ** above silently ignore any invocations that pass a NULL pointer instead
8346 ** of a valid mutex handle. The implementations of the methods defined
8347 ** by this structure are not required to handle this case. The results
8348 ** of passing a NULL pointer instead of a valid mutex handle are undefined
8349 ** (i.e. it is acceptable to provide an implementation that segfaults if
8350 ** it is passed a NULL pointer).
8351 **
8352 ** The xMutexInit() method must be threadsafe. It must be harmless to
8353 ** invoke xMutexInit() multiple times within the same process and without
8354 ** intervening calls to xMutexEnd(). Second and subsequent calls to
8355 ** xMutexInit() must be no-ops.
8356 **
8357 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8358 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8359 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8360 ** memory allocation for a fast or recursive mutex.
8361 **
8362 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8363 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8364 ** If xMutexInit fails in any way, it is expected to clean up after itself
8365 ** prior to returning.
8366 */
8367 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8368 struct sqlite3_mutex_methods {
8369 int (*xMutexInit)(void);
8370 int (*xMutexEnd)(void);
8371 sqlite3_mutex *(*xMutexAlloc)(int);
8372 void (*xMutexFree)(sqlite3_mutex *);
8373 void (*xMutexEnter)(sqlite3_mutex *);
8374 int (*xMutexTry)(sqlite3_mutex *);
8375 void (*xMutexLeave)(sqlite3_mutex *);
8376 int (*xMutexHeld)(sqlite3_mutex *);
8377 int (*xMutexNotheld)(sqlite3_mutex *);
8378 };
8379 8380 /*
8381 ** CAPI3REF: Mutex Verification Routines
8382 **
8383 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8384 ** are intended for use inside assert() statements. The SQLite core
8385 ** never uses these routines except inside an assert() and applications
8386 ** are advised to follow the lead of the core. The SQLite core only
8387 ** provides implementations for these routines when it is compiled
8388 ** with the SQLITE_DEBUG flag. External mutex implementations
8389 ** are only required to provide these routines if SQLITE_DEBUG is
8390 ** defined and if NDEBUG is not defined.
8391 **
8392 ** These routines should return true if the mutex in their argument
8393 ** is held or not held, respectively, by the calling thread.
8394 **
8395 ** The implementation is not required to provide versions of these
8396 ** routines that actually work. If the implementation does not provide working
8397 ** versions of these routines, it should at least provide stubs that always
8398 ** return true so that one does not get spurious assertion failures.
8399 **
8400 ** If the argument to sqlite3_mutex_held() is a NULL pointer then
8401 ** the routine should return 1. This seems counter-intuitive since
8402 ** clearly the mutex cannot be held if it does not exist. But
8403 ** the reason the mutex does not exist is because the build is not
8404 ** using mutexes. And we do not want the assert() containing the
8405 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
8406 ** the appropriate thing to do. The sqlite3_mutex_notheld()
8407 ** interface should also return 1 when given a NULL pointer.
8408 */
8409 #ifndef NDEBUG
8410 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8411 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8412 #endif
8413 8414 /*
8415 ** CAPI3REF: Mutex Types
8416 **
8417 ** The [sqlite3_mutex_alloc()] interface takes a single argument
8418 ** which is one of these integer constants.
8419 **
8420 ** The set of static mutexes may change from one SQLite release to the
8421 ** next. Applications that override the built-in mutex logic must be
8422 ** prepared to accommodate additional static mutexes.
8423 */
8424 #define SQLITE_MUTEX_FAST 0
8425 #define SQLITE_MUTEX_RECURSIVE 1
8426 #define SQLITE_MUTEX_STATIC_MAIN 2
8427 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8428 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8429 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8430 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8431 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8432 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8433 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8434 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8435 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8436 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8437 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8438 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8439 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8440 8441 /* Legacy compatibility: */
8442 #define SQLITE_MUTEX_STATIC_MASTER 2
8443 8444 8445 /*
8446 ** CAPI3REF: Retrieve the mutex for a database connection
8447 ** METHOD: sqlite3
8448 **
8449 ** ^This interface returns a pointer to the [sqlite3_mutex] object that
8450 ** serializes access to the [database connection] given in the argument
8451 ** when the [threading mode] is Serialized.
8452 ** ^If the [threading mode] is Single-thread or Multi-thread then this
8453 ** routine returns a NULL pointer.
8454 */
8455 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8456 8457 /*
8458 ** CAPI3REF: Low-Level Control Of Database Files
8459 ** METHOD: sqlite3
8460 ** KEYWORDS: {file control}
8461 **
8462 ** ^The [sqlite3_file_control()] interface makes a direct call to the
8463 ** xFileControl method for the [sqlite3_io_methods] object associated
8464 ** with a particular database identified by the second argument. ^The
8465 ** name of the database is "main" for the main database or "temp" for the
8466 ** TEMP database, or the name that appears after the AS keyword for
8467 ** databases that are added using the [ATTACH] SQL command.
8468 ** ^A NULL pointer can be used in place of "main" to refer to the
8469 ** main database file.
8470 ** ^The third and fourth parameters to this routine
8471 ** are passed directly through to the second and third parameters of
8472 ** the xFileControl method. ^The return value of the xFileControl
8473 ** method becomes the return value of this routine.
8474 **
8475 ** A few opcodes for [sqlite3_file_control()] are handled directly
8476 ** by the SQLite core and never invoke the
8477 ** sqlite3_io_methods.xFileControl method.
8478 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8479 ** a pointer to the underlying [sqlite3_file] object to be written into
8480 ** the space pointed to by the 4th parameter. The
8481 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8482 ** the [sqlite3_file] object associated with the journal file instead of
8483 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8484 ** a pointer to the underlying [sqlite3_vfs] object for the file.
8485 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8486 ** from the pager.
8487 **
8488 ** ^If the second parameter (zDbName) does not match the name of any
8489 ** open database file, then SQLITE_ERROR is returned. ^This error
8490 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
8491 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
8492 ** also return SQLITE_ERROR. There is no way to distinguish between
8493 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8494 ** xFileControl method.
8495 **
8496 ** See also: [file control opcodes]
8497 */
8498 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8499 8500 /*
8501 ** CAPI3REF: Testing Interface
8502 **
8503 ** ^The sqlite3_test_control() interface is used to read out internal
8504 ** state of SQLite and to inject faults into SQLite for testing
8505 ** purposes. ^The first parameter is an operation code that determines
8506 ** the number, meaning, and operation of all subsequent parameters.
8507 **
8508 ** This interface is not for use by applications. It exists solely
8509 ** for verifying the correct operation of the SQLite library. Depending
8510 ** on how the SQLite library is compiled, this interface might not exist.
8511 **
8512 ** The details of the operation codes, their meanings, the parameters
8513 ** they take, and what they do are all subject to change without notice.
8514 ** Unlike most of the SQLite API, this function is not guaranteed to
8515 ** operate consistently from one release to the next.
8516 */
8517 SQLITE_API int sqlite3_test_control(int op, ...);
8518 8519 /*
8520 ** CAPI3REF: Testing Interface Operation Codes
8521 **
8522 ** These constants are the valid operation code parameters used
8523 ** as the first argument to [sqlite3_test_control()].
8524 **
8525 ** These parameters and their meanings are subject to change
8526 ** without notice. These values are for testing purposes only.
8527 ** Applications should not use any of these parameters or the
8528 ** [sqlite3_test_control()] interface.
8529 */
8530 #define SQLITE_TESTCTRL_FIRST 5
8531 #define SQLITE_TESTCTRL_PRNG_SAVE 5
8532 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
8533 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8534 #define SQLITE_TESTCTRL_FK_NO_ACTION 7
8535 #define SQLITE_TESTCTRL_BITVEC_TEST 8
8536 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
8537 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8538 #define SQLITE_TESTCTRL_PENDING_BYTE 11
8539 #define SQLITE_TESTCTRL_ASSERT 12
8540 #define SQLITE_TESTCTRL_ALWAYS 13
8541 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8542 #define SQLITE_TESTCTRL_JSON_SELFCHECK 14
8543 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8544 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8545 #define SQLITE_TESTCTRL_GETOPT 16
8546 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8547 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8548 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8549 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8550 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8551 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8552 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8553 #define SQLITE_TESTCTRL_BYTEORDER 22
8554 #define SQLITE_TESTCTRL_ISINIT 23
8555 #define SQLITE_TESTCTRL_SORTER_MMAP 24
8556 #define SQLITE_TESTCTRL_IMPOSTER 25
8557 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8558 #define SQLITE_TESTCTRL_RESULT_INTREAL 27
8559 #define SQLITE_TESTCTRL_PRNG_SEED 28
8560 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8561 #define SQLITE_TESTCTRL_SEEK_COUNT 30
8562 #define SQLITE_TESTCTRL_TRACEFLAGS 31
8563 #define SQLITE_TESTCTRL_TUNE 32
8564 #define SQLITE_TESTCTRL_LOGEST 33
8565 #define SQLITE_TESTCTRL_USELONGDOUBLE 34 /* NOT USED */
8566 #define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8567 8568 /*
8569 ** CAPI3REF: SQL Keyword Checking
8570 **
8571 ** These routines provide access to the set of SQL language keywords
8572 ** recognized by SQLite. Applications can use these routines to determine
8573 ** whether or not a specific identifier needs to be escaped (for example,
8574 ** by enclosing in double-quotes) so as not to confuse the parser.
8575 **
8576 ** The sqlite3_keyword_count() interface returns the number of distinct
8577 ** keywords understood by SQLite.
8578 **
8579 ** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
8580 ** makes *Z point to that keyword expressed as UTF8 and writes the number
8581 ** of bytes in the keyword into *L. The string that *Z points to is not
8582 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8583 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8584 ** or L are NULL or invalid pointers then calls to
8585 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8586 **
8587 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8588 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8589 ** if it is and zero if not.
8590 **
8591 ** The parser used by SQLite is forgiving. It is often possible to use
8592 ** a keyword as an identifier as long as such use does not result in a
8593 ** parsing ambiguity. For example, the statement
8594 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8595 ** creates a new table named "BEGIN" with three columns named
8596 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8597 ** using keywords as identifiers. Common techniques used to avoid keyword
8598 ** name collisions include:
8599 ** <ul>
8600 ** <li> Put all identifier names inside double-quotes. This is the official
8601 ** SQL way to escape identifier names.
8602 ** <li> Put identifier names inside [...]. This is not standard SQL,
8603 ** but it is what SQL Server does and so lots of programmers use this
8604 ** technique.
8605 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8606 ** with "Z".
8607 ** <li> Include a digit somewhere in every identifier name.
8608 ** </ul>
8609 **
8610 ** Note that the number of keywords understood by SQLite can depend on
8611 ** compile-time options. For example, "VACUUM" is not a keyword if
8612 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8613 ** new keywords may be added to future releases of SQLite.
8614 */
8615 SQLITE_API int sqlite3_keyword_count(void);
8616 SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8617 SQLITE_API int sqlite3_keyword_check(const char*,int);
8618 8619 /*
8620 ** CAPI3REF: Dynamic String Object
8621 ** KEYWORDS: {dynamic string}
8622 **
8623 ** An instance of the sqlite3_str object contains a dynamically-sized
8624 ** string under construction.
8625 **
8626 ** The lifecycle of an sqlite3_str object is as follows:
8627 ** <ol>
8628 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8629 ** <li> ^Text is appended to the sqlite3_str object using various
8630 ** methods, such as [sqlite3_str_appendf()].
8631 ** <li> ^The sqlite3_str object is destroyed and the string it created
8632 ** is returned using the [sqlite3_str_finish()] interface.
8633 ** </ol>
8634 */
8635 typedef struct sqlite3_str sqlite3_str;
8636 8637 /*
8638 ** CAPI3REF: Create A New Dynamic String Object
8639 ** CONSTRUCTOR: sqlite3_str
8640 **
8641 ** ^The [sqlite3_str_new(D)] interface allocates and initializes
8642 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8643 ** [sqlite3_str_new()] must be freed by a subsequent call to
8644 ** [sqlite3_str_finish(X)].
8645 **
8646 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8647 ** valid [sqlite3_str] object, though in the event of an out-of-memory
8648 ** error the returned object might be a special singleton that will
8649 ** silently reject new text, always return SQLITE_NOMEM from
8650 ** [sqlite3_str_errcode()], always return 0 for
8651 ** [sqlite3_str_length()], and always return NULL from
8652 ** [sqlite3_str_finish(X)]. It is always safe to use the value
8653 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8654 ** to any of the other [sqlite3_str] methods.
8655 **
8656 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8657 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8658 ** length of the string contained in the [sqlite3_str] object will be
8659 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8660 ** of [SQLITE_MAX_LENGTH].
8661 */
8662 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8663 8664 /*
8665 ** CAPI3REF: Finalize A Dynamic String
8666 ** DESTRUCTOR: sqlite3_str
8667 **
8668 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8669 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8670 ** that contains the constructed string. The calling application should
8671 ** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8672 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8673 ** errors were encountered during construction of the string. ^The
8674 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8675 ** string in [sqlite3_str] object X is zero bytes long.
8676 */
8677 SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8678 8679 /*
8680 ** CAPI3REF: Add Content To A Dynamic String
8681 ** METHOD: sqlite3_str
8682 **
8683 ** These interfaces add content to an sqlite3_str object previously obtained
8684 ** from [sqlite3_str_new()].
8685 **
8686 ** ^The [sqlite3_str_appendf(X,F,...)] and
8687 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8688 ** functionality of SQLite to append formatted text onto the end of
8689 ** [sqlite3_str] object X.
8690 **
8691 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8692 ** onto the end of the [sqlite3_str] object X. N must be non-negative.
8693 ** S must contain at least N non-zero bytes of content. To append a
8694 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8695 ** method instead.
8696 **
8697 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8698 ** zero-terminated string S onto the end of [sqlite3_str] object X.
8699 **
8700 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8701 ** single-byte character C onto the end of [sqlite3_str] object X.
8702 ** ^This method can be used, for example, to add whitespace indentation.
8703 **
8704 ** ^The [sqlite3_str_reset(X)] method resets the string under construction
8705 ** inside [sqlite3_str] object X back to zero bytes in length.
8706 **
8707 ** These methods do not return a result code. ^If an error occurs, that fact
8708 ** is recorded in the [sqlite3_str] object and can be recovered by a
8709 ** subsequent call to [sqlite3_str_errcode(X)].
8710 */
8711 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8712 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8713 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8714 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8715 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8716 SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8717 8718 /*
8719 ** CAPI3REF: Status Of A Dynamic String
8720 ** METHOD: sqlite3_str
8721 **
8722 ** These interfaces return the current status of an [sqlite3_str] object.
8723 **
8724 ** ^If any prior errors have occurred while constructing the dynamic string
8725 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8726 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8727 ** [SQLITE_NOMEM] following any out-of-memory error, or
8728 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8729 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8730 **
8731 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8732 ** of the dynamic string under construction in [sqlite3_str] object X.
8733 ** ^The length returned by [sqlite3_str_length(X)] does not include the
8734 ** zero-termination byte.
8735 **
8736 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8737 ** content of the dynamic string under construction in X. The value
8738 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8739 ** and might be freed or altered by any subsequent method on the same
8740 ** [sqlite3_str] object. Applications must not use the pointer returned by
8741 ** [sqlite3_str_value(X)] after any subsequent method call on the same
8742 ** object. ^Applications may change the content of the string returned
8743 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8744 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8745 ** write any byte after any subsequent sqlite3_str method call.
8746 */
8747 SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8748 SQLITE_API int sqlite3_str_length(sqlite3_str*);
8749 SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8750 8751 /*
8752 ** CAPI3REF: SQLite Runtime Status
8753 **
8754 ** ^These interfaces are used to retrieve runtime status information
8755 ** about the performance of SQLite, and optionally to reset various
8756 ** highwater marks. ^The first argument is an integer code for
8757 ** the specific parameter to measure. ^(Recognized integer codes
8758 ** are of the form [status parameters | SQLITE_STATUS_...].)^
8759 ** ^The current value of the parameter is returned into *pCurrent.
8760 ** ^The highest recorded value is returned in *pHighwater. ^If the
8761 ** resetFlag is true, then the highest record value is reset after
8762 ** *pHighwater is written. ^(Some parameters do not record the highest
8763 ** value. For those parameters
8764 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
8765 ** ^(Other parameters record only the highwater mark and not the current
8766 ** value. For these latter parameters nothing is written into *pCurrent.)^
8767 **
8768 ** ^The sqlite3_status() and sqlite3_status64() routines return
8769 ** SQLITE_OK on success and a non-zero [error code] on failure.
8770 **
8771 ** If either the current value or the highwater mark is too large to
8772 ** be represented by a 32-bit integer, then the values returned by
8773 ** sqlite3_status() are undefined.
8774 **
8775 ** See also: [sqlite3_db_status()]
8776 */
8777 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8778 SQLITE_API int sqlite3_status64(
8779 int op,
8780 sqlite3_int64 *pCurrent,
8781 sqlite3_int64 *pHighwater,
8782 int resetFlag
8783 );
8784 8785 8786 /*
8787 ** CAPI3REF: Status Parameters
8788 ** KEYWORDS: {status parameters}
8789 **
8790 ** These integer constants designate various run-time status parameters
8791 ** that can be returned by [sqlite3_status()].
8792 **
8793 ** <dl>
8794 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8795 ** <dd>This parameter is the current amount of memory checked out
8796 ** using [sqlite3_malloc()], either directly or indirectly. The
8797 ** figure includes calls made to [sqlite3_malloc()] by the application
8798 ** and internal memory usage by the SQLite library. Auxiliary page-cache
8799 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8800 ** this parameter. The amount returned is the sum of the allocation
8801 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8802 **
8803 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8804 ** <dd>This parameter records the largest memory allocation request
8805 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8806 ** internal equivalents). Only the value returned in the
8807 ** *pHighwater parameter to [sqlite3_status()] is of interest.
8808 ** The value written into the *pCurrent parameter is undefined.</dd>)^
8809 **
8810 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8811 ** <dd>This parameter records the number of separate memory allocations
8812 ** currently checked out.</dd>)^
8813 **
8814 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8815 ** <dd>This parameter returns the number of pages used out of the
8816 ** [pagecache memory allocator] that was configured using
8817 ** [SQLITE_CONFIG_PAGECACHE]. The
8818 ** value returned is in pages, not in bytes.</dd>)^
8819 **
8820 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8821 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8822 ** <dd>This parameter returns the number of bytes of page cache
8823 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8824 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
8825 ** returned value includes allocations that overflowed because they
8826 ** were too large (they were larger than the "sz" parameter to
8827 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8828 ** no space was left in the page cache.</dd>)^
8829 **
8830 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8831 ** <dd>This parameter records the largest memory allocation request
8832 ** handed to the [pagecache memory allocator]. Only the value returned in the
8833 ** *pHighwater parameter to [sqlite3_status()] is of interest.
8834 ** The value written into the *pCurrent parameter is undefined.</dd>)^
8835 **
8836 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8837 ** <dd>No longer used.</dd>
8838 **
8839 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8840 ** <dd>No longer used.</dd>
8841 **
8842 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8843 ** <dd>No longer used.</dd>
8844 **
8845 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8846 ** <dd>The *pHighwater parameter records the deepest parser stack.
8847 ** The *pCurrent value is undefined. The *pHighwater value is only
8848 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8849 ** </dl>
8850 **
8851 ** New status parameters may be added from time to time.
8852 */
8853 #define SQLITE_STATUS_MEMORY_USED 0
8854 #define SQLITE_STATUS_PAGECACHE_USED 1
8855 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8856 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8857 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8858 #define SQLITE_STATUS_MALLOC_SIZE 5
8859 #define SQLITE_STATUS_PARSER_STACK 6
8860 #define SQLITE_STATUS_PAGECACHE_SIZE 7
8861 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8862 #define SQLITE_STATUS_MALLOC_COUNT 9
8863 8864 /*
8865 ** CAPI3REF: Database Connection Status
8866 ** METHOD: sqlite3
8867 **
8868 ** ^This interface is used to retrieve runtime status information
8869 ** about a single [database connection]. ^The first argument is the
8870 ** database connection object to be interrogated. ^The second argument
8871 ** is an integer constant, taken from the set of
8872 ** [SQLITE_DBSTATUS options], that
8873 ** determines the parameter to interrogate. The set of
8874 ** [SQLITE_DBSTATUS options] is likely
8875 ** to grow in future releases of SQLite.
8876 **
8877 ** ^The current value of the requested parameter is written into *pCur
8878 ** and the highest instantaneous value is written into *pHiwtr. ^If
8879 ** the resetFlg is true, then the highest instantaneous value is
8880 ** reset back down to the current value.
8881 **
8882 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8883 ** non-zero [error code] on failure.
8884 **
8885 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8886 */
8887 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8888 8889 /*
8890 ** CAPI3REF: Status Parameters for database connections
8891 ** KEYWORDS: {SQLITE_DBSTATUS options}
8892 **
8893 ** These constants are the available integer "verbs" that can be passed as
8894 ** the second argument to the [sqlite3_db_status()] interface.
8895 **
8896 ** New verbs may be added in future releases of SQLite. Existing verbs
8897 ** might be discontinued. Applications should check the return code from
8898 ** [sqlite3_db_status()] to make sure that the call worked.
8899 ** The [sqlite3_db_status()] interface will return a non-zero error code
8900 ** if a discontinued or unsupported verb is invoked.
8901 **
8902 ** <dl>
8903 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8904 ** <dd>This parameter returns the number of lookaside memory slots currently
8905 ** checked out.</dd>)^
8906 **
8907 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8908 ** <dd>This parameter returns the number of malloc attempts that were
8909 ** satisfied using lookaside memory. Only the high-water value is meaningful;
8910 ** the current value is always zero.</dd>)^
8911 **
8912 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8913 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8914 ** <dd>This parameter returns the number of malloc attempts that might have
8915 ** been satisfied using lookaside memory but failed due to the amount of
8916 ** memory requested being larger than the lookaside slot size.
8917 ** Only the high-water value is meaningful;
8918 ** the current value is always zero.</dd>)^
8919 **
8920 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8921 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8922 ** <dd>This parameter returns the number of malloc attempts that might have
8923 ** been satisfied using lookaside memory but failed due to all lookaside
8924 ** memory already being in use.
8925 ** Only the high-water value is meaningful;
8926 ** the current value is always zero.</dd>)^
8927 **
8928 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8929 ** <dd>This parameter returns the approximate number of bytes of heap
8930 ** memory used by all pager caches associated with the database connection.)^
8931 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8932 ** </dd>
8933 **
8934 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8935 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8936 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8937 ** pager cache is shared between two or more connections the bytes of heap
8938 ** memory used by that pager cache is divided evenly between the attached
8939 ** connections.)^ In other words, if none of the pager caches associated
8940 ** with the database connection are shared, this request returns the same
8941 ** value as DBSTATUS_CACHE_USED. Or, if one or more of the pager caches are
8942 ** shared, the value returned by this call will be smaller than that returned
8943 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8944 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</dd>
8945 **
8946 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8947 ** <dd>This parameter returns the approximate number of bytes of heap
8948 ** memory used to store the schema for all databases associated
8949 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8950 ** ^The full amount of memory used by the schemas is reported, even if the
8951 ** schema memory is shared with other database connections due to
8952 ** [shared cache mode] being enabled.
8953 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8954 ** </dd>
8955 **
8956 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8957 ** <dd>This parameter returns the approximate number of bytes of heap
8958 ** and lookaside memory used by all prepared statements associated with
8959 ** the database connection.)^
8960 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8961 ** </dd>
8962 **
8963 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8964 ** <dd>This parameter returns the number of pager cache hits that have
8965 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8966 ** is always 0.
8967 ** </dd>
8968 **
8969 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8970 ** <dd>This parameter returns the number of pager cache misses that have
8971 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8972 ** is always 0.
8973 ** </dd>
8974 **
8975 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8976 ** <dd>This parameter returns the number of dirty cache entries that have
8977 ** been written to disk. Specifically, the number of pages written to the
8978 ** wal file in wal mode databases, or the number of pages written to the
8979 ** database file in rollback mode databases. Any pages written as part of
8980 ** transaction rollback or database recovery operations are not included.
8981 ** If an IO or other error occurs while writing a page to disk, the effect
8982 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8983 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8984 ** </dd>
8985 **
8986 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8987 ** <dd>This parameter returns the number of dirty cache entries that have
8988 ** been written to disk in the middle of a transaction due to the page
8989 ** cache overflowing. Transactions are more efficient if they are written
8990 ** to disk all at once. When pages spill mid-transaction, that introduces
8991 ** additional overhead. This parameter can be used to help identify
8992 ** inefficiencies that can be resolved by increasing the cache size.
8993 ** </dd>
8994 **
8995 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8996 ** <dd>This parameter returns zero for the current value if and only if
8997 ** all foreign key constraints (deferred or immediate) have been
8998 ** resolved.)^ ^The highwater mark is always 0.
8999 ** </dd>
9000 ** </dl>
9001 */
9002 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
9003 #define SQLITE_DBSTATUS_CACHE_USED 1
9004 #define SQLITE_DBSTATUS_SCHEMA_USED 2
9005 #define SQLITE_DBSTATUS_STMT_USED 3
9006 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
9007 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
9008 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
9009 #define SQLITE_DBSTATUS_CACHE_HIT 7
9010 #define SQLITE_DBSTATUS_CACHE_MISS 8
9011 #define SQLITE_DBSTATUS_CACHE_WRITE 9
9012 #define SQLITE_DBSTATUS_DEFERRED_FKS 10
9013 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
9014 #define SQLITE_DBSTATUS_CACHE_SPILL 12
9015 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
9016 9017 9018 /*
9019 ** CAPI3REF: Prepared Statement Status
9020 ** METHOD: sqlite3_stmt
9021 **
9022 ** ^(Each prepared statement maintains various
9023 ** [SQLITE_STMTSTATUS counters] that measure the number
9024 ** of times it has performed specific operations.)^ These counters can
9025 ** be used to monitor the performance characteristics of the prepared
9026 ** statements. For example, if the number of table steps greatly exceeds
9027 ** the number of table searches or result rows, that would tend to indicate
9028 ** that the prepared statement is using a full table scan rather than
9029 ** an index.
9030 **
9031 ** ^(This interface is used to retrieve and reset counter values from
9032 ** a [prepared statement]. The first argument is the prepared statement
9033 ** object to be interrogated. The second argument
9034 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
9035 ** to be interrogated.)^
9036 ** ^The current value of the requested counter is returned.
9037 ** ^If the resetFlg is true, then the counter is reset to zero after this
9038 ** interface call returns.
