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1 /*
2 ** 2001-09-15
3 **
4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
6 **
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** This header file defines the interface that the SQLite library
13 ** presents to client programs. If a C-function, structure, datatype,
14 ** or constant definition does not appear in this file, then it is
15 ** not a published API of SQLite, is subject to change without
16 ** notice, and should not be referenced by programs that use SQLite.
17 **
18 ** Some of the definitions that are in this file are marked as
19 ** "experimental". Experimental interfaces are normally new
20 ** features recently added to SQLite. We do not anticipate changes
21 ** to experimental interfaces but reserve the right to make minor changes
22 ** if experience from use "in the wild" suggest such changes are prudent.
23 **
24 ** The official C-language API documentation for SQLite is derived
25 ** from comments in this file. This file is the authoritative source
26 ** on how SQLite interfaces are supposed to operate.
27 **
28 ** The name of this file under configuration management is "sqlite.h.in".
29 ** The makefile makes some minor changes to this file (such as inserting
30 ** the version number) and changes its name to "sqlite3.h" as
31 ** part of the build process.
32 */
33 #ifndef SQLITE3_H
34 #define SQLITE3_H
35 #include <stdarg.h> /* Needed for the definition of va_list */
36
37 /*
38 ** Make sure we can call this stuff from C++.
39 */
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
43
44
45 /*
46 ** Facilitate override of interface linkage and calling conventions.
47 ** Be aware that these macros may not be used within this particular
48 ** translation of the amalgamation and its associated header file.
49 **
50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51 ** compiler that the target identifier should have external linkage.
52 **
53 ** The SQLITE_CDECL macro is used to set the calling convention for
54 ** public functions that accept a variable number of arguments.
55 **
56 ** The SQLITE_APICALL macro is used to set the calling convention for
57 ** public functions that accept a fixed number of arguments.
58 **
59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated.
60 **
61 ** The SQLITE_CALLBACK macro is used to set the calling convention for
62 ** function pointers.
63 **
64 ** The SQLITE_SYSAPI macro is used to set the calling convention for
65 ** functions provided by the operating system.
66 **
67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68 ** SQLITE_SYSAPI macros are used only when building for environments
69 ** that require non-default calling conventions.
70 */
71 #ifndef SQLITE_EXTERN
72 # define SQLITE_EXTERN extern
73 #endif
74 #ifndef SQLITE_API
75 # define SQLITE_API
76 #endif
77 #ifndef SQLITE_CDECL
78 # define SQLITE_CDECL
79 #endif
80 #ifndef SQLITE_APICALL
81 # define SQLITE_APICALL
82 #endif
83 #ifndef SQLITE_STDCALL
84 # define SQLITE_STDCALL SQLITE_APICALL
85 #endif
86 #ifndef SQLITE_CALLBACK
87 # define SQLITE_CALLBACK
88 #endif
89 #ifndef SQLITE_SYSAPI
90 # define SQLITE_SYSAPI
91 #endif
92
93 /*
94 ** These no-op macros are used in front of interfaces to mark those
95 ** interfaces as either deprecated or experimental. New applications
96 ** should not use deprecated interfaces - they are supported for backwards
97 ** compatibility only. Application writers should be aware that
98 ** experimental interfaces are subject to change in point releases.
99 **
100 ** These macros used to resolve to various kinds of compiler magic that
101 ** would generate warning messages when they were used. But that
102 ** compiler magic ended up generating such a flurry of bug reports
103 ** that we have taken it all out and gone back to using simple
104 ** noop macros.
105 */
106 #define SQLITE_DEPRECATED
107 #define SQLITE_EXPERIMENTAL
108
109 /*
110 ** Ensure these symbols were not defined by some previous header file.
111 */
112 #ifdef SQLITE_VERSION
113 # undef SQLITE_VERSION
114 #endif
115 #ifdef SQLITE_VERSION_NUMBER
116 # undef SQLITE_VERSION_NUMBER
117 #endif
118
119 /*
120 ** CAPI3REF: Compile-Time Library Version Numbers
121 **
122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123 ** evaluates to a string literal that is the SQLite version in the
124 ** format "X.Y.Z" where X is the major version number (always 3 for
125 ** SQLite3) and Y is the minor version number and Z is the release number.)^
126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128 ** numbers used in [SQLITE_VERSION].)^
129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130 ** be larger than the release from which it is derived. Either Y will
131 ** be held constant and Z will be incremented or else Y will be incremented
132 ** and Z will be reset to zero.
133 **
134 ** Since [version 3.6.18] ([dateof:3.6.18]),
135 ** SQLite source code has been stored in the
136 ** <a href="http://fossil-scm.org/">Fossil configuration management
137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138 ** a string which identifies a particular check-in of SQLite
139 ** within its configuration management system. ^The SQLITE_SOURCE_ID
140 ** string contains the date and time of the check-in (UTC) and a SHA1
141 ** or SHA3-256 hash of the entire source tree. If the source code has
142 ** been edited in any way since it was last checked in, then the last
143 ** four hexadecimal digits of the hash may be modified.
144 **
145 ** See also: [sqlite3_libversion()],
146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147 ** [sqlite_version()] and [sqlite_source_id()].
148 */
149 #define SQLITE_VERSION "3.50.4"
150 #define SQLITE_VERSION_NUMBER 3050004
151 #define SQLITE_SOURCE_ID "2025-07-30 19:33:53 4d8adfb30e03f9cf27f800a2c1ba3c48fb4ca1b08b0f5ed59a4d5ecbf45e20a3"
152
153 /*
154 ** CAPI3REF: Run-Time Library Version Numbers
155 ** KEYWORDS: sqlite3_version sqlite3_sourceid
156 **
157 ** These interfaces provide the same information as the [SQLITE_VERSION],
158 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
159 ** but are associated with the library instead of the header file. ^(Cautious
160 ** programmers might include assert() statements in their application to
161 ** verify that values returned by these interfaces match the macros in
162 ** the header, and thus ensure that the application is
163 ** compiled with matching library and header files.
164 **
165 ** <blockquote><pre>
166 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
167 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
168 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
169 ** </pre></blockquote>)^
170 **
171 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
172 ** macro. ^The sqlite3_libversion() function returns a pointer to the
173 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
174 ** function is provided for use in DLLs since DLL users usually do not have
175 ** direct access to string constants within the DLL. ^The
176 ** sqlite3_libversion_number() function returns an integer equal to
177 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
178 ** a pointer to a string constant whose value is the same as the
179 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
180 ** using an edited copy of [the amalgamation], then the last four characters
181 ** of the hash might be different from [SQLITE_SOURCE_ID].)^
182 **
183 ** See also: [sqlite_version()] and [sqlite_source_id()].
184 */
185 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
186 SQLITE_API const char *sqlite3_libversion(void);
187 SQLITE_API const char *sqlite3_sourceid(void);
188 SQLITE_API int sqlite3_libversion_number(void);
189
190 /*
191 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
192 **
193 ** ^The sqlite3_compileoption_used() function returns 0 or 1
194 ** indicating whether the specified option was defined at
195 ** compile time. ^The SQLITE_ prefix may be omitted from the
196 ** option name passed to sqlite3_compileoption_used().
197 **
198 ** ^The sqlite3_compileoption_get() function allows iterating
199 ** over the list of options that were defined at compile time by
200 ** returning the N-th compile time option string. ^If N is out of range,
201 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
202 ** prefix is omitted from any strings returned by
203 ** sqlite3_compileoption_get().
204 **
205 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
206 ** and sqlite3_compileoption_get() may be omitted by specifying the
207 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
208 **
209 ** See also: SQL functions [sqlite_compileoption_used()] and
210 ** [sqlite_compileoption_get()] and the [compile_options pragma].
211 */
212 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
213 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
214 SQLITE_API const char *sqlite3_compileoption_get(int N);
215 #else
216 # define sqlite3_compileoption_used(X) 0
217 # define sqlite3_compileoption_get(X) ((void*)0)
218 #endif
219
220 /*
221 ** CAPI3REF: Test To See If The Library Is Threadsafe
222 **
223 ** ^The sqlite3_threadsafe() function returns zero if and only if
224 ** SQLite was compiled with mutexing code omitted due to the
225 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
226 **
227 ** SQLite can be compiled with or without mutexes. When
228 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
229 ** are enabled and SQLite is threadsafe. When the
230 ** [SQLITE_THREADSAFE] macro is 0,
231 ** the mutexes are omitted. Without the mutexes, it is not safe
232 ** to use SQLite concurrently from more than one thread.
233 **
234 ** Enabling mutexes incurs a measurable performance penalty.
235 ** So if speed is of utmost importance, it makes sense to disable
236 ** the mutexes. But for maximum safety, mutexes should be enabled.
237 ** ^The default behavior is for mutexes to be enabled.
238 **
239 ** This interface can be used by an application to make sure that the
240 ** version of SQLite that it is linking against was compiled with
241 ** the desired setting of the [SQLITE_THREADSAFE] macro.
242 **
243 ** This interface only reports on the compile-time mutex setting
244 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
245 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
246 ** can be fully or partially disabled using a call to [sqlite3_config()]
247 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
248 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
249 ** sqlite3_threadsafe() function shows only the compile-time setting of
250 ** thread safety, not any run-time changes to that setting made by
251 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
252 ** is unchanged by calls to sqlite3_config().)^
253 **
254 ** See the [threading mode] documentation for additional information.
255 */
256 SQLITE_API int sqlite3_threadsafe(void);
257
258 /*
259 ** CAPI3REF: Database Connection Handle
260 ** KEYWORDS: {database connection} {database connections}
261 **
262 ** Each open SQLite database is represented by a pointer to an instance of
263 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
264 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
265 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
266 ** and [sqlite3_close_v2()] are its destructors. There are many other
267 ** interfaces (such as
268 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
269 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
270 ** sqlite3 object.
271 */
272 typedef struct sqlite3 sqlite3;
273
274 /*
275 ** CAPI3REF: 64-Bit Integer Types
276 ** KEYWORDS: sqlite_int64 sqlite_uint64
277 **
278 ** Because there is no cross-platform way to specify 64-bit integer types
279 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
280 **
281 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
282 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
283 ** compatibility only.
284 **
285 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
286 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
287 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
288 ** between 0 and +18446744073709551615 inclusive.
289 */
290 #ifdef SQLITE_INT64_TYPE
291 typedef SQLITE_INT64_TYPE sqlite_int64;
292 # ifdef SQLITE_UINT64_TYPE
293 typedef SQLITE_UINT64_TYPE sqlite_uint64;
294 # else
295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
296 # endif
297 #elif defined(_MSC_VER) || defined(__BORLANDC__)
298 typedef __int64 sqlite_int64;
299 typedef unsigned __int64 sqlite_uint64;
300 #else
301 typedef long long int sqlite_int64;
302 typedef unsigned long long int sqlite_uint64;
303 #endif
304 typedef sqlite_int64 sqlite3_int64;
305 typedef sqlite_uint64 sqlite3_uint64;
306
307 /*
308 ** If compiling for a processor that lacks floating point support,
309 ** substitute integer for floating-point.
310 */
311 #ifdef SQLITE_OMIT_FLOATING_POINT
312 # define double sqlite3_int64
313 #endif
314
315 /*
316 ** CAPI3REF: Closing A Database Connection
317 ** DESTRUCTOR: sqlite3
318 **
319 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
320 ** for the [sqlite3] object.
321 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
322 ** the [sqlite3] object is successfully destroyed and all associated
323 ** resources are deallocated.
324 **
325 ** Ideally, applications should [sqlite3_finalize | finalize] all
326 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
327 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
328 ** with the [sqlite3] object prior to attempting to close the object.
329 ** ^If the database connection is associated with unfinalized prepared
330 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
331 ** sqlite3_close() will leave the database connection open and return
332 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
333 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
334 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database
335 ** connection immediately, it marks the database connection as an unusable
336 ** "zombie" and makes arrangements to automatically deallocate the database
337 ** connection after all prepared statements are finalized, all BLOB handles
338 ** are closed, and all backups have finished. The sqlite3_close_v2() interface
339 ** is intended for use with host languages that are garbage collected, and
340 ** where the order in which destructors are called is arbitrary.
341 **
342 ** ^If an [sqlite3] object is destroyed while a transaction is open,
343 ** the transaction is automatically rolled back.
344 **
345 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
346 ** must be either a NULL
347 ** pointer or an [sqlite3] object pointer obtained
348 ** from [sqlite3_open()], [sqlite3_open16()], or
349 ** [sqlite3_open_v2()], and not previously closed.
350 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
351 ** argument is a harmless no-op.
352 */
353 SQLITE_API int sqlite3_close(sqlite3*);
354 SQLITE_API int sqlite3_close_v2(sqlite3*);
355
356 /*
357 ** The type for a callback function.
358 ** This is legacy and deprecated. It is included for historical
359 ** compatibility and is not documented.
360 */
361 typedef int (*sqlite3_callback)(void*,int,char**, char**);
362
363 /*
364 ** CAPI3REF: One-Step Query Execution Interface
365 ** METHOD: sqlite3
366 **
367 ** The sqlite3_exec() interface is a convenience wrapper around
368 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
369 ** that allows an application to run multiple statements of SQL
370 ** without having to use a lot of C code.