9039 **
9040 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
9041 */
9042 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
9043 9044 /*
9045 ** CAPI3REF: Status Parameters for prepared statements
9046 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
9047 **
9048 ** These preprocessor macros define integer codes that name counter
9049 ** values associated with the [sqlite3_stmt_status()] interface.
9050 ** The meanings of the various counters are as follows:
9051 **
9052 ** <dl>
9053 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
9054 ** <dd>^This is the number of times that SQLite has stepped forward in
9055 ** a table as part of a full table scan. Large numbers for this counter
9056 ** may indicate opportunities for performance improvement through
9057 ** careful use of indices.</dd>
9058 **
9059 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
9060 ** <dd>^This is the number of sort operations that have occurred.
9061 ** A non-zero value in this counter may indicate an opportunity to
9062 ** improve performance through careful use of indices.</dd>
9063 **
9064 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
9065 ** <dd>^This is the number of rows inserted into transient indices that
9066 ** were created automatically in order to help joins run faster.
9067 ** A non-zero value in this counter may indicate an opportunity to
9068 ** improve performance by adding permanent indices that do not
9069 ** need to be reinitialized each time the statement is run.</dd>
9070 **
9071 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
9072 ** <dd>^This is the number of virtual machine operations executed
9073 ** by the prepared statement if that number is less than or equal
9074 ** to 2147483647. The number of virtual machine operations can be
9075 ** used as a proxy for the total work done by the prepared statement.
9076 ** If the number of virtual machine operations exceeds 2147483647
9077 ** then the value returned by this statement status code is undefined.</dd>
9078 **
9079 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
9080 ** <dd>^This is the number of times that the prepare statement has been
9081 ** automatically regenerated due to schema changes or changes to
9082 ** [bound parameters] that might affect the query plan.</dd>
9083 **
9084 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
9085 ** <dd>^This is the number of times that the prepared statement has
9086 ** been run. A single "run" for the purposes of this counter is one
9087 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
9088 ** The counter is incremented on the first [sqlite3_step()] call of each
9089 ** cycle.</dd>
9090 **
9091 ** [[SQLITE_STMTSTATUS_FILTER_MISS]]
9092 ** [[SQLITE_STMTSTATUS_FILTER HIT]]
9093 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
9094 ** SQLITE_STMTSTATUS_FILTER_MISS</dt>
9095 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
9096 ** step was bypassed because a Bloom filter returned not-found. The
9097 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
9098 ** times that the Bloom filter returned a find, and thus the join step
9099 ** had to be processed as normal.</dd>
9100 **
9101 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
9102 ** <dd>^This is the approximate number of bytes of heap memory
9103 ** used to store the prepared statement. ^This value is not actually
9104 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
9105 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
9106 ** </dd>
9107 ** </dl>
9108 */
9109 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
9110 #define SQLITE_STMTSTATUS_SORT 2
9111 #define SQLITE_STMTSTATUS_AUTOINDEX 3
9112 #define SQLITE_STMTSTATUS_VM_STEP 4
9113 #define SQLITE_STMTSTATUS_REPREPARE 5
9114 #define SQLITE_STMTSTATUS_RUN 6
9115 #define SQLITE_STMTSTATUS_FILTER_MISS 7
9116 #define SQLITE_STMTSTATUS_FILTER_HIT 8
9117 #define SQLITE_STMTSTATUS_MEMUSED 99
9118 9119 /*
9120 ** CAPI3REF: Custom Page Cache Object
9121 **
9122 ** The sqlite3_pcache type is opaque. It is implemented by
9123 ** the pluggable module. The SQLite core has no knowledge of
9124 ** its size or internal structure and never deals with the
9125 ** sqlite3_pcache object except by holding and passing pointers
9126 ** to the object.
9127 **
9128 ** See [sqlite3_pcache_methods2] for additional information.
9129 */
9130 typedef struct sqlite3_pcache sqlite3_pcache;
9131 9132 /*
9133 ** CAPI3REF: Custom Page Cache Object
9134 **
9135 ** The sqlite3_pcache_page object represents a single page in the
9136 ** page cache. The page cache will allocate instances of this
9137 ** object. Various methods of the page cache use pointers to instances
9138 ** of this object as parameters or as their return value.
9139 **
9140 ** See [sqlite3_pcache_methods2] for additional information.
9141 */
9142 typedef struct sqlite3_pcache_page sqlite3_pcache_page;
9143 struct sqlite3_pcache_page {
9144 void *pBuf; /* The content of the page */
9145 void *pExtra; /* Extra information associated with the page */
9146 };
9147 9148 /*
9149 ** CAPI3REF: Application Defined Page Cache.
9150 ** KEYWORDS: {page cache}
9151 **
9152 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
9153 ** register an alternative page cache implementation by passing in an
9154 ** instance of the sqlite3_pcache_methods2 structure.)^
9155 ** In many applications, most of the heap memory allocated by
9156 ** SQLite is used for the page cache.
9157 ** By implementing a
9158 ** custom page cache using this API, an application can better control
9159 ** the amount of memory consumed by SQLite, the way in which
9160 ** that memory is allocated and released, and the policies used to
9161 ** determine exactly which parts of a database file are cached and for
9162 ** how long.
9163 **
9164 ** The alternative page cache mechanism is an
9165 ** extreme measure that is only needed by the most demanding applications.
9166 ** The built-in page cache is recommended for most uses.
9167 **
9168 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
9169 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
9170 ** the application may discard the parameter after the call to
9171 ** [sqlite3_config()] returns.)^
9172 **
9173 ** [[the xInit() page cache method]]
9174 ** ^(The xInit() method is called once for each effective
9175 ** call to [sqlite3_initialize()])^
9176 ** (usually only once during the lifetime of the process). ^(The xInit()
9177 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
9178 ** The intent of the xInit() method is to set up global data structures
9179 ** required by the custom page cache implementation.
9180 ** ^(If the xInit() method is NULL, then the
9181 ** built-in default page cache is used instead of the application defined
9182 ** page cache.)^
9183 **
9184 ** [[the xShutdown() page cache method]]
9185 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
9186 ** It can be used to clean up
9187 ** any outstanding resources before process shutdown, if required.
9188 ** ^The xShutdown() method may be NULL.
9189 **
9190 ** ^SQLite automatically serializes calls to the xInit method,
9191 ** so the xInit method need not be threadsafe. ^The
9192 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
9193 ** not need to be threadsafe either. All other methods must be threadsafe
9194 ** in multithreaded applications.
9195 **
9196 ** ^SQLite will never invoke xInit() more than once without an intervening
9197 ** call to xShutdown().
9198 **
9199 ** [[the xCreate() page cache methods]]
9200 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
9201 ** SQLite will typically create one cache instance for each open database file,
9202 ** though this is not guaranteed. ^The
9203 ** first parameter, szPage, is the size in bytes of the pages that must
9204 ** be allocated by the cache. ^szPage will always be a power of two. ^The
9205 ** second parameter szExtra is a number of bytes of extra storage
9206 ** associated with each page cache entry. ^The szExtra parameter will be
9207 ** a number less than 250. SQLite will use the
9208 ** extra szExtra bytes on each page to store metadata about the underlying
9209 ** database page on disk. The value passed into szExtra depends
9210 ** on the SQLite version, the target platform, and how SQLite was compiled.
9211 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
9212 ** created will be used to cache database pages of a file stored on disk, or
9213 ** false if it is used for an in-memory database. The cache implementation
9214 ** does not have to do anything special based upon the value of bPurgeable;
9215 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
9216 ** never invoke xUnpin() except to deliberately delete a page.
9217 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
9218 ** false will always have the "discard" flag set to true.
9219 ** ^Hence, a cache created with bPurgeable set to false will
9220 ** never contain any unpinned pages.
9221 **
9222 ** [[the xCachesize() page cache method]]
9223 ** ^(The xCachesize() method may be called at any time by SQLite to set the
9224 ** suggested maximum cache-size (number of pages stored) for the cache
9225 ** instance passed as the first argument. This is the value configured using
9226 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
9227 ** parameter, the implementation is not required to do anything with this
9228 ** value; it is advisory only.
9229 **
9230 ** [[the xPagecount() page cache methods]]
9231 ** The xPagecount() method must return the number of pages currently
9232 ** stored in the cache, both pinned and unpinned.
9233 **
9234 ** [[the xFetch() page cache methods]]
9235 ** The xFetch() method locates a page in the cache and returns a pointer to
9236 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
9237 ** The pBuf element of the returned sqlite3_pcache_page object will be a
9238 ** pointer to a buffer of szPage bytes used to store the content of a
9239 ** single database page. The pExtra element of sqlite3_pcache_page will be
9240 ** a pointer to the szExtra bytes of extra storage that SQLite has requested
9241 ** for each entry in the page cache.
9242 **
9243 ** The page to be fetched is determined by the key. ^The minimum key value
9244 ** is 1. After it has been retrieved using xFetch, the page is considered
9245 ** to be "pinned".
9246 **
9247 ** If the requested page is already in the page cache, then the page cache
9248 ** implementation must return a pointer to the page buffer with its content
9249 ** intact. If the requested page is not already in the cache, then the
9250 ** cache implementation should use the value of the createFlag
9251 ** parameter to help it determine what action to take:
9252 **
9253 ** <table border=1 width=85% align=center>
9254 ** <tr><th> createFlag <th> Behavior when page is not already in cache
9255 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
9256 ** <tr><td> 1 <td> Allocate a new page if it is easy and convenient to do so.
9257 ** Otherwise return NULL.
9258 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
9259 ** NULL if allocating a new page is effectively impossible.
9260 ** </table>
9261 **
9262 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
9263 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
9264 ** failed.)^ In between the xFetch() calls, SQLite may
9265 ** attempt to unpin one or more cache pages by spilling the content of
9266 ** pinned pages to disk and synching the operating system disk cache.
9267 **
9268 ** [[the xUnpin() page cache method]]
9269 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
9270 ** as its second argument. If the third parameter, discard, is non-zero,
9271 ** then the page must be evicted from the cache.
9272 ** ^If the discard parameter is
9273 ** zero, then the page may be discarded or retained at the discretion of the
9274 ** page cache implementation. ^The page cache implementation
9275 ** may choose to evict unpinned pages at any time.
9276 **
9277 ** The cache must not perform any reference counting. A single
9278 ** call to xUnpin() unpins the page regardless of the number of prior calls
9279 ** to xFetch().
9280 **
9281 ** [[the xRekey() page cache methods]]
9282 ** The xRekey() method is used to change the key value associated with the
9283 ** page passed as the second argument. If the cache
9284 ** previously contains an entry associated with newKey, it must be
9285 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
9286 ** to be pinned.
9287 **
9288 ** When SQLite calls the xTruncate() method, the cache must discard all
9289 ** existing cache entries with page numbers (keys) greater than or equal
9290 ** to the value of the iLimit parameter passed to xTruncate(). If any
9291 ** of these pages are pinned, they become implicitly unpinned, meaning that
9292 ** they can be safely discarded.
9293 **
9294 ** [[the xDestroy() page cache method]]
9295 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
9296 ** All resources associated with the specified cache should be freed. ^After
9297 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
9298 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
9299 ** functions.
9300 **
9301 ** [[the xShrink() page cache method]]
9302 ** ^SQLite invokes the xShrink() method when it wants the page cache to
9303 ** free up as much of heap memory as possible. The page cache implementation
9304 ** is not obligated to free any memory, but well-behaved implementations should
9305 ** do their best.
9306 */
9307 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
9308 struct sqlite3_pcache_methods2 {
9309 int iVersion;
9310 void *pArg;
9311 int (*xInit)(void*);
9312 void (*xShutdown)(void*);
9313 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
9314 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9315 int (*xPagecount)(sqlite3_pcache*);
9316 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9317 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
9318 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
9319 unsigned oldKey, unsigned newKey);
9320 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9321 void (*xDestroy)(sqlite3_pcache*);
9322 void (*xShrink)(sqlite3_pcache*);
9323 };
9324 9325 /*
9326 ** This is the obsolete pcache_methods object that has now been replaced
9327 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
9328 ** retained in the header file for backwards compatibility only.
9329 */
9330 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
9331 struct sqlite3_pcache_methods {
9332 void *pArg;
9333 int (*xInit)(void*);
9334 void (*xShutdown)(void*);
9335 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
9336 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9337 int (*xPagecount)(sqlite3_pcache*);
9338 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9339 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
9340 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
9341 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9342 void (*xDestroy)(sqlite3_pcache*);
9343 };
9344 9345 9346 /*
9347 ** CAPI3REF: Online Backup Object
9348 **
9349 ** The sqlite3_backup object records state information about an ongoing
9350 ** online backup operation. ^The sqlite3_backup object is created by
9351 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
9352 ** [sqlite3_backup_finish()].
9353 **
9354 ** See Also: [Using the SQLite Online Backup API]
9355 */
9356 typedef struct sqlite3_backup sqlite3_backup;
9357 9358 /*
9359 ** CAPI3REF: Online Backup API.
9360 **
9361 ** The backup API copies the content of one database into another.
9362 ** It is useful either for creating backups of databases or
9363 ** for copying in-memory databases to or from persistent files.
9364 **
9365 ** See Also: [Using the SQLite Online Backup API]
9366 **
9367 ** ^SQLite holds a write transaction open on the destination database file
9368 ** for the duration of the backup operation.
9369 ** ^The source database is read-locked only while it is being read;
9370 ** it is not locked continuously for the entire backup operation.
9371 ** ^Thus, the backup may be performed on a live source database without
9372 ** preventing other database connections from
9373 ** reading or writing to the source database while the backup is underway.
9374 **
9375 ** ^(To perform a backup operation:
9376 ** <ol>
9377 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9378 ** backup,
9379 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9380 ** the data between the two databases, and finally
9381 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9382 ** associated with the backup operation.
9383 ** </ol>)^
9384 ** There should be exactly one call to sqlite3_backup_finish() for each
9385 ** successful call to sqlite3_backup_init().
9386 **
9387 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9388 **
9389 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9390 ** [database connection] associated with the destination database
9391 ** and the database name, respectively.
9392 ** ^The database name is "main" for the main database, "temp" for the
9393 ** temporary database, or the name specified after the AS keyword in
9394 ** an [ATTACH] statement for an attached database.
9395 ** ^The S and M arguments passed to
9396 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9397 ** and database name of the source database, respectively.
9398 ** ^The source and destination [database connections] (parameters S and D)
9399 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9400 ** an error.
9401 **
9402 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9403 ** there is already a read or read-write transaction open on the
9404 ** destination database.
9405 **
9406 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9407 ** returned and an error code and error message are stored in the
9408 ** destination [database connection] D.
9409 ** ^The error code and message for the failed call to sqlite3_backup_init()
9410 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9411 ** [sqlite3_errmsg16()] functions.
9412 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
9413 ** [sqlite3_backup] object.
9414 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9415 ** sqlite3_backup_finish() functions to perform the specified backup
9416 ** operation.
9417 **
9418 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9419 **
9420 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9421 ** the source and destination databases specified by [sqlite3_backup] object B.
9422 ** ^If N is negative, all remaining source pages are copied.
9423 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9424 ** are still more pages to be copied, then the function returns [SQLITE_OK].
9425 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9426 ** from source to destination, then it returns [SQLITE_DONE].
9427 ** ^If an error occurs while running sqlite3_backup_step(B,N),
9428 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
9429 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9430 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9431 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9432 **
9433 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9434 ** <ol>
9435 ** <li> the destination database was opened read-only, or
9436 ** <li> the destination database is using write-ahead-log journaling
9437 ** and the destination and source page sizes differ, or
9438 ** <li> the destination database is an in-memory database and the
9439 ** destination and source page sizes differ.
9440 ** </ol>)^
9441 **
9442 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9443 ** the [sqlite3_busy_handler | busy-handler function]
9444 ** is invoked (if one is specified). ^If the
9445 ** busy-handler returns non-zero before the lock is available, then
9446 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9447 ** sqlite3_backup_step() can be retried later. ^If the source
9448 ** [database connection]
9449 ** is being used to write to the source database when sqlite3_backup_step()
9450 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9451 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
9452 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9453 ** [SQLITE_READONLY] is returned, then
9454 ** there is no point in retrying the call to sqlite3_backup_step(). These
9455 ** errors are considered fatal.)^ The application must accept
9456 ** that the backup operation has failed and pass the backup operation handle
9457 ** to the sqlite3_backup_finish() to release associated resources.
9458 **
9459 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9460 ** on the destination file. ^The exclusive lock is not released until either
9461 ** sqlite3_backup_finish() is called or the backup operation is complete
9462 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9463 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
9464 ** lasts for the duration of the sqlite3_backup_step() call.
9465 ** ^Because the source database is not locked between calls to
9466 ** sqlite3_backup_step(), the source database may be modified mid-way
9467 ** through the backup process. ^If the source database is modified by an
9468 ** external process or via a database connection other than the one being
9469 ** used by the backup operation, then the backup will be automatically
9470 ** restarted by the next call to sqlite3_backup_step(). ^If the source
9471 ** database is modified by using the same database connection as is used
9472 ** by the backup operation, then the backup database is automatically
9473 ** updated at the same time.
9474 **
9475 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9476 **
9477 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9478 ** application wishes to abandon the backup operation, the application
9479 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9480 ** ^The sqlite3_backup_finish() interfaces releases all
9481 ** resources associated with the [sqlite3_backup] object.
9482 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9483 ** active write-transaction on the destination database is rolled back.
9484 ** The [sqlite3_backup] object is invalid
9485 ** and may not be used following a call to sqlite3_backup_finish().
9486 **
9487 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9488 ** sqlite3_backup_step() errors occurred, regardless of whether or not
9489 ** sqlite3_backup_step() completed.
9490 ** ^If an out-of-memory condition or IO error occurred during any prior
9491 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9492 ** sqlite3_backup_finish() returns the corresponding [error code].
9493 **
9494 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9495 ** is not a permanent error and does not affect the return value of
9496 ** sqlite3_backup_finish().
9497 **
9498 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9499 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9500 **
9501 ** ^The sqlite3_backup_remaining() routine returns the number of pages still
9502 ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9503 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9504 ** in the source database at the conclusion of the most recent
9505 ** sqlite3_backup_step().
9506 ** ^(The values returned by these functions are only updated by
9507 ** sqlite3_backup_step(). If the source database is modified in a way that
9508 ** changes the size of the source database or the number of pages remaining,
9509 ** those changes are not reflected in the output of sqlite3_backup_pagecount()
9510 ** and sqlite3_backup_remaining() until after the next
9511 ** sqlite3_backup_step().)^
9512 **
9513 ** <b>Concurrent Usage of Database Handles</b>
9514 **
9515 ** ^The source [database connection] may be used by the application for other
9516 ** purposes while a backup operation is underway or being initialized.
9517 ** ^If SQLite is compiled and configured to support threadsafe database
9518 ** connections, then the source database connection may be used concurrently
9519 ** from within other threads.
9520 **
9521 ** However, the application must guarantee that the destination
9522 ** [database connection] is not passed to any other API (by any thread) after
9523 ** sqlite3_backup_init() is called and before the corresponding call to
9524 ** sqlite3_backup_finish(). SQLite does not currently check to see
9525 ** if the application incorrectly accesses the destination [database connection]
9526 ** and so no error code is reported, but the operations may malfunction
9527 ** nevertheless. Use of the destination database connection while a
9528 ** backup is in progress might also cause a mutex deadlock.
9529 **
9530 ** If running in [shared cache mode], the application must
9531 ** guarantee that the shared cache used by the destination database
9532 ** is not accessed while the backup is running. In practice this means
9533 ** that the application must guarantee that the disk file being
9534 ** backed up to is not accessed by any connection within the process,
9535 ** not just the specific connection that was passed to sqlite3_backup_init().
9536 **
9537 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9538 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9539 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9540 ** APIs are not strictly speaking threadsafe. If they are invoked at the
9541 ** same time as another thread is invoking sqlite3_backup_step() it is
9542 ** possible that they return invalid values.
9543 **
9544 ** <b>Alternatives To Using The Backup API</b>
9545 **
9546 ** Other techniques for safely creating a consistent backup of an SQLite
9547 ** database include:
9548 **
9549 ** <ul>
9550 ** <li> The [VACUUM INTO] command.
9551 ** <li> The [sqlite3_rsync] utility program.
9552 ** </ul>
9553 */
9554 SQLITE_API sqlite3_backup *sqlite3_backup_init(
9555 sqlite3 *pDest, /* Destination database handle */
9556 const char *zDestName, /* Destination database name */
9557 sqlite3 *pSource, /* Source database handle */
9558 const char *zSourceName /* Source database name */
9559 );
9560 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9561 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9562 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9563 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9564 9565 /*
9566 ** CAPI3REF: Unlock Notification
9567 ** METHOD: sqlite3
9568 **
9569 ** ^When running in shared-cache mode, a database operation may fail with
9570 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9571 ** individual tables within the shared-cache cannot be obtained. See
9572 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9573 ** ^This API may be used to register a callback that SQLite will invoke
9574 ** when the connection currently holding the required lock relinquishes it.
9575 ** ^This API is only available if the library was compiled with the
9576 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9577 **
9578 ** See Also: [Using the SQLite Unlock Notification Feature].
9579 **
9580 ** ^Shared-cache locks are released when a database connection concludes
9581 ** its current transaction, either by committing it or rolling it back.
9582 **
9583 ** ^When a connection (known as the blocked connection) fails to obtain a
9584 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9585 ** identity of the database connection (the blocking connection) that
9586 ** has locked the required resource is stored internally. ^After an
9587 ** application receives an SQLITE_LOCKED error, it may call the
9588 ** sqlite3_unlock_notify() method with the blocked connection handle as
9589 ** the first argument to register for a callback that will be invoked
9590 ** when the blocking connection's current transaction is concluded. ^The
9591 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9592 ** call that concludes the blocking connection's transaction.
9593 **
9594 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9595 ** there is a chance that the blocking connection will have already
9596 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9597 ** If this happens, then the specified callback is invoked immediately,
9598 ** from within the call to sqlite3_unlock_notify().)^
9599 **
9600 ** ^If the blocked connection is attempting to obtain a write-lock on a
9601 ** shared-cache table, and more than one other connection currently holds
9602 ** a read-lock on the same table, then SQLite arbitrarily selects one of
9603 ** the other connections to use as the blocking connection.
9604 **
9605 ** ^(There may be at most one unlock-notify callback registered by a
9606 ** blocked connection. If sqlite3_unlock_notify() is called when the
9607 ** blocked connection already has a registered unlock-notify callback,
9608 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9609 ** called with a NULL pointer as its second argument, then any existing
9610 ** unlock-notify callback is canceled. ^The blocked connection's
9611 ** unlock-notify callback may also be canceled by closing the blocked
9612 ** connection using [sqlite3_close()].
9613 **
9614 ** The unlock-notify callback is not reentrant. If an application invokes
9615 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
9616 ** crash or deadlock may be the result.
9617 **
9618 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9619 ** returns SQLITE_OK.
9620 **
9621 ** <b>Callback Invocation Details</b>
9622 **
9623 ** When an unlock-notify callback is registered, the application provides a
9624 ** single void* pointer that is passed to the callback when it is invoked.
9625 ** However, the signature of the callback function allows SQLite to pass
9626 ** it an array of void* context pointers. The first argument passed to
9627 ** an unlock-notify callback is a pointer to an array of void* pointers,
9628 ** and the second is the number of entries in the array.
9629 **
9630 ** When a blocking connection's transaction is concluded, there may be
9631 ** more than one blocked connection that has registered for an unlock-notify
9632 ** callback. ^If two or more such blocked connections have specified the
9633 ** same callback function, then instead of invoking the callback function
9634 ** multiple times, it is invoked once with the set of void* context pointers
9635 ** specified by the blocked connections bundled together into an array.
9636 ** This gives the application an opportunity to prioritize any actions
9637 ** related to the set of unblocked database connections.
9638 **
9639 ** <b>Deadlock Detection</b>
9640 **
9641 ** Assuming that after registering for an unlock-notify callback a
9642 ** database waits for the callback to be issued before taking any further
9643 ** action (a reasonable assumption), then using this API may cause the
9644 ** application to deadlock. For example, if connection X is waiting for
9645 ** connection Y's transaction to be concluded, and similarly connection
9646 ** Y is waiting on connection X's transaction, then neither connection
9647 ** will proceed and the system may remain deadlocked indefinitely.
9648 **
9649 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9650 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
9651 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9652 ** unlock-notify callback is registered. The system is said to be in
9653 ** a deadlocked state if connection A has registered for an unlock-notify
9654 ** callback on the conclusion of connection B's transaction, and connection
9655 ** B has itself registered for an unlock-notify callback when connection
9656 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
9657 ** the system is also considered to be deadlocked if connection B has
9658 ** registered for an unlock-notify callback on the conclusion of connection
9659 ** C's transaction, where connection C is waiting on connection A. ^Any
9660 ** number of levels of indirection are allowed.
9661 **
9662 ** <b>The "DROP TABLE" Exception</b>
9663 **
9664 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9665 ** always appropriate to call sqlite3_unlock_notify(). There is however,
9666 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9667 ** SQLite checks if there are any currently executing SELECT statements
9668 ** that belong to the same connection. If there are, SQLITE_LOCKED is
9669 ** returned. In this case there is no "blocking connection", so invoking
9670 ** sqlite3_unlock_notify() results in the unlock-notify callback being
9671 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
9672 ** or "DROP INDEX" query, an infinite loop might be the result.
9673 **
9674 ** One way around this problem is to check the extended error code returned
9675 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9676 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9677 ** the special "DROP TABLE/INDEX" case, the extended error code is just
9678 ** SQLITE_LOCKED.)^
9679 */
9680 SQLITE_API int sqlite3_unlock_notify(
9681 sqlite3 *pBlocked, /* Waiting connection */
9682 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9683 void *pNotifyArg /* Argument to pass to xNotify */
9684 );
9685 9686 9687 /*
9688 ** CAPI3REF: String Comparison
9689 **
9690 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9691 ** and extensions to compare the contents of two buffers containing UTF-8
9692 ** strings in a case-independent fashion, using the same definition of "case
9693 ** independence" that SQLite uses internally when comparing identifiers.
9694 */
9695 SQLITE_API int sqlite3_stricmp(const char *, const char *);
9696 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9697 9698 /*
9699 ** CAPI3REF: String Globbing
9700 *
9701 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9702 ** string X matches the [GLOB] pattern P.
9703 ** ^The definition of [GLOB] pattern matching used in
9704 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9705 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9706 ** is case sensitive.
9707 **
9708 ** Note that this routine returns zero on a match and non-zero if the strings
9709 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9710 **
9711 ** See also: [sqlite3_strlike()].
9712 */
9713 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9714 9715 /*
9716 ** CAPI3REF: String LIKE Matching
9717 *
9718 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9719 ** string X matches the [LIKE] pattern P with escape character E.
9720 ** ^The definition of [LIKE] pattern matching used in
9721 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9722 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9723 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9724 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9725 ** insensitive - equivalent upper and lower case ASCII characters match
9726 ** one another.
9727 **
9728 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9729 ** only ASCII characters are case folded.
9730 **
9731 ** Note that this routine returns zero on a match and non-zero if the strings
9732 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9733 **
9734 ** See also: [sqlite3_strglob()].
9735 */
9736 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9737 9738 /*
9739 ** CAPI3REF: Error Logging Interface
9740 **
9741 ** ^The [sqlite3_log()] interface writes a message into the [error log]
9742 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9743 ** ^If logging is enabled, the zFormat string and subsequent arguments are
9744 ** used with [sqlite3_snprintf()] to generate the final output string.
9745 **
9746 ** The sqlite3_log() interface is intended for use by extensions such as
9747 ** virtual tables, collating functions, and SQL functions. While there is
9748 ** nothing to prevent an application from calling sqlite3_log(), doing so
9749 ** is considered bad form.
9750 **
9751 ** The zFormat string must not be NULL.
9752 **
9753 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9754 ** will not use dynamically allocated memory. The log message is stored in
9755 ** a fixed-length buffer on the stack. If the log message is longer than
9756 ** a few hundred characters, it will be truncated to the length of the
9757 ** buffer.
9758 */
9759 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9760 9761 /*
9762 ** CAPI3REF: Write-Ahead Log Commit Hook
9763 ** METHOD: sqlite3
9764 **
9765 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
9766 ** is invoked each time data is committed to a database in wal mode.
9767 **
9768 ** ^(The callback is invoked by SQLite after the commit has taken place and
9769 ** the associated write-lock on the database released)^, so the implementation
9770 ** may read, write or [checkpoint] the database as required.
9771 **
9772 ** ^The first parameter passed to the callback function when it is invoked
9773 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
9774 ** registering the callback. ^The second is a copy of the database handle.
9775 ** ^The third parameter is the name of the database that was written to -
9776 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9777 ** is the number of pages currently in the write-ahead log file,
9778 ** including those that were just committed.
9779 **
9780 ** The callback function should normally return [SQLITE_OK]. ^If an error
9781 ** code is returned, that error will propagate back up through the
9782 ** SQLite code base to cause the statement that provoked the callback
9783 ** to report an error, though the commit will have still occurred. If the
9784 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9785 ** that does not correspond to any valid SQLite error code, the results
9786 ** are undefined.
9787 **
9788 ** A single database handle may have at most a single write-ahead log callback
9789 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9790 ** previously registered write-ahead log callback. ^The return value is
9791 ** a copy of the third parameter from the previous call, if any, or 0.
9792 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9793 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9794 ** overwrite any prior [sqlite3_wal_hook()] settings.
9795 */
9796 SQLITE_API void *sqlite3_wal_hook(
9797 sqlite3*,
9798 int(*)(void *,sqlite3*,const char*,int),
9799 void*
9800 );
9801 9802 /*
9803 ** CAPI3REF: Configure an auto-checkpoint
9804 ** METHOD: sqlite3
9805 **
9806 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9807 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
9808 ** to automatically [checkpoint]
9809 ** after committing a transaction if there are N or
9810 ** more frames in the [write-ahead log] file. ^Passing zero or
9811 ** a negative value as the nFrame parameter disables automatic
9812 ** checkpoints entirely.
9813 **
9814 ** ^The callback registered by this function replaces any existing callback
9815 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9816 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9817 ** configured by this function.
9818 **
9819 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9820 ** from SQL.
9821 **
9822 ** ^Checkpoints initiated by this mechanism are
9823 ** [sqlite3_wal_checkpoint_v2|PASSIVE].
9824 **
9825 ** ^Every new [database connection] defaults to having the auto-checkpoint
9826 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9827 ** pages. The use of this interface
9828 ** is only necessary if the default setting is found to be suboptimal
9829 ** for a particular application.
9830 */
9831 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9832 9833 /*
9834 ** CAPI3REF: Checkpoint a database
9835 ** METHOD: sqlite3
9836 **
9837 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9838 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9839 **
9840 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9841 ** [write-ahead log] for database X on [database connection] D to be
9842 ** transferred into the database file and for the write-ahead log to
9843 ** be reset. See the [checkpointing] documentation for addition
9844 ** information.
9845 **
9846 ** This interface used to be the only way to cause a checkpoint to
9847 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9848 ** interface was added. This interface is retained for backwards
9849 ** compatibility and as a convenience for applications that need to manually
9850 ** start a callback but which do not need the full power (and corresponding
9851 ** complication) of [sqlite3_wal_checkpoint_v2()].
9852 */
9853 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9854 9855 /*
9856 ** CAPI3REF: Checkpoint a database
9857 ** METHOD: sqlite3
9858 **
9859 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9860 ** operation on database X of [database connection] D in mode M. Status
9861 ** information is written back into integers pointed to by L and C.)^
9862 ** ^(The M parameter must be a valid [checkpoint mode]:)^
9863 **
9864 ** <dl>
9865 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9866 ** ^Checkpoint as many frames as possible without waiting for any database
9867 ** readers or writers to finish, then sync the database file if all frames
9868 ** in the log were checkpointed. ^The [busy-handler callback]
9869 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9870 ** ^On the other hand, passive mode might leave the checkpoint unfinished
9871 ** if there are concurrent readers or writers.
9872 **
9873 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
9874 ** ^This mode blocks (it invokes the
9875 ** [sqlite3_busy_handler|busy-handler callback]) until there is no
9876 ** database writer and all readers are reading from the most recent database
9877 ** snapshot. ^It then checkpoints all frames in the log file and syncs the
9878 ** database file. ^This mode blocks new database writers while it is pending,
9879 ** but new database readers are allowed to continue unimpeded.
9880 **
9881 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9882 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9883 ** that after checkpointing the log file it blocks (calls the
9884 ** [busy-handler callback])
9885 ** until all readers are reading from the database file only. ^This ensures
9886 ** that the next writer will restart the log file from the beginning.
9887 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9888 ** database writer attempts while it is pending, but does not impede readers.
9889 **
9890 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9891 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9892 ** addition that it also truncates the log file to zero bytes just prior
9893 ** to a successful return.
9894 ** </dl>
9895 **
9896 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9897 ** the log file or to -1 if the checkpoint could not run because
9898 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9899 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9900 ** log file (including any that were already checkpointed before the function
9901 ** was called) or to -1 if the checkpoint could not run due to an error or
9902 ** because the database is not in WAL mode. ^Note that upon successful
9903 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9904 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9905 **
9906 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9907 ** any other process is running a checkpoint operation at the same time, the
9908 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9909 ** busy-handler configured, it will not be invoked in this case.
9910 **
9911 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9912 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9913 ** obtained immediately, and a busy-handler is configured, it is invoked and
9914 ** the writer lock retried until either the busy-handler returns 0 or the lock
9915 ** is successfully obtained. ^The busy-handler is also invoked while waiting for
9916 ** database readers as described above. ^If the busy-handler returns 0 before
9917 ** the writer lock is obtained or while waiting for database readers, the
9918 ** checkpoint operation proceeds from that point in the same way as
9919 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9920 ** without blocking any further. ^SQLITE_BUSY is returned in this case.
9921 **
9922 ** ^If parameter zDb is NULL or points to a zero length string, then the
9923 ** specified operation is attempted on all WAL databases [attached] to
9924 ** [database connection] db. In this case the
9925 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9926 ** an SQLITE_BUSY error is encountered when processing one or more of the
9927 ** attached WAL databases, the operation is still attempted on any remaining
9928 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9929 ** error occurs while processing an attached database, processing is abandoned
9930 ** and the error code is returned to the caller immediately. ^If no error
9931 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9932 ** databases, SQLITE_OK is returned.
9933 **
9934 ** ^If database zDb is the name of an attached database that is not in WAL
9935 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9936 ** zDb is not NULL (or a zero length string) and is not the name of any
9937 ** attached database, SQLITE_ERROR is returned to the caller.
9938 **
9939 ** ^Unless it returns SQLITE_MISUSE,
9940 ** the sqlite3_wal_checkpoint_v2() interface
9941 ** sets the error information that is queried by
9942 ** [sqlite3_errcode()] and [sqlite3_errmsg()].
9943 **
9944 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9945 ** from SQL.
9946 */
9947 SQLITE_API int sqlite3_wal_checkpoint_v2(
9948 sqlite3 *db, /* Database handle */
9949 const char *zDb, /* Name of attached database (or NULL) */
9950 int eMode, /* SQLITE_CHECKPOINT_* value */
9951 int *pnLog, /* OUT: Size of WAL log in frames */
9952 int *pnCkpt /* OUT: Total number of frames checkpointed */
9953 );
9954 9955 /*
9956 ** CAPI3REF: Checkpoint Mode Values
9957 ** KEYWORDS: {checkpoint mode}
9958 **
9959 ** These constants define all valid values for the "checkpoint mode" passed
9960 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9961 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9962 ** meaning of each of these checkpoint modes.
9963 */
9964 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9965 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9966 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
9967 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9968 9969 /*
9970 ** CAPI3REF: Virtual Table Interface Configuration
9971 **
9972 ** This function may be called by either the [xConnect] or [xCreate] method
9973 ** of a [virtual table] implementation to configure
9974 ** various facets of the virtual table interface.
9975 **
9976 ** If this interface is invoked outside the context of an xConnect or
9977 ** xCreate virtual table method then the behavior is undefined.
9978 **
9979 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9980 ** [database connection] in which the virtual table is being created and
9981 ** which is passed in as the first argument to the [xConnect] or [xCreate]
9982 ** method that is invoking sqlite3_vtab_config(). The C parameter is one
9983 ** of the [virtual table configuration options]. The presence and meaning
9984 ** of parameters after C depend on which [virtual table configuration option]
9985 ** is used.
9986 */
9987 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9988 9989 /*
9990 ** CAPI3REF: Virtual Table Configuration Options
9991 ** KEYWORDS: {virtual table configuration options}
9992 ** KEYWORDS: {virtual table configuration option}
9993 **
9994 ** These macros define the various options to the
9995 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
9996 ** can use to customize and optimize their behavior.
9997 **
9998 ** <dl>
9999 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
10000 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
10001 ** <dd>Calls of the form
10002 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
10003 ** where X is an integer. If X is zero, then the [virtual table] whose
10004 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
10005 ** support constraints. In this configuration (which is the default) if
10006 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
10007 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
10008 ** specified as part of the user's SQL statement, regardless of the actual
10009 ** ON CONFLICT mode specified.
10010 **
10011 ** If X is non-zero, then the virtual table implementation guarantees
10012 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
10013 ** any modifications to internal or persistent data structures have been made.
10014 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
10015 ** is able to roll back a statement or database transaction, and abandon
10016 ** or continue processing the current SQL statement as appropriate.
10017 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
10018 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
10019 ** had been ABORT.
10020 **
10021 ** Virtual table implementations that are required to handle OR REPLACE
10022 ** must do so within the [xUpdate] method. If a call to the
10023 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
10024 ** CONFLICT policy is REPLACE, the virtual table implementation should
10025 ** silently replace the appropriate rows within the xUpdate callback and
10026 ** return SQLITE_OK. Or, if this is not possible, it may return
10027 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
10028 ** constraint handling.
10029 ** </dd>
10030 **
10031 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
10032 ** <dd>Calls of the form
10033 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
10034 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10035 ** prohibits that virtual table from being used from within triggers and
10036 ** views.
10037 ** </dd>
10038 **
10039 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
10040 ** <dd>Calls of the form
10041 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
10042 ** [xConnect] or [xCreate] methods of a [virtual table] implementation
10043 ** identify that virtual table as being safe to use from within triggers
10044 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
10045 ** virtual table can do no serious harm even if it is controlled by a
10046 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
10047 ** flag unless absolutely necessary.
10048 ** </dd>
10049 **
10050 ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
10051 ** <dd>Calls of the form
10052 ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
10053 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10054 ** instruct the query planner to begin at least a read transaction on
10055 ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
10056 ** virtual table is used.
10057 ** </dd>
10058 ** </dl>
10059 */
10060 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
10061 #define SQLITE_VTAB_INNOCUOUS 2
10062 #define SQLITE_VTAB_DIRECTONLY 3
10063 #define SQLITE_VTAB_USES_ALL_SCHEMAS 4
10064 10065 /*
10066 ** CAPI3REF: Determine The Virtual Table Conflict Policy
10067 **
10068 ** This function may only be called from within a call to the [xUpdate] method
10069 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
10070 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
10071 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
10072 ** of the SQL statement that triggered the call to the [xUpdate] method of the
10073 ** [virtual table].
10074 */
10075 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
10076 10077 /*
10078 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
10079 **
10080 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
10081 ** method of a [virtual table], then it might return true if the
10082 ** column is being fetched as part of an UPDATE operation during which the
10083 ** column value will not change. The virtual table implementation can use
10084 ** this hint as permission to substitute a return value that is less
10085 ** expensive to compute and that the corresponding
10086 ** [xUpdate] method understands as a "no-change" value.
10087 **
10088 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
10089 ** the column is not changed by the UPDATE statement, then the xColumn
10090 ** method can optionally return without setting a result, without calling
10091 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
10092 ** In that case, [sqlite3_value_nochange(X)] will return true for the
10093 ** same column in the [xUpdate] method.
10094 **
10095 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
10096 ** implementations should continue to give a correct answer even if the
10097 ** sqlite3_vtab_nochange() interface were to always return false. In the
10098 ** current implementation, the sqlite3_vtab_nochange() interface does always
10099 ** returns false for the enhanced [UPDATE FROM] statement.
10100 */
10101 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
10102 10103 /*
10104 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint
10105 ** METHOD: sqlite3_index_info
10106 **
10107 ** This function may only be called from within a call to the [xBestIndex]
10108 ** method of a [virtual table]. This function returns a pointer to a string
10109 ** that is the name of the appropriate collation sequence to use for text
10110 ** comparisons on the constraint identified by its arguments.
10111 **
10112 ** The first argument must be the pointer to the [sqlite3_index_info] object
10113 ** that is the first parameter to the xBestIndex() method. The second argument
10114 ** must be an index into the aConstraint[] array belonging to the
10115 ** sqlite3_index_info structure passed to xBestIndex.
10116 **
10117 ** Important:
10118 ** The first parameter must be the same pointer that is passed into the
10119 ** xBestMethod() method. The first parameter may not be a pointer to a
10120 ** different [sqlite3_index_info] object, even an exact copy.
10121 **
10122 ** The return value is computed as follows:
10123 **
10124 ** <ol>
10125 ** <li><p> If the constraint comes from a WHERE clause expression that contains
10126 ** a [COLLATE operator], then the name of the collation specified by
10127 ** that COLLATE operator is returned.
10128 ** <li><p> If there is no COLLATE operator, but the column that is the subject
10129 ** of the constraint specifies an alternative collating sequence via
10130 ** a [COLLATE clause] on the column definition within the CREATE TABLE
10131 ** statement that was passed into [sqlite3_declare_vtab()], then the
10132 ** name of that alternative collating sequence is returned.
10133 ** <li><p> Otherwise, "BINARY" is returned.
10134 ** </ol>
10135 */
10136 SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
10137 10138 /*
10139 ** CAPI3REF: Determine if a virtual table query is DISTINCT
10140 ** METHOD: sqlite3_index_info
10141 **
10142 ** This API may only be used from within an [xBestIndex|xBestIndex method]
10143 ** of a [virtual table] implementation. The result of calling this
10144 ** interface from outside of xBestIndex() is undefined and probably harmful.
10145 **
10146 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
10147 ** 3. The integer returned by sqlite3_vtab_distinct()
10148 ** gives the virtual table additional information about how the query
10149 ** planner wants the output to be ordered. As long as the virtual table
10150 ** can meet the ordering requirements of the query planner, it may set
10151 ** the "orderByConsumed" flag.
10152 **
10153 ** <ol><li value="0"><p>
10154 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means
10155 ** that the query planner needs the virtual table to return all rows in the
10156 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
10157 ** [sqlite3_index_info] object. This is the default expectation. If the
10158 ** virtual table outputs all rows in sorted order, then it is always safe for
10159 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of
10160 ** the return value from sqlite3_vtab_distinct().
10161 ** <li value="1"><p>
10162 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
10163 ** that the query planner does not need the rows to be returned in sorted order
10164 ** as long as all rows with the same values in all columns identified by the
10165 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
10166 ** is doing a GROUP BY.
10167 ** <li value="2"><p>
10168 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
10169 ** that the query planner does not need the rows returned in any particular
10170 ** order, as long as rows with the same values in all columns identified
10171 ** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows
10172 ** contain the same values for all columns identified by "colUsed", all but
10173 ** one such row may optionally be omitted from the result.)^
10174 ** The virtual table is not required to omit rows that are duplicates
10175 ** over the "colUsed" columns, but if the virtual table can do that without
10176 ** too much extra effort, it could potentially help the query to run faster.
10177 ** This mode is used for a DISTINCT query.
10178 ** <li value="3"><p>
10179 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the
10180 ** virtual table must return rows in the order defined by "aOrderBy" as
10181 ** if the sqlite3_vtab_distinct() interface had returned 0. However if
10182 ** two or more rows in the result have the same values for all columns
10183 ** identified by "colUsed", then all but one such row may optionally be
10184 ** omitted.)^ Like when the return value is 2, the virtual table
10185 ** is not required to omit rows that are duplicates over the "colUsed"
10186 ** columns, but if the virtual table can do that without
10187 ** too much extra effort, it could potentially help the query to run faster.
10188 ** This mode is used for queries
10189 ** that have both DISTINCT and ORDER BY clauses.
10190 ** </ol>
10191 **
10192 ** <p>The following table summarizes the conditions under which the
10193 ** virtual table is allowed to set the "orderByConsumed" flag based on
10194 ** the value returned by sqlite3_vtab_distinct(). This table is a
10195 ** restatement of the previous four paragraphs:
10196 **
10197 ** <table border=1 cellspacing=0 cellpadding=10 width="90%">
10198 ** <tr>
10199 ** <td valign="top">sqlite3_vtab_distinct() return value
10200 ** <td valign="top">Rows are returned in aOrderBy order
10201 ** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent
10202 ** <td valign="top">Duplicates over all colUsed columns may be omitted
10203 ** <tr><td>0<td>yes<td>yes<td>no
10204 ** <tr><td>1<td>no<td>yes<td>no
10205 ** <tr><td>2<td>no<td>yes<td>yes
10206 ** <tr><td>3<td>yes<td>yes<td>yes
10207 ** </table>
10208 **
10209 ** ^For the purposes of comparing virtual table output values to see if the
10210 ** values are the same value for sorting purposes, two NULL values are considered
10211 ** to be the same. In other words, the comparison operator is "IS"
10212 ** (or "IS NOT DISTINCT FROM") and not "==".
10213 **
10214 ** If a virtual table implementation is unable to meet the requirements
10215 ** specified above, then it must not set the "orderByConsumed" flag in the
10216 ** [sqlite3_index_info] object or an incorrect answer may result.
10217 **
10218 ** ^A virtual table implementation is always free to return rows in any order
10219 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the
10220 ** "orderByConsumed" flag is unset, the query planner will add extra
10221 ** [bytecode] to ensure that the final results returned by the SQL query are
10222 ** ordered correctly. The use of the "orderByConsumed" flag and the
10223 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
10224 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
10225 ** flag might help queries against a virtual table to run faster. Being
10226 ** overly aggressive and setting the "orderByConsumed" flag when it is not
10227 ** valid to do so, on the other hand, might cause SQLite to return incorrect
10228 ** results.
10229 */
10230 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
10231 10232 /*
10233 ** CAPI3REF: Identify and handle IN constraints in xBestIndex
10234 **
10235 ** This interface may only be used from within an
10236 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
10237 ** The result of invoking this interface from any other context is
10238 ** undefined and probably harmful.
10239 **
10240 ** ^(A constraint on a virtual table of the form
10241 ** "[IN operator|column IN (...)]" is
10242 ** communicated to the xBestIndex method as a
10243 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
10244 ** this constraint, it must set the corresponding
10245 ** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
10246 ** the usual mode of handling IN operators, SQLite generates [bytecode]
10247 ** that invokes the [xFilter|xFilter() method] once for each value
10248 ** on the right-hand side of the IN operator.)^ Thus the virtual table
10249 ** only sees a single value from the right-hand side of the IN operator
10250 ** at a time.
10251 **
10252 ** In some cases, however, it would be advantageous for the virtual
10253 ** table to see all values on the right-hand of the IN operator all at
10254 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
10255 **
10256 ** <ol>
10257 ** <li><p>
10258 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
10259 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
10260 ** is an [IN operator] that can be processed all at once. ^In other words,
10261 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism
10262 ** by which the virtual table can ask SQLite if all-at-once processing
10263 ** of the IN operator is even possible.
10264 **
10265 ** <li><p>
10266 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
10267 ** to SQLite that the virtual table does or does not want to process
10268 ** the IN operator all-at-once, respectively. ^Thus when the third
10269 ** parameter (F) is non-negative, this interface is the mechanism by
10270 ** which the virtual table tells SQLite how it wants to process the
10271 ** IN operator.
10272 ** </ol>
10273 **
10274 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
10275 ** within the same xBestIndex method call. ^For any given P,N pair,
10276 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same
10277 ** within the same xBestIndex call. ^If the interface returns true
10278 ** (non-zero), that means that the constraint is an IN operator
10279 ** that can be processed all-at-once. ^If the constraint is not an IN
10280 ** operator or cannot be processed all-at-once, then the interface returns
10281 ** false.
10282 **
10283 ** ^(All-at-once processing of the IN operator is selected if both of the
10284 ** following conditions are met:
10285 **
10286 ** <ol>
10287 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
10288 ** integer. This is how the virtual table tells SQLite that it wants to
10289 ** use the N-th constraint.
10290 **
10291 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
10292 ** non-negative had F>=1.
10293 ** </ol>)^
10294 **
10295 ** ^If either or both of the conditions above are false, then SQLite uses
10296 ** the traditional one-at-a-time processing strategy for the IN constraint.
10297 ** ^If both conditions are true, then the argvIndex-th parameter to the
10298 ** xFilter method will be an [sqlite3_value] that appears to be NULL,
10299 ** but which can be passed to [sqlite3_vtab_in_first()] and
10300 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side
10301 ** of the IN constraint.
10302 */
10303 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
10304 10305 /*
10306 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
10307 **
10308 ** These interfaces are only useful from within the
10309 ** [xFilter|xFilter() method] of a [virtual table] implementation.
10310 ** The result of invoking these interfaces from any other context
10311 ** is undefined and probably harmful.
10312 **
10313 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
10314 ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
10315 ** xFilter method which invokes these routines, and specifically
10316 ** a parameter that was previously selected for all-at-once IN constraint
10317 ** processing using the [sqlite3_vtab_in()] interface in the
10318 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
10319 ** an xFilter argument that was selected for all-at-once IN constraint
10320 ** processing, then these routines return [SQLITE_ERROR].)^
10321 **
10322 ** ^(Use these routines to access all values on the right-hand side
10323 ** of the IN constraint using code like the following:
10324 **
10325 ** <blockquote><pre>
10326 ** for(rc=sqlite3_vtab_in_first(pList, &pVal);
10327 ** rc==SQLITE_OK && pVal;
10328 ** rc=sqlite3_vtab_in_next(pList, &pVal)
10329 ** ){
10330 ** // do something with pVal
10331 ** }
10332 ** if( rc!=SQLITE_OK ){
10333 ** // an error has occurred
10334 ** }
10335 ** </pre></blockquote>)^
10336 **
10337 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
10338 ** routines return SQLITE_OK and set *P to point to the first or next value
10339 ** on the RHS of the IN constraint. ^If there are no more values on the
10340 ** right hand side of the IN constraint, then *P is set to NULL and these
10341 ** routines return [SQLITE_DONE]. ^The return value might be
10342 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
10343 **
10344 ** The *ppOut values returned by these routines are only valid until the
10345 ** next call to either of these routines or until the end of the xFilter
10346 ** method from which these routines were called. If the virtual table
10347 ** implementation needs to retain the *ppOut values for longer, it must make
10348 ** copies. The *ppOut values are [protected sqlite3_value|protected].
10349 */
10350 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
10351 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
10352 10353 /*
10354 ** CAPI3REF: Constraint values in xBestIndex()
10355 ** METHOD: sqlite3_index_info
10356 **
10357 ** This API may only be used from within the [xBestIndex|xBestIndex method]
10358 ** of a [virtual table] implementation. The result of calling this interface
10359 ** from outside of an xBestIndex method are undefined and probably harmful.
10360 **
10361 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
10362 ** the [xBestIndex] method of a [virtual table] implementation, with P being
10363 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
10364 ** J being a 0-based index into P->aConstraint[], then this routine
10365 ** attempts to set *V to the value of the right-hand operand of
10366 ** that constraint if the right-hand operand is known. ^If the
10367 ** right-hand operand is not known, then *V is set to a NULL pointer.
10368 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
10369 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
10370 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
10371 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
10372 ** can return a result code other than SQLITE_OK or SQLITE_NOTFOUND if
10373 ** something goes wrong.
10374 **
10375 ** The sqlite3_vtab_rhs_value() interface is usually only successful if
10376 ** the right-hand operand of a constraint is a literal value in the original
10377 ** SQL statement. If the right-hand operand is an expression or a reference
10378 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
10379 ** will probably return [SQLITE_NOTFOUND].
10380 **
10381 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
10382 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10383 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10384 **
10385 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10386 ** and remains valid for the duration of the xBestIndex method call.
10387 ** ^When xBestIndex returns, the sqlite3_value object returned by
10388 ** sqlite3_vtab_rhs_value() is automatically deallocated.
10389 **
10390 ** The "_rhs_" in the name of this routine is an abbreviation for
10391 ** "Right-Hand Side".
10392 */
10393 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10394 10395 /*
10396 ** CAPI3REF: Conflict resolution modes
10397 ** KEYWORDS: {conflict resolution mode}
10398 **
10399 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
10400 ** inform a [virtual table] implementation of the [ON CONFLICT] mode
10401 ** for the SQL statement being evaluated.
10402 **
10403 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
10404 ** return value from the [sqlite3_set_authorizer()] callback and that
10405 ** [SQLITE_ABORT] is also a [result code].
10406 */
10407 #define SQLITE_ROLLBACK 1
10408 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10409 #define SQLITE_FAIL 3
10410 /* #define SQLITE_ABORT 4 // Also an error code */
10411 #define SQLITE_REPLACE 5
10412 10413 /*
10414 ** CAPI3REF: Prepared Statement Scan Status Opcodes
10415 ** KEYWORDS: {scanstatus options}
10416 **
10417 ** The following constants can be used for the T parameter to the
10418 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10419 ** different metric for sqlite3_stmt_scanstatus() to return.