371 **
372 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
373 ** semicolon-separate SQL statements passed into its 2nd argument,
374 ** in the context of the [database connection] passed in as its 1st
375 ** argument. ^If the callback function of the 3rd argument to
376 ** sqlite3_exec() is not NULL, then it is invoked for each result row
377 ** coming out of the evaluated SQL statements. ^The 4th argument to
378 ** sqlite3_exec() is relayed through to the 1st argument of each
379 ** callback invocation. ^If the callback pointer to sqlite3_exec()
380 ** is NULL, then no callback is ever invoked and result rows are
381 ** ignored.
382 **
383 ** ^If an error occurs while evaluating the SQL statements passed into
384 ** sqlite3_exec(), then execution of the current statement stops and
385 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
386 ** is not NULL then any error message is written into memory obtained
387 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
388 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
389 ** on error message strings returned through the 5th parameter of
390 ** sqlite3_exec() after the error message string is no longer needed.
391 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
392 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
393 ** NULL before returning.
394 **
395 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
396 ** routine returns SQLITE_ABORT without invoking the callback again and
397 ** without running any subsequent SQL statements.
398 **
399 ** ^The 2nd argument to the sqlite3_exec() callback function is the
400 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
401 ** callback is an array of pointers to strings obtained as if from
402 ** [sqlite3_column_text()], one for each column. ^If an element of a
403 ** result row is NULL then the corresponding string pointer for the
404 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
405 ** sqlite3_exec() callback is an array of pointers to strings where each
406 ** entry represents the name of corresponding result column as obtained
407 ** from [sqlite3_column_name()].
408 **
409 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
410 ** to an empty string, or a pointer that contains only whitespace and/or
411 ** SQL comments, then no SQL statements are evaluated and the database
412 ** is not changed.
413 **
414 ** Restrictions:
415 **
416 ** <ul>
417 ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
418 ** is a valid and open [database connection].
419 ** <li> The application must not close the [database connection] specified by
420 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
421 ** <li> The application must not modify the SQL statement text passed into
422 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
423 ** <li> The application must not dereference the arrays or string pointers
424 ** passed as the 3rd and 4th callback parameters after it returns.
425 ** </ul>
426 */
427 SQLITE_API int sqlite3_exec(
428 sqlite3*, /* An open database */
429 const char *sql, /* SQL to be evaluated */
430 int (*callback)(void*,int,char**,char**), /* Callback function */
431 void *, /* 1st argument to callback */
432 char **errmsg /* Error msg written here */
433 );
434
435 /*
436 ** CAPI3REF: Result Codes
437 ** KEYWORDS: {result code definitions}
438 **
439 ** Many SQLite functions return an integer result code from the set shown
440 ** here in order to indicate success or failure.
441 **
442 ** New error codes may be added in future versions of SQLite.
443 **
444 ** See also: [extended result code definitions]
445 */
446 #define SQLITE_OK 0 /* Successful result */
447 /* beginning-of-error-codes */
448 #define SQLITE_ERROR 1 /* Generic error */
449 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
450 #define SQLITE_PERM 3 /* Access permission denied */
451 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
452 #define SQLITE_BUSY 5 /* The database file is locked */
453 #define SQLITE_LOCKED 6 /* A table in the database is locked */
454 #define SQLITE_NOMEM 7 /* A malloc() failed */
455 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
456 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
457 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
458 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
459 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
460 #define SQLITE_FULL 13 /* Insertion failed because database is full */
461 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
462 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
463 #define SQLITE_EMPTY 16 /* Internal use only */
464 #define SQLITE_SCHEMA 17 /* The database schema changed */
465 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
466 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
467 #define SQLITE_MISMATCH 20 /* Data type mismatch */
468 #define SQLITE_MISUSE 21 /* Library used incorrectly */
469 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
470 #define SQLITE_AUTH 23 /* Authorization denied */
471 #define SQLITE_FORMAT 24 /* Not used */
472 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
473 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
474 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
475 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
476 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
477 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
478 /* end-of-error-codes */
479
480 /*
481 ** CAPI3REF: Extended Result Codes
482 ** KEYWORDS: {extended result code definitions}
483 **
484 ** In its default configuration, SQLite API routines return one of 30 integer
485 ** [result codes]. However, experience has shown that many of
486 ** these result codes are too coarse-grained. They do not provide as
487 ** much information about problems as programmers might like. In an effort to
488 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
489 ** and later) include
490 ** support for additional result codes that provide more detailed information
491 ** about errors. These [extended result codes] are enabled or disabled
492 ** on a per database connection basis using the
493 ** [sqlite3_extended_result_codes()] API. Or, the extended code for
494 ** the most recent error can be obtained using
495 ** [sqlite3_extended_errcode()].
496 */
497 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
498 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
499 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
500 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
501 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
502 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
503 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
504 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
505 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
506 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
507 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
508 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
509 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
510 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
511 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
512 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
513 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
514 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
515 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
516 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
517 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
518 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
519 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
520 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
521 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
522 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
523 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
524 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
525 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
526 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
527 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
528 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
529 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
530 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
531 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
532 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
533 #define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
534 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
535 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
536 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
537 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
538 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
539 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
540 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
541 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
542 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
543 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
544 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
545 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
546 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
547 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
548 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
549 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
550 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
551 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
552 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
553 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
554 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
555 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
556 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
557 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
558 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
559 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
560 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
561 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
562 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
563 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
564 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
565 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
566 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
567 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
568 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
569 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
570 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
571 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
572 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
573 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
574
575 /*
576 ** CAPI3REF: Flags For File Open Operations
577 **
578 ** These bit values are intended for use in the
579 ** 3rd parameter to the [sqlite3_open_v2()] interface and
580 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
581 **
582 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be
583 ** used as the third argument to the [sqlite3_open_v2()] interface.
584 ** The other flags have historically been ignored by sqlite3_open_v2(),
585 ** though future versions of SQLite might change so that an error is
586 ** raised if any of the disallowed bits are passed into sqlite3_open_v2().
587 ** Applications should not depend on the historical behavior.
588 **
589 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
590 ** [sqlite3_open_v2()] does *not* cause the underlying database file
591 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
592 ** [sqlite3_open_v2()] has historically be a no-op and might become an
593 ** error in future versions of SQLite.
594 */
595 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
596 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
597 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
598 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
599 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
600 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
601 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
602 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
603 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
604 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
605 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
606 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
607 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
608 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
609 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
610 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
611 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
612 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
613 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
614 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
615 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
616 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
617
618 /* Reserved: 0x00F00000 */
619 /* Legacy compatibility: */
620 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
621
622
623 /*
624 ** CAPI3REF: Device Characteristics
625 **
626 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
627 ** object returns an integer which is a vector of these
628 ** bit values expressing I/O characteristics of the mass storage
629 ** device that holds the file that the [sqlite3_io_methods]
630 ** refers to.
631 **
632 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
633 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
634 ** mean that writes of blocks that are nnn bytes in size and
635 ** are aligned to an address which is an integer multiple of
636 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
637 ** that when data is appended to a file, the data is appended
638 ** first then the size of the file is extended, never the other
639 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
640 ** information is written to disk in the same order as calls
641 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
642 ** after reboot following a crash or power loss, the only bytes in a
643 ** file that were written at the application level might have changed
644 ** and that adjacent bytes, even bytes within the same sector are
645 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
646 ** flag indicates that a file cannot be deleted when open. The
647 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
648 ** read-only media and cannot be changed even by processes with
649 ** elevated privileges.
650 **
651 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
652 ** filesystem supports doing multiple write operations atomically when those
653 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
654 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
655 **
656 ** The SQLITE_IOCAP_SUBPAGE_READ property means that it is ok to read
657 ** from the database file in amounts that are not a multiple of the
658 ** page size and that do not begin at a page boundary. Without this
659 ** property, SQLite is careful to only do full-page reads and write
660 ** on aligned pages, with the one exception that it will do a sub-page
661 ** read of the first page to access the database header.
662 */
663 #define SQLITE_IOCAP_ATOMIC 0x00000001
664 #define SQLITE_IOCAP_ATOMIC512 0x00000002
665 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
666 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
667 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
668 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
669 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
670 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
671 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
672 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
673 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
674 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
675 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
676 #define SQLITE_IOCAP_IMMUTABLE 0x00002000
677 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
678 #define SQLITE_IOCAP_SUBPAGE_READ 0x00008000
679
680 /*
681 ** CAPI3REF: File Locking Levels
682 **
683 ** SQLite uses one of these integer values as the second
684 ** argument to calls it makes to the xLock() and xUnlock() methods
685 ** of an [sqlite3_io_methods] object. These values are ordered from
686 ** lest restrictive to most restrictive.
687 **
688 ** The argument to xLock() is always SHARED or higher. The argument to
689 ** xUnlock is either SHARED or NONE.
690 */
691 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */
692 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
693 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */
694 #define SQLITE_LOCK_PENDING 3 /* xLock() only */
695 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
696
697 /*
698 ** CAPI3REF: Synchronization Type Flags
699 **
700 ** When SQLite invokes the xSync() method of an
701 ** [sqlite3_io_methods] object it uses a combination of
702 ** these integer values as the second argument.
703 **
704 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
705 ** sync operation only needs to flush data to mass storage. Inode
706 ** information need not be flushed. If the lower four bits of the flag
707 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
708 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
709 ** to use Mac OS X style fullsync instead of fsync().
710 **
711 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
712 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
713 ** settings. The [synchronous pragma] determines when calls to the
714 ** xSync VFS method occur and applies uniformly across all platforms.
715 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
716 ** energetic or rigorous or forceful the sync operations are and
717 ** only make a difference on Mac OSX for the default SQLite code.
718 ** (Third-party VFS implementations might also make the distinction
719 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
720 ** operating systems natively supported by SQLite, only Mac OSX
721 ** cares about the difference.)
722 */
723 #define SQLITE_SYNC_NORMAL 0x00002
724 #define SQLITE_SYNC_FULL 0x00003
725 #define SQLITE_SYNC_DATAONLY 0x00010
726
727 /*
728 ** CAPI3REF: OS Interface Open File Handle
729 **
730 ** An [sqlite3_file] object represents an open file in the
731 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
732 ** implementations will
733 ** want to subclass this object by appending additional fields
734 ** for their own use. The pMethods entry is a pointer to an
735 ** [sqlite3_io_methods] object that defines methods for performing
736 ** I/O operations on the open file.
737 */
738 typedef struct sqlite3_file sqlite3_file;
739 struct sqlite3_file {
740 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
741 };
742
743 /*
744 ** CAPI3REF: OS Interface File Virtual Methods Object
745 **
746 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
747 ** [sqlite3_file] object (or, more commonly, a subclass of the
748 ** [sqlite3_file] object) with a pointer to an instance of this object.
749 ** This object defines the methods used to perform various operations
750 ** against the open file represented by the [sqlite3_file] object.
751 **
752 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
753 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
754 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
755 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
756 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
757 ** to NULL.
758 **
759 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
760 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
761 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
762 ** flag may be ORed in to indicate that only the data of the file
763 ** and not its inode needs to be synced.
764 **
765 ** The integer values to xLock() and xUnlock() are one of
766 ** <ul>
767 ** <li> [SQLITE_LOCK_NONE],
768 ** <li> [SQLITE_LOCK_SHARED],
769 ** <li> [SQLITE_LOCK_RESERVED],
770 ** <li> [SQLITE_LOCK_PENDING], or
771 ** <li> [SQLITE_LOCK_EXCLUSIVE].
772 ** </ul>
773 ** xLock() upgrades the database file lock. In other words, xLock() moves the
774 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to
775 ** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
776 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the
777 ** requested lock, then the call to xLock() is a no-op.
778 ** xUnlock() downgrades the database file lock to either SHARED or NONE.
779 ** If the lock is already at or below the requested lock state, then the call
780 ** to xUnlock() is a no-op.
781 ** The xCheckReservedLock() method checks whether any database connection,
782 ** either in this process or in some other process, is holding a RESERVED,
783 ** PENDING, or EXCLUSIVE lock on the file. It returns, via its output
784 ** pointer parameter, true if such a lock exists and false otherwise.
785 **
786 ** The xFileControl() method is a generic interface that allows custom
787 ** VFS implementations to directly control an open file using the
788 ** [sqlite3_file_control()] interface. The second "op" argument is an
789 ** integer opcode. The third argument is a generic pointer intended to
790 ** point to a structure that may contain arguments or space in which to
791 ** write return values. Potential uses for xFileControl() might be
792 ** functions to enable blocking locks with timeouts, to change the
793 ** locking strategy (for example to use dot-file locks), to inquire
794 ** about the status of a lock, or to break stale locks. The SQLite
795 ** core reserves all opcodes less than 100 for its own use.
796 ** A [file control opcodes | list of opcodes] less than 100 is available.
797 ** Applications that define a custom xFileControl method should use opcodes
798 ** greater than 100 to avoid conflicts. VFS implementations should
799 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
800 ** recognize.