10420 **
10421 ** When the value returned to V is a string, space to hold that string is
10422 ** managed by the prepared statement S and will be automatically freed when
10423 ** S is finalized.
10424 **
10425 ** Not all values are available for all query elements. When a value is
10426 ** not available, the output variable is set to -1 if the value is numeric,
10427 ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10428 **
10429 ** <dl>
10430 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10431 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10432 ** set to the total number of times that the X-th loop has run.</dd>
10433 **
10434 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10435 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10436 ** to the total number of rows examined by all iterations of the X-th loop.</dd>
10437 **
10438 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10439 ** <dd>^The "double" variable pointed to by the V parameter will be set to the
10440 ** query planner's estimate for the average number of rows output from each
10441 ** iteration of the X-th loop. If the query planner's estimate was accurate,
10442 ** then this value will approximate the quotient NVISIT/NLOOP and the
10443 ** product of this value for all prior loops with the same SELECTID will
10444 ** be the NLOOP value for the current loop.</dd>
10445 **
10446 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10447 ** <dd>^The "const char *" variable pointed to by the V parameter will be set
10448 ** to a zero-terminated UTF-8 string containing the name of the index or table
10449 ** used for the X-th loop.</dd>
10450 **
10451 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10452 ** <dd>^The "const char *" variable pointed to by the V parameter will be set
10453 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10454 ** description for the X-th loop.</dd>
10455 **
10456 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10457 ** <dd>^The "int" variable pointed to by the V parameter will be set to the
10458 ** id for the X-th query plan element. The id value is unique within the
10459 ** statement. The select-id is the same value as is output in the first
10460 ** column of an [EXPLAIN QUERY PLAN] query.</dd>
10461 **
10462 ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10463 ** <dd>The "int" variable pointed to by the V parameter will be set to the
10464 ** id of the parent of the current query element, if applicable, or
10465 ** to zero if the query element has no parent. This is the same value as
10466 ** returned in the second column of an [EXPLAIN QUERY PLAN] query.</dd>
10467 **
10468 ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10469 ** <dd>The sqlite3_int64 output value is set to the number of cycles,
10470 ** according to the processor time-stamp counter, that elapsed while the
10471 ** query element was being processed. This value is not available for
10472 ** all query elements - if it is unavailable the output variable is
10473 ** set to -1.</dd>
10474 ** </dl>
10475 */
10476 #define SQLITE_SCANSTAT_NLOOP 0
10477 #define SQLITE_SCANSTAT_NVISIT 1
10478 #define SQLITE_SCANSTAT_EST 2
10479 #define SQLITE_SCANSTAT_NAME 3
10480 #define SQLITE_SCANSTAT_EXPLAIN 4
10481 #define SQLITE_SCANSTAT_SELECTID 5
10482 #define SQLITE_SCANSTAT_PARENTID 6
10483 #define SQLITE_SCANSTAT_NCYCLE 7
10484 10485 /*
10486 ** CAPI3REF: Prepared Statement Scan Status
10487 ** METHOD: sqlite3_stmt
10488 **
10489 ** These interfaces return information about the predicted and measured
10490 ** performance for pStmt. Advanced applications can use this
10491 ** interface to compare the predicted and the measured performance and
10492 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10493 **
10494 ** Since this interface is expected to be rarely used, it is only
10495 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10496 ** compile-time option.
10497 **
10498 ** The "iScanStatusOp" parameter determines which status information to return.
10499 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10500 ** of this interface is undefined. ^The requested measurement is written into
10501 ** a variable pointed to by the "pOut" parameter.
10502 **
10503 ** The "flags" parameter must be passed a mask of flags. At present only
10504 ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
10505 ** is specified, then status information is available for all elements
10506 ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
10507 ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10508 ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10509 ** the EXPLAIN QUERY PLAN output) are available. Invoking API
10510 ** sqlite3_stmt_scanstatus() is equivalent to calling
10511 ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10512 **
10513 ** Parameter "idx" identifies the specific query element to retrieve statistics
10514 ** for. Query elements are numbered starting from zero. A value of -1 may
10515 ** retrieve statistics for the entire query. ^If idx is out of range
10516 ** - less than -1 or greater than or equal to the total number of query
10517 ** elements used to implement the statement - a non-zero value is returned and
10518 ** the variable that pOut points to is unchanged.
10519 **
10520 ** See also: [sqlite3_stmt_scanstatus_reset()]
10521 */
10522 SQLITE_API int sqlite3_stmt_scanstatus(
10523 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10524 int idx, /* Index of loop to report on */
10525 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10526 void *pOut /* Result written here */
10527 );
10528 SQLITE_API int sqlite3_stmt_scanstatus_v2(
10529 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10530 int idx, /* Index of loop to report on */
10531 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10532 int flags, /* Mask of flags defined below */
10533 void *pOut /* Result written here */
10534 );
10535 10536 /*
10537 ** CAPI3REF: Prepared Statement Scan Status
10538 ** KEYWORDS: {scan status flags}
10539 */
10540 #define SQLITE_SCANSTAT_COMPLEX 0x0001
10541 10542 /*
10543 ** CAPI3REF: Zero Scan-Status Counters
10544 ** METHOD: sqlite3_stmt
10545 **
10546 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10547 **
10548 ** This API is only available if the library is built with pre-processor
10549 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10550 */
10551 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10552 10553 /*
10554 ** CAPI3REF: Flush caches to disk mid-transaction
10555 ** METHOD: sqlite3
10556 **
10557 ** ^If a write-transaction is open on [database connection] D when the
10558 ** [sqlite3_db_cacheflush(D)] interface is invoked, any dirty
10559 ** pages in the pager-cache that are not currently in use are written out
10560 ** to disk. A dirty page may be in use if a database cursor created by an
10561 ** active SQL statement is reading from it, or if it is page 1 of a database
10562 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10563 ** interface flushes caches for all schemas - "main", "temp", and
10564 ** any [attached] databases.
10565 **
10566 ** ^If this function needs to obtain extra database locks before dirty pages
10567 ** can be flushed to disk, it does so. ^If those locks cannot be obtained
10568 ** immediately and there is a busy-handler callback configured, it is invoked
10569 ** in the usual manner. ^If the required lock still cannot be obtained, then
10570 ** the database is skipped and an attempt made to flush any dirty pages
10571 ** belonging to the next (if any) database. ^If any databases are skipped
10572 ** because locks cannot be obtained, but no other error occurs, this
10573 ** function returns SQLITE_BUSY.
10574 **
10575 ** ^If any other error occurs while flushing dirty pages to disk (for
10576 ** example an IO error or out-of-memory condition), then processing is
10577 ** abandoned and an SQLite [error code] is returned to the caller immediately.
10578 **
10579 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10580 **
10581 ** ^This function does not set the database handle error code or message
10582 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10583 */
10584 SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10585 10586 /*
10587 ** CAPI3REF: The pre-update hook.
10588 ** METHOD: sqlite3
10589 **
10590 ** ^These interfaces are only available if SQLite is compiled using the
10591 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10592 **
10593 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10594 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10595 ** on a database table.
10596 ** ^At most one preupdate hook may be registered at a time on a single
10597 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10598 ** the previous setting.
10599 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10600 ** with a NULL pointer as the second parameter.
10601 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10602 ** the first parameter to callbacks.
10603 **
10604 ** ^The preupdate hook only fires for changes to real database tables; the
10605 ** preupdate hook is not invoked for changes to [virtual tables] or to
10606 ** system tables like sqlite_sequence or sqlite_stat1.
10607 **
10608 ** ^The second parameter to the preupdate callback is a pointer to
10609 ** the [database connection] that registered the preupdate hook.
10610 ** ^The third parameter to the preupdate callback is one of the constants
10611 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10612 ** kind of update operation that is about to occur.
10613 ** ^(The fourth parameter to the preupdate callback is the name of the
10614 ** database within the database connection that is being modified. This
10615 ** will be "main" for the main database or "temp" for TEMP tables or
10616 ** the name given after the AS keyword in the [ATTACH] statement for attached
10617 ** databases.)^
10618 ** ^The fifth parameter to the preupdate callback is the name of the
10619 ** table that is being modified.
10620 **
10621 ** For an UPDATE or DELETE operation on a [rowid table], the sixth
10622 ** parameter passed to the preupdate callback is the initial [rowid] of the
10623 ** row being modified or deleted. For an INSERT operation on a rowid table,
10624 ** or any operation on a WITHOUT ROWID table, the value of the sixth
10625 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10626 ** seventh parameter is the final rowid value of the row being inserted
10627 ** or updated. The value of the seventh parameter passed to the callback
10628 ** function is not defined for operations on WITHOUT ROWID tables, or for
10629 ** DELETE operations on rowid tables.
10630 **
10631 ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10632 ** the previous call on the same [database connection] D, or NULL for
10633 ** the first call on D.
10634 **
10635 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10636 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10637 ** provide additional information about a preupdate event. These routines
10638 ** may only be called from within a preupdate callback. Invoking any of
10639 ** these routines from outside of a preupdate callback or with a
10640 ** [database connection] pointer that is different from the one supplied
10641 ** to the preupdate callback results in undefined and probably undesirable
10642 ** behavior.
10643 **
10644 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10645 ** in the row that is being inserted, updated, or deleted.
10646 **
10647 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10648 ** a [protected sqlite3_value] that contains the value of the Nth column of
10649 ** the table row before it is updated. The N parameter must be between 0
10650 ** and one less than the number of columns or the behavior will be
10651 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10652 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10653 ** behavior is undefined. The [sqlite3_value] that P points to
10654 ** will be destroyed when the preupdate callback returns.
10655 **
10656 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10657 ** a [protected sqlite3_value] that contains the value of the Nth column of
10658 ** the table row after it is updated. The N parameter must be between 0
10659 ** and one less than the number of columns or the behavior will be
10660 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10661 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10662 ** behavior is undefined. The [sqlite3_value] that P points to
10663 ** will be destroyed when the preupdate callback returns.
10664 **
10665 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10666 ** callback was invoked as a result of a direct insert, update, or delete
10667 ** operation; or 1 for inserts, updates, or deletes invoked by top-level
10668 ** triggers; or 2 for changes resulting from triggers called by top-level
10669 ** triggers; and so forth.
10670 **
10671 ** When the [sqlite3_blob_write()] API is used to update a blob column,
10672 ** the pre-update hook is invoked with SQLITE_DELETE, because
10673 ** the new values are not yet available. In this case, when a
10674 ** callback made with op==SQLITE_DELETE is actually a write using the
10675 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10676 ** the index of the column being written. In other cases, where the
10677 ** pre-update hook is being invoked for some other reason, including a
10678 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10679 **
10680 ** See also: [sqlite3_update_hook()]
10681 */
10682 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10683 SQLITE_API void *sqlite3_preupdate_hook(
10684 sqlite3 *db,
10685 void(*xPreUpdate)(
10686 void *pCtx, /* Copy of third arg to preupdate_hook() */
10687 sqlite3 *db, /* Database handle */
10688 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10689 char const *zDb, /* Database name */
10690 char const *zName, /* Table name */
10691 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10692 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10693 ),
10694 void*
10695 );
10696 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10697 SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10698 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10699 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10700 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10701 #endif
10702 10703 /*
10704 ** CAPI3REF: Low-level system error code
10705 ** METHOD: sqlite3
10706 **
10707 ** ^Attempt to return the underlying operating system error code or error
10708 ** number that caused the most recent I/O error or failure to open a file.
10709 ** The return value is OS-dependent. For example, on unix systems, after
10710 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10711 ** called to get back the underlying "errno" that caused the problem, such
10712 ** as ENOSPC, EAUTH, EISDIR, and so forth.
10713 */
10714 SQLITE_API int sqlite3_system_errno(sqlite3*);
10715 10716 /*
10717 ** CAPI3REF: Database Snapshot
10718 ** KEYWORDS: {snapshot} {sqlite3_snapshot}
10719 **
10720 ** An instance of the snapshot object records the state of a [WAL mode]
10721 ** database for some specific point in history.
10722 **
10723 ** In [WAL mode], multiple [database connections] that are open on the
10724 ** same database file can each be reading a different historical version
10725 ** of the database file. When a [database connection] begins a read
10726 ** transaction, that connection sees an unchanging copy of the database
10727 ** as it existed for the point in time when the transaction first started.
10728 ** Subsequent changes to the database from other connections are not seen
10729 ** by the reader until a new read transaction is started.
10730 **
10731 ** The sqlite3_snapshot object records state information about an historical
10732 ** version of the database file so that it is possible to later open a new read
10733 ** transaction that sees that historical version of the database rather than
10734 ** the most recent version.
10735 */
10736 typedef struct sqlite3_snapshot {
10737 unsigned char hidden[48];
10738 } sqlite3_snapshot;
10739 10740 /*
10741 ** CAPI3REF: Record A Database Snapshot
10742 ** CONSTRUCTOR: sqlite3_snapshot
10743 **
10744 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10745 ** new [sqlite3_snapshot] object that records the current state of
10746 ** schema S in database connection D. ^On success, the
10747 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10748 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10749 ** If there is not already a read-transaction open on schema S when
10750 ** this function is called, one is opened automatically.
10751 **
10752 ** If a read-transaction is opened by this function, then it is guaranteed
10753 ** that the returned snapshot object may not be invalidated by a database
10754 ** writer or checkpointer until after the read-transaction is closed. This
10755 ** is not guaranteed if a read-transaction is already open when this
10756 ** function is called. In that case, any subsequent write or checkpoint
10757 ** operation on the database may invalidate the returned snapshot handle,
10758 ** even while the read-transaction remains open.
10759 **
10760 ** The following must be true for this function to succeed. If any of
10761 ** the following statements are false when sqlite3_snapshot_get() is
10762 ** called, SQLITE_ERROR is returned. The final value of *P is undefined
10763 ** in this case.
10764 **
10765 ** <ul>
10766 ** <li> The database handle must not be in [autocommit mode].
10767 **
10768 ** <li> Schema S of [database connection] D must be a [WAL mode] database.
10769 **
10770 ** <li> There must not be a write transaction open on schema S of database
10771 ** connection D.
10772 **
10773 ** <li> One or more transactions must have been written to the current wal
10774 ** file since it was created on disk (by any connection). This means
10775 ** that a snapshot cannot be taken on a wal mode database with no wal
10776 ** file immediately after it is first opened. At least one transaction
10777 ** must be written to it first.
10778 ** </ul>
10779 **
10780 ** This function may also return SQLITE_NOMEM. If it is called with the
10781 ** database handle in autocommit mode but fails for some other reason,
10782 ** whether or not a read transaction is opened on schema S is undefined.
10783 **
10784 ** The [sqlite3_snapshot] object returned from a successful call to
10785 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10786 ** to avoid a memory leak.
10787 **
10788 ** The [sqlite3_snapshot_get()] interface is only available when the
10789 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10790 */
10791 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
10792 sqlite3 *db,
10793 const char *zSchema,
10794 sqlite3_snapshot **ppSnapshot
10795 );
10796 10797 /*
10798 ** CAPI3REF: Start a read transaction on an historical snapshot
10799 ** METHOD: sqlite3_snapshot
10800 **
10801 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10802 ** transaction or upgrades an existing one for schema S of
10803 ** [database connection] D such that the read transaction refers to
10804 ** historical [snapshot] P, rather than the most recent change to the
10805 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10806 ** on success or an appropriate [error code] if it fails.
10807 **
10808 ** ^In order to succeed, the database connection must not be in
10809 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10810 ** is already a read transaction open on schema S, then the database handle
10811 ** must have no active statements (SELECT statements that have been passed
10812 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10813 ** SQLITE_ERROR is returned if either of these conditions is violated, or
10814 ** if schema S does not exist, or if the snapshot object is invalid.
10815 **
10816 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10817 ** snapshot has been overwritten by a [checkpoint]. In this case
10818 ** SQLITE_ERROR_SNAPSHOT is returned.
10819 **
10820 ** If there is already a read transaction open when this function is
10821 ** invoked, then the same read transaction remains open (on the same
10822 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10823 ** is returned. If another error code - for example SQLITE_PROTOCOL or an
10824 ** SQLITE_IOERR error code - is returned, then the final state of the
10825 ** read transaction is undefined. If SQLITE_OK is returned, then the
10826 ** read transaction is now open on database snapshot P.
10827 **
10828 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10829 ** database connection D does not know that the database file for
10830 ** schema S is in [WAL mode]. A database connection might not know
10831 ** that the database file is in [WAL mode] if there has been no prior
10832 ** I/O on that database connection, or if the database entered [WAL mode]
10833 ** after the most recent I/O on the database connection.)^
10834 ** (Hint: Run "[PRAGMA application_id]" against a newly opened
10835 ** database connection in order to make it ready to use snapshots.)
10836 **
10837 ** The [sqlite3_snapshot_open()] interface is only available when the
10838 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10839 */
10840 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
10841 sqlite3 *db,
10842 const char *zSchema,
10843 sqlite3_snapshot *pSnapshot
10844 );
10845 10846 /*
10847 ** CAPI3REF: Destroy a snapshot
10848 ** DESTRUCTOR: sqlite3_snapshot
10849 **
10850 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10851 ** The application must eventually free every [sqlite3_snapshot] object
10852 ** using this routine to avoid a memory leak.
10853 **
10854 ** The [sqlite3_snapshot_free()] interface is only available when the
10855 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10856 */
10857 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
10858 10859 /*
10860 ** CAPI3REF: Compare the ages of two snapshot handles.
10861 ** METHOD: sqlite3_snapshot
10862 **
10863 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10864 ** of two valid snapshot handles.
10865 **
10866 ** If the two snapshot handles are not associated with the same database
10867 ** file, the result of the comparison is undefined.
10868 **
10869 ** Additionally, the result of the comparison is only valid if both of the
10870 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10871 ** last time the wal file was deleted. The wal file is deleted when the
10872 ** database is changed back to rollback mode or when the number of database
10873 ** clients drops to zero. If either snapshot handle was obtained before the
10874 ** wal file was last deleted, the value returned by this function
10875 ** is undefined.
10876 **
10877 ** Otherwise, this API returns a negative value if P1 refers to an older
10878 ** snapshot than P2, zero if the two handles refer to the same database
10879 ** snapshot, and a positive value if P1 is a newer snapshot than P2.
10880 **
10881 ** This interface is only available if SQLite is compiled with the
10882 ** [SQLITE_ENABLE_SNAPSHOT] option.
10883 */
10884 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
10885 sqlite3_snapshot *p1,
10886 sqlite3_snapshot *p2
10887 );
10888 10889 /*
10890 ** CAPI3REF: Recover snapshots from a wal file
10891 ** METHOD: sqlite3_snapshot
10892 **
10893 ** If a [WAL file] remains on disk after all database connections close
10894 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10895 ** or because the last process to have the database opened exited without
10896 ** calling [sqlite3_close()]) and a new connection is subsequently opened
10897 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10898 ** will only be able to open the last transaction added to the WAL file
10899 ** even though the WAL file contains other valid transactions.
10900 **
10901 ** This function attempts to scan the WAL file associated with database zDb
10902 ** of database handle db and make all valid snapshots available to
10903 ** sqlite3_snapshot_open(). It is an error if there is already a read
10904 ** transaction open on the database, or if the database is not a WAL mode
10905 ** database.
10906 **
10907 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
10908 **
10909 ** This interface is only available if SQLite is compiled with the
10910 ** [SQLITE_ENABLE_SNAPSHOT] option.
10911 */
10912 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
10913 10914 /*
10915 ** CAPI3REF: Serialize a database
10916 **
10917 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to
10918 ** memory that is a serialization of the S database on
10919 ** [database connection] D. If S is a NULL pointer, the main database is used.
10920 ** If P is not a NULL pointer, then the size of the database in bytes
10921 ** is written into *P.
10922 **
10923 ** For an ordinary on-disk database file, the serialization is just a
10924 ** copy of the disk file. For an in-memory database or a "TEMP" database,
10925 ** the serialization is the same sequence of bytes which would be written
10926 ** to disk if that database were backed up to disk.
10927 **
10928 ** The usual case is that sqlite3_serialize() copies the serialization of
10929 ** the database into memory obtained from [sqlite3_malloc64()] and returns
10930 ** a pointer to that memory. The caller is responsible for freeing the
10931 ** returned value to avoid a memory leak. However, if the F argument
10932 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
10933 ** are made, and the sqlite3_serialize() function will return a pointer
10934 ** to the contiguous memory representation of the database that SQLite
10935 ** is currently using for that database, or NULL if no such contiguous
10936 ** memory representation of the database exists. A contiguous memory
10937 ** representation of the database will usually only exist if there has
10938 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
10939 ** values of D and S.
10940 ** The size of the database is written into *P even if the
10941 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
10942 ** of the database exists.
10943 **
10944 ** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
10945 ** the returned buffer content will remain accessible and unchanged
10946 ** until either the next write operation on the connection or when
10947 ** the connection is closed, and applications must not modify the
10948 ** buffer. If the bit had been clear, the returned buffer will not
10949 ** be accessed by SQLite after the call.
10950 **
10951 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
10952 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
10953 ** allocation error occurs.
10954 **
10955 ** This interface is omitted if SQLite is compiled with the
10956 ** [SQLITE_OMIT_DESERIALIZE] option.
10957 */
10958 SQLITE_API unsigned char *sqlite3_serialize(
10959 sqlite3 *db, /* The database connection */
10960 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
10961 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
10962 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
10963 );
10964 10965 /*
10966 ** CAPI3REF: Flags for sqlite3_serialize
10967 **
10968 ** Zero or more of the following constants can be OR-ed together for
10969 ** the F argument to [sqlite3_serialize(D,S,P,F)].
10970 **
10971 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
10972 ** a pointer to contiguous in-memory database that it is currently using,
10973 ** without making a copy of the database. If SQLite is not currently using
10974 ** a contiguous in-memory database, then this option causes
10975 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
10976 ** using a contiguous in-memory database if it has been initialized by a
10977 ** prior call to [sqlite3_deserialize()].
10978 */
10979 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
10980 10981 /*
10982 ** CAPI3REF: Deserialize a database
10983 **
10984 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
10985 ** [database connection] D to disconnect from database S and then
10986 ** reopen S as an in-memory database based on the serialization contained
10987 ** in P. The serialized database P is N bytes in size. M is the size of
10988 ** the buffer P, which might be larger than N. If M is larger than N, and
10989 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10990 ** permitted to add content to the in-memory database as long as the total
10991 ** size does not exceed M bytes.
10992 **
10993 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10994 ** invoke sqlite3_free() on the serialization buffer when the database
10995 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10996 ** SQLite will try to increase the buffer size using sqlite3_realloc64()
10997 ** if writes on the database cause it to grow larger than M bytes.
10998 **
10999 ** Applications must not modify the buffer P or invalidate it before
11000 ** the database connection D is closed.
11001 **
11002 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
11003 ** database is currently in a read transaction or is involved in a backup
11004 ** operation.
11005 **
11006 ** It is not possible to deserialize into the TEMP database. If the
11007 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
11008 ** function returns SQLITE_ERROR.
11009 **
11010 ** The deserialized database should not be in [WAL mode]. If the database
11011 ** is in WAL mode, then any attempt to use the database file will result
11012 ** in an [SQLITE_CANTOPEN] error. The application can set the
11013 ** [file format version numbers] (bytes 18 and 19) of the input database P
11014 ** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
11015 ** database file into rollback mode and work around this limitation.
11016 **
11017 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
11018 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
11019 ** [sqlite3_free()] is invoked on argument P prior to returning.
11020 **
11021 ** This interface is omitted if SQLite is compiled with the
11022 ** [SQLITE_OMIT_DESERIALIZE] option.
11023 */
11024 SQLITE_API int sqlite3_deserialize(
11025 sqlite3 *db, /* The database connection */
11026 const char *zSchema, /* Which DB to reopen with the deserialization */
11027 unsigned char *pData, /* The serialized database content */
11028 sqlite3_int64 szDb, /* Number of bytes in the deserialization */
11029 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
11030 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
11031 );
11032 11033 /*
11034 ** CAPI3REF: Flags for sqlite3_deserialize()
11035 **
11036 ** The following are allowed values for the 6th argument (the F argument) to
11037 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
11038 **
11039 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
11040 ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
11041 ** and that SQLite should take ownership of this memory and automatically
11042 ** free it when it has finished using it. Without this flag, the caller
11043 ** is responsible for freeing any dynamically allocated memory.
11044 **
11045 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
11046 ** grow the size of the database using calls to [sqlite3_realloc64()]. This
11047 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
11048 ** Without this flag, the deserialized database cannot increase in size beyond
11049 ** the number of bytes specified by the M parameter.
11050 **
11051 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
11052 ** should be treated as read-only.
11053 */
11054 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
11055 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
11056 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
11057 11058 /*
11059 ** Undo the hack that converts floating point types to integer for
11060 ** builds on processors without floating point support.
11061 */
11062 #ifdef SQLITE_OMIT_FLOATING_POINT
11063 # undef double
11064 #endif
11065 11066 #if defined(__wasi__)
11067 # undef SQLITE_WASI
11068 # define SQLITE_WASI 1
11069 # ifndef SQLITE_OMIT_LOAD_EXTENSION
11070 # define SQLITE_OMIT_LOAD_EXTENSION
11071 # endif
11072 # ifndef SQLITE_THREADSAFE
11073 # define SQLITE_THREADSAFE 0
11074 # endif
11075 #endif
11076 11077 #ifdef __cplusplus
11078 } /* End of the 'extern "C"' block */
11079 #endif
11080 /* #endif for SQLITE3_H will be added by mksqlite3.tcl */
11081 11082 /******** Begin file sqlite3rtree.h *********/
11083 /*
11084 ** 2010 August 30
11085 **
11086 ** The author disclaims copyright to this source code. In place of
11087 ** a legal notice, here is a blessing:
11088 **
11089 ** May you do good and not evil.
11090 ** May you find forgiveness for yourself and forgive others.
11091 ** May you share freely, never taking more than you give.
11092 **
11093 *************************************************************************
11094 */
11095 11096 #ifndef _SQLITE3RTREE_H_
11097 #define _SQLITE3RTREE_H_
11098 11099 11100 #ifdef __cplusplus
11101 extern "C" {
11102 #endif
11103 11104 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
11105 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
11106 11107 /* The double-precision datatype used by RTree depends on the
11108 ** SQLITE_RTREE_INT_ONLY compile-time option.
11109 */
11110 #ifdef SQLITE_RTREE_INT_ONLY
11111 typedef sqlite3_int64 sqlite3_rtree_dbl;
11112 #else
11113 typedef double sqlite3_rtree_dbl;
11114 #endif
11115 11116 /*
11117 ** Register a geometry callback named zGeom that can be used as part of an
11118 ** R-Tree geometry query as follows:
11119 **
11120 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
11121 */
11122 SQLITE_API int sqlite3_rtree_geometry_callback(
11123 sqlite3 *db,
11124 const char *zGeom,
11125 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
11126 void *pContext
11127 );
11128 11129 11130 /*
11131 ** A pointer to a structure of the following type is passed as the first
11132 ** argument to callbacks registered using rtree_geometry_callback().
11133 */
11134 struct sqlite3_rtree_geometry {
11135 void *pContext; /* Copy of pContext passed to s_r_g_c() */
11136 int nParam; /* Size of array aParam[] */
11137 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
11138 void *pUser; /* Callback implementation user data */
11139 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
11140 };
11141 11142 /*
11143 ** Register a 2nd-generation geometry callback named zScore that can be
11144 ** used as part of an R-Tree geometry query as follows:
11145 **
11146 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
11147 */
11148 SQLITE_API int sqlite3_rtree_query_callback(
11149 sqlite3 *db,
11150 const char *zQueryFunc,
11151 int (*xQueryFunc)(sqlite3_rtree_query_info*),
11152 void *pContext,
11153 void (*xDestructor)(void*)
11154 );
11155 11156 11157 /*
11158 ** A pointer to a structure of the following type is passed as the
11159 ** argument to scored geometry callback registered using
11160 ** sqlite3_rtree_query_callback().
11161 **
11162 ** Note that the first 5 fields of this structure are identical to
11163 ** sqlite3_rtree_geometry. This structure is a subclass of
11164 ** sqlite3_rtree_geometry.
11165 */
11166 struct sqlite3_rtree_query_info {
11167 void *pContext; /* pContext from when function registered */
11168 int nParam; /* Number of function parameters */
11169 sqlite3_rtree_dbl *aParam; /* value of function parameters */
11170 void *pUser; /* callback can use this, if desired */
11171 void (*xDelUser)(void*); /* function to free pUser */
11172 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
11173 unsigned int *anQueue; /* Number of pending entries in the queue */
11174 int nCoord; /* Number of coordinates */
11175 int iLevel; /* Level of current node or entry */
11176 int mxLevel; /* The largest iLevel value in the tree */
11177 sqlite3_int64 iRowid; /* Rowid for current entry */
11178 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
11179 int eParentWithin; /* Visibility of parent node */
11180 int eWithin; /* OUT: Visibility */
11181 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
11182 /* The following fields are only available in 3.8.11 and later */
11183 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
11184 };
11185 11186 /*
11187 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
11188 */
11189 #define NOT_WITHIN 0 /* Object completely outside of query region */
11190 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */
11191 #define FULLY_WITHIN 2 /* Object fully contained within query region */
11192 11193 11194 #ifdef __cplusplus
11195 } /* end of the 'extern "C"' block */
11196 #endif
11197 11198 #endif /* ifndef _SQLITE3RTREE_H_ */
11199 11200 /******** End of sqlite3rtree.h *********/
11201 /******** Begin file sqlite3session.h *********/
11202 11203 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
11204 #define __SQLITESESSION_H_ 1
11205 11206 /*
11207 ** Make sure we can call this stuff from C++.
11208 */
11209 #ifdef __cplusplus
11210 extern "C" {
11211 #endif
11212 11213 11214 /*
11215 ** CAPI3REF: Session Object Handle
11216 **
11217 ** An instance of this object is a [session] that can be used to
11218 ** record changes to a database.
11219 */
11220 typedef struct sqlite3_session sqlite3_session;
11221 11222 /*
11223 ** CAPI3REF: Changeset Iterator Handle
11224 **
11225 ** An instance of this object acts as a cursor for iterating
11226 ** over the elements of a [changeset] or [patchset].
11227 */
11228 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
11229 11230 /*
11231 ** CAPI3REF: Create A New Session Object
11232 ** CONSTRUCTOR: sqlite3_session
11233 **
11234 ** Create a new session object attached to database handle db. If successful,
11235 ** a pointer to the new object is written to *ppSession and SQLITE_OK is
11236 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
11237 ** error code (e.g. SQLITE_NOMEM) is returned.
11238 **
11239 ** It is possible to create multiple session objects attached to a single
11240 ** database handle.
11241 **
11242 ** Session objects created using this function should be deleted using the
11243 ** [sqlite3session_delete()] function before the database handle that they
11244 ** are attached to is itself closed. If the database handle is closed before
11245 ** the session object is deleted, then the results of calling any session
11246 ** module function, including [sqlite3session_delete()] on the session object
11247 ** are undefined.
11248 **
11249 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
11250 ** is not possible for an application to register a pre-update hook on a
11251 ** database handle that has one or more session objects attached. Nor is
11252 ** it possible to create a session object attached to a database handle for
11253 ** which a pre-update hook is already defined. The results of attempting
11254 ** either of these things are undefined.
11255 **
11256 ** The session object will be used to create changesets for tables in
11257 ** database zDb, where zDb is either "main", or "temp", or the name of an
11258 ** attached database. It is not an error if database zDb is not attached
11259 ** to the database when the session object is created.
11260 */
11261 SQLITE_API int sqlite3session_create(
11262 sqlite3 *db, /* Database handle */
11263 const char *zDb, /* Name of db (e.g. "main") */
11264 sqlite3_session **ppSession /* OUT: New session object */
11265 );
11266 11267 /*
11268 ** CAPI3REF: Delete A Session Object
11269 ** DESTRUCTOR: sqlite3_session
11270 **
11271 ** Delete a session object previously allocated using
11272 ** [sqlite3session_create()]. Once a session object has been deleted, the
11273 ** results of attempting to use pSession with any other session module
11274 ** function are undefined.
11275 **
11276 ** Session objects must be deleted before the database handle to which they
11277 ** are attached is closed. Refer to the documentation for
11278 ** [sqlite3session_create()] for details.
11279 */
11280 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
11281 11282 /*
11283 ** CAPI3REF: Configure a Session Object
11284 ** METHOD: sqlite3_session
11285 **
11286 ** This method is used to configure a session object after it has been
11287 ** created. At present the only valid values for the second parameter are
11288 ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
11289 **
11290 */
11291 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
11292 11293 /*
11294 ** CAPI3REF: Options for sqlite3session_object_config
11295 **
11296 ** The following values may passed as the the 2nd parameter to
11297 ** sqlite3session_object_config().
11298 **
11299 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
11300 ** This option is used to set, clear or query the flag that enables
11301 ** the [sqlite3session_changeset_size()] API. Because it imposes some
11302 ** computational overhead, this API is disabled by default. Argument
11303 ** pArg must point to a value of type (int). If the value is initially
11304 ** 0, then the sqlite3session_changeset_size() API is disabled. If it
11305 ** is greater than 0, then the same API is enabled. Or, if the initial
11306 ** value is less than zero, no change is made. In all cases the (int)
11307 ** variable is set to 1 if the sqlite3session_changeset_size() API is
11308 ** enabled following the current call, or 0 otherwise.
11309 **
11310 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11311 ** the first table has been attached to the session object.
11312 **
11313 ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
11314 ** This option is used to set, clear or query the flag that enables
11315 ** collection of data for tables with no explicit PRIMARY KEY.
11316 **
11317 ** Normally, tables with no explicit PRIMARY KEY are simply ignored
11318 ** by the sessions module. However, if this flag is set, it behaves
11319 ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
11320 ** as their leftmost columns.
11321 **
11322 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11323 ** the first table has been attached to the session object.
11324 */
11325 #define SQLITE_SESSION_OBJCONFIG_SIZE 1
11326 #define SQLITE_SESSION_OBJCONFIG_ROWID 2
11327 11328 /*
11329 ** CAPI3REF: Enable Or Disable A Session Object
11330 ** METHOD: sqlite3_session
11331 **
11332 ** Enable or disable the recording of changes by a session object. When
11333 ** enabled, a session object records changes made to the database. When
11334 ** disabled - it does not. A newly created session object is enabled.
11335 ** Refer to the documentation for [sqlite3session_changeset()] for further
11336 ** details regarding how enabling and disabling a session object affects
11337 ** the eventual changesets.
11338 **
11339 ** Passing zero to this function disables the session. Passing a value
11340 ** greater than zero enables it. Passing a value less than zero is a
11341 ** no-op, and may be used to query the current state of the session.
11342 **
11343 ** The return value indicates the final state of the session object: 0 if
11344 ** the session is disabled, or 1 if it is enabled.
11345 */
11346 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
11347 11348 /*
11349 ** CAPI3REF: Set Or Clear the Indirect Change Flag
11350 ** METHOD: sqlite3_session
11351 **
11352 ** Each change recorded by a session object is marked as either direct or
11353 ** indirect. A change is marked as indirect if either:
11354 **
11355 ** <ul>
11356 ** <li> The session object "indirect" flag is set when the change is
11357 ** made, or
11358 ** <li> The change is made by an SQL trigger or foreign key action
11359 ** instead of directly as a result of a users SQL statement.
11360 ** </ul>
11361 **
11362 ** If a single row is affected by more than one operation within a session,
11363 ** then the change is considered indirect if all operations meet the criteria
11364 ** for an indirect change above, or direct otherwise.
11365 **
11366 ** This function is used to set, clear or query the session object indirect
11367 ** flag. If the second argument passed to this function is zero, then the
11368 ** indirect flag is cleared. If it is greater than zero, the indirect flag
11369 ** is set. Passing a value less than zero does not modify the current value
11370 ** of the indirect flag, and may be used to query the current state of the
11371 ** indirect flag for the specified session object.
11372 **
11373 ** The return value indicates the final state of the indirect flag: 0 if
11374 ** it is clear, or 1 if it is set.
11375 */
11376 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
11377 11378 /*
11379 ** CAPI3REF: Attach A Table To A Session Object
11380 ** METHOD: sqlite3_session
11381 **
11382 ** If argument zTab is not NULL, then it is the name of a table to attach
11383 ** to the session object passed as the first argument. All subsequent changes
11384 ** made to the table while the session object is enabled will be recorded. See
11385 ** documentation for [sqlite3session_changeset()] for further details.
11386 **
11387 ** Or, if argument zTab is NULL, then changes are recorded for all tables
11388 ** in the database. If additional tables are added to the database (by
11389 ** executing "CREATE TABLE" statements) after this call is made, changes for
11390 ** the new tables are also recorded.
11391 **
11392 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
11393 ** defined as part of their CREATE TABLE statement. It does not matter if the
11394 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
11395 ** KEY may consist of a single column, or may be a composite key.
11396 **
11397 ** It is not an error if the named table does not exist in the database. Nor
11398 ** is it an error if the named table does not have a PRIMARY KEY. However,
11399 ** no changes will be recorded in either of these scenarios.
11400 **
11401 ** Changes are not recorded for individual rows that have NULL values stored
11402 ** in one or more of their PRIMARY KEY columns.
11403 **
11404 ** SQLITE_OK is returned if the call completes without error. Or, if an error
11405 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
11406 **
11407 ** <h3>Special sqlite_stat1 Handling</h3>
11408 **
11409 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11410 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11411 ** <pre>
11412 ** CREATE TABLE sqlite_stat1(tbl,idx,stat)
11413 ** </pre>
11414 **
11415 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11416 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11417 ** are recorded for rows for which (idx IS NULL) is true. However, for such
11418 ** rows a zero-length blob (SQL value X'') is stored in the changeset or
11419 ** patchset instead of a NULL value. This allows such changesets to be
11420 ** manipulated by legacy implementations of sqlite3changeset_invert(),
11421 ** concat() and similar.
11422 **
11423 ** The sqlite3changeset_apply() function automatically converts the
11424 ** zero-length blob back to a NULL value when updating the sqlite_stat1
11425 ** table. However, if the application calls sqlite3changeset_new(),
11426 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11427 ** iterator directly (including on a changeset iterator passed to a
11428 ** conflict-handler callback) then the X'' value is returned. The application
11429 ** must translate X'' to NULL itself if required.
11430 **
11431 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11432 ** changes made to the sqlite_stat1 table. Legacy versions of the
11433 ** sqlite3changeset_apply() function silently ignore any modifications to the
11434 ** sqlite_stat1 table that are part of a changeset or patchset.
11435 */
11436 SQLITE_API int sqlite3session_attach(
11437 sqlite3_session *pSession, /* Session object */
11438 const char *zTab /* Table name */
11439 );
11440 11441 /*
11442 ** CAPI3REF: Set a table filter on a Session Object.
11443 ** METHOD: sqlite3_session
11444 **
11445 ** The second argument (xFilter) is the "filter callback". For changes to rows
11446 ** in tables that are not attached to the Session object, the filter is called
11447 ** to determine whether changes to the table's rows should be tracked or not.
11448 ** If xFilter returns 0, changes are not tracked. Note that once a table is
11449 ** attached, xFilter will not be called again.
11450 */
11451 SQLITE_API void sqlite3session_table_filter(
11452 sqlite3_session *pSession, /* Session object */
11453 int(*xFilter)(
11454 void *pCtx, /* Copy of third arg to _filter_table() */
11455 const char *zTab /* Table name */
11456 ),
11457 void *pCtx /* First argument passed to xFilter */
11458 );
11459 11460 /*
11461 ** CAPI3REF: Generate A Changeset From A Session Object
11462 ** METHOD: sqlite3_session
11463 **
11464 ** Obtain a changeset containing changes to the tables attached to the
11465 ** session object passed as the first argument. If successful,
11466 ** set *ppChangeset to point to a buffer containing the changeset
11467 ** and *pnChangeset to the size of the changeset in bytes before returning
11468 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11469 ** zero and return an SQLite error code.
11470 **
11471 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11472 ** each representing a change to a single row of an attached table. An INSERT
11473 ** change contains the values of each field of a new database row. A DELETE
11474 ** contains the original values of each field of a deleted database row. An
11475 ** UPDATE change contains the original values of each field of an updated
11476 ** database row along with the updated values for each updated non-primary-key
11477 ** column. It is not possible for an UPDATE change to represent a change that
11478 ** modifies the values of primary key columns. If such a change is made, it
11479 ** is represented in a changeset as a DELETE followed by an INSERT.
11480 **
11481 ** Changes are not recorded for rows that have NULL values stored in one or
11482 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11483 ** no corresponding change is present in the changesets returned by this
11484 ** function. If an existing row with one or more NULL values stored in
11485 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11486 ** only an INSERT is appears in the changeset. Similarly, if an existing row
11487 ** with non-NULL PRIMARY KEY values is updated so that one or more of its
11488 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11489 ** DELETE change only.
11490 **
11491 ** The contents of a changeset may be traversed using an iterator created
11492 ** using the [sqlite3changeset_start()] API. A changeset may be applied to
11493 ** a database with a compatible schema using the [sqlite3changeset_apply()]
11494 ** API.
11495 **
11496 ** Within a changeset generated by this function, all changes related to a
11497 ** single table are grouped together. In other words, when iterating through
11498 ** a changeset or when applying a changeset to a database, all changes related
11499 ** to a single table are processed before moving on to the next table. Tables
11500 ** are sorted in the same order in which they were attached (or auto-attached)
11501 ** to the sqlite3_session object. The order in which the changes related to
11502 ** a single table are stored is undefined.
11503 **
11504 ** Following a successful call to this function, it is the responsibility of
11505 ** the caller to eventually free the buffer that *ppChangeset points to using
11506 ** [sqlite3_free()].
11507 **
11508 ** <h3>Changeset Generation</h3>
11509 **
11510 ** Once a table has been attached to a session object, the session object
11511 ** records the primary key values of all new rows inserted into the table.
11512 ** It also records the original primary key and other column values of any
11513 ** deleted or updated rows. For each unique primary key value, data is only
11514 ** recorded once - the first time a row with said primary key is inserted,
11515 ** updated or deleted in the lifetime of the session.
11516 **
11517 ** There is one exception to the previous paragraph: when a row is inserted,
11518 ** updated or deleted, if one or more of its primary key columns contain a
11519 ** NULL value, no record of the change is made.
11520 **
11521 ** The session object therefore accumulates two types of records - those
11522 ** that consist of primary key values only (created when the user inserts
11523 ** a new record) and those that consist of the primary key values and the
11524 ** original values of other table columns (created when the users deletes
11525 ** or updates a record).
11526 **
11527 ** When this function is called, the requested changeset is created using
11528 ** both the accumulated records and the current contents of the database
11529 ** file. Specifically:
11530 **
11531 ** <ul>
11532 ** <li> For each record generated by an insert, the database is queried
11533 ** for a row with a matching primary key. If one is found, an INSERT
11534 ** change is added to the changeset. If no such row is found, no change
11535 ** is added to the changeset.
11536 **
11537 ** <li> For each record generated by an update or delete, the database is
11538 ** queried for a row with a matching primary key. If such a row is
11539 ** found and one or more of the non-primary key fields have been
11540 ** modified from their original values, an UPDATE change is added to
11541 ** the changeset. Or, if no such row is found in the table, a DELETE
11542 ** change is added to the changeset. If there is a row with a matching
11543 ** primary key in the database, but all fields contain their original
11544 ** values, no change is added to the changeset.
11545 ** </ul>
11546 **
11547 ** This means, amongst other things, that if a row is inserted and then later
11548 ** deleted while a session object is active, neither the insert nor the delete
11549 ** will be present in the changeset. Or if a row is deleted and then later a
11550 ** row with the same primary key values inserted while a session object is
11551 ** active, the resulting changeset will contain an UPDATE change instead of
11552 ** a DELETE and an INSERT.
11553 **
11554 ** When a session object is disabled (see the [sqlite3session_enable()] API),
11555 ** it does not accumulate records when rows are inserted, updated or deleted.
11556 ** This may appear to have some counter-intuitive effects if a single row
11557 ** is written to more than once during a session. For example, if a row
11558 ** is inserted while a session object is enabled, then later deleted while
11559 ** the same session object is disabled, no INSERT record will appear in the
11560 ** changeset, even though the delete took place while the session was disabled.
11561 ** Or, if one field of a row is updated while a session is enabled, and
11562 ** then another field of the same row is updated while the session is disabled,
11563 ** the resulting changeset will contain an UPDATE change that updates both
11564 ** fields.
11565 */
11566 SQLITE_API int sqlite3session_changeset(
11567 sqlite3_session *pSession, /* Session object */
11568 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11569 void **ppChangeset /* OUT: Buffer containing changeset */
11570 );
11571 11572 /*
11573 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11574 ** METHOD: sqlite3_session
11575 **
11576 ** By default, this function always returns 0. For it to return
11577 ** a useful result, the sqlite3_session object must have been configured
11578 ** to enable this API using sqlite3session_object_config() with the
11579 ** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11580 **
11581 ** When enabled, this function returns an upper limit, in bytes, for the size
11582 ** of the changeset that might be produced if sqlite3session_changeset() were
11583 ** called. The final changeset size might be equal to or smaller than the
11584 ** size in bytes returned by this function.
11585 */
11586 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11587 11588 /*
11589 ** CAPI3REF: Load The Difference Between Tables Into A Session
11590 ** METHOD: sqlite3_session
11591 **
11592 ** If it is not already attached to the session object passed as the first
11593 ** argument, this function attaches table zTbl in the same manner as the
11594 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11595 ** does not have a primary key, this function is a no-op (but does not return
11596 ** an error).
11597 **
11598 ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11599 ** attached to the same database handle as the session object that contains
11600 ** a table compatible with the table attached to the session by this function.
11601 ** A table is considered compatible if it:
11602 **
11603 ** <ul>
11604 ** <li> Has the same name,
11605 ** <li> Has the same set of columns declared in the same order, and
11606 ** <li> Has the same PRIMARY KEY definition.
11607 ** </ul>
11608 **
11609 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11610 ** are compatible but do not have any PRIMARY KEY columns, it is not an error
11611 ** but no changes are added to the session object. As with other session
11612 ** APIs, tables without PRIMARY KEYs are simply ignored.
11613 **
11614 ** This function adds a set of changes to the session object that could be
11615 ** used to update the table in database zFrom (call this the "from-table")
11616 ** so that its content is the same as the table attached to the session
11617 ** object (call this the "to-table"). Specifically:
11618 **
11619 ** <ul>
11620 ** <li> For each row (primary key) that exists in the to-table but not in
11621 ** the from-table, an INSERT record is added to the session object.
11622 **
11623 ** <li> For each row (primary key) that exists in the to-table but not in
11624 ** the from-table, a DELETE record is added to the session object.
11625 **
11626 ** <li> For each row (primary key) that exists in both tables, but features
11627 ** different non-PK values in each, an UPDATE record is added to the
11628 ** session.
11629 ** </ul>
11630 **
11631 ** To clarify, if this function is called and then a changeset constructed
11632 ** using [sqlite3session_changeset()], then after applying that changeset to
11633 ** database zFrom the contents of the two compatible tables would be
11634 ** identical.
11635 **
11636 ** Unless the call to this function is a no-op as described above, it is an
11637 ** error if database zFrom does not exist or does not contain the required
11638 ** compatible table.
11639 **
11640 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11641 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11642 ** may be set to point to a buffer containing an English language error
11643 ** message. It is the responsibility of the caller to free this buffer using
11644 ** sqlite3_free().
11645 */
11646 SQLITE_API int sqlite3session_diff(
11647 sqlite3_session *pSession,
11648 const char *zFromDb,
11649 const char *zTbl,
11650 char **pzErrMsg
11651 );
11652 11653 11654 /*
11655 ** CAPI3REF: Generate A Patchset From A Session Object
11656 ** METHOD: sqlite3_session
11657 **
11658 ** The differences between a patchset and a changeset are that:
11659 **
11660 ** <ul>
11661 ** <li> DELETE records consist of the primary key fields only. The
11662 ** original values of other fields are omitted.
11663 ** <li> The original values of any modified fields are omitted from
11664 ** UPDATE records.
11665 ** </ul>
11666 **
11667 ** A patchset blob may be used with up to date versions of all
11668 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11669 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11670 ** attempting to use a patchset blob with old versions of the
11671 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11672 **
11673 ** Because the non-primary key "old.*" fields are omitted, no
11674 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11675 ** is passed to the sqlite3changeset_apply() API. Other conflict types work
11676 ** in the same way as for changesets.
11677 **
11678 ** Changes within a patchset are ordered in the same way as for changesets
11679 ** generated by the sqlite3session_changeset() function (i.e. all changes for
11680 ** a single table are grouped together, tables appear in the order in which
11681 ** they were attached to the session object).
11682 */
11683 SQLITE_API int sqlite3session_patchset(
11684 sqlite3_session *pSession, /* Session object */
11685 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11686 void **ppPatchset /* OUT: Buffer containing patchset */
11687 );
11688 11689 /*
11690 ** CAPI3REF: Test if a changeset has recorded any changes.
11691 **
11692 ** Return non-zero if no changes to attached tables have been recorded by
11693 ** the session object passed as the first argument. Otherwise, if one or
11694 ** more changes have been recorded, return zero.
11695 **
11696 ** Even if this function returns zero, it is possible that calling
11697 ** [sqlite3session_changeset()] on the session handle may still return a
11698 ** changeset that contains no changes. This can happen when a row in
11699 ** an attached table is modified and then later on the original values
11700 ** are restored. However, if this function returns non-zero, then it is
11701 ** guaranteed that a call to sqlite3session_changeset() will return a
11702 ** changeset containing zero changes.
11703 */
11704 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11705 11706 /*
11707 ** CAPI3REF: Query for the amount of heap memory used by a session object.
11708 **
11709 ** This API returns the total amount of heap memory in bytes currently
11710 ** used by the session object passed as the only argument.
11711 */
11712 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11713 11714 /*
11715 ** CAPI3REF: Create An Iterator To Traverse A Changeset
11716 ** CONSTRUCTOR: sqlite3_changeset_iter
11717 **
11718 ** Create an iterator used to iterate through the contents of a changeset.
11719 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11720 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11721 ** SQLite error code is returned.
11722 **
11723 ** The following functions can be used to advance and query a changeset
11724 ** iterator created by this function:
11725 **
11726 ** <ul>
11727 ** <li> [sqlite3changeset_next()]
11728 ** <li> [sqlite3changeset_op()]
11729 ** <li> [sqlite3changeset_new()]
11730 ** <li> [sqlite3changeset_old()]
11731 ** </ul>
11732 **
11733 ** It is the responsibility of the caller to eventually destroy the iterator
11734 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11735 ** changeset (pChangeset) must remain valid until after the iterator is
11736 ** destroyed.
11737 **
11738 ** Assuming the changeset blob was created by one of the
11739 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11740 ** [sqlite3changeset_invert()] functions, all changes within the changeset
11741 ** that apply to a single table are grouped together. This means that when
11742 ** an application iterates through a changeset using an iterator created by
11743 ** this function, all changes that relate to a single table are visited
11744 ** consecutively. There is no chance that the iterator will visit a change
11745 ** the applies to table X, then one for table Y, and then later on visit
11746 ** another change for table X.
11747 **
11748 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11749 ** may be modified by passing a combination of
11750 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11751 **
11752 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11753 ** and therefore subject to change.
11754 */
11755 SQLITE_API int sqlite3changeset_start(
11756 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11757 int nChangeset, /* Size of changeset blob in bytes */
11758 void *pChangeset /* Pointer to blob containing changeset */
11759 );
11760 SQLITE_API int sqlite3changeset_start_v2(
11761 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11762 int nChangeset, /* Size of changeset blob in bytes */
11763 void *pChangeset, /* Pointer to blob containing changeset */
11764 int flags /* SESSION_CHANGESETSTART_* flags */
11765 );
11766 11767 /*
11768 ** CAPI3REF: Flags for sqlite3changeset_start_v2
11769 **
11770 ** The following flags may passed via the 4th parameter to
11771 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11772 **
11773 ** <dt>SQLITE_CHANGESETSTART_INVERT <dd>
11774 ** Invert the changeset while iterating through it. This is equivalent to
11775 ** inverting a changeset using sqlite3changeset_invert() before applying it.
11776 ** It is an error to specify this flag with a patchset.
11777 */
11778 #define SQLITE_CHANGESETSTART_INVERT 0x0002
11779 11780 11781 /*
11782 ** CAPI3REF: Advance A Changeset Iterator
11783 ** METHOD: sqlite3_changeset_iter
11784 **
11785 ** This function may only be used with iterators created by the function
11786 ** [sqlite3changeset_start()]. If it is called on an iterator passed to
11787 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11788 ** is returned and the call has no effect.
11789 **
11790 ** Immediately after an iterator is created by sqlite3changeset_start(), it
11791 ** does not point to any change in the changeset. Assuming the changeset
11792 ** is not empty, the first call to this function advances the iterator to
11793 ** point to the first change in the changeset. Each subsequent call advances
11794 ** the iterator to point to the next change in the changeset (if any). If
11795 ** no error occurs and the iterator points to a valid change after a call
11796 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11797 ** Otherwise, if all changes in the changeset have already been visited,
11798 ** SQLITE_DONE is returned.