801 **
802 ** The xSectorSize() method returns the sector size of the
803 ** device that underlies the file. The sector size is the
804 ** minimum write that can be performed without disturbing
805 ** other bytes in the file. The xDeviceCharacteristics()
806 ** method returns a bit vector describing behaviors of the
807 ** underlying device:
808 **
809 ** <ul>
810 ** <li> [SQLITE_IOCAP_ATOMIC]
811 ** <li> [SQLITE_IOCAP_ATOMIC512]
812 ** <li> [SQLITE_IOCAP_ATOMIC1K]
813 ** <li> [SQLITE_IOCAP_ATOMIC2K]
814 ** <li> [SQLITE_IOCAP_ATOMIC4K]
815 ** <li> [SQLITE_IOCAP_ATOMIC8K]
816 ** <li> [SQLITE_IOCAP_ATOMIC16K]
817 ** <li> [SQLITE_IOCAP_ATOMIC32K]
818 ** <li> [SQLITE_IOCAP_ATOMIC64K]
819 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
820 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
821 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
822 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
823 ** <li> [SQLITE_IOCAP_IMMUTABLE]
824 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
825 ** <li> [SQLITE_IOCAP_SUBPAGE_READ]
826 ** </ul>
827 **
828 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
829 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
830 ** mean that writes of blocks that are nnn bytes in size and
831 ** are aligned to an address which is an integer multiple of
832 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
833 ** that when data is appended to a file, the data is appended
834 ** first then the size of the file is extended, never the other
835 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
836 ** information is written to disk in the same order as calls
837 ** to xWrite().
838 **
839 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
840 ** in the unread portions of the buffer with zeros. A VFS that
841 ** fails to zero-fill short reads might seem to work. However,
842 ** failure to zero-fill short reads will eventually lead to
843 ** database corruption.
844 */
845 typedef struct sqlite3_io_methods sqlite3_io_methods;
846 struct sqlite3_io_methods {
847 int iVersion;
848 int (*xClose)(sqlite3_file*);
849 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
850 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
851 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
852 int (*xSync)(sqlite3_file*, int flags);
853 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
854 int (*xLock)(sqlite3_file*, int);
855 int (*xUnlock)(sqlite3_file*, int);
856 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
857 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
858 int (*xSectorSize)(sqlite3_file*);
859 int (*xDeviceCharacteristics)(sqlite3_file*);
860 /* Methods above are valid for version 1 */
861 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
862 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
863 void (*xShmBarrier)(sqlite3_file*);
864 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
865 /* Methods above are valid for version 2 */
866 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
867 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
868 /* Methods above are valid for version 3 */
869 /* Additional methods may be added in future releases */
870 };
871
872 /*
873 ** CAPI3REF: Standard File Control Opcodes
874 ** KEYWORDS: {file control opcodes} {file control opcode}
875 **
876 ** These integer constants are opcodes for the xFileControl method
877 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
878 ** interface.
879 **
880 ** <ul>
881 ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
882 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
883 ** opcode causes the xFileControl method to write the current state of
884 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
885 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
886 ** into an integer that the pArg argument points to.
887 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
888 **
889 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
890 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
891 ** layer a hint of how large the database file will grow to be during the
892 ** current transaction. This hint is not guaranteed to be accurate but it
893 ** is often close. The underlying VFS might choose to preallocate database
894 ** file space based on this hint in order to help writes to the database
895 ** file run faster.
896 **
897 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
898 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
899 ** implements [sqlite3_deserialize()] to set an upper bound on the size
900 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
901 ** If the integer pointed to is negative, then it is filled in with the
902 ** current limit. Otherwise the limit is set to the larger of the value
903 ** of the integer pointed to and the current database size. The integer
904 ** pointed to is set to the new limit.
905 **
906 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
907 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
908 ** extends and truncates the database file in chunks of a size specified
909 ** by the user. The fourth argument to [sqlite3_file_control()] should
910 ** point to an integer (type int) containing the new chunk-size to use
911 ** for the nominated database. Allocating database file space in large
912 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
913 ** improve performance on some systems.
914 **
915 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
916 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
917 ** to the [sqlite3_file] object associated with a particular database
918 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
919 **
920 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
921 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
922 ** to the [sqlite3_file] object associated with the journal file (either
923 ** the [rollback journal] or the [write-ahead log]) for a particular database
924 ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
925 **
926 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
927 ** No longer in use.
928 **
929 ** <li>[[SQLITE_FCNTL_SYNC]]
930 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
931 ** sent to the VFS immediately before the xSync method is invoked on a
932 ** database file descriptor. Or, if the xSync method is not invoked
933 ** because the user has configured SQLite with
934 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
935 ** of the xSync method. In most cases, the pointer argument passed with
936 ** this file-control is NULL. However, if the database file is being synced
937 ** as part of a multi-database commit, the argument points to a nul-terminated
938 ** string containing the transactions super-journal file name. VFSes that
939 ** do not need this signal should silently ignore this opcode. Applications
940 ** should not call [sqlite3_file_control()] with this opcode as doing so may
941 ** disrupt the operation of the specialized VFSes that do require it.
942 **
943 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
944 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
945 ** and sent to the VFS after a transaction has been committed immediately
946 ** but before the database is unlocked. VFSes that do not need this signal
947 ** should silently ignore this opcode. Applications should not call
948 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
949 ** operation of the specialized VFSes that do require it.
950 **
951 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
952 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
953 ** retry counts and intervals for certain disk I/O operations for the
954 ** windows [VFS] in order to provide robustness in the presence of
955 ** anti-virus programs. By default, the windows VFS will retry file read,
956 ** file write, and file delete operations up to 10 times, with a delay
957 ** of 25 milliseconds before the first retry and with the delay increasing
958 ** by an additional 25 milliseconds with each subsequent retry. This
959 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
960 ** to be adjusted. The values are changed for all database connections
961 ** within the same process. The argument is a pointer to an array of two
962 ** integers where the first integer is the new retry count and the second
963 ** integer is the delay. If either integer is negative, then the setting
964 ** is not changed but instead the prior value of that setting is written
965 ** into the array entry, allowing the current retry settings to be
966 ** interrogated. The zDbName parameter is ignored.
967 **
968 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
969 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
970 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
971 ** write ahead log ([WAL file]) and shared memory
972 ** files used for transaction control
973 ** are automatically deleted when the latest connection to the database
974 ** closes. Setting persistent WAL mode causes those files to persist after
975 ** close. Persisting the files is useful when other processes that do not
976 ** have write permission on the directory containing the database file want
977 ** to read the database file, as the WAL and shared memory files must exist
978 ** in order for the database to be readable. The fourth parameter to
979 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
980 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
981 ** WAL mode. If the integer is -1, then it is overwritten with the current
982 ** WAL persistence setting.
983 **
984 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
985 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
986 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
987 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
988 ** xDeviceCharacteristics methods. The fourth parameter to
989 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
990 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
991 ** mode. If the integer is -1, then it is overwritten with the current
992 ** zero-damage mode setting.
993 **
994 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
995 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
996 ** a write transaction to indicate that, unless it is rolled back for some
997 ** reason, the entire database file will be overwritten by the current
998 ** transaction. This is used by VACUUM operations.
999 **
1000 ** <li>[[SQLITE_FCNTL_VFSNAME]]
1001 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
1002 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
1003 ** final bottom-level VFS are written into memory obtained from
1004 ** [sqlite3_malloc()] and the result is stored in the char* variable
1005 ** that the fourth parameter of [sqlite3_file_control()] points to.
1006 ** The caller is responsible for freeing the memory when done. As with
1007 ** all file-control actions, there is no guarantee that this will actually
1008 ** do anything. Callers should initialize the char* variable to a NULL
1009 ** pointer in case this file-control is not implemented. This file-control
1010 ** is intended for diagnostic use only.
1011 **
1012 ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1013 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1014 ** [VFSes] currently in use. ^(The argument X in
1015 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1016 ** of type "[sqlite3_vfs] **". This opcodes will set *X
1017 ** to a pointer to the top-level VFS.)^
1018 ** ^When there are multiple VFS shims in the stack, this opcode finds the
1019 ** upper-most shim only.
1020 **
1021 ** <li>[[SQLITE_FCNTL_PRAGMA]]
1022 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1023 ** file control is sent to the open [sqlite3_file] object corresponding
1024 ** to the database file to which the pragma statement refers. ^The argument
1025 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1026 ** pointers to strings (char**) in which the second element of the array
1027 ** is the name of the pragma and the third element is the argument to the
1028 ** pragma or NULL if the pragma has no argument. ^The handler for an
1029 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1030 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1031 ** or the equivalent and that string will become the result of the pragma or
1032 ** the error message if the pragma fails. ^If the
1033 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1034 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1035 ** file control returns [SQLITE_OK], then the parser assumes that the
1036 ** VFS has handled the PRAGMA itself and the parser generates a no-op
1037 ** prepared statement if result string is NULL, or that returns a copy
1038 ** of the result string if the string is non-NULL.
1039 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1040 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1041 ** that the VFS encountered an error while handling the [PRAGMA] and the
1042 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1043 ** file control occurs at the beginning of pragma statement analysis and so
1044 ** it is able to override built-in [PRAGMA] statements.
1045 **
1046 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1047 ** ^The [SQLITE_FCNTL_BUSYHANDLER]
1048 ** file-control may be invoked by SQLite on the database file handle
1049 ** shortly after it is opened in order to provide a custom VFS with access
1050 ** to the connection's busy-handler callback. The argument is of type (void**)
1051 ** - an array of two (void *) values. The first (void *) actually points
1052 ** to a function of type (int (*)(void *)). In order to invoke the connection's
1053 ** busy-handler, this function should be invoked with the second (void *) in
1054 ** the array as the only argument. If it returns non-zero, then the operation
1055 ** should be retried. If it returns zero, the custom VFS should abandon the
1056 ** current operation.
1057 **
1058 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1059 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1060 ** to have SQLite generate a
1061 ** temporary filename using the same algorithm that is followed to generate
1062 ** temporary filenames for TEMP tables and other internal uses. The
1063 ** argument should be a char** which will be filled with the filename
1064 ** written into memory obtained from [sqlite3_malloc()]. The caller should
1065 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
1066 **
1067 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1068 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1069 ** maximum number of bytes that will be used for memory-mapped I/O.
1070 ** The argument is a pointer to a value of type sqlite3_int64 that
1071 ** is an advisory maximum number of bytes in the file to memory map. The
1072 ** pointer is overwritten with the old value. The limit is not changed if
1073 ** the value originally pointed to is negative, and so the current limit
1074 ** can be queried by passing in a pointer to a negative number. This
1075 ** file-control is used internally to implement [PRAGMA mmap_size].
1076 **
1077 ** <li>[[SQLITE_FCNTL_TRACE]]
1078 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1079 ** to the VFS about what the higher layers of the SQLite stack are doing.
1080 ** This file control is used by some VFS activity tracing [shims].
1081 ** The argument is a zero-terminated string. Higher layers in the
1082 ** SQLite stack may generate instances of this file control if
1083 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1084 **
1085 ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1086 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1087 ** pointer to an integer and it writes a boolean into that integer depending
1088 ** on whether or not the file has been renamed, moved, or deleted since it
1089 ** was first opened.
1090 **
1091 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1092 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1093 ** underlying native file handle associated with a file handle. This file
1094 ** control interprets its argument as a pointer to a native file handle and
1095 ** writes the resulting value there.
1096 **
1097 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1098 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1099 ** opcode causes the xFileControl method to swap the file handle with the one
1100 ** pointed to by the pArg argument. This capability is used during testing
1101 ** and only needs to be supported when SQLITE_TEST is defined.
1102 **
1103 ** <li>[[SQLITE_FCNTL_NULL_IO]]
1104 ** The [SQLITE_FCNTL_NULL_IO] opcode sets the low-level file descriptor
1105 ** or file handle for the [sqlite3_file] object such that it will no longer
1106 ** read or write to the database file.
1107 **
1108 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1109 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1110 ** be advantageous to block on the next WAL lock if the lock is not immediately
1111 ** available. The WAL subsystem issues this signal during rare
1112 ** circumstances in order to fix a problem with priority inversion.
1113 ** Applications should <em>not</em> use this file-control.
1114 **
1115 ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1116 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1117 ** VFS should return SQLITE_NOTFOUND for this opcode.
1118 **
1119 ** <li>[[SQLITE_FCNTL_RBU]]
1120 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1121 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1122 ** this opcode.
1123 **
1124 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1125 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1126 ** the file descriptor is placed in "batch write mode", which
1127 ** means all subsequent write operations will be deferred and done
1128 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1129 ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1130 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1131 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1132 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1133 ** no VFS interface calls on the same [sqlite3_file] file descriptor
1134 ** except for calls to the xWrite method and the xFileControl method
1135 ** with [SQLITE_FCNTL_SIZE_HINT].
1136 **
1137 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1138 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1139 ** operations since the previous successful call to
1140 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1141 ** This file control returns [SQLITE_OK] if and only if the writes were
1142 ** all performed successfully and have been committed to persistent storage.
1143 ** ^Regardless of whether or not it is successful, this file control takes
1144 ** the file descriptor out of batch write mode so that all subsequent
1145 ** write operations are independent.
1146 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1147 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1148 **
1149 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1150 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1151 ** operations since the previous successful call to
1152 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1153 ** ^This file control takes the file descriptor out of batch write mode
1154 ** so that all subsequent write operations are independent.
1155 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1156 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1157 **
1158 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1159 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1160 ** to block for up to M milliseconds before failing when attempting to
1161 ** obtain a file lock using the xLock or xShmLock methods of the VFS.
1162 ** The parameter is a pointer to a 32-bit signed integer that contains
1163 ** the value that M is to be set to. Before returning, the 32-bit signed
1164 ** integer is overwritten with the previous value of M.
1165 **
1166 ** <li>[[SQLITE_FCNTL_BLOCK_ON_CONNECT]]
1167 ** The [SQLITE_FCNTL_BLOCK_ON_CONNECT] opcode is used to configure the
1168 ** VFS to block when taking a SHARED lock to connect to a wal mode database.
1169 ** This is used to implement the functionality associated with
1170 ** SQLITE_SETLK_BLOCK_ON_CONNECT.
1171 **
1172 ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1173 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1174 ** a database file. The argument is a pointer to a 32-bit unsigned integer.
1175 ** The "data version" for the pager is written into the pointer. The
1176 ** "data version" changes whenever any change occurs to the corresponding
1177 ** database file, either through SQL statements on the same database
1178 ** connection or through transactions committed by separate database
1179 ** connections possibly in other processes. The [sqlite3_total_changes()]
1180 ** interface can be used to find if any database on the connection has changed,
1181 ** but that interface responds to changes on TEMP as well as MAIN and does
1182 ** not provide a mechanism to detect changes to MAIN only. Also, the
1183 ** [sqlite3_total_changes()] interface responds to internal changes only and
1184 ** omits changes made by other database connections. The
1185 ** [PRAGMA data_version] command provides a mechanism to detect changes to
1186 ** a single attached database that occur due to other database connections,
1187 ** but omits changes implemented by the database connection on which it is
1188 ** called. This file control is the only mechanism to detect changes that
1189 ** happen either internally or externally and that are associated with
1190 ** a particular attached database.
1191 **
1192 ** <li>[[SQLITE_FCNTL_CKPT_START]]
1193 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1194 ** in wal mode before the client starts to copy pages from the wal
1195 ** file to the database file.
1196 **
1197 ** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1198 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1199 ** in wal mode after the client has finished copying pages from the wal
1200 ** file to the database file, but before the *-shm file is updated to
1201 ** record the fact that the pages have been checkpointed.
1202 **
1203 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1204 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1205 ** whether or not there is a database client in another process with a wal-mode
1206 ** transaction open on the database or not. It is only available on unix.The
1207 ** (void*) argument passed with this file-control should be a pointer to a
1208 ** value of type (int). The integer value is set to 1 if the database is a wal
1209 ** mode database and there exists at least one client in another process that
1210 ** currently has an SQL transaction open on the database. It is set to 0 if
1211 ** the database is not a wal-mode db, or if there is no such connection in any
1212 ** other process. This opcode cannot be used to detect transactions opened
1213 ** by clients within the current process, only within other processes.
1214 **
1215 ** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1216 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1217 ** [checksum VFS shim] only.
1218 **
1219 ** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1220 ** If there is currently no transaction open on the database, and the
1221 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1222 ** purges the contents of the in-memory page cache. If there is an open
1223 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1224 ** </ul>
1225 */
1226 #define SQLITE_FCNTL_LOCKSTATE 1
1227 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1228 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1229 #define SQLITE_FCNTL_LAST_ERRNO 4
1230 #define SQLITE_FCNTL_SIZE_HINT 5
1231 #define SQLITE_FCNTL_CHUNK_SIZE 6
1232 #define SQLITE_FCNTL_FILE_POINTER 7
1233 #define SQLITE_FCNTL_SYNC_OMITTED 8
1234 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1235 #define SQLITE_FCNTL_PERSIST_WAL 10
1236 #define SQLITE_FCNTL_OVERWRITE 11
1237 #define SQLITE_FCNTL_VFSNAME 12
1238 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1239 #define SQLITE_FCNTL_PRAGMA 14
1240 #define SQLITE_FCNTL_BUSYHANDLER 15
1241 #define SQLITE_FCNTL_TEMPFILENAME 16
1242 #define SQLITE_FCNTL_MMAP_SIZE 18
1243 #define SQLITE_FCNTL_TRACE 19
1244 #define SQLITE_FCNTL_HAS_MOVED 20
1245 #define SQLITE_FCNTL_SYNC 21
1246 #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1247 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1248 #define SQLITE_FCNTL_WAL_BLOCK 24
1249 #define SQLITE_FCNTL_ZIPVFS 25
1250 #define SQLITE_FCNTL_RBU 26
1251 #define SQLITE_FCNTL_VFS_POINTER 27
1252 #define SQLITE_FCNTL_JOURNAL_POINTER 28
1253 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1254 #define SQLITE_FCNTL_PDB 30
1255 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1256 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1257 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1258 #define SQLITE_FCNTL_LOCK_TIMEOUT 34
1259 #define SQLITE_FCNTL_DATA_VERSION 35
1260 #define SQLITE_FCNTL_SIZE_LIMIT 36
1261 #define SQLITE_FCNTL_CKPT_DONE 37
1262 #define SQLITE_FCNTL_RESERVE_BYTES 38
1263 #define SQLITE_FCNTL_CKPT_START 39
1264 #define SQLITE_FCNTL_EXTERNAL_READER 40
1265 #define SQLITE_FCNTL_CKSM_FILE 41
1266 #define SQLITE_FCNTL_RESET_CACHE 42
1267 #define SQLITE_FCNTL_NULL_IO 43
1268 #define SQLITE_FCNTL_BLOCK_ON_CONNECT 44
1269
1270 /* deprecated names */
1271 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1272 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1273 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1274
1275
1276 /*
1277 ** CAPI3REF: Mutex Handle
1278 **
1279 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1280 ** abstract type for a mutex object. The SQLite core never looks
1281 ** at the internal representation of an [sqlite3_mutex]. It only
1282 ** deals with pointers to the [sqlite3_mutex] object.
1283 **
1284 ** Mutexes are created using [sqlite3_mutex_alloc()].
1285 */
1286 typedef struct sqlite3_mutex sqlite3_mutex;
1287
1288 /*
1289 ** CAPI3REF: Loadable Extension Thunk
1290 **
1291 ** A pointer to the opaque sqlite3_api_routines structure is passed as
1292 ** the third parameter to entry points of [loadable extensions]. This
1293 ** structure must be typedefed in order to work around compiler warnings
1294 ** on some platforms.
1295 */
1296 typedef struct sqlite3_api_routines sqlite3_api_routines;
1297
1298 /*
1299 ** CAPI3REF: File Name
1300 **
1301 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1302 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1303 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1304 ** may also be passed to special APIs such as:
1305 **
1306 ** <ul>
1307 ** <li> sqlite3_filename_database()
1308 ** <li> sqlite3_filename_journal()
1309 ** <li> sqlite3_filename_wal()
1310 ** <li> sqlite3_uri_parameter()
1311 ** <li> sqlite3_uri_boolean()
1312 ** <li> sqlite3_uri_int64()
1313 ** <li> sqlite3_uri_key()
1314 ** </ul>
1315 */
1316 typedef const char *sqlite3_filename;
1317
1318 /*
1319 ** CAPI3REF: OS Interface Object
1320 **
1321 ** An instance of the sqlite3_vfs object defines the interface between
1322 ** the SQLite core and the underlying operating system. The "vfs"
1323 ** in the name of the object stands for "virtual file system". See
1324 ** the [VFS | VFS documentation] for further information.
1325 **
1326 ** The VFS interface is sometimes extended by adding new methods onto
1327 ** the end. Each time such an extension occurs, the iVersion field
1328 ** is incremented. The iVersion value started out as 1 in
1329 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1330 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1331 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1332 ** may be appended to the sqlite3_vfs object and the iVersion value
1333 ** may increase again in future versions of SQLite.
1334 ** Note that due to an oversight, the structure
1335 ** of the sqlite3_vfs object changed in the transition from
1336 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1337 ** and yet the iVersion field was not increased.
1338 **
1339 ** The szOsFile field is the size of the subclassed [sqlite3_file]
1340 ** structure used by this VFS. mxPathname is the maximum length of
1341 ** a pathname in this VFS.
1342 **
1343 ** Registered sqlite3_vfs objects are kept on a linked list formed by
1344 ** the pNext pointer. The [sqlite3_vfs_register()]
1345 ** and [sqlite3_vfs_unregister()] interfaces manage this list
1346 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1347 ** searches the list. Neither the application code nor the VFS
1348 ** implementation should use the pNext pointer.
1349 **
1350 ** The pNext field is the only field in the sqlite3_vfs
1351 ** structure that SQLite will ever modify. SQLite will only access
1352 ** or modify this field while holding a particular static mutex.
1353 ** The application should never modify anything within the sqlite3_vfs
1354 ** object once the object has been registered.
1355 **
1356 ** The zName field holds the name of the VFS module. The name must
1357 ** be unique across all VFS modules.
1358 **
1359 ** [[sqlite3_vfs.xOpen]]
1360 ** ^SQLite guarantees that the zFilename parameter to xOpen
1361 ** is either a NULL pointer or string obtained
1362 ** from xFullPathname() with an optional suffix added.
1363 ** ^If a suffix is added to the zFilename parameter, it will
1364 ** consist of a single "-" character followed by no more than
1365 ** 11 alphanumeric and/or "-" characters.
1366 ** ^SQLite further guarantees that
1367 ** the string will be valid and unchanged until xClose() is
1368 ** called. Because of the previous sentence,
1369 ** the [sqlite3_file] can safely store a pointer to the
1370 ** filename if it needs to remember the filename for some reason.
1371 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1372 ** must invent its own temporary name for the file. ^Whenever the
1373 ** xFilename parameter is NULL it will also be the case that the
1374 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1375 **
1376 ** The flags argument to xOpen() includes all bits set in
1377 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1378 ** or [sqlite3_open16()] is used, then flags includes at least
1379 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1380 ** If xOpen() opens a file read-only then it sets *pOutFlags to
1381 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1382 **
1383 ** ^(SQLite will also add one of the following flags to the xOpen()
1384 ** call, depending on the object being opened:
1385 **
1386 ** <ul>
1387 ** <li> [SQLITE_OPEN_MAIN_DB]
1388 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1389 ** <li> [SQLITE_OPEN_TEMP_DB]
1390 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1391 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1392 ** <li> [SQLITE_OPEN_SUBJOURNAL]
1393 ** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1394 ** <li> [SQLITE_OPEN_WAL]
1395 ** </ul>)^
1396 **
1397 ** The file I/O implementation can use the object type flags to
1398 ** change the way it deals with files. For example, an application
1399 ** that does not care about crash recovery or rollback might make
1400 ** the open of a journal file a no-op. Writes to this journal would
1401 ** also be no-ops, and any attempt to read the journal would return
1402 ** SQLITE_IOERR. Or the implementation might recognize that a database
1403 ** file will be doing page-aligned sector reads and writes in a random
1404 ** order and set up its I/O subsystem accordingly.
1405 **
1406 ** SQLite might also add one of the following flags to the xOpen method:
1407 **
1408 ** <ul>
1409 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1410 ** <li> [SQLITE_OPEN_EXCLUSIVE]
1411 ** </ul>
1412 **
1413 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1414 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1415 ** will be set for TEMP databases and their journals, transient
1416 ** databases, and subjournals.
1417 **
1418 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1419 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1420 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1421 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1422 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1423 ** be created, and that it is an error if it already exists.
1424 ** It is <i>not</i> used to indicate the file should be opened
1425 ** for exclusive access.
1426 **
1427 ** ^At least szOsFile bytes of memory are allocated by SQLite
1428 ** to hold the [sqlite3_file] structure passed as the third
1429 ** argument to xOpen. The xOpen method does not have to
1430 ** allocate the structure; it should just fill it in. Note that
1431 ** the xOpen method must set the sqlite3_file.pMethods to either
1432 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1433 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1434 ** element will be valid after xOpen returns regardless of the success
1435 ** or failure of the xOpen call.
1436 **
1437 ** [[sqlite3_vfs.xAccess]]
1438 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1439 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1440 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1441 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1442 ** flag is never actually used and is not implemented in the built-in
1443 ** VFSes of SQLite. The file is named by the second argument and can be a
1444 ** directory. The xAccess method returns [SQLITE_OK] on success or some
1445 ** non-zero error code if there is an I/O error or if the name of
1446 ** the file given in the second argument is illegal. If SQLITE_OK
1447 ** is returned, then non-zero or zero is written into *pResOut to indicate
1448 ** whether or not the file is accessible.
1449 **
1450 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1451 ** output buffer xFullPathname. The exact size of the output buffer
1452 ** is also passed as a parameter to both methods. If the output buffer
1453 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1454 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1455 ** to prevent this by setting mxPathname to a sufficiently large value.
1456 **
1457 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1458 ** interfaces are not strictly a part of the filesystem, but they are
1459 ** included in the VFS structure for completeness.
1460 ** The xRandomness() function attempts to return nBytes bytes
1461 ** of good-quality randomness into zOut. The return value is
1462 ** the actual number of bytes of randomness obtained.
1463 ** The xSleep() method causes the calling thread to sleep for at
1464 ** least the number of microseconds given. ^The xCurrentTime()
1465 ** method returns a Julian Day Number for the current date and time as
1466 ** a floating point value.