11799 **
11800 ** If an error occurs, an SQLite error code is returned. Possible error
11801 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11802 ** SQLITE_NOMEM.
11803 */
11804 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11805 11806 /*
11807 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11808 ** METHOD: sqlite3_changeset_iter
11809 **
11810 ** The pIter argument passed to this function may either be an iterator
11811 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11812 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11813 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11814 ** is not the case, this function returns [SQLITE_MISUSE].
11815 **
11816 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11817 ** outputs are set through these pointers:
11818 **
11819 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11820 ** depending on the type of change that the iterator currently points to;
11821 **
11822 ** *pnCol is set to the number of columns in the table affected by the change; and
11823 **
11824 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11825 ** the name of the table affected by the current change. The buffer remains
11826 ** valid until either sqlite3changeset_next() is called on the iterator
11827 ** or until the conflict-handler function returns.
11828 **
11829 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11830 ** is an indirect change, or false (0) otherwise. See the documentation for
11831 ** [sqlite3session_indirect()] for a description of direct and indirect
11832 ** changes.
11833 **
11834 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11835 ** SQLite error code is returned. The values of the output variables may not
11836 ** be trusted in this case.
11837 */
11838 SQLITE_API int sqlite3changeset_op(
11839 sqlite3_changeset_iter *pIter, /* Iterator object */
11840 const char **pzTab, /* OUT: Pointer to table name */
11841 int *pnCol, /* OUT: Number of columns in table */
11842 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11843 int *pbIndirect /* OUT: True for an 'indirect' change */
11844 );
11845 11846 /*
11847 ** CAPI3REF: Obtain The Primary Key Definition Of A Table
11848 ** METHOD: sqlite3_changeset_iter
11849 **
11850 ** For each modified table, a changeset includes the following:
11851 **
11852 ** <ul>
11853 ** <li> The number of columns in the table, and
11854 ** <li> Which of those columns make up the tables PRIMARY KEY.
11855 ** </ul>
11856 **
11857 ** This function is used to find which columns comprise the PRIMARY KEY of
11858 ** the table modified by the change that iterator pIter currently points to.
11859 ** If successful, *pabPK is set to point to an array of nCol entries, where
11860 ** nCol is the number of columns in the table. Elements of *pabPK are set to
11861 ** 0x01 if the corresponding column is part of the tables primary key, or
11862 ** 0x00 if it is not.
11863 **
11864 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
11865 ** in the table.
11866 **
11867 ** If this function is called when the iterator does not point to a valid
11868 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
11869 ** SQLITE_OK is returned and the output variables populated as described
11870 ** above.
11871 */
11872 SQLITE_API int sqlite3changeset_pk(
11873 sqlite3_changeset_iter *pIter, /* Iterator object */
11874 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
11875 int *pnCol /* OUT: Number of entries in output array */
11876 );
11877 11878 /*
11879 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
11880 ** METHOD: sqlite3_changeset_iter
11881 **
11882 ** The pIter argument passed to this function may either be an iterator
11883 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11884 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11885 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11886 ** Furthermore, it may only be called if the type of change that the iterator
11887 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
11888 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11889 **
11890 ** Argument iVal must be greater than or equal to 0, and less than the number
11891 ** of columns in the table affected by the current change. Otherwise,
11892 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11893 **
11894 ** If successful, this function sets *ppValue to point to a protected
11895 ** sqlite3_value object containing the iVal'th value from the vector of
11896 ** original row values stored as part of the UPDATE or DELETE change and
11897 ** returns SQLITE_OK. The name of the function comes from the fact that this
11898 ** is similar to the "old.*" columns available to update or delete triggers.
11899 **
11900 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11901 ** is returned and *ppValue is set to NULL.
11902 */
11903 SQLITE_API int sqlite3changeset_old(
11904 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11905 int iVal, /* Column number */
11906 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
11907 );
11908 11909 /*
11910 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
11911 ** METHOD: sqlite3_changeset_iter
11912 **
11913 ** The pIter argument passed to this function may either be an iterator
11914 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11915 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11916 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11917 ** Furthermore, it may only be called if the type of change that the iterator
11918 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
11919 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11920 **
11921 ** Argument iVal must be greater than or equal to 0, and less than the number
11922 ** of columns in the table affected by the current change. Otherwise,
11923 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11924 **
11925 ** If successful, this function sets *ppValue to point to a protected
11926 ** sqlite3_value object containing the iVal'th value from the vector of
11927 ** new row values stored as part of the UPDATE or INSERT change and
11928 ** returns SQLITE_OK. If the change is an UPDATE and does not include
11929 ** a new value for the requested column, *ppValue is set to NULL and
11930 ** SQLITE_OK returned. The name of the function comes from the fact that
11931 ** this is similar to the "new.*" columns available to update or delete
11932 ** triggers.
11933 **
11934 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11935 ** is returned and *ppValue is set to NULL.
11936 */
11937 SQLITE_API int sqlite3changeset_new(
11938 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11939 int iVal, /* Column number */
11940 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
11941 );
11942 11943 /*
11944 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
11945 ** METHOD: sqlite3_changeset_iter
11946 **
11947 ** This function should only be used with iterator objects passed to a
11948 ** conflict-handler callback by [sqlite3changeset_apply()] with either
11949 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
11950 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
11951 ** is set to NULL.
11952 **
11953 ** Argument iVal must be greater than or equal to 0, and less than the number
11954 ** of columns in the table affected by the current change. Otherwise,
11955 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11956 **
11957 ** If successful, this function sets *ppValue to point to a protected
11958 ** sqlite3_value object containing the iVal'th value from the
11959 ** "conflicting row" associated with the current conflict-handler callback
11960 ** and returns SQLITE_OK.
11961 **
11962 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11963 ** is returned and *ppValue is set to NULL.
11964 */
11965 SQLITE_API int sqlite3changeset_conflict(
11966 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11967 int iVal, /* Column number */
11968 sqlite3_value **ppValue /* OUT: Value from conflicting row */
11969 );
11970 11971 /*
11972 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
11973 ** METHOD: sqlite3_changeset_iter
11974 **
11975 ** This function may only be called with an iterator passed to an
11976 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
11977 ** it sets the output variable to the total number of known foreign key
11978 ** violations in the destination database and returns SQLITE_OK.
11979 **
11980 ** In all other cases this function returns SQLITE_MISUSE.
11981 */
11982 SQLITE_API int sqlite3changeset_fk_conflicts(
11983 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11984 int *pnOut /* OUT: Number of FK violations */
11985 );
11986 11987 11988 /*
11989 ** CAPI3REF: Finalize A Changeset Iterator
11990 ** METHOD: sqlite3_changeset_iter
11991 **
11992 ** This function is used to finalize an iterator allocated with
11993 ** [sqlite3changeset_start()].
11994 **
11995 ** This function should only be called on iterators created using the
11996 ** [sqlite3changeset_start()] function. If an application calls this
11997 ** function with an iterator passed to a conflict-handler by
11998 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
11999 ** call has no effect.
12000 **
12001 ** If an error was encountered within a call to an sqlite3changeset_xxx()
12002 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
12003 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
12004 ** to that error is returned by this function. Otherwise, SQLITE_OK is
12005 ** returned. This is to allow the following pattern (pseudo-code):
12006 **
12007 ** <pre>
12008 ** sqlite3changeset_start();
12009 ** while( SQLITE_ROW==sqlite3changeset_next() ){
12010 ** // Do something with change.
12011 ** }
12012 ** rc = sqlite3changeset_finalize();
12013 ** if( rc!=SQLITE_OK ){
12014 ** // An error has occurred
12015 ** }
12016 ** </pre>
12017 */
12018 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
12019 12020 /*
12021 ** CAPI3REF: Invert A Changeset
12022 **
12023 ** This function is used to "invert" a changeset object. Applying an inverted
12024 ** changeset to a database reverses the effects of applying the uninverted
12025 ** changeset. Specifically:
12026 **
12027 ** <ul>
12028 ** <li> Each DELETE change is changed to an INSERT, and
12029 ** <li> Each INSERT change is changed to a DELETE, and
12030 ** <li> For each UPDATE change, the old.* and new.* values are exchanged.
12031 ** </ul>
12032 **
12033 ** This function does not change the order in which changes appear within
12034 ** the changeset. It merely reverses the sense of each individual change.
12035 **
12036 ** If successful, a pointer to a buffer containing the inverted changeset
12037 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
12038 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
12039 ** zeroed and an SQLite error code returned.
12040 **
12041 ** It is the responsibility of the caller to eventually call sqlite3_free()
12042 ** on the *ppOut pointer to free the buffer allocation following a successful
12043 ** call to this function.
12044 **
12045 ** WARNING/TODO: This function currently assumes that the input is a valid
12046 ** changeset. If it is not, the results are undefined.
12047 */
12048 SQLITE_API int sqlite3changeset_invert(
12049 int nIn, const void *pIn, /* Input changeset */
12050 int *pnOut, void **ppOut /* OUT: Inverse of input */
12051 );
12052 12053 /*
12054 ** CAPI3REF: Concatenate Two Changeset Objects
12055 **
12056 ** This function is used to concatenate two changesets, A and B, into a
12057 ** single changeset. The result is a changeset equivalent to applying
12058 ** changeset A followed by changeset B.
12059 **
12060 ** This function combines the two input changesets using an
12061 ** sqlite3_changegroup object. Calling it produces similar results as the
12062 ** following code fragment:
12063 **
12064 ** <pre>
12065 ** sqlite3_changegroup *pGrp;
12066 ** rc = sqlite3_changegroup_new(&pGrp);
12067 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
12068 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
12069 ** if( rc==SQLITE_OK ){
12070 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
12071 ** }else{
12072 ** *ppOut = 0;
12073 ** *pnOut = 0;
12074 ** }
12075 ** </pre>
12076 **
12077 ** Refer to the sqlite3_changegroup documentation below for details.
12078 */
12079 SQLITE_API int sqlite3changeset_concat(
12080 int nA, /* Number of bytes in buffer pA */
12081 void *pA, /* Pointer to buffer containing changeset A */
12082 int nB, /* Number of bytes in buffer pB */
12083 void *pB, /* Pointer to buffer containing changeset B */
12084 int *pnOut, /* OUT: Number of bytes in output changeset */
12085 void **ppOut /* OUT: Buffer containing output changeset */
12086 );
12087 12088 /*
12089 ** CAPI3REF: Changegroup Handle
12090 **
12091 ** A changegroup is an object used to combine two or more
12092 ** [changesets] or [patchsets]
12093 */
12094 typedef struct sqlite3_changegroup sqlite3_changegroup;
12095 12096 /*
12097 ** CAPI3REF: Create A New Changegroup Object
12098 ** CONSTRUCTOR: sqlite3_changegroup
12099 **
12100 ** An sqlite3_changegroup object is used to combine two or more changesets
12101 ** (or patchsets) into a single changeset (or patchset). A single changegroup
12102 ** object may combine changesets or patchsets, but not both. The output is
12103 ** always in the same format as the input.
12104 **
12105 ** If successful, this function returns SQLITE_OK and populates (*pp) with
12106 ** a pointer to a new sqlite3_changegroup object before returning. The caller
12107 ** should eventually free the returned object using a call to
12108 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
12109 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
12110 **
12111 ** The usual usage pattern for an sqlite3_changegroup object is as follows:
12112 **
12113 ** <ul>
12114 ** <li> It is created using a call to sqlite3changegroup_new().
12115 **
12116 ** <li> Zero or more changesets (or patchsets) are added to the object
12117 ** by calling sqlite3changegroup_add().
12118 **
12119 ** <li> The result of combining all input changesets together is obtained
12120 ** by the application via a call to sqlite3changegroup_output().
12121 **
12122 ** <li> The object is deleted using a call to sqlite3changegroup_delete().
12123 ** </ul>
12124 **
12125 ** Any number of calls to add() and output() may be made between the calls to
12126 ** new() and delete(), and in any order.
12127 **
12128 ** As well as the regular sqlite3changegroup_add() and
12129 ** sqlite3changegroup_output() functions, also available are the streaming
12130 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
12131 */
12132 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
12133 12134 /*
12135 ** CAPI3REF: Add a Schema to a Changegroup
12136 ** METHOD: sqlite3_changegroup_schema
12137 **
12138 ** This method may be used to optionally enforce the rule that the changesets
12139 ** added to the changegroup handle must match the schema of database zDb
12140 ** ("main", "temp", or the name of an attached database). If
12141 ** sqlite3changegroup_add() is called to add a changeset that is not compatible
12142 ** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
12143 ** object is left in an undefined state.
12144 **
12145 ** A changeset schema is considered compatible with the database schema in
12146 ** the same way as for sqlite3changeset_apply(). Specifically, for each
12147 ** table in the changeset, there exists a database table with:
12148 **
12149 ** <ul>
12150 ** <li> The name identified by the changeset, and
12151 ** <li> at least as many columns as recorded in the changeset, and
12152 ** <li> the primary key columns in the same position as recorded in
12153 ** the changeset.
12154 ** </ul>
12155 **
12156 ** The output of the changegroup object always has the same schema as the
12157 ** database nominated using this function. In cases where changesets passed
12158 ** to sqlite3changegroup_add() have fewer columns than the corresponding table
12159 ** in the database schema, these are filled in using the default column
12160 ** values from the database schema. This makes it possible to combined
12161 ** changesets that have different numbers of columns for a single table
12162 ** within a changegroup, provided that they are otherwise compatible.
12163 */
12164 SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
12165 12166 /*
12167 ** CAPI3REF: Add A Changeset To A Changegroup
12168 ** METHOD: sqlite3_changegroup
12169 **
12170 ** Add all changes within the changeset (or patchset) in buffer pData (size
12171 ** nData bytes) to the changegroup.
12172 **
12173 ** If the buffer contains a patchset, then all prior calls to this function
12174 ** on the same changegroup object must also have specified patchsets. Or, if
12175 ** the buffer contains a changeset, so must have the earlier calls to this
12176 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
12177 ** to the changegroup.
12178 **
12179 ** Rows within the changeset and changegroup are identified by the values in
12180 ** their PRIMARY KEY columns. A change in the changeset is considered to
12181 ** apply to the same row as a change already present in the changegroup if
12182 ** the two rows have the same primary key.
12183 **
12184 ** Changes to rows that do not already appear in the changegroup are
12185 ** simply copied into it. Or, if both the new changeset and the changegroup
12186 ** contain changes that apply to a single row, the final contents of the
12187 ** changegroup depends on the type of each change, as follows:
12188 **
12189 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
12190 ** <tr><th style="white-space:pre">Existing Change </th>
12191 ** <th style="white-space:pre">New Change </th>
12192 ** <th>Output Change
12193 ** <tr><td>INSERT <td>INSERT <td>
12194 ** The new change is ignored. This case does not occur if the new
12195 ** changeset was recorded immediately after the changesets already
12196 ** added to the changegroup.
12197 ** <tr><td>INSERT <td>UPDATE <td>
12198 ** The INSERT change remains in the changegroup. The values in the
12199 ** INSERT change are modified as if the row was inserted by the
12200 ** existing change and then updated according to the new change.
12201 ** <tr><td>INSERT <td>DELETE <td>
12202 ** The existing INSERT is removed from the changegroup. The DELETE is
12203 ** not added.
12204 ** <tr><td>UPDATE <td>INSERT <td>
12205 ** The new change is ignored. This case does not occur if the new
12206 ** changeset was recorded immediately after the changesets already
12207 ** added to the changegroup.
12208 ** <tr><td>UPDATE <td>UPDATE <td>
12209 ** The existing UPDATE remains within the changegroup. It is amended
12210 ** so that the accompanying values are as if the row was updated once
12211 ** by the existing change and then again by the new change.
12212 ** <tr><td>UPDATE <td>DELETE <td>
12213 ** The existing UPDATE is replaced by the new DELETE within the
12214 ** changegroup.
12215 ** <tr><td>DELETE <td>INSERT <td>
12216 ** If one or more of the column values in the row inserted by the
12217 ** new change differ from those in the row deleted by the existing
12218 ** change, the existing DELETE is replaced by an UPDATE within the
12219 ** changegroup. Otherwise, if the inserted row is exactly the same
12220 ** as the deleted row, the existing DELETE is simply discarded.
12221 ** <tr><td>DELETE <td>UPDATE <td>
12222 ** The new change is ignored. This case does not occur if the new
12223 ** changeset was recorded immediately after the changesets already
12224 ** added to the changegroup.
12225 ** <tr><td>DELETE <td>DELETE <td>
12226 ** The new change is ignored. This case does not occur if the new
12227 ** changeset was recorded immediately after the changesets already
12228 ** added to the changegroup.
12229 ** </table>
12230 **
12231 ** If the new changeset contains changes to a table that is already present
12232 ** in the changegroup, then the number of columns and the position of the
12233 ** primary key columns for the table must be consistent. If this is not the
12234 ** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
12235 ** object has been configured with a database schema using the
12236 ** sqlite3changegroup_schema() API, then it is possible to combine changesets
12237 ** with different numbers of columns for a single table, provided that
12238 ** they are otherwise compatible.
12239 **
12240 ** If the input changeset appears to be corrupt and the corruption is
12241 ** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
12242 ** occurs during processing, this function returns SQLITE_NOMEM.
12243 **
12244 ** In all cases, if an error occurs the state of the final contents of the
12245 ** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
12246 */
12247 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
12248 12249 /*
12250 ** CAPI3REF: Add A Single Change To A Changegroup
12251 ** METHOD: sqlite3_changegroup
12252 **
12253 ** This function adds the single change currently indicated by the iterator
12254 ** passed as the second argument to the changegroup object. The rules for
12255 ** adding the change are just as described for [sqlite3changegroup_add()].
12256 **
12257 ** If the change is successfully added to the changegroup, SQLITE_OK is
12258 ** returned. Otherwise, an SQLite error code is returned.
12259 **
12260 ** The iterator must point to a valid entry when this function is called.
12261 ** If it does not, SQLITE_ERROR is returned and no change is added to the
12262 ** changegroup. Additionally, the iterator must not have been opened with
12263 ** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
12264 ** returned.
12265 */
12266 SQLITE_API int sqlite3changegroup_add_change(
12267 sqlite3_changegroup*,
12268 sqlite3_changeset_iter*
12269 );
12270 12271 12272 12273 /*
12274 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
12275 ** METHOD: sqlite3_changegroup
12276 **
12277 ** Obtain a buffer containing a changeset (or patchset) representing the
12278 ** current contents of the changegroup. If the inputs to the changegroup
12279 ** were themselves changesets, the output is a changeset. Or, if the
12280 ** inputs were patchsets, the output is also a patchset.
12281 **
12282 ** As with the output of the sqlite3session_changeset() and
12283 ** sqlite3session_patchset() functions, all changes related to a single
12284 ** table are grouped together in the output of this function. Tables appear
12285 ** in the same order as for the very first changeset added to the changegroup.
12286 ** If the second or subsequent changesets added to the changegroup contain
12287 ** changes for tables that do not appear in the first changeset, they are
12288 ** appended onto the end of the output changeset, again in the order in
12289 ** which they are first encountered.
12290 **
12291 ** If an error occurs, an SQLite error code is returned and the output
12292 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
12293 ** is returned and the output variables are set to the size of and a
12294 ** pointer to the output buffer, respectively. In this case it is the
12295 ** responsibility of the caller to eventually free the buffer using a
12296 ** call to sqlite3_free().
12297 */
12298 SQLITE_API int sqlite3changegroup_output(
12299 sqlite3_changegroup*,
12300 int *pnData, /* OUT: Size of output buffer in bytes */
12301 void **ppData /* OUT: Pointer to output buffer */
12302 );
12303 12304 /*
12305 ** CAPI3REF: Delete A Changegroup Object
12306 ** DESTRUCTOR: sqlite3_changegroup
12307 */
12308 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
12309 12310 /*
12311 ** CAPI3REF: Apply A Changeset To A Database
12312 **
12313 ** Apply a changeset or patchset to a database. These functions attempt to
12314 ** update the "main" database attached to handle db with the changes found in
12315 ** the changeset passed via the second and third arguments.
12316 **
12317 ** The fourth argument (xFilter) passed to these functions is the "filter
12318 ** callback". If it is not NULL, then for each table affected by at least one
12319 ** change in the changeset, the filter callback is invoked with
12320 ** the table name as the second argument, and a copy of the context pointer
12321 ** passed as the sixth argument as the first. If the "filter callback"
12322 ** returns zero, then no attempt is made to apply any changes to the table.
12323 ** Otherwise, if the return value is non-zero or the xFilter argument to
12324 ** is NULL, all changes related to the table are attempted.
12325 **
12326 ** For each table that is not excluded by the filter callback, this function
12327 ** tests that the target database contains a compatible table. A table is
12328 ** considered compatible if all of the following are true:
12329 **
12330 ** <ul>
12331 ** <li> The table has the same name as the name recorded in the
12332 ** changeset, and
12333 ** <li> The table has at least as many columns as recorded in the
12334 ** changeset, and
12335 ** <li> The table has primary key columns in the same position as
12336 ** recorded in the changeset.
12337 ** </ul>
12338 **
12339 ** If there is no compatible table, it is not an error, but none of the
12340 ** changes associated with the table are applied. A warning message is issued
12341 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
12342 ** one such warning is issued for each table in the changeset.
12343 **
12344 ** For each change for which there is a compatible table, an attempt is made
12345 ** to modify the table contents according to the UPDATE, INSERT or DELETE
12346 ** change. If a change cannot be applied cleanly, the conflict handler
12347 ** function passed as the fifth argument to sqlite3changeset_apply() may be
12348 ** invoked. A description of exactly when the conflict handler is invoked for
12349 ** each type of change is below.
12350 **
12351 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
12352 ** of passing anything other than a valid function pointer as the xConflict
12353 ** argument are undefined.
12354 **
12355 ** Each time the conflict handler function is invoked, it must return one
12356 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
12357 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
12358 ** if the second argument passed to the conflict handler is either
12359 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
12360 ** returns an illegal value, any changes already made are rolled back and
12361 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
12362 ** actions are taken by sqlite3changeset_apply() depending on the value
12363 ** returned by each invocation of the conflict-handler function. Refer to
12364 ** the documentation for the three
12365 ** [SQLITE_CHANGESET_OMIT|available return values] for details.
12366 **
12367 ** <dl>
12368 ** <dt>DELETE Changes<dd>
12369 ** For each DELETE change, the function checks if the target database
12370 ** contains a row with the same primary key value (or values) as the
12371 ** original row values stored in the changeset. If it does, and the values
12372 ** stored in all non-primary key columns also match the values stored in
12373 ** the changeset the row is deleted from the target database.
12374 **
12375 ** If a row with matching primary key values is found, but one or more of
12376 ** the non-primary key fields contains a value different from the original
12377 ** row value stored in the changeset, the conflict-handler function is
12378 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
12379 ** database table has more columns than are recorded in the changeset,
12380 ** only the values of those non-primary key fields are compared against
12381 ** the current database contents - any trailing database table columns
12382 ** are ignored.
12383 **
12384 ** If no row with matching primary key values is found in the database,
12385 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12386 ** passed as the second argument.
12387 **
12388 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
12389 ** (which can only happen if a foreign key constraint is violated), the
12390 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
12391 ** passed as the second argument. This includes the case where the DELETE
12392 ** operation is attempted because an earlier call to the conflict handler
12393 ** function returned [SQLITE_CHANGESET_REPLACE].
12394 **
12395 ** <dt>INSERT Changes<dd>
12396 ** For each INSERT change, an attempt is made to insert the new row into
12397 ** the database. If the changeset row contains fewer fields than the
12398 ** database table, the trailing fields are populated with their default
12399 ** values.
12400 **
12401 ** If the attempt to insert the row fails because the database already
12402 ** contains a row with the same primary key values, the conflict handler
12403 ** function is invoked with the second argument set to
12404 ** [SQLITE_CHANGESET_CONFLICT].
12405 **
12406 ** If the attempt to insert the row fails because of some other constraint
12407 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
12408 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
12409 ** This includes the case where the INSERT operation is re-attempted because
12410 ** an earlier call to the conflict handler function returned
12411 ** [SQLITE_CHANGESET_REPLACE].
12412 **
12413 ** <dt>UPDATE Changes<dd>
12414 ** For each UPDATE change, the function checks if the target database
12415 ** contains a row with the same primary key value (or values) as the
12416 ** original row values stored in the changeset. If it does, and the values
12417 ** stored in all modified non-primary key columns also match the values
12418 ** stored in the changeset the row is updated within the target database.
12419 **
12420 ** If a row with matching primary key values is found, but one or more of
12421 ** the modified non-primary key fields contains a value different from an
12422 ** original row value stored in the changeset, the conflict-handler function
12423 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
12424 ** UPDATE changes only contain values for non-primary key fields that are
12425 ** to be modified, only those fields need to match the original values to
12426 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
12427 **
12428 ** If no row with matching primary key values is found in the database,
12429 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12430 ** passed as the second argument.
12431 **
12432 ** If the UPDATE operation is attempted, but SQLite returns
12433 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
12434 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
12435 ** This includes the case where the UPDATE operation is attempted after
12436 ** an earlier call to the conflict handler function returned
12437 ** [SQLITE_CHANGESET_REPLACE].
12438 ** </dl>
12439 **
12440 ** It is safe to execute SQL statements, including those that write to the
12441 ** table that the callback related to, from within the xConflict callback.
12442 ** This can be used to further customize the application's conflict
12443 ** resolution strategy.
12444 **
12445 ** All changes made by these functions are enclosed in a savepoint transaction.
12446 ** If any other error (aside from a constraint failure when attempting to
12447 ** write to the target database) occurs, then the savepoint transaction is
12448 ** rolled back, restoring the target database to its original state, and an
12449 ** SQLite error code returned.
12450 **
12451 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
12452 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
12453 ** may set (*ppRebase) to point to a "rebase" that may be used with the
12454 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
12455 ** is set to the size of the buffer in bytes. It is the responsibility of the
12456 ** caller to eventually free any such buffer using sqlite3_free(). The buffer
12457 ** is only allocated and populated if one or more conflicts were encountered
12458 ** while applying the patchset. See comments surrounding the sqlite3_rebaser
12459 ** APIs for further details.
12460 **
12461 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
12462 ** may be modified by passing a combination of
12463 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
12464 **
12465 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
12466 ** and therefore subject to change.