1467 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1468 ** Day Number multiplied by 86400000 (the number of milliseconds in
1469 ** a 24-hour day).
1470 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1471 ** date and time if that method is available (if iVersion is 2 or
1472 ** greater and the function pointer is not NULL) and will fall back
1473 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1474 **
1475 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1476 ** are not used by the SQLite core. These optional interfaces are provided
1477 ** by some VFSes to facilitate testing of the VFS code. By overriding
1478 ** system calls with functions under its control, a test program can
1479 ** simulate faults and error conditions that would otherwise be difficult
1480 ** or impossible to induce. The set of system calls that can be overridden
1481 ** varies from one VFS to another, and from one version of the same VFS to the
1482 ** next. Applications that use these interfaces must be prepared for any
1483 ** or all of these interfaces to be NULL or for their behavior to change
1484 ** from one release to the next. Applications must not attempt to access
1485 ** any of these methods if the iVersion of the VFS is less than 3.
1486 */
1487 typedef struct sqlite3_vfs sqlite3_vfs;
1488 typedef void (*sqlite3_syscall_ptr)(void);
1489 struct sqlite3_vfs {
1490 int iVersion; /* Structure version number (currently 3) */
1491 int szOsFile; /* Size of subclassed sqlite3_file */
1492 int mxPathname; /* Maximum file pathname length */
1493 sqlite3_vfs *pNext; /* Next registered VFS */
1494 const char *zName; /* Name of this virtual file system */
1495 void *pAppData; /* Pointer to application-specific data */
1496 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1497 int flags, int *pOutFlags);
1498 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1499 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1500 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1501 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1502 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1503 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1504 void (*xDlClose)(sqlite3_vfs*, void*);
1505 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1506 int (*xSleep)(sqlite3_vfs*, int microseconds);
1507 int (*xCurrentTime)(sqlite3_vfs*, double*);
1508 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1509 /*
1510 ** The methods above are in version 1 of the sqlite_vfs object
1511 ** definition. Those that follow are added in version 2 or later
1512 */
1513 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1514 /*
1515 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1516 ** Those below are for version 3 and greater.
1517 */
1518 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1519 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1520 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1521 /*
1522 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1523 ** New fields may be appended in future versions. The iVersion
1524 ** value will increment whenever this happens.
1525 */
1526 };
1527
1528 /*
1529 ** CAPI3REF: Flags for the xAccess VFS method
1530 **
1531 ** These integer constants can be used as the third parameter to
1532 ** the xAccess method of an [sqlite3_vfs] object. They determine
1533 ** what kind of permissions the xAccess method is looking for.
1534 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1535 ** simply checks whether the file exists.
1536 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1537 ** checks whether the named directory is both readable and writable
1538 ** (in other words, if files can be added, removed, and renamed within
1539 ** the directory).
1540 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1541 ** [temp_store_directory pragma], though this could change in a future
1542 ** release of SQLite.
1543 ** With SQLITE_ACCESS_READ, the xAccess method
1544 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1545 ** currently unused, though it might be used in a future release of
1546 ** SQLite.
1547 */
1548 #define SQLITE_ACCESS_EXISTS 0
1549 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1550 #define SQLITE_ACCESS_READ 2 /* Unused */
1551
1552 /*
1553 ** CAPI3REF: Flags for the xShmLock VFS method
1554 **
1555 ** These integer constants define the various locking operations
1556 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1557 ** following are the only legal combinations of flags to the
1558 ** xShmLock method:
1559 **
1560 ** <ul>
1561 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1562 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1563 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1564 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1565 ** </ul>
1566 **
1567 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1568 ** was given on the corresponding lock.
1569 **
1570 ** The xShmLock method can transition between unlocked and SHARED or
1571 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1572 ** and EXCLUSIVE.
1573 */
1574 #define SQLITE_SHM_UNLOCK 1
1575 #define SQLITE_SHM_LOCK 2
1576 #define SQLITE_SHM_SHARED 4
1577 #define SQLITE_SHM_EXCLUSIVE 8
1578
1579 /*
1580 ** CAPI3REF: Maximum xShmLock index
1581 **
1582 ** The xShmLock method on [sqlite3_io_methods] may use values
1583 ** between 0 and this upper bound as its "offset" argument.
1584 ** The SQLite core will never attempt to acquire or release a
1585 ** lock outside of this range
1586 */
1587 #define SQLITE_SHM_NLOCK 8
1588
1589
1590 /*
1591 ** CAPI3REF: Initialize The SQLite Library
1592 **
1593 ** ^The sqlite3_initialize() routine initializes the
1594 ** SQLite library. ^The sqlite3_shutdown() routine
1595 ** deallocates any resources that were allocated by sqlite3_initialize().
1596 ** These routines are designed to aid in process initialization and
1597 ** shutdown on embedded systems. Workstation applications using
1598 ** SQLite normally do not need to invoke either of these routines.
1599 **
1600 ** A call to sqlite3_initialize() is an "effective" call if it is
1601 ** the first time sqlite3_initialize() is invoked during the lifetime of
1602 ** the process, or if it is the first time sqlite3_initialize() is invoked
1603 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1604 ** of sqlite3_initialize() does any initialization. All other calls
1605 ** are harmless no-ops.)^
1606 **
1607 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1608 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1609 ** an effective call to sqlite3_shutdown() does any deinitialization.
1610 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1611 **
1612 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1613 ** is not. The sqlite3_shutdown() interface must only be called from a
1614 ** single thread. All open [database connections] must be closed and all
1615 ** other SQLite resources must be deallocated prior to invoking
1616 ** sqlite3_shutdown().
1617 **
1618 ** Among other things, ^sqlite3_initialize() will invoke
1619 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1620 ** will invoke sqlite3_os_end().
1621 **
1622 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1623 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1624 ** the library (perhaps it is unable to allocate a needed resource such
1625 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1626 **
1627 ** ^The sqlite3_initialize() routine is called internally by many other
1628 ** SQLite interfaces so that an application usually does not need to
1629 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1630 ** calls sqlite3_initialize() so the SQLite library will be automatically
1631 ** initialized when [sqlite3_open()] is called if it has not be initialized
1632 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1633 ** compile-time option, then the automatic calls to sqlite3_initialize()
1634 ** are omitted and the application must call sqlite3_initialize() directly
1635 ** prior to using any other SQLite interface. For maximum portability,
1636 ** it is recommended that applications always invoke sqlite3_initialize()
1637 ** directly prior to using any other SQLite interface. Future releases
1638 ** of SQLite may require this. In other words, the behavior exhibited
1639 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1640 ** default behavior in some future release of SQLite.
1641 **
1642 ** The sqlite3_os_init() routine does operating-system specific
1643 ** initialization of the SQLite library. The sqlite3_os_end()
1644 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1645 ** performed by these routines include allocation or deallocation
1646 ** of static resources, initialization of global variables,
1647 ** setting up a default [sqlite3_vfs] module, or setting up
1648 ** a default configuration using [sqlite3_config()].
1649 **
1650 ** The application should never invoke either sqlite3_os_init()
1651 ** or sqlite3_os_end() directly. The application should only invoke
1652 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1653 ** interface is called automatically by sqlite3_initialize() and
1654 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1655 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1656 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1657 ** When [custom builds | built for other platforms]
1658 ** (using the [SQLITE_OS_OTHER=1] compile-time
1659 ** option) the application must supply a suitable implementation for
1660 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1661 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1662 ** must return [SQLITE_OK] on success and some other [error code] upon
1663 ** failure.
1664 */
1665 SQLITE_API int sqlite3_initialize(void);
1666 SQLITE_API int sqlite3_shutdown(void);
1667 SQLITE_API int sqlite3_os_init(void);
1668 SQLITE_API int sqlite3_os_end(void);
1669
1670 /*
1671 ** CAPI3REF: Configuring The SQLite Library
1672 **
1673 ** The sqlite3_config() interface is used to make global configuration
1674 ** changes to SQLite in order to tune SQLite to the specific needs of
1675 ** the application. The default configuration is recommended for most
1676 ** applications and so this routine is usually not necessary. It is
1677 ** provided to support rare applications with unusual needs.
1678 **
1679 ** <b>The sqlite3_config() interface is not threadsafe. The application
1680 ** must ensure that no other SQLite interfaces are invoked by other
1681 ** threads while sqlite3_config() is running.</b>
1682 **
1683 ** The first argument to sqlite3_config() is an integer
1684 ** [configuration option] that determines
1685 ** what property of SQLite is to be configured. Subsequent arguments
1686 ** vary depending on the [configuration option]
1687 ** in the first argument.
1688 **
1689 ** For most configuration options, the sqlite3_config() interface
1690 ** may only be invoked prior to library initialization using
1691 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1692 ** The exceptional configuration options that may be invoked at any time
1693 ** are called "anytime configuration options".
1694 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1695 ** [sqlite3_shutdown()] with a first argument that is not an anytime
1696 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1697 ** Note, however, that ^sqlite3_config() can be called as part of the
1698 ** implementation of an application-defined [sqlite3_os_init()].
1699 **
1700 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1701 ** ^If the option is unknown or SQLite is unable to set the option
1702 ** then this routine returns a non-zero [error code].
1703 */
1704 SQLITE_API int sqlite3_config(int, ...);
1705
1706 /*
1707 ** CAPI3REF: Configure database connections
1708 ** METHOD: sqlite3
1709 **
1710 ** The sqlite3_db_config() interface is used to make configuration
1711 ** changes to a [database connection]. The interface is similar to
1712 ** [sqlite3_config()] except that the changes apply to a single
1713 ** [database connection] (specified in the first argument).
1714 **
1715 ** The second argument to sqlite3_db_config(D,V,...) is the
1716 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1717 ** that indicates what aspect of the [database connection] is being configured.
1718 ** Subsequent arguments vary depending on the configuration verb.
1719 **
1720 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1721 ** the call is considered successful.
1722 */
1723 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1724
1725 /*
1726 ** CAPI3REF: Memory Allocation Routines
1727 **
1728 ** An instance of this object defines the interface between SQLite
1729 ** and low-level memory allocation routines.
1730 **
1731 ** This object is used in only one place in the SQLite interface.
1732 ** A pointer to an instance of this object is the argument to
1733 ** [sqlite3_config()] when the configuration option is
1734 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1735 ** By creating an instance of this object
1736 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1737 ** during configuration, an application can specify an alternative
1738 ** memory allocation subsystem for SQLite to use for all of its
1739 ** dynamic memory needs.
1740 **
1741 ** Note that SQLite comes with several [built-in memory allocators]
1742 ** that are perfectly adequate for the overwhelming majority of applications
1743 ** and that this object is only useful to a tiny minority of applications
1744 ** with specialized memory allocation requirements. This object is
1745 ** also used during testing of SQLite in order to specify an alternative
1746 ** memory allocator that simulates memory out-of-memory conditions in
1747 ** order to verify that SQLite recovers gracefully from such
1748 ** conditions.
1749 **
1750 ** The xMalloc, xRealloc, and xFree methods must work like the
1751 ** malloc(), realloc() and free() functions from the standard C library.
1752 ** ^SQLite guarantees that the second argument to
1753 ** xRealloc is always a value returned by a prior call to xRoundup.
1754 **
1755 ** xSize should return the allocated size of a memory allocation
1756 ** previously obtained from xMalloc or xRealloc. The allocated size
1757 ** is always at least as big as the requested size but may be larger.
1758 **
1759 ** The xRoundup method returns what would be the allocated size of
1760 ** a memory allocation given a particular requested size. Most memory
1761 ** allocators round up memory allocations at least to the next multiple
1762 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1763 ** Every memory allocation request coming in through [sqlite3_malloc()]
1764 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1765 ** that causes the corresponding memory allocation to fail.
1766 **
1767 ** The xInit method initializes the memory allocator. For example,
1768 ** it might allocate any required mutexes or initialize internal data
1769 ** structures. The xShutdown method is invoked (indirectly) by
1770 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1771 ** by xInit. The pAppData pointer is used as the only parameter to
1772 ** xInit and xShutdown.
1773 **
1774 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1775 ** the xInit method, so the xInit method need not be threadsafe. The
1776 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1777 ** not need to be threadsafe either. For all other methods, SQLite
1778 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1779 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1780 ** it is by default) and so the methods are automatically serialized.
1781 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1782 ** methods must be threadsafe or else make their own arrangements for
1783 ** serialization.
1784 **
1785 ** SQLite will never invoke xInit() more than once without an intervening
1786 ** call to xShutdown().
1787 */
1788 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1789 struct sqlite3_mem_methods {
1790 void *(*xMalloc)(int); /* Memory allocation function */
1791 void (*xFree)(void*); /* Free a prior allocation */
1792 void *(*xRealloc)(void*,int); /* Resize an allocation */
1793 int (*xSize)(void*); /* Return the size of an allocation */
1794 int (*xRoundup)(int); /* Round up request size to allocation size */
1795 int (*xInit)(void*); /* Initialize the memory allocator */
1796 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1797 void *pAppData; /* Argument to xInit() and xShutdown() */
1798 };
1799
1800 /*
1801 ** CAPI3REF: Configuration Options
1802 ** KEYWORDS: {configuration option}
1803 **
1804 ** These constants are the available integer configuration options that
1805 ** can be passed as the first argument to the [sqlite3_config()] interface.
1806 **
1807 ** Most of the configuration options for sqlite3_config()
1808 ** will only work if invoked prior to [sqlite3_initialize()] or after
1809 ** [sqlite3_shutdown()]. The few exceptions to this rule are called
1810 ** "anytime configuration options".
1811 ** ^Calling [sqlite3_config()] with a first argument that is not an
1812 ** anytime configuration option in between calls to [sqlite3_initialize()] and
1813 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1814 **
1815 ** The set of anytime configuration options can change (by insertions
1816 ** and/or deletions) from one release of SQLite to the next.
1817 ** As of SQLite version 3.42.0, the complete set of anytime configuration
1818 ** options is:
1819 ** <ul>
1820 ** <li> SQLITE_CONFIG_LOG
1821 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1822 ** </ul>
1823 **
1824 ** New configuration options may be added in future releases of SQLite.
1825 ** Existing configuration options might be discontinued. Applications
1826 ** should check the return code from [sqlite3_config()] to make sure that
1827 ** the call worked. The [sqlite3_config()] interface will return a
1828 ** non-zero [error code] if a discontinued or unsupported configuration option
1829 ** is invoked.
1830 **
1831 ** <dl>
1832 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1833 ** <dd>There are no arguments to this option. ^This option sets the
1834 ** [threading mode] to Single-thread. In other words, it disables
1835 ** all mutexing and puts SQLite into a mode where it can only be used
1836 ** by a single thread. ^If SQLite is compiled with
1837 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1838 ** it is not possible to change the [threading mode] from its default
1839 ** value of Single-thread and so [sqlite3_config()] will return
1840 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1841 ** configuration option.</dd>
1842 **
1843 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1844 ** <dd>There are no arguments to this option. ^This option sets the
1845 ** [threading mode] to Multi-thread. In other words, it disables
1846 ** mutexing on [database connection] and [prepared statement] objects.
1847 ** The application is responsible for serializing access to
1848 ** [database connections] and [prepared statements]. But other mutexes
1849 ** are enabled so that SQLite will be safe to use in a multi-threaded
1850 ** environment as long as no two threads attempt to use the same
1851 ** [database connection] at the same time. ^If SQLite is compiled with
1852 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1853 ** it is not possible to set the Multi-thread [threading mode] and
1854 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1855 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1856 **
1857 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1858 ** <dd>There are no arguments to this option. ^This option sets the
1859 ** [threading mode] to Serialized. In other words, this option enables
1860 ** all mutexes including the recursive
1861 ** mutexes on [database connection] and [prepared statement] objects.
1862 ** In this mode (which is the default when SQLite is compiled with
1863 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1864 ** to [database connections] and [prepared statements] so that the
1865 ** application is free to use the same [database connection] or the
1866 ** same [prepared statement] in different threads at the same time.
1867 ** ^If SQLite is compiled with
1868 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1869 ** it is not possible to set the Serialized [threading mode] and
1870 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1871 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1872 **
1873 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1874 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1875 ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1876 ** The argument specifies
1877 ** alternative low-level memory allocation routines to be used in place of
1878 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1879 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1880 ** before the [sqlite3_config()] call returns.</dd>
1881 **
1882 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1883 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1884 ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1885 ** The [sqlite3_mem_methods]
1886 ** structure is filled with the currently defined memory allocation routines.)^
1887 ** This option can be used to overload the default memory allocation
1888 ** routines with a wrapper that simulations memory allocation failure or
1889 ** tracks memory usage, for example. </dd>
1890 **
1891 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1892 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1893 ** type int, interpreted as a boolean, which if true provides a hint to
1894 ** SQLite that it should avoid large memory allocations if possible.
1895 ** SQLite will run faster if it is free to make large memory allocations,
1896 ** but some application might prefer to run slower in exchange for
1897 ** guarantees about memory fragmentation that are possible if large
1898 ** allocations are avoided. This hint is normally off.
1899 ** </dd>
1900 **
1901 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1902 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1903 ** interpreted as a boolean, which enables or disables the collection of
1904 ** memory allocation statistics. ^(When memory allocation statistics are
1905 ** disabled, the following SQLite interfaces become non-operational:
1906 ** <ul>
1907 ** <li> [sqlite3_hard_heap_limit64()]
1908 ** <li> [sqlite3_memory_used()]
1909 ** <li> [sqlite3_memory_highwater()]
1910 ** <li> [sqlite3_soft_heap_limit64()]
1911 ** <li> [sqlite3_status64()]
1912 ** </ul>)^
1913 ** ^Memory allocation statistics are enabled by default unless SQLite is
1914 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1915 ** allocation statistics are disabled by default.
1916 ** </dd>
1917 **
1918 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1919 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1920 ** </dd>
1921 **
1922 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1923 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1924 ** that SQLite can use for the database page cache with the default page
1925 ** cache implementation.
1926 ** This configuration option is a no-op if an application-defined page
1927 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1928 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1929 ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1930 ** and the number of cache lines (N).
1931 ** The sz argument should be the size of the largest database page
1932 ** (a power of two between 512 and 65536) plus some extra bytes for each
1933 ** page header. ^The number of extra bytes needed by the page header
1934 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1935 ** ^It is harmless, apart from the wasted memory,
1936 ** for the sz parameter to be larger than necessary. The pMem
1937 ** argument must be either a NULL pointer or a pointer to an 8-byte
1938 ** aligned block of memory of at least sz*N bytes, otherwise
1939 ** subsequent behavior is undefined.
1940 ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1941 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1942 ** a page cache line is larger than sz bytes or if all of the pMem buffer
1943 ** is exhausted.
1944 ** ^If pMem is NULL and N is non-zero, then each database connection
1945 ** does an initial bulk allocation for page cache memory
1946 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1947 ** of -1024*N bytes if N is negative, . ^If additional
1948 ** page cache memory is needed beyond what is provided by the initial
1949 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1950 ** additional cache line. </dd>
1951 **
1952 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1953 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1954 ** that SQLite will use for all of its dynamic memory allocation needs
1955 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1956 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1957 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1958 ** [SQLITE_ERROR] if invoked otherwise.
1959 ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1960 ** An 8-byte aligned pointer to the memory,
1961 ** the number of bytes in the memory buffer, and the minimum allocation size.
1962 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1963 ** to using its default memory allocator (the system malloc() implementation),
1964 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1965 ** memory pointer is not NULL then the alternative memory
1966 ** allocator is engaged to handle all of SQLites memory allocation needs.
1967 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1968 ** boundary or subsequent behavior of SQLite will be undefined.
1969 ** The minimum allocation size is capped at 2**12. Reasonable values
1970 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1971 **
1972 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1973 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1974 ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1975 ** The argument specifies alternative low-level mutex routines to be used
1976 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1977 ** the content of the [sqlite3_mutex_methods] structure before the call to
1978 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1979 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1980 ** the entire mutexing subsystem is omitted from the build and hence calls to
1981 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1982 ** return [SQLITE_ERROR].</dd>
1983 **
1984 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1985 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1986 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1987 ** [sqlite3_mutex_methods]
1988 ** structure is filled with the currently defined mutex routines.)^
1989 ** This option can be used to overload the default mutex allocation
1990 ** routines with a wrapper used to track mutex usage for performance
1991 ** profiling or testing, for example. ^If SQLite is compiled with
1992 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1993 ** the entire mutexing subsystem is omitted from the build and hence calls to
1994 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1995 ** return [SQLITE_ERROR].</dd>
1996 **
1997 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1998 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1999 ** the default size of [lookaside memory] on each [database connection].
2000 ** The first argument is the
2001 ** size of each lookaside buffer slot ("sz") and the second is the number of
2002 ** slots allocated to each database connection ("cnt").)^
2003 ** ^(SQLITE_CONFIG_LOOKASIDE sets the <i>default</i> lookaside size.
2004 ** The [SQLITE_DBCONFIG_LOOKASIDE] option to [sqlite3_db_config()] can
2005 ** be used to change the lookaside configuration on individual connections.)^
2006 ** The [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to change the
2007 ** default lookaside configuration at compile-time.
2008 ** </dd>
2009 **
2010 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
2011 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
2012 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
2013 ** the interface to a custom page cache implementation.)^
2014 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
2015 **
2016 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
2017 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
2018 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
2019 ** the current page cache implementation into that object.)^ </dd>
2020 **
2021 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
2022 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
2023 ** global [error log].
2024 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
2025 ** function with a call signature of void(*)(void*,int,const char*),
2026 ** and a pointer to void. ^If the function pointer is not NULL, it is
2027 ** invoked by [sqlite3_log()] to process each logging event. ^If the
2028 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2029 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2030 ** passed through as the first parameter to the application-defined logger
2031 ** function whenever that function is invoked. ^The second parameter to
2032 ** the logger function is a copy of the first parameter to the corresponding
2033 ** [sqlite3_log()] call and is intended to be a [result code] or an
2034 ** [extended result code]. ^The third parameter passed to the logger is
2035 ** log message after formatting via [sqlite3_snprintf()].
2036 ** The SQLite logging interface is not reentrant; the logger function
2037 ** supplied by the application must not invoke any SQLite interface.
2038 ** In a multi-threaded application, the application-defined logger
2039 ** function must be threadsafe. </dd>
2040 **
2041 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2042 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2043 ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2044 ** then URI handling is globally disabled.)^ ^If URI handling is globally
2045 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2046 ** [sqlite3_open16()] or
2047 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2048 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2049 ** connection is opened. ^If it is globally disabled, filenames are
2050 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2051 ** database connection is opened. ^(By default, URI handling is globally
2052 ** disabled. The default value may be changed by compiling with the
2053 ** [SQLITE_USE_URI] symbol defined.)^
2054 **
2055 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2056 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2057 ** argument which is interpreted as a boolean in order to enable or disable
2058 ** the use of covering indices for full table scans in the query optimizer.
2059 ** ^The default setting is determined
2060 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2061 ** if that compile-time option is omitted.
2062 ** The ability to disable the use of covering indices for full table scans
2063 ** is because some incorrectly coded legacy applications might malfunction
2064 ** when the optimization is enabled. Providing the ability to
2065 ** disable the optimization allows the older, buggy application code to work
2066 ** without change even with newer versions of SQLite.
2067 **
2068 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2069 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2070 ** <dd> These options are obsolete and should not be used by new code.
2071 ** They are retained for backwards compatibility but are now no-ops.
2072 ** </dd>
2073 **
2074 ** [[SQLITE_CONFIG_SQLLOG]]
2075 ** <dt>SQLITE_CONFIG_SQLLOG
2076 ** <dd>This option is only available if sqlite is compiled with the
2077 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2078 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2079 ** The second should be of type (void*). The callback is invoked by the library
2080 ** in three separate circumstances, identified by the value passed as the
2081 ** fourth parameter. If the fourth parameter is 0, then the database connection
2082 ** passed as the second argument has just been opened. The third argument
2083 ** points to a buffer containing the name of the main database file. If the
2084 ** fourth parameter is 1, then the SQL statement that the third parameter
2085 ** points to has just been executed. Or, if the fourth parameter is 2, then
2086 ** the connection being passed as the second parameter is being closed. The
2087 ** third parameter is passed NULL In this case. An example of using this
2088 ** configuration option can be seen in the "test_sqllog.c" source file in
2089 ** the canonical SQLite source tree.</dd>
2090 **
2091 ** [[SQLITE_CONFIG_MMAP_SIZE]]
2092 ** <dt>SQLITE_CONFIG_MMAP_SIZE
2093 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2094 ** that are the default mmap size limit (the default setting for
2095 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2096 ** ^The default setting can be overridden by each database connection using
2097 ** either the [PRAGMA mmap_size] command, or by using the
2098 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2099 ** will be silently truncated if necessary so that it does not exceed the
2100 ** compile-time maximum mmap size set by the
2101 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2102 ** ^If either argument to this option is negative, then that argument is
2103 ** changed to its compile-time default.
2104 **
2105 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2106 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2107 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2108 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2109 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2110 ** that specifies the maximum size of the created heap.
2111 **
2112 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2113 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2114 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2115 ** is a pointer to an integer and writes into that integer the number of extra
2116 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2117 ** The amount of extra space required can change depending on the compiler,
2118 ** target platform, and SQLite version.
2119 **
2120 ** [[SQLITE_CONFIG_PMASZ]]
2121 ** <dt>SQLITE_CONFIG_PMASZ
2122 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2123 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2124 ** sorter to that integer. The default minimum PMA Size is set by the
2125 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2126 ** to help with sort operations when multithreaded sorting
2127 ** is enabled (using the [PRAGMA threads] command) and the amount of content
2128 ** to be sorted exceeds the page size times the minimum of the
2129 ** [PRAGMA cache_size] setting and this value.
2130 **
2131 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2132 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2133 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2134 ** becomes the [statement journal] spill-to-disk threshold.
2135 ** [Statement journals] are held in memory until their size (in bytes)
2136 ** exceeds this threshold, at which point they are written to disk.
2137 ** Or if the threshold is -1, statement journals are always held
2138 ** exclusively in memory.
2139 ** Since many statement journals never become large, setting the spill
2140 ** threshold to a value such as 64KiB can greatly reduce the amount of
2141 ** I/O required to support statement rollback.