12467 */
12468 SQLITE_API int sqlite3changeset_apply(
12469 sqlite3 *db, /* Apply change to "main" db of this handle */
12470 int nChangeset, /* Size of changeset in bytes */
12471 void *pChangeset, /* Changeset blob */
12472 int(*xFilter)(
12473 void *pCtx, /* Copy of sixth arg to _apply() */
12474 const char *zTab /* Table name */
12475 ),
12476 int(*xConflict)(
12477 void *pCtx, /* Copy of sixth arg to _apply() */
12478 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12479 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12480 ),
12481 void *pCtx /* First argument passed to xConflict */
12482 );
12483 SQLITE_API int sqlite3changeset_apply_v2(
12484 sqlite3 *db, /* Apply change to "main" db of this handle */
12485 int nChangeset, /* Size of changeset in bytes */
12486 void *pChangeset, /* Changeset blob */
12487 int(*xFilter)(
12488 void *pCtx, /* Copy of sixth arg to _apply() */
12489 const char *zTab /* Table name */
12490 ),
12491 int(*xConflict)(
12492 void *pCtx, /* Copy of sixth arg to _apply() */
12493 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12494 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12495 ),
12496 void *pCtx, /* First argument passed to xConflict */
12497 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12498 int flags /* SESSION_CHANGESETAPPLY_* flags */
12499 );
12500 12501 /*
12502 ** CAPI3REF: Flags for sqlite3changeset_apply_v2
12503 **
12504 ** The following flags may passed via the 9th parameter to
12505 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12506 **
12507 ** <dl>
12508 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12509 ** Usually, the sessions module encloses all operations performed by
12510 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12511 ** SAVEPOINT is committed if the changeset or patchset is successfully
12512 ** applied, or rolled back if an error occurs. Specifying this flag
12513 ** causes the sessions module to omit this savepoint. In this case, if the
12514 ** caller has an open transaction or savepoint when apply_v2() is called,
12515 ** it may revert the partially applied changeset by rolling it back.
12516 **
12517 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12518 ** Invert the changeset before applying it. This is equivalent to inverting
12519 ** a changeset using sqlite3changeset_invert() before applying it. It is
12520 ** an error to specify this flag with a patchset.
12521 **
12522 ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12523 ** Do not invoke the conflict handler callback for any changes that
12524 ** would not actually modify the database even if they were applied.
12525 ** Specifically, this means that the conflict handler is not invoked
12526 ** for:
12527 ** <ul>
12528 ** <li>a delete change if the row being deleted cannot be found,
12529 ** <li>an update change if the modified fields are already set to
12530 ** their new values in the conflicting row, or
12531 ** <li>an insert change if all fields of the conflicting row match
12532 ** the row being inserted.
12533 ** </ul>
12534 **
12535 ** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
12536 ** If this flag it set, then all foreign key constraints in the target
12537 ** database behave as if they were declared with "ON UPDATE NO ACTION ON
12538 ** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
12539 ** or SET DEFAULT.
12540 */
12541 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12542 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12543 #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12544 #define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
12545 12546 /*
12547 ** CAPI3REF: Constants Passed To The Conflict Handler
12548 **
12549 ** Values that may be passed as the second argument to a conflict-handler.
12550 **
12551 ** <dl>
12552 ** <dt>SQLITE_CHANGESET_DATA<dd>
12553 ** The conflict handler is invoked with CHANGESET_DATA as the second argument
12554 ** when processing a DELETE or UPDATE change if a row with the required
12555 ** PRIMARY KEY fields is present in the database, but one or more other
12556 ** (non primary-key) fields modified by the update do not contain the
12557 ** expected "before" values.
12558 **
12559 ** The conflicting row, in this case, is the database row with the matching
12560 ** primary key.
12561 **
12562 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12563 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12564 ** argument when processing a DELETE or UPDATE change if a row with the
12565 ** required PRIMARY KEY fields is not present in the database.
12566 **
12567 ** There is no conflicting row in this case. The results of invoking the
12568 ** sqlite3changeset_conflict() API are undefined.
12569 **
12570 ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12571 ** CHANGESET_CONFLICT is passed as the second argument to the conflict
12572 ** handler while processing an INSERT change if the operation would result
12573 ** in duplicate primary key values.
12574 **
12575 ** The conflicting row in this case is the database row with the matching
12576 ** primary key.
12577 **
12578 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12579 ** If foreign key handling is enabled, and applying a changeset leaves the
12580 ** database in a state containing foreign key violations, the conflict
12581 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12582 ** exactly once before the changeset is committed. If the conflict handler
12583 ** returns CHANGESET_OMIT, the changes, including those that caused the
12584 ** foreign key constraint violation, are committed. Or, if it returns
12585 ** CHANGESET_ABORT, the changeset is rolled back.
12586 **
12587 ** No current or conflicting row information is provided. The only function
12588 ** it is possible to call on the supplied sqlite3_changeset_iter handle
12589 ** is sqlite3changeset_fk_conflicts().
12590 **
12591 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12592 ** If any other constraint violation occurs while applying a change (i.e.
12593 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12594 ** invoked with CHANGESET_CONSTRAINT as the second argument.
12595 **
12596 ** There is no conflicting row in this case. The results of invoking the
12597 ** sqlite3changeset_conflict() API are undefined.
12598 **
12599 ** </dl>
12600 */
12601 #define SQLITE_CHANGESET_DATA 1
12602 #define SQLITE_CHANGESET_NOTFOUND 2
12603 #define SQLITE_CHANGESET_CONFLICT 3
12604 #define SQLITE_CHANGESET_CONSTRAINT 4
12605 #define SQLITE_CHANGESET_FOREIGN_KEY 5
12606 12607 /*
12608 ** CAPI3REF: Constants Returned By The Conflict Handler
12609 **
12610 ** A conflict handler callback must return one of the following three values.
12611 **
12612 ** <dl>
12613 ** <dt>SQLITE_CHANGESET_OMIT<dd>
12614 ** If a conflict handler returns this value no special action is taken. The
12615 ** change that caused the conflict is not applied. The session module
12616 ** continues to the next change in the changeset.
12617 **
12618 ** <dt>SQLITE_CHANGESET_REPLACE<dd>
12619 ** This value may only be returned if the second argument to the conflict
12620 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12621 ** is not the case, any changes applied so far are rolled back and the
12622 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12623 **
12624 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12625 ** handler, then the conflicting row is either updated or deleted, depending
12626 ** on the type of change.
12627 **
12628 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12629 ** handler, then the conflicting row is removed from the database and a
12630 ** second attempt to apply the change is made. If this second attempt fails,
12631 ** the original row is restored to the database before continuing.
12632 **
12633 ** <dt>SQLITE_CHANGESET_ABORT<dd>
12634 ** If this value is returned, any changes applied so far are rolled back
12635 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12636 ** </dl>
12637 */
12638 #define SQLITE_CHANGESET_OMIT 0
12639 #define SQLITE_CHANGESET_REPLACE 1
12640 #define SQLITE_CHANGESET_ABORT 2
12641 12642 /*
12643 ** CAPI3REF: Rebasing changesets
12644 ** EXPERIMENTAL
12645 **
12646 ** Suppose there is a site hosting a database in state S0. And that
12647 ** modifications are made that move that database to state S1 and a
12648 ** changeset recorded (the "local" changeset). Then, a changeset based
12649 ** on S0 is received from another site (the "remote" changeset) and
12650 ** applied to the database. The database is then in state
12651 ** (S1+"remote"), where the exact state depends on any conflict
12652 ** resolution decisions (OMIT or REPLACE) made while applying "remote".
12653 ** Rebasing a changeset is to update it to take those conflict
12654 ** resolution decisions into account, so that the same conflicts
12655 ** do not have to be resolved elsewhere in the network.
12656 **
12657 ** For example, if both the local and remote changesets contain an
12658 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12659 **
12660 ** local: INSERT INTO t1 VALUES(1, 'v1');
12661 ** remote: INSERT INTO t1 VALUES(1, 'v2');
12662 **
12663 ** and the conflict resolution is REPLACE, then the INSERT change is
12664 ** removed from the local changeset (it was overridden). Or, if the
12665 ** conflict resolution was "OMIT", then the local changeset is modified
12666 ** to instead contain:
12667 **
12668 ** UPDATE t1 SET b = 'v2' WHERE a=1;
12669 **
12670 ** Changes within the local changeset are rebased as follows:
12671 **
12672 ** <dl>
12673 ** <dt>Local INSERT<dd>
12674 ** This may only conflict with a remote INSERT. If the conflict
12675 ** resolution was OMIT, then add an UPDATE change to the rebased
12676 ** changeset. Or, if the conflict resolution was REPLACE, add
12677 ** nothing to the rebased changeset.
12678 **
12679 ** <dt>Local DELETE<dd>
12680 ** This may conflict with a remote UPDATE or DELETE. In both cases the
12681 ** only possible resolution is OMIT. If the remote operation was a
12682 ** DELETE, then add no change to the rebased changeset. If the remote
12683 ** operation was an UPDATE, then the old.* fields of change are updated
12684 ** to reflect the new.* values in the UPDATE.
12685 **
12686 ** <dt>Local UPDATE<dd>
12687 ** This may conflict with a remote UPDATE or DELETE. If it conflicts
12688 ** with a DELETE, and the conflict resolution was OMIT, then the update
12689 ** is changed into an INSERT. Any undefined values in the new.* record
12690 ** from the update change are filled in using the old.* values from
12691 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
12692 ** the UPDATE change is simply omitted from the rebased changeset.
12693 **
12694 ** If conflict is with a remote UPDATE and the resolution is OMIT, then
12695 ** the old.* values are rebased using the new.* values in the remote
12696 ** change. Or, if the resolution is REPLACE, then the change is copied
12697 ** into the rebased changeset with updates to columns also updated by
12698 ** the conflicting remote UPDATE removed. If this means no columns would
12699 ** be updated, the change is omitted.
12700 ** </dl>
12701 **
12702 ** A local change may be rebased against multiple remote changes
12703 ** simultaneously. If a single key is modified by multiple remote
12704 ** changesets, they are combined as follows before the local changeset
12705 ** is rebased:
12706 **
12707 ** <ul>
12708 ** <li> If there has been one or more REPLACE resolutions on a
12709 ** key, it is rebased according to a REPLACE.
12710 **
12711 ** <li> If there have been no REPLACE resolutions on a key, then
12712 ** the local changeset is rebased according to the most recent
12713 ** of the OMIT resolutions.
12714 ** </ul>
12715 **
12716 ** Note that conflict resolutions from multiple remote changesets are
12717 ** combined on a per-field basis, not per-row. This means that in the
12718 ** case of multiple remote UPDATE operations, some fields of a single
12719 ** local change may be rebased for REPLACE while others are rebased for
12720 ** OMIT.
12721 **
12722 ** In order to rebase a local changeset, the remote changeset must first
12723 ** be applied to the local database using sqlite3changeset_apply_v2() and
12724 ** the buffer of rebase information captured. Then:
12725 **
12726 ** <ol>
12727 ** <li> An sqlite3_rebaser object is created by calling
12728 ** sqlite3rebaser_create().
12729 ** <li> The new object is configured with the rebase buffer obtained from
12730 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12731 ** If the local changeset is to be rebased against multiple remote
12732 ** changesets, then sqlite3rebaser_configure() should be called
12733 ** multiple times, in the same order that the multiple
12734 ** sqlite3changeset_apply_v2() calls were made.
12735 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12736 ** <li> The sqlite3_rebaser object is deleted by calling
12737 ** sqlite3rebaser_delete().
12738 ** </ol>
12739 */
12740 typedef struct sqlite3_rebaser sqlite3_rebaser;
12741 12742 /*
12743 ** CAPI3REF: Create a changeset rebaser object.
12744 ** EXPERIMENTAL
12745 **
12746 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12747 ** point to the new object and return SQLITE_OK. Otherwise, if an error
12748 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12749 ** to NULL.
12750 */
12751 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12752 12753 /*
12754 ** CAPI3REF: Configure a changeset rebaser object.
12755 ** EXPERIMENTAL
12756 **
12757 ** Configure the changeset rebaser object to rebase changesets according
12758 ** to the conflict resolutions described by buffer pRebase (size nRebase
12759 ** bytes), which must have been obtained from a previous call to
12760 ** sqlite3changeset_apply_v2().
12761 */
12762 SQLITE_API int sqlite3rebaser_configure(
12763 sqlite3_rebaser*,
12764 int nRebase, const void *pRebase
12765 );
12766 12767 /*
12768 ** CAPI3REF: Rebase a changeset
12769 ** EXPERIMENTAL
12770 **
12771 ** Argument pIn must point to a buffer containing a changeset nIn bytes
12772 ** in size. This function allocates and populates a buffer with a copy
12773 ** of the changeset rebased according to the configuration of the
12774 ** rebaser object passed as the first argument. If successful, (*ppOut)
12775 ** is set to point to the new buffer containing the rebased changeset and
12776 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12777 ** responsibility of the caller to eventually free the new buffer using
12778 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12779 ** are set to zero and an SQLite error code returned.
12780 */
12781 SQLITE_API int sqlite3rebaser_rebase(
12782 sqlite3_rebaser*,
12783 int nIn, const void *pIn,
12784 int *pnOut, void **ppOut
12785 );
12786 12787 /*
12788 ** CAPI3REF: Delete a changeset rebaser object.
12789 ** EXPERIMENTAL
12790 **
12791 ** Delete the changeset rebaser object and all associated resources. There
12792 ** should be one call to this function for each successful invocation
12793 ** of sqlite3rebaser_create().
12794 */
12795 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12796 12797 /*
12798 ** CAPI3REF: Streaming Versions of API functions.
12799 **
12800 ** The six streaming API xxx_strm() functions serve similar purposes to the
12801 ** corresponding non-streaming API functions:
12802 **
12803 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
12804 ** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12805 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12806 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12807 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12808 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12809 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12810 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12811 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12812 ** </table>
12813 **
12814 ** Non-streaming functions that accept changesets (or patchsets) as input
12815 ** require that the entire changeset be stored in a single buffer in memory.
12816 ** Similarly, those that return a changeset or patchset do so by returning
12817 ** a pointer to a single large buffer allocated using sqlite3_malloc().
12818 ** Normally this is convenient. However, if an application running in a
12819 ** low-memory environment is required to handle very large changesets, the
12820 ** large contiguous memory allocations required can become onerous.
12821 **
12822 ** In order to avoid this problem, instead of a single large buffer, input
12823 ** is passed to a streaming API functions by way of a callback function that
12824 ** the sessions module invokes to incrementally request input data as it is
12825 ** required. In all cases, a pair of API function parameters such as
12826 **
12827 ** <pre>
12828 ** int nChangeset,
12829 ** void *pChangeset,
12830 ** </pre>
12831 **
12832 ** Is replaced by:
12833 **
12834 ** <pre>
12835 ** int (*xInput)(void *pIn, void *pData, int *pnData),
12836 ** void *pIn,
12837 ** </pre>
12838 **
12839 ** Each time the xInput callback is invoked by the sessions module, the first
12840 ** argument passed is a copy of the supplied pIn context pointer. The second
12841 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
12842 ** error occurs the xInput method should copy up to (*pnData) bytes of data
12843 ** into the buffer and set (*pnData) to the actual number of bytes copied
12844 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
12845 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
12846 ** error code should be returned. In all cases, if an xInput callback returns
12847 ** an error, all processing is abandoned and the streaming API function
12848 ** returns a copy of the error code to the caller.
12849 **
12850 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
12851 ** invoked by the sessions module at any point during the lifetime of the
12852 ** iterator. If such an xInput callback returns an error, the iterator enters
12853 ** an error state, whereby all subsequent calls to iterator functions
12854 ** immediately fail with the same error code as returned by xInput.
12855 **
12856 ** Similarly, streaming API functions that return changesets (or patchsets)
12857 ** return them in chunks by way of a callback function instead of via a
12858 ** pointer to a single large buffer. In this case, a pair of parameters such
12859 ** as:
12860 **
12861 ** <pre>
12862 ** int *pnChangeset,
12863 ** void **ppChangeset,
12864 ** </pre>
12865 **
12866 ** Is replaced by:
12867 **
12868 ** <pre>
12869 ** int (*xOutput)(void *pOut, const void *pData, int nData),
12870 ** void *pOut
12871 ** </pre>
12872 **
12873 ** The xOutput callback is invoked zero or more times to return data to
12874 ** the application. The first parameter passed to each call is a copy of the
12875 ** pOut pointer supplied by the application. The second parameter, pData,
12876 ** points to a buffer nData bytes in size containing the chunk of output
12877 ** data being returned. If the xOutput callback successfully processes the
12878 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
12879 ** it should return some other SQLite error code. In this case processing
12880 ** is immediately abandoned and the streaming API function returns a copy
12881 ** of the xOutput error code to the application.
12882 **
12883 ** The sessions module never invokes an xOutput callback with the third
12884 ** parameter set to a value less than or equal to zero. Other than this,
12885 ** no guarantees are made as to the size of the chunks of data returned.
12886 */
12887 SQLITE_API int sqlite3changeset_apply_strm(
12888 sqlite3 *db, /* Apply change to "main" db of this handle */
12889 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12890 void *pIn, /* First arg for xInput */
12891 int(*xFilter)(
12892 void *pCtx, /* Copy of sixth arg to _apply() */
12893 const char *zTab /* Table name */
12894 ),
12895 int(*xConflict)(
12896 void *pCtx, /* Copy of sixth arg to _apply() */
12897 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12898 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12899 ),
12900 void *pCtx /* First argument passed to xConflict */
12901 );
12902 SQLITE_API int sqlite3changeset_apply_v2_strm(
12903 sqlite3 *db, /* Apply change to "main" db of this handle */
12904 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12905 void *pIn, /* First arg for xInput */
12906 int(*xFilter)(
12907 void *pCtx, /* Copy of sixth arg to _apply() */
12908 const char *zTab /* Table name */
12909 ),
12910 int(*xConflict)(
12911 void *pCtx, /* Copy of sixth arg to _apply() */
12912 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12913 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12914 ),
12915 void *pCtx, /* First argument passed to xConflict */
12916 void **ppRebase, int *pnRebase,
12917 int flags
12918 );
12919 SQLITE_API int sqlite3changeset_concat_strm(
12920 int (*xInputA)(void *pIn, void *pData, int *pnData),
12921 void *pInA,
12922 int (*xInputB)(void *pIn, void *pData, int *pnData),
12923 void *pInB,
12924 int (*xOutput)(void *pOut, const void *pData, int nData),
12925 void *pOut
12926 );
12927 SQLITE_API int sqlite3changeset_invert_strm(
12928 int (*xInput)(void *pIn, void *pData, int *pnData),
12929 void *pIn,
12930 int (*xOutput)(void *pOut, const void *pData, int nData),
12931 void *pOut
12932 );
12933 SQLITE_API int sqlite3changeset_start_strm(
12934 sqlite3_changeset_iter **pp,
12935 int (*xInput)(void *pIn, void *pData, int *pnData),
12936 void *pIn
12937 );
12938 SQLITE_API int sqlite3changeset_start_v2_strm(
12939 sqlite3_changeset_iter **pp,
12940 int (*xInput)(void *pIn, void *pData, int *pnData),
12941 void *pIn,
12942 int flags
12943 );
12944 SQLITE_API int sqlite3session_changeset_strm(
12945 sqlite3_session *pSession,
12946 int (*xOutput)(void *pOut, const void *pData, int nData),
12947 void *pOut
12948 );
12949 SQLITE_API int sqlite3session_patchset_strm(
12950 sqlite3_session *pSession,
12951 int (*xOutput)(void *pOut, const void *pData, int nData),
12952 void *pOut
12953 );
12954 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
12955 int (*xInput)(void *pIn, void *pData, int *pnData),
12956 void *pIn
12957 );
12958 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
12959 int (*xOutput)(void *pOut, const void *pData, int nData),
12960 void *pOut
12961 );
12962 SQLITE_API int sqlite3rebaser_rebase_strm(
12963 sqlite3_rebaser *pRebaser,
12964 int (*xInput)(void *pIn, void *pData, int *pnData),
12965 void *pIn,
12966 int (*xOutput)(void *pOut, const void *pData, int nData),
12967 void *pOut
12968 );
12969 12970 /*
12971 ** CAPI3REF: Configure global parameters
12972 **
12973 ** The sqlite3session_config() interface is used to make global configuration
12974 ** changes to the sessions module in order to tune it to the specific needs
12975 ** of the application.
12976 **
12977 ** The sqlite3session_config() interface is not threadsafe. If it is invoked
12978 ** while any other thread is inside any other sessions method then the
12979 ** results are undefined. Furthermore, if it is invoked after any sessions
12980 ** related objects have been created, the results are also undefined.
12981 **
12982 ** The first argument to the sqlite3session_config() function must be one
12983 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
12984 ** interpretation of the (void*) value passed as the second parameter and
12985 ** the effect of calling this function depends on the value of the first
12986 ** parameter.
12987 **
12988 ** <dl>
12989 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
12990 ** By default, the sessions module streaming interfaces attempt to input
12991 ** and output data in approximately 1 KiB chunks. This operand may be used
12992 ** to set and query the value of this configuration setting. The pointer
12993 ** passed as the second argument must point to a value of type (int).
12994 ** If this value is greater than 0, it is used as the new streaming data
12995 ** chunk size for both input and output. Before returning, the (int) value
12996 ** pointed to by pArg is set to the final value of the streaming interface
12997 ** chunk size.
12998 ** </dl>
12999 **
13000 ** This function returns SQLITE_OK if successful, or an SQLite error code
13001 ** otherwise.
13002 */
13003 SQLITE_API int sqlite3session_config(int op, void *pArg);
13004 13005 /*
13006 ** CAPI3REF: Values for sqlite3session_config().
13007 */
13008 #define SQLITE_SESSION_CONFIG_STRMSIZE 1
13009 13010 /*
13011 ** Make sure we can call this stuff from C++.
13012 */
13013 #ifdef __cplusplus
13014 }
13015 #endif
13016 13017 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
13018 13019 /******** End of sqlite3session.h *********/
13020 /******** Begin file fts5.h *********/
13021 /*
13022 ** 2014 May 31
13023 **
13024 ** The author disclaims copyright to this source code. In place of
13025 ** a legal notice, here is a blessing:
13026 **
13027 ** May you do good and not evil.
13028 ** May you find forgiveness for yourself and forgive others.
13029 ** May you share freely, never taking more than you give.
13030 **
13031 ******************************************************************************
13032 **
13033 ** Interfaces to extend FTS5. Using the interfaces defined in this file,
13034 ** FTS5 may be extended with:
13035 **
13036 ** * custom tokenizers, and
13037 ** * custom auxiliary functions.
13038 */
13039 13040 13041 #ifndef _FTS5_H
13042 #define _FTS5_H
13043 13044 13045 #ifdef __cplusplus
13046 extern "C" {
13047 #endif
13048 13049 /*************************************************************************
13050 ** CUSTOM AUXILIARY FUNCTIONS
13051 **
13052 ** Virtual table implementations may overload SQL functions by implementing
13053 ** the sqlite3_module.xFindFunction() method.
13054 */
13055 13056 typedef struct Fts5ExtensionApi Fts5ExtensionApi;
13057 typedef struct Fts5Context Fts5Context;
13058 typedef struct Fts5PhraseIter Fts5PhraseIter;
13059 13060 typedef void (*fts5_extension_function)(
13061 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
13062 Fts5Context *pFts, /* First arg to pass to pApi functions */
13063 sqlite3_context *pCtx, /* Context for returning result/error */
13064 int nVal, /* Number of values in apVal[] array */
13065 sqlite3_value **apVal /* Array of trailing arguments */
13066 );
13067 13068 struct Fts5PhraseIter {
13069 const unsigned char *a;
13070 const unsigned char *b;
13071 };
13072 13073 /*
13074 ** EXTENSION API FUNCTIONS
13075 **
13076 ** xUserData(pFts):
13077 ** Return a copy of the pUserData pointer passed to the xCreateFunction()
13078 ** API when the extension function was registered.
13079 **
13080 ** xColumnTotalSize(pFts, iCol, pnToken):
13081 ** If parameter iCol is less than zero, set output variable *pnToken
13082 ** to the total number of tokens in the FTS5 table. Or, if iCol is
13083 ** non-negative but less than the number of columns in the table, return
13084 ** the total number of tokens in column iCol, considering all rows in
13085 ** the FTS5 table.
13086 **
13087 ** If parameter iCol is greater than or equal to the number of columns
13088 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13089 ** an OOM condition or IO error), an appropriate SQLite error code is
13090 ** returned.
13091 **
13092 ** xColumnCount(pFts):
13093 ** Return the number of columns in the table.
13094 **
13095 ** xColumnSize(pFts, iCol, pnToken):
13096 ** If parameter iCol is less than zero, set output variable *pnToken
13097 ** to the total number of tokens in the current row. Or, if iCol is
13098 ** non-negative but less than the number of columns in the table, set
13099 ** *pnToken to the number of tokens in column iCol of the current row.
13100 **
13101 ** If parameter iCol is greater than or equal to the number of columns
13102 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13103 ** an OOM condition or IO error), an appropriate SQLite error code is
13104 ** returned.
13105 **
13106 ** This function may be quite inefficient if used with an FTS5 table
13107 ** created with the "columnsize=0" option.
13108 **
13109 ** xColumnText:
13110 ** If parameter iCol is less than zero, or greater than or equal to the
13111 ** number of columns in the table, SQLITE_RANGE is returned.
13112 **
13113 ** Otherwise, this function attempts to retrieve the text of column iCol of
13114 ** the current document. If successful, (*pz) is set to point to a buffer
13115 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
13116 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
13117 ** if an error occurs, an SQLite error code is returned and the final values
13118 ** of (*pz) and (*pn) are undefined.
13119 **
13120 ** xPhraseCount:
13121 ** Returns the number of phrases in the current query expression.
13122 **
13123 ** xPhraseSize:
13124 ** If parameter iCol is less than zero, or greater than or equal to the
13125 ** number of phrases in the current query, as returned by xPhraseCount,
13126 ** 0 is returned. Otherwise, this function returns the number of tokens in
13127 ** phrase iPhrase of the query. Phrases are numbered starting from zero.
13128 **
13129 ** xInstCount:
13130 ** Set *pnInst to the total number of occurrences of all phrases within
13131 ** the query within the current row. Return SQLITE_OK if successful, or
13132 ** an error code (i.e. SQLITE_NOMEM) if an error occurs.
13133 **
13134 ** This API can be quite slow if used with an FTS5 table created with the
13135 ** "detail=none" or "detail=column" option. If the FTS5 table is created
13136 ** with either "detail=none" or "detail=column" and "content=" option
13137 ** (i.e. if it is a contentless table), then this API always returns 0.
13138 **
13139 ** xInst:
13140 ** Query for the details of phrase match iIdx within the current row.