2142 ** The default value for this setting is controlled by the
2143 ** [SQLITE_STMTJRNL_SPILL] compile-time option.
2144 **
2145 ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2146 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2147 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2148 ** of type (int) - the new value of the sorter-reference size threshold.
2149 ** Usually, when SQLite uses an external sort to order records according
2150 ** to an ORDER BY clause, all fields required by the caller are present in the
2151 ** sorted records. However, if SQLite determines based on the declared type
2152 ** of a table column that its values are likely to be very large - larger
2153 ** than the configured sorter-reference size threshold - then a reference
2154 ** is stored in each sorted record and the required column values loaded
2155 ** from the database as records are returned in sorted order. The default
2156 ** value for this option is to never use this optimization. Specifying a
2157 ** negative value for this option restores the default behavior.
2158 ** This option is only available if SQLite is compiled with the
2159 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2160 **
2161 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2162 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2163 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2164 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2165 ** database created using [sqlite3_deserialize()]. This default maximum
2166 ** size can be adjusted up or down for individual databases using the
2167 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2168 ** configuration setting is never used, then the default maximum is determined
2169 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2170 ** compile-time option is not set, then the default maximum is 1073741824.
2171 **
2172 ** [[SQLITE_CONFIG_ROWID_IN_VIEW]]
2173 ** <dt>SQLITE_CONFIG_ROWID_IN_VIEW
2174 ** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability
2175 ** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is
2176 ** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability
2177 ** defaults to on. This configuration option queries the current setting or
2178 ** changes the setting to off or on. The argument is a pointer to an integer.
2179 ** If that integer initially holds a value of 1, then the ability for VIEWs to
2180 ** have ROWIDs is activated. If the integer initially holds zero, then the
2181 ** ability is deactivated. Any other initial value for the integer leaves the
2182 ** setting unchanged. After changes, if any, the integer is written with
2183 ** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite
2184 ** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and
2185 ** recommended case) then the integer is always filled with zero, regardless
2186 ** if its initial value.
2187 ** </dl>
2188 */
2189 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2190 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2191 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2192 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2193 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2194 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2195 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2196 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2197 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2198 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2199 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2200 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2201 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2202 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
2203 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2204 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2205 #define SQLITE_CONFIG_URI 17 /* int */
2206 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2207 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2208 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2209 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2210 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2211 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2212 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2213 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2214 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2215 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2216 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2217 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2218 #define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */
2219
2220 /*
2221 ** CAPI3REF: Database Connection Configuration Options
2222 **
2223 ** These constants are the available integer configuration options that
2224 ** can be passed as the second parameter to the [sqlite3_db_config()] interface.
2225 **
2226 ** The [sqlite3_db_config()] interface is a var-args functions. It takes a
2227 ** variable number of parameters, though always at least two. The number of
2228 ** parameters passed into sqlite3_db_config() depends on which of these
2229 ** constants is given as the second parameter. This documentation page
2230 ** refers to parameters beyond the second as "arguments". Thus, when this
2231 ** page says "the N-th argument" it means "the N-th parameter past the
2232 ** configuration option" or "the (N+2)-th parameter to sqlite3_db_config()".
2233 **
2234 ** New configuration options may be added in future releases of SQLite.
2235 ** Existing configuration options might be discontinued. Applications
2236 ** should check the return code from [sqlite3_db_config()] to make sure that
2237 ** the call worked. ^The [sqlite3_db_config()] interface will return a
2238 ** non-zero [error code] if a discontinued or unsupported configuration option
2239 ** is invoked.
2240 **
2241 ** <dl>
2242 ** [[SQLITE_DBCONFIG_LOOKASIDE]]
2243 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2244 ** <dd> The SQLITE_DBCONFIG_LOOKASIDE option is used to adjust the
2245 ** configuration of the [lookaside memory allocator] within a database
2246 ** connection.
2247 ** The arguments to the SQLITE_DBCONFIG_LOOKASIDE option are <i>not</i>
2248 ** in the [DBCONFIG arguments|usual format].
2249 ** The SQLITE_DBCONFIG_LOOKASIDE option takes three arguments, not two,
2250 ** so that a call to [sqlite3_db_config()] that uses SQLITE_DBCONFIG_LOOKASIDE
2251 ** should have a total of five parameters.
2252 ** <ol>
2253 ** <li><p>The first argument ("buf") is a
2254 ** pointer to a memory buffer to use for lookaside memory.
2255 ** The first argument may be NULL in which case SQLite will allocate the
2256 ** lookaside buffer itself using [sqlite3_malloc()].
2257 ** <li><P>The second argument ("sz") is the
2258 ** size of each lookaside buffer slot. Lookaside is disabled if "sz"
2259 ** is less than 8. The "sz" argument should be a multiple of 8 less than
2260 ** 65536. If "sz" does not meet this constraint, it is reduced in size until
2261 ** it does.
2262 ** <li><p>The third argument ("cnt") is the number of slots. Lookaside is disabled
2263 ** if "cnt"is less than 1. The "cnt" value will be reduced, if necessary, so
2264 ** that the product of "sz" and "cnt" does not exceed 2,147,418,112. The "cnt"
2265 ** parameter is usually chosen so that the product of "sz" and "cnt" is less
2266 ** than 1,000,000.
2267 ** </ol>
2268 ** <p>If the "buf" argument is not NULL, then it must
2269 ** point to a memory buffer with a size that is greater than
2270 ** or equal to the product of "sz" and "cnt".
2271 ** The buffer must be aligned to an 8-byte boundary.
2272 ** The lookaside memory
2273 ** configuration for a database connection can only be changed when that
2274 ** connection is not currently using lookaside memory, or in other words
2275 ** when the value returned by [SQLITE_DBSTATUS_LOOKASIDE_USED] is zero.
2276 ** Any attempt to change the lookaside memory configuration when lookaside
2277 ** memory is in use leaves the configuration unchanged and returns
2278 ** [SQLITE_BUSY].
2279 ** If the "buf" argument is NULL and an attempt
2280 ** to allocate memory based on "sz" and "cnt" fails, then
2281 ** lookaside is silently disabled.
2282 ** <p>
2283 ** The [SQLITE_CONFIG_LOOKASIDE] configuration option can be used to set the
2284 ** default lookaside configuration at initialization. The
2285 ** [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to set the default lookaside
2286 ** configuration at compile-time. Typical values for lookaside are 1200 for
2287 ** "sz" and 40 to 100 for "cnt".
2288 ** </dd>
2289 **
2290 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2291 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2292 ** <dd> ^This option is used to enable or disable the enforcement of
2293 ** [foreign key constraints]. This is the same setting that is
2294 ** enabled or disabled by the [PRAGMA foreign_keys] statement.
2295 ** The first argument is an integer which is 0 to disable FK enforcement,
2296 ** positive to enable FK enforcement or negative to leave FK enforcement
2297 ** unchanged. The second parameter is a pointer to an integer into which
2298 ** is written 0 or 1 to indicate whether FK enforcement is off or on
2299 ** following this call. The second parameter may be a NULL pointer, in
2300 ** which case the FK enforcement setting is not reported back. </dd>
2301 **
2302 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2303 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2304 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2305 ** There should be two additional arguments.
2306 ** The first argument is an integer which is 0 to disable triggers,
2307 ** positive to enable triggers or negative to leave the setting unchanged.
2308 ** The second parameter is a pointer to an integer into which
2309 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
2310 ** following this call. The second parameter may be a NULL pointer, in
2311 ** which case the trigger setting is not reported back.
2312 **
2313 ** <p>Originally this option disabled all triggers. ^(However, since
2314 ** SQLite version 3.35.0, TEMP triggers are still allowed even if
2315 ** this option is off. So, in other words, this option now only disables
2316 ** triggers in the main database schema or in the schemas of [ATTACH]-ed
2317 ** databases.)^ </dd>
2318 **
2319 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2320 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2321 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2322 ** There must be two additional arguments.
2323 ** The first argument is an integer which is 0 to disable views,
2324 ** positive to enable views or negative to leave the setting unchanged.
2325 ** The second parameter is a pointer to an integer into which
2326 ** is written 0 or 1 to indicate whether views are disabled or enabled
2327 ** following this call. The second parameter may be a NULL pointer, in
2328 ** which case the view setting is not reported back.
2329 **
2330 ** <p>Originally this option disabled all views. ^(However, since
2331 ** SQLite version 3.35.0, TEMP views are still allowed even if
2332 ** this option is off. So, in other words, this option now only disables
2333 ** views in the main database schema or in the schemas of ATTACH-ed
2334 ** databases.)^ </dd>
2335 **
2336 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2337 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2338 ** <dd> ^This option is used to enable or disable the
2339 ** [fts3_tokenizer()] function which is part of the
2340 ** [FTS3] full-text search engine extension.
2341 ** There must be two additional arguments.
2342 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2343 ** positive to enable fts3_tokenizer() or negative to leave the setting
2344 ** unchanged.
2345 ** The second parameter is a pointer to an integer into which
2346 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2347 ** following this call. The second parameter may be a NULL pointer, in
2348 ** which case the new setting is not reported back. </dd>
2349 **
2350 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2351 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2352 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2353 ** interface independently of the [load_extension()] SQL function.
2354 ** The [sqlite3_enable_load_extension()] API enables or disables both the
2355 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2356 ** There must be two additional arguments.
2357 ** When the first argument to this interface is 1, then only the C-API is
2358 ** enabled and the SQL function remains disabled. If the first argument to
2359 ** this interface is 0, then both the C-API and the SQL function are disabled.
2360 ** If the first argument is -1, then no changes are made to state of either the
2361 ** C-API or the SQL function.
2362 ** The second parameter is a pointer to an integer into which
2363 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2364 ** is disabled or enabled following this call. The second parameter may
2365 ** be a NULL pointer, in which case the new setting is not reported back.
2366 ** </dd>
2367 **
2368 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2369 ** <dd> ^This option is used to change the name of the "main" database
2370 ** schema. This option does not follow the
2371 ** [DBCONFIG arguments|usual SQLITE_DBCONFIG argument format].
2372 ** This option takes exactly one additional argument so that the
2373 ** [sqlite3_db_config()] call has a total of three parameters. The
2374 ** extra argument must be a pointer to a constant UTF8 string which
2375 ** will become the new schema name in place of "main". ^SQLite does
2376 ** not make a copy of the new main schema name string, so the application
2377 ** must ensure that the argument passed into SQLITE_DBCONFIG MAINDBNAME
2378 ** is unchanged until after the database connection closes.
2379 ** </dd>
2380 **
2381 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2382 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2383 ** <dd> Usually, when a database in [WAL mode] is closed or detached from a
2384 ** database handle, SQLite checks if if there are other connections to the
2385 ** same database, and if there are no other database connection (if the
2386 ** connection being closed is the last open connection to the database),
2387 ** then SQLite performs a [checkpoint] before closing the connection and
2388 ** deletes the WAL file. The SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE option can
2389 ** be used to override that behavior. The first argument passed to this
2390 ** operation (the third parameter to [sqlite3_db_config()]) is an integer
2391 ** which is positive to disable checkpoints-on-close, or zero (the default)
2392 ** to enable them, and negative to leave the setting unchanged.
2393 ** The second argument (the fourth parameter) is a pointer to an integer
2394 ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2395 ** have been disabled - 0 if they are not disabled, 1 if they are.
2396 ** </dd>
2397 **
2398 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2399 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2400 ** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2401 ** a single SQL query statement will always use the same algorithm regardless
2402 ** of values of [bound parameters].)^ The QPSG disables some query optimizations
2403 ** that look at the values of bound parameters, which can make some queries
2404 ** slower. But the QPSG has the advantage of more predictable behavior. With
2405 ** the QPSG active, SQLite will always use the same query plan in the field as
2406 ** was used during testing in the lab.
2407 ** The first argument to this setting is an integer which is 0 to disable
2408 ** the QPSG, positive to enable QPSG, or negative to leave the setting
2409 ** unchanged. The second parameter is a pointer to an integer into which
2410 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2411 ** following this call.
2412 ** </dd>
2413 **
2414 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2415 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2416 ** include output for any operations performed by trigger programs. This
2417 ** option is used to set or clear (the default) a flag that governs this
2418 ** behavior. The first parameter passed to this operation is an integer -
2419 ** positive to enable output for trigger programs, or zero to disable it,
2420 ** or negative to leave the setting unchanged.
2421 ** The second parameter is a pointer to an integer into which is written
2422 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2423 ** it is not disabled, 1 if it is.
2424 ** </dd>
2425 **
2426 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2427 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2428 ** [VACUUM] in order to reset a database back to an empty database
2429 ** with no schema and no content. The following process works even for
2430 ** a badly corrupted database file:
2431 ** <ol>
2432 ** <li> If the database connection is newly opened, make sure it has read the
2433 ** database schema by preparing then discarding some query against the
2434 ** database, or calling sqlite3_table_column_metadata(), ignoring any
2435 ** errors. This step is only necessary if the application desires to keep
2436 ** the database in WAL mode after the reset if it was in WAL mode before
2437 ** the reset.