13141 ** Phrase matches are numbered starting from zero, so the iIdx argument
13142 ** should be greater than or equal to zero and smaller than the value
13143 ** output by xInstCount(). If iIdx is less than zero or greater than
13144 ** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
13145 **
13146 ** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
13147 ** to the column in which it occurs and *piOff the token offset of the
13148 ** first token of the phrase. SQLITE_OK is returned if successful, or an
13149 ** error code (i.e. SQLITE_NOMEM) if an error occurs.
13150 **
13151 ** This API can be quite slow if used with an FTS5 table created with the
13152 ** "detail=none" or "detail=column" option.
13153 **
13154 ** xRowid:
13155 ** Returns the rowid of the current row.
13156 **
13157 ** xTokenize:
13158 ** Tokenize text using the tokenizer belonging to the FTS5 table.
13159 **
13160 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
13161 ** This API function is used to query the FTS table for phrase iPhrase
13162 ** of the current query. Specifically, a query equivalent to:
13163 **
13164 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
13165 **
13166 ** with $p set to a phrase equivalent to the phrase iPhrase of the
13167 ** current query is executed. Any column filter that applies to
13168 ** phrase iPhrase of the current query is included in $p. For each
13169 ** row visited, the callback function passed as the fourth argument
13170 ** is invoked. The context and API objects passed to the callback
13171 ** function may be used to access the properties of each matched row.
13172 ** Invoking Api.xUserData() returns a copy of the pointer passed as
13173 ** the third argument to pUserData.
13174 **
13175 ** If parameter iPhrase is less than zero, or greater than or equal to
13176 ** the number of phrases in the query, as returned by xPhraseCount(),
13177 ** this function returns SQLITE_RANGE.
13178 **
13179 ** If the callback function returns any value other than SQLITE_OK, the
13180 ** query is abandoned and the xQueryPhrase function returns immediately.
13181 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
13182 ** Otherwise, the error code is propagated upwards.
13183 **
13184 ** If the query runs to completion without incident, SQLITE_OK is returned.
13185 ** Or, if some error occurs before the query completes or is aborted by
13186 ** the callback, an SQLite error code is returned.
13187 **
13188 **
13189 ** xSetAuxdata(pFts5, pAux, xDelete)
13190 **
13191 ** Save the pointer passed as the second argument as the extension function's
13192 ** "auxiliary data". The pointer may then be retrieved by the current or any
13193 ** future invocation of the same fts5 extension function made as part of
13194 ** the same MATCH query using the xGetAuxdata() API.
13195 **
13196 ** Each extension function is allocated a single auxiliary data slot for
13197 ** each FTS query (MATCH expression). If the extension function is invoked
13198 ** more than once for a single FTS query, then all invocations share a
13199 ** single auxiliary data context.
13200 **
13201 ** If there is already an auxiliary data pointer when this function is
13202 ** invoked, then it is replaced by the new pointer. If an xDelete callback
13203 ** was specified along with the original pointer, it is invoked at this
13204 ** point.
13205 **
13206 ** The xDelete callback, if one is specified, is also invoked on the
13207 ** auxiliary data pointer after the FTS5 query has finished.
13208 **
13209 ** If an error (e.g. an OOM condition) occurs within this function,
13210 ** the auxiliary data is set to NULL and an error code returned. If the
13211 ** xDelete parameter was not NULL, it is invoked on the auxiliary data
13212 ** pointer before returning.
13213 **
13214 **
13215 ** xGetAuxdata(pFts5, bClear)
13216 **
13217 ** Returns the current auxiliary data pointer for the fts5 extension
13218 ** function. See the xSetAuxdata() method for details.
13219 **
13220 ** If the bClear argument is non-zero, then the auxiliary data is cleared
13221 ** (set to NULL) before this function returns. In this case the xDelete,
13222 ** if any, is not invoked.
13223 **
13224 **
13225 ** xRowCount(pFts5, pnRow)
13226 **
13227 ** This function is used to retrieve the total number of rows in the table.
13228 ** In other words, the same value that would be returned by:
13229 **
13230 ** SELECT count(*) FROM ftstable;
13231 **
13232 ** xPhraseFirst()
13233 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext
13234 ** method, to iterate through all instances of a single query phrase within
13235 ** the current row. This is the same information as is accessible via the
13236 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
13237 ** to use, this API may be faster under some circumstances. To iterate
13238 ** through instances of phrase iPhrase, use the following code:
13239 **
13240 ** Fts5PhraseIter iter;
13241 ** int iCol, iOff;
13242 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
13243 ** iCol>=0;
13244 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
13245 ** ){
13246 ** // An instance of phrase iPhrase at offset iOff of column iCol
13247 ** }
13248 **
13249 ** The Fts5PhraseIter structure is defined above. Applications should not
13250 ** modify this structure directly - it should only be used as shown above
13251 ** with the xPhraseFirst() and xPhraseNext() API methods (and by
13252 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
13253 **
13254 ** This API can be quite slow if used with an FTS5 table created with the
13255 ** "detail=none" or "detail=column" option. If the FTS5 table is created
13256 ** with either "detail=none" or "detail=column" and "content=" option
13257 ** (i.e. if it is a contentless table), then this API always iterates
13258 ** through an empty set (all calls to xPhraseFirst() set iCol to -1).
13259 **
13260 ** In all cases, matches are visited in (column ASC, offset ASC) order.
13261 ** i.e. all those in column 0, sorted by offset, followed by those in
13262 ** column 1, etc.
13263 **
13264 ** xPhraseNext()
13265 ** See xPhraseFirst above.
13266 **
13267 ** xPhraseFirstColumn()
13268 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
13269 ** and xPhraseNext() APIs described above. The difference is that instead
13270 ** of iterating through all instances of a phrase in the current row, these
13271 ** APIs are used to iterate through the set of columns in the current row
13272 ** that contain one or more instances of a specified phrase. For example:
13273 **
13274 ** Fts5PhraseIter iter;
13275 ** int iCol;
13276 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
13277 ** iCol>=0;
13278 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
13279 ** ){
13280 ** // Column iCol contains at least one instance of phrase iPhrase
13281 ** }
13282 **
13283 ** This API can be quite slow if used with an FTS5 table created with the
13284 ** "detail=none" option. If the FTS5 table is created with either
13285 ** "detail=none" "content=" option (i.e. if it is a contentless table),
13286 ** then this API always iterates through an empty set (all calls to
13287 ** xPhraseFirstColumn() set iCol to -1).
13288 **
13289 ** The information accessed using this API and its companion
13290 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
13291 ** (or xInst/xInstCount). The chief advantage of this API is that it is
13292 ** significantly more efficient than those alternatives when used with
13293 ** "detail=column" tables.
13294 **
13295 ** xPhraseNextColumn()
13296 ** See xPhraseFirstColumn above.
13297 **
13298 ** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
13299 ** This is used to access token iToken of phrase iPhrase of the current
13300 ** query. Before returning, output parameter *ppToken is set to point
13301 ** to a buffer containing the requested token, and *pnToken to the
13302 ** size of this buffer in bytes.
13303 **
13304 ** If iPhrase or iToken are less than zero, or if iPhrase is greater than
13305 ** or equal to the number of phrases in the query as reported by
13306 ** xPhraseCount(), or if iToken is equal to or greater than the number of
13307 ** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
13308 are both zeroed.
13309 **
13310 ** The output text is not a copy of the query text that specified the
13311 ** token. It is the output of the tokenizer module. For tokendata=1
13312 ** tables, this includes any embedded 0x00 and trailing data.
13313 **
13314 ** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
13315 ** This is used to access token iToken of phrase hit iIdx within the
13316 ** current row. If iIdx is less than zero or greater than or equal to the
13317 ** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise,
13318 ** output variable (*ppToken) is set to point to a buffer containing the
13319 ** matching document token, and (*pnToken) to the size of that buffer in
13320 ** bytes.
13321 **
13322 ** The output text is not a copy of the document text that was tokenized.
13323 ** It is the output of the tokenizer module. For tokendata=1 tables, this
13324 ** includes any embedded 0x00 and trailing data.
13325 **
13326 ** This API may be slow in some cases if the token identified by parameters
13327 ** iIdx and iToken matched a prefix token in the query. In most cases, the
13328 ** first call to this API for each prefix token in the query is forced
13329 ** to scan the portion of the full-text index that matches the prefix
13330 ** token to collect the extra data required by this API. If the prefix
13331 ** token matches a large number of token instances in the document set,
13332 ** this may be a performance problem.
13333 **
13334 ** If the user knows in advance that a query may use this API for a
13335 ** prefix token, FTS5 may be configured to collect all required data as part
13336 ** of the initial querying of the full-text index, avoiding the second scan
13337 ** entirely. This also causes prefix queries that do not use this API to
13338 ** run more slowly and use more memory. FTS5 may be configured in this way
13339 ** either on a per-table basis using the [FTS5 insttoken | 'insttoken']
13340 ** option, or on a per-query basis using the
13341 ** [fts5_insttoken | fts5_insttoken()] user function.
13342 **
13343 ** This API can be quite slow if used with an FTS5 table created with the
13344 ** "detail=none" or "detail=column" option.
13345 **
13346 ** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale)
13347 ** If parameter iCol is less than zero, or greater than or equal to the
13348 ** number of columns in the table, SQLITE_RANGE is returned.
13349 **
13350 ** Otherwise, this function attempts to retrieve the locale associated
13351 ** with column iCol of the current row. Usually, there is no associated
13352 ** locale, and output parameters (*pzLocale) and (*pnLocale) are set
13353 ** to NULL and 0, respectively. However, if the fts5_locale() function
13354 ** was used to associate a locale with the value when it was inserted
13355 ** into the fts5 table, then (*pzLocale) is set to point to a nul-terminated
13356 ** buffer containing the name of the locale in utf-8 encoding. (*pnLocale)
13357 ** is set to the size in bytes of the buffer, not including the
13358 ** nul-terminator.
13359 **
13360 ** If successful, SQLITE_OK is returned. Or, if an error occurs, an
13361 ** SQLite error code is returned. The final value of the output parameters
13362 ** is undefined in this case.
13363 **
13364 ** xTokenize_v2:
13365 ** Tokenize text using the tokenizer belonging to the FTS5 table. This
13366 ** API is the same as the xTokenize() API, except that it allows a tokenizer
13367 ** locale to be specified.
13368 */
13369 struct Fts5ExtensionApi {
13370 int iVersion; /* Currently always set to 4 */
13371 13372 void *(*xUserData)(Fts5Context*);
13373 13374 int (*xColumnCount)(Fts5Context*);
13375 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
13376 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
13377 13378 int (*xTokenize)(Fts5Context*,
13379 const char *pText, int nText, /* Text to tokenize */
13380 void *pCtx, /* Context passed to xToken() */
13381 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13382 );
13383 13384 int (*xPhraseCount)(Fts5Context*);
13385 int (*xPhraseSize)(Fts5Context*, int iPhrase);
13386 13387 int (*xInstCount)(Fts5Context*, int *pnInst);
13388 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
13389 13390 sqlite3_int64 (*xRowid)(Fts5Context*);
13391 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
13392 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
13393 13394 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
13395 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
13396 );
13397 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
13398 void *(*xGetAuxdata)(Fts5Context*, int bClear);
13399 13400 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
13401 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
13402 13403 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
13404 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
13405 13406 /* Below this point are iVersion>=3 only */
13407 int (*xQueryToken)(Fts5Context*,
13408 int iPhrase, int iToken,
13409 const char **ppToken, int *pnToken
13410 );
13411 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
13412 13413 /* Below this point are iVersion>=4 only */
13414 int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn);
13415 int (*xTokenize_v2)(Fts5Context*,
13416 const char *pText, int nText, /* Text to tokenize */
13417 const char *pLocale, int nLocale, /* Locale to pass to tokenizer */
13418 void *pCtx, /* Context passed to xToken() */
13419 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13420 );
13421 };
13422 13423 /*
13424 ** CUSTOM AUXILIARY FUNCTIONS
13425 *************************************************************************/
13426 13427 /*************************************************************************
13428 ** CUSTOM TOKENIZERS
13429 **
13430 ** Applications may also register custom tokenizer types. A tokenizer
13431 ** is registered by providing fts5 with a populated instance of the
13432 ** following structure. All structure methods must be defined, setting
13433 ** any member of the fts5_tokenizer struct to NULL leads to undefined
13434 ** behaviour. The structure methods are expected to function as follows:
13435 **
13436 ** xCreate:
13437 ** This function is used to allocate and initialize a tokenizer instance.
13438 ** A tokenizer instance is required to actually tokenize text.
13439 **
13440 ** The first argument passed to this function is a copy of the (void*)
13441 ** pointer provided by the application when the fts5_tokenizer_v2 object
13442 ** was registered with FTS5 (the third argument to xCreateTokenizer()).
13443 ** The second and third arguments are an array of nul-terminated strings
13444 ** containing the tokenizer arguments, if any, specified following the
13445 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
13446 ** to create the FTS5 table.
13447 **
13448 ** The final argument is an output variable. If successful, (*ppOut)
13449 ** should be set to point to the new tokenizer handle and SQLITE_OK
13450 ** returned. If an error occurs, some value other than SQLITE_OK should
13451 ** be returned. In this case, fts5 assumes that the final value of *ppOut
13452 ** is undefined.
13453 **
13454 ** xDelete:
13455 ** This function is invoked to delete a tokenizer handle previously
13456 ** allocated using xCreate(). Fts5 guarantees that this function will
13457 ** be invoked exactly once for each successful call to xCreate().
13458 **
13459 ** xTokenize:
13460 ** This function is expected to tokenize the nText byte string indicated
13461 ** by argument pText. pText may or may not be nul-terminated. The first
13462 ** argument passed to this function is a pointer to an Fts5Tokenizer object
13463 ** returned by an earlier call to xCreate().
13464 **
13465 ** The third argument indicates the reason that FTS5 is requesting
13466 ** tokenization of the supplied text. This is always one of the following
13467 ** four values:
13468 **
13469 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
13470 ** or removed from the FTS table. The tokenizer is being invoked to
13471 ** determine the set of tokens to add to (or delete from) the
13472 ** FTS index.
13473 **
13474 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
13475 ** against the FTS index. The tokenizer is being called to tokenize
13476 ** a bareword or quoted string specified as part of the query.
13477 **
13478 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
13479 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
13480 ** followed by a "*" character, indicating that the last token
13481 ** returned by the tokenizer will be treated as a token prefix.
13482 **
13483 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
13484 ** satisfy an fts5_api.xTokenize() request made by an auxiliary
13485 ** function. Or an fts5_api.xColumnSize() request made by the same
13486 ** on a columnsize=0 database.
13487 ** </ul>
13488 **
13489 ** The sixth and seventh arguments passed to xTokenize() - pLocale and
13490 ** nLocale - are a pointer to a buffer containing the locale to use for
13491 ** tokenization (e.g. "en_US") and its size in bytes, respectively. The
13492 ** pLocale buffer is not nul-terminated. pLocale may be passed NULL (in
13493 ** which case nLocale is always 0) to indicate that the tokenizer should
13494 ** use its default locale.
13495 **
13496 ** For each token in the input string, the supplied callback xToken() must
13497 ** be invoked. The first argument to it should be a copy of the pointer
13498 ** passed as the second argument to xTokenize(). The third and fourth
13499 ** arguments are a pointer to a buffer containing the token text, and the
13500 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets
13501 ** of the first byte of and first byte immediately following the text from
13502 ** which the token is derived within the input.
13503 **
13504 ** The second argument passed to the xToken() callback ("tflags") should
13505 ** normally be set to 0. The exception is if the tokenizer supports
13506 ** synonyms. In this case see the discussion below for details.
13507 **
13508 ** FTS5 assumes the xToken() callback is invoked for each token in the
13509 ** order that they occur within the input text.
13510 **
13511 ** If an xToken() callback returns any value other than SQLITE_OK, then
13512 ** the tokenization should be abandoned and the xTokenize() method should
13513 ** immediately return a copy of the xToken() return value. Or, if the
13514 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
13515 ** if an error occurs with the xTokenize() implementation itself, it
13516 ** may abandon the tokenization and return any error code other than
13517 ** SQLITE_OK or SQLITE_DONE.
13518 **
13519 ** If the tokenizer is registered using an fts5_tokenizer_v2 object,
13520 ** then the xTokenize() method has two additional arguments - pLocale
13521 ** and nLocale. These specify the locale that the tokenizer should use
13522 ** for the current request. If pLocale and nLocale are both 0, then the
13523 ** tokenizer should use its default locale. Otherwise, pLocale points to
13524 ** an nLocale byte buffer containing the name of the locale to use as utf-8
13525 ** text. pLocale is not nul-terminated.
13526 **
13527 ** FTS5_TOKENIZER
13528 **
13529 ** There is also an fts5_tokenizer object. This is an older, deprecated,
13530 ** version of fts5_tokenizer_v2. It is similar except that:
13531 **
13532 ** <ul>
13533 ** <li> There is no "iVersion" field, and
13534 ** <li> The xTokenize() method does not take a locale argument.
13535 ** </ul>
13536 **
13537 ** Legacy fts5_tokenizer tokenizers must be registered using the
13538 ** legacy xCreateTokenizer() function, instead of xCreateTokenizer_v2().
13539 **
13540 ** Tokenizer implementations registered using either API may be retrieved
13541 ** using both xFindTokenizer() and xFindTokenizer_v2().
13542 **
13543 ** SYNONYM SUPPORT
13544 **
13545 ** Custom tokenizers may also support synonyms. Consider a case in which a
13546 ** user wishes to query for a phrase such as "first place". Using the
13547 ** built-in tokenizers, the FTS5 query 'first + place' will match instances
13548 ** of "first place" within the document set, but not alternative forms
13549 ** such as "1st place". In some applications, it would be better to match
13550 ** all instances of "first place" or "1st place" regardless of which form
13551 ** the user specified in the MATCH query text.
13552 **
13553 ** There are several ways to approach this in FTS5:
13554 **
13555 ** <ol><li> By mapping all synonyms to a single token. In this case, using
13556 ** the above example, this means that the tokenizer returns the
13557 ** same token for inputs "first" and "1st". Say that token is in
13558 ** fact "first", so that when the user inserts the document "I won
13559 ** 1st place" entries are added to the index for tokens "i", "won",
13560 ** "first" and "place". If the user then queries for '1st + place',
13561 ** the tokenizer substitutes "first" for "1st" and the query works
13562 ** as expected.
13563 **
13564 ** <li> By querying the index for all synonyms of each query term
13565 ** separately. In this case, when tokenizing query text, the
13566 ** tokenizer may provide multiple synonyms for a single term
13567 ** within the document. FTS5 then queries the index for each
13568 ** synonym individually. For example, faced with the query:
13569 **
13570 ** <codeblock>
13571 ** ... MATCH 'first place'</codeblock>
13572 **
13573 ** the tokenizer offers both "1st" and "first" as synonyms for the
13574 ** first token in the MATCH query and FTS5 effectively runs a query
13575 ** similar to:
13576 **
13577 ** <codeblock>
13578 ** ... MATCH '(first OR 1st) place'</codeblock>
13579 **
13580 ** except that, for the purposes of auxiliary functions, the query
13581 ** still appears to contain just two phrases - "(first OR 1st)"
13582 ** being treated as a single phrase.
13583 **
13584 ** <li> By adding multiple synonyms for a single term to the FTS index.
13585 ** Using this method, when tokenizing document text, the tokenizer
13586 ** provides multiple synonyms for each token. So that when a
13587 ** document such as "I won first place" is tokenized, entries are
13588 ** added to the FTS index for "i", "won", "first", "1st" and
13589 ** "place".
13590 **
13591 ** This way, even if the tokenizer does not provide synonyms
13592 ** when tokenizing query text (it should not - to do so would be
13593 ** inefficient), it doesn't matter if the user queries for
13594 ** 'first + place' or '1st + place', as there are entries in the
13595 ** FTS index corresponding to both forms of the first token.
13596 ** </ol>
13597 **
13598 ** Whether it is parsing document or query text, any call to xToken that
13599 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
13600 ** is considered to supply a synonym for the previous token. For example,
13601 ** when parsing the document "I won first place", a tokenizer that supports
13602 ** synonyms would call xToken() 5 times, as follows:
13603 **
13604 ** <codeblock>
13605 ** xToken(pCtx, 0, "i", 1, 0, 1);
13606 ** xToken(pCtx, 0, "won", 3, 2, 5);
13607 ** xToken(pCtx, 0, "first", 5, 6, 11);
13608 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13609 ** xToken(pCtx, 0, "place", 5, 12, 17);
13610 **</codeblock>
13611 **
13612 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13613 ** xToken() is called. Multiple synonyms may be specified for a single token
13614 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13615 ** There is no limit to the number of synonyms that may be provided for a
13616 ** single token.
13617 **
13618 ** In many cases, method (1) above is the best approach. It does not add
13619 ** extra data to the FTS index or require FTS5 to query for multiple terms,
13620 ** so it is efficient in terms of disk space and query speed. However, it
13621 ** does not support prefix queries very well. If, as suggested above, the
13622 ** token "first" is substituted for "1st" by the tokenizer, then the query:
13623 **
13624 ** <codeblock>
13625 ** ... MATCH '1s*'</codeblock>
13626 **
13627 ** will not match documents that contain the token "1st" (as the tokenizer
13628 ** will probably not map "1s" to any prefix of "first").
13629 **
13630 ** For full prefix support, method (3) may be preferred. In this case,
13631 ** because the index contains entries for both "first" and "1st", prefix
13632 ** queries such as 'fi*' or '1s*' will match correctly. However, because
13633 ** extra entries are added to the FTS index, this method uses more space
13634 ** within the database.
13635 **
13636 ** Method (2) offers a midpoint between (1) and (3). Using this method,
13637 ** a query such as '1s*' will match documents that contain the literal
13638 ** token "1st", but not "first" (assuming the tokenizer is not able to
13639 ** provide synonyms for prefixes). However, a non-prefix query like '1st'
13640 ** will match against "1st" and "first". This method does not require
13641 ** extra disk space, as no extra entries are added to the FTS index.
13642 ** On the other hand, it may require more CPU cycles to run MATCH queries,
13643 ** as separate queries of the FTS index are required for each synonym.
13644 **
13645 ** When using methods (2) or (3), it is important that the tokenizer only
13646 ** provide synonyms when tokenizing document text (method (3)) or query
13647 ** text (method (2)), not both. Doing so will not cause any errors, but is
13648 ** inefficient.
13649 */
13650 typedef struct Fts5Tokenizer Fts5Tokenizer;
13651 typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2;
13652 struct fts5_tokenizer_v2 {
13653 int iVersion; /* Currently always 2 */
13654 13655 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13656 void (*xDelete)(Fts5Tokenizer*);
13657 int (*xTokenize)(Fts5Tokenizer*,
13658 void *pCtx,
13659 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13660 const char *pText, int nText,
13661 const char *pLocale, int nLocale,
13662 int (*xToken)(
13663 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13664 int tflags, /* Mask of FTS5_TOKEN_* flags */
13665 const char *pToken, /* Pointer to buffer containing token */
13666 int nToken, /* Size of token in bytes */
13667 int iStart, /* Byte offset of token within input text */
13668 int iEnd /* Byte offset of end of token within input text */
13669 )
13670 );
13671 };
13672 13673 /*
13674 ** New code should use the fts5_tokenizer_v2 type to define tokenizer
13675 ** implementations. The following type is included for legacy applications
13676 ** that still use it.
13677 */
13678 typedef struct fts5_tokenizer fts5_tokenizer;
13679 struct fts5_tokenizer {
13680 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13681 void (*xDelete)(Fts5Tokenizer*);
13682 int (*xTokenize)(Fts5Tokenizer*,
13683 void *pCtx,
13684 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13685 const char *pText, int nText,
13686 int (*xToken)(
13687 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13688 int tflags, /* Mask of FTS5_TOKEN_* flags */
13689 const char *pToken, /* Pointer to buffer containing token */
13690 int nToken, /* Size of token in bytes */
13691 int iStart, /* Byte offset of token within input text */
13692 int iEnd /* Byte offset of end of token within input text */
13693 )
13694 );
13695 };
13696 13697 13698 /* Flags that may be passed as the third argument to xTokenize() */
13699 #define FTS5_TOKENIZE_QUERY 0x0001
13700 #define FTS5_TOKENIZE_PREFIX 0x0002
13701 #define FTS5_TOKENIZE_DOCUMENT 0x0004
13702 #define FTS5_TOKENIZE_AUX 0x0008
13703 13704 /* Flags that may be passed by the tokenizer implementation back to FTS5
13705 ** as the third argument to the supplied xToken callback. */
13706 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
13707 13708 /*
13709 ** END OF CUSTOM TOKENIZERS
13710 *************************************************************************/
13711 13712 /*************************************************************************
13713 ** FTS5 EXTENSION REGISTRATION API
13714 */
13715 typedef struct fts5_api fts5_api;
13716 struct fts5_api {
13717 int iVersion; /* Currently always set to 3 */
13718 13719 /* Create a new tokenizer */
13720 int (*xCreateTokenizer)(
13721 fts5_api *pApi,
13722 const char *zName,
13723 void *pUserData,
13724 fts5_tokenizer *pTokenizer,
13725 void (*xDestroy)(void*)
13726 );
13727 13728 /* Find an existing tokenizer */
13729 int (*xFindTokenizer)(
13730 fts5_api *pApi,
13731 const char *zName,
13732 void **ppUserData,
13733 fts5_tokenizer *pTokenizer
13734 );
13735 13736 /* Create a new auxiliary function */
13737 int (*xCreateFunction)(
13738 fts5_api *pApi,
13739 const char *zName,
13740 void *pUserData,
13741 fts5_extension_function xFunction,
13742 void (*xDestroy)(void*)
13743 );
13744 13745 /* APIs below this point are only available if iVersion>=3 */
13746 13747 /* Create a new tokenizer */
13748 int (*xCreateTokenizer_v2)(
13749 fts5_api *pApi,
13750 const char *zName,
13751 void *pUserData,
13752 fts5_tokenizer_v2 *pTokenizer,
13753 void (*xDestroy)(void*)
13754 );
13755 13756 /* Find an existing tokenizer */
13757 int (*xFindTokenizer_v2)(
13758 fts5_api *pApi,
13759 const char *zName,
13760 void **ppUserData,
13761 fts5_tokenizer_v2 **ppTokenizer
13762 );
13763 };
13764 13765 /*
13766 ** END OF REGISTRATION API
13767 *************************************************************************/
13768 13769 #ifdef __cplusplus
13770 } /* end of the 'extern "C"' block */
13771 #endif
13772 13773 #endif /* _FTS5_H */
13774 13775 /******** End of fts5.h *********/
13776 #endif /* SQLITE3_H */
13777 #else // USE_LIBSQLITE3
13778 // If users really want to link against the system sqlite3 we
13779 // need to make this file a noop.
13780 #endif