2438 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2439 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2440 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2441 ** </ol>
2442 ** Because resetting a database is destructive and irreversible, the
2443 ** process requires the use of this obscure API and multiple steps to
2444 ** help ensure that it does not happen by accident. Because this
2445 ** feature must be capable of resetting corrupt databases, and
2446 ** shutting down virtual tables may require access to that corrupt
2447 ** storage, the library must abandon any installed virtual tables
2448 ** without calling their xDestroy() methods.
2449 **
2450 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2451 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2452 ** "defensive" flag for a database connection. When the defensive
2453 ** flag is enabled, language features that allow ordinary SQL to
2454 ** deliberately corrupt the database file are disabled. The disabled
2455 ** features include but are not limited to the following:
2456 ** <ul>
2457 ** <li> The [PRAGMA writable_schema=ON] statement.
2458 ** <li> The [PRAGMA journal_mode=OFF] statement.
2459 ** <li> The [PRAGMA schema_version=N] statement.
2460 ** <li> Writes to the [sqlite_dbpage] virtual table.
2461 ** <li> Direct writes to [shadow tables].
2462 ** </ul>
2463 ** </dd>
2464 **
2465 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2466 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2467 ** "writable_schema" flag. This has the same effect and is logically equivalent
2468 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2469 ** The first argument to this setting is an integer which is 0 to disable
2470 ** the writable_schema, positive to enable writable_schema, or negative to
2471 ** leave the setting unchanged. The second parameter is a pointer to an
2472 ** integer into which is written 0 or 1 to indicate whether the writable_schema
2473 ** is enabled or disabled following this call.
2474 ** </dd>
2475 **
2476 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2477 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2478 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2479 ** the legacy behavior of the [ALTER TABLE RENAME] command such it
2480 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2481 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2482 ** additional information. This feature can also be turned on and off
2483 ** using the [PRAGMA legacy_alter_table] statement.
2484 ** </dd>
2485 **
2486 ** [[SQLITE_DBCONFIG_DQS_DML]]
2487 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2488 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2489 ** the legacy [double-quoted string literal] misfeature for DML statements
2490 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2491 ** default value of this setting is determined by the [-DSQLITE_DQS]
2492 ** compile-time option.
2493 ** </dd>
2494 **
2495 ** [[SQLITE_DBCONFIG_DQS_DDL]]
2496 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2497 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2498 ** the legacy [double-quoted string literal] misfeature for DDL statements,
2499 ** such as CREATE TABLE and CREATE INDEX. The
2500 ** default value of this setting is determined by the [-DSQLITE_DQS]
2501 ** compile-time option.
2502 ** </dd>
2503 **
2504 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2505 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2506 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2507 ** assume that database schemas are untainted by malicious content.
2508 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2509 ** takes additional defensive steps to protect the application from harm
2510 ** including:
2511 ** <ul>
2512 ** <li> Prohibit the use of SQL functions inside triggers, views,
2513 ** CHECK constraints, DEFAULT clauses, expression indexes,
2514 ** partial indexes, or generated columns
2515 ** unless those functions are tagged with [SQLITE_INNOCUOUS].
2516 ** <li> Prohibit the use of virtual tables inside of triggers or views
2517 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2518 ** </ul>
2519 ** This setting defaults to "on" for legacy compatibility, however
2520 ** all applications are advised to turn it off if possible. This setting
2521 ** can also be controlled using the [PRAGMA trusted_schema] statement.
2522 ** </dd>
2523 **
2524 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2525 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2526 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2527 ** the legacy file format flag. When activated, this flag causes all newly
2528 ** created database file to have a schema format version number (the 4-byte
2529 ** integer found at offset 44 into the database header) of 1. This in turn
2530 ** means that the resulting database file will be readable and writable by
2531 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2532 ** newly created databases are generally not understandable by SQLite versions
2533 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2534 ** is now scarcely any need to generate database files that are compatible
2535 ** all the way back to version 3.0.0, and so this setting is of little
2536 ** practical use, but is provided so that SQLite can continue to claim the
2537 ** ability to generate new database files that are compatible with version
2538 ** 3.0.0.
2539 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2540 ** the [VACUUM] command will fail with an obscure error when attempting to
2541 ** process a table with generated columns and a descending index. This is
2542 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2543 ** either generated columns or descending indexes.
2544 ** </dd>
2545 **
2546 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2547 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2548 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2549 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2550 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2551 ** statistics. For statistics to be collected, the flag must be set on
2552 ** the database handle both when the SQL statement is prepared and when it
2553 ** is stepped. The flag is set (collection of statistics is enabled)
2554 ** by default. <p>This option takes two arguments: an integer and a pointer to
2555 ** an integer.. The first argument is 1, 0, or -1 to enable, disable, or
2556 ** leave unchanged the statement scanstatus option. If the second argument
2557 ** is not NULL, then the value of the statement scanstatus setting after
2558 ** processing the first argument is written into the integer that the second
2559 ** argument points to.
2560 ** </dd>
2561 **
2562 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2563 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2564 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2565 ** in which tables and indexes are scanned so that the scans start at the end
2566 ** and work toward the beginning rather than starting at the beginning and
2567 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2568 ** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes
2569 ** two arguments which are an integer and a pointer to an integer. The first
2570 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2571 ** reverse scan order flag, respectively. If the second argument is not NULL,
2572 ** then 0 or 1 is written into the integer that the second argument points to
2573 ** depending on if the reverse scan order flag is set after processing the
2574 ** first argument.
2575 ** </dd>
2576 **
2577 ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]]
2578 ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt>
2579 ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables
2580 ** the ability of the [ATTACH DATABASE] SQL command to create a new database
2581 ** file if the database filed named in the ATTACH command does not already
2582 ** exist. This ability of ATTACH to create a new database is enabled by
2583 ** default. Applications can disable or reenable the ability for ATTACH to
2584 ** create new database files using this DBCONFIG option.<p>
2585 ** This option takes two arguments which are an integer and a pointer
2586 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2587 ** leave unchanged the attach-create flag, respectively. If the second
2588 ** argument is not NULL, then 0 or 1 is written into the integer that the
2589 ** second argument points to depending on if the attach-create flag is set
2590 ** after processing the first argument.
2591 ** </dd>
2592 **
2593 ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]]
2594 ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt>
2595 ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the
2596 ** ability of the [ATTACH DATABASE] SQL command to open a database for writing.
2597 ** This capability is enabled by default. Applications can disable or
2598 ** reenable this capability using the current DBCONFIG option. If the
2599 ** the this capability is disabled, the [ATTACH] command will still work,
2600 ** but the database will be opened read-only. If this option is disabled,
2601 ** then the ability to create a new database using [ATTACH] is also disabled,
2602 ** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]
2603 ** option.<p>
2604 ** This option takes two arguments which are an integer and a pointer
2605 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2606 ** leave unchanged the ability to ATTACH another database for writing,
2607 ** respectively. If the second argument is not NULL, then 0 or 1 is written
2608 ** into the integer to which the second argument points, depending on whether
2609 ** the ability to ATTACH a read/write database is enabled or disabled
2610 ** after processing the first argument.
2611 ** </dd>
2612 **
2613 ** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]]
2614 ** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt>
2615 ** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the
2616 ** ability to include comments in SQL text. Comments are enabled by default.
2617 ** An application can disable or reenable comments in SQL text using this
2618 ** DBCONFIG option.<p>
2619 ** This option takes two arguments which are an integer and a pointer
2620 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2621 ** leave unchanged the ability to use comments in SQL text,
2622 ** respectively. If the second argument is not NULL, then 0 or 1 is written
2623 ** into the integer that the second argument points to depending on if
2624 ** comments are allowed in SQL text after processing the first argument.
2625 ** </dd>
2626 **
2627 ** </dl>
2628 **
2629 ** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3>
2630 **
2631 ** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the
2632 ** overall call to [sqlite3_db_config()] has a total of four parameters.
2633 ** The first argument (the third parameter to sqlite3_db_config()) is a integer.
2634 ** The second argument is a pointer to an integer. If the first argument is 1,
2635 ** then the option becomes enabled. If the first integer argument is 0, then the
2636 ** option is disabled. If the first argument is -1, then the option setting
2637 ** is unchanged. The second argument, the pointer to an integer, may be NULL.
2638 ** If the second argument is not NULL, then a value of 0 or 1 is written into
2639 ** the integer to which the second argument points, depending on whether the
2640 ** setting is disabled or enabled after applying any changes specified by
2641 ** the first argument.
2642 **
2643 ** <p>While most SQLITE_DBCONFIG options use the argument format
2644 ** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME]
2645 ** and [SQLITE_DBCONFIG_LOOKASIDE] options are different. See the
2646 ** documentation of those exceptional options for details.
2647 */
2648 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2649 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2650 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2651 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2652 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2653 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2654 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2655 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2656 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2657 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2658 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2659 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2660 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2661 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2662 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2663 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2664 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2665 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2666 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2667 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2668 #define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE 1020 /* int int* */
2669 #define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE 1021 /* int int* */
2670 #define SQLITE_DBCONFIG_ENABLE_COMMENTS 1022 /* int int* */
2671 #define SQLITE_DBCONFIG_MAX 1022 /* Largest DBCONFIG */
2672
2673 /*
2674 ** CAPI3REF: Enable Or Disable Extended Result Codes
2675 ** METHOD: sqlite3
2676 **
2677 ** ^The sqlite3_extended_result_codes() routine enables or disables the
2678 ** [extended result codes] feature of SQLite. ^The extended result
2679 ** codes are disabled by default for historical compatibility.
2680 */
2681 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2682
2683 /*
2684 ** CAPI3REF: Last Insert Rowid
2685 ** METHOD: sqlite3
2686 **
2687 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2688 ** has a unique 64-bit signed
2689 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2690 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2691 ** names are not also used by explicitly declared columns. ^If
2692 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2693 ** is another alias for the rowid.
2694 **
2695 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2696 ** the most recent successful [INSERT] into a rowid table or [virtual table]
2697 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2698 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2699 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2700 ** zero.
2701 **
2702 ** As well as being set automatically as rows are inserted into database
2703 ** tables, the value returned by this function may be set explicitly by
2704 ** [sqlite3_set_last_insert_rowid()]
2705 **
2706 ** Some virtual table implementations may INSERT rows into rowid tables as
2707 ** part of committing a transaction (e.g. to flush data accumulated in memory
2708 ** to disk). In this case subsequent calls to this function return the rowid
2709 ** associated with these internal INSERT operations, which leads to
2710 ** unintuitive results. Virtual table implementations that do write to rowid
2711 ** tables in this way can avoid this problem by restoring the original
2712 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2713 ** control to the user.
2714 **
2715 ** ^(If an [INSERT] occurs within a trigger then this routine will
2716 ** return the [rowid] of the inserted row as long as the trigger is
2717 ** running. Once the trigger program ends, the value returned
2718 ** by this routine reverts to what it was before the trigger was fired.)^
2719 **
2720 ** ^An [INSERT] that fails due to a constraint violation is not a
2721 ** successful [INSERT] and does not change the value returned by this
2722 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2723 ** and INSERT OR ABORT make no changes to the return value of this
2724 ** routine when their insertion fails. ^(When INSERT OR REPLACE
2725 ** encounters a constraint violation, it does not fail. The
2726 ** INSERT continues to completion after deleting rows that caused
2727 ** the constraint problem so INSERT OR REPLACE will always change
2728 ** the return value of this interface.)^
2729 **
2730 ** ^For the purposes of this routine, an [INSERT] is considered to
2731 ** be successful even if it is subsequently rolled back.
2732 **
2733 ** This function is accessible to SQL statements via the
2734 ** [last_insert_rowid() SQL function].
2735 **
2736 ** If a separate thread performs a new [INSERT] on the same
2737 ** database connection while the [sqlite3_last_insert_rowid()]
2738 ** function is running and thus changes the last insert [rowid],
2739 ** then the value returned by [sqlite3_last_insert_rowid()] is
2740 ** unpredictable and might not equal either the old or the new
2741 ** last insert [rowid].
2742 */
2743 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2744
2745 /*
2746 ** CAPI3REF: Set the Last Insert Rowid value.
2747 ** METHOD: sqlite3
2748 **
2749 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2750 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2751 ** without inserting a row into the database.
2752 */
2753 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2754
2755 /*
2756 ** CAPI3REF: Count The Number Of Rows Modified
2757 ** METHOD: sqlite3
2758 **
2759 ** ^These functions return the number of rows modified, inserted or
2760 ** deleted by the most recently completed INSERT, UPDATE or DELETE
2761 ** statement on the database connection specified by the only parameter.
2762 ** The two functions are identical except for the type of the return value
2763 ** and that if the number of rows modified by the most recent INSERT, UPDATE,
2764 ** or DELETE is greater than the maximum value supported by type "int", then
2765 ** the return value of sqlite3_changes() is undefined. ^Executing any other
2766 ** type of SQL statement does not modify the value returned by these functions.
2767 ** For the purposes of this interface, a CREATE TABLE AS SELECT statement
2768 ** does not count as an INSERT, UPDATE or DELETE statement and hence the rows
2769 ** added to the new table by the CREATE TABLE AS SELECT statement are not
2770 ** counted.
2771 **
2772 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2773 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2774 ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2775 **
2776 ** Changes to a view that are intercepted by
2777 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2778 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2779 ** DELETE statement run on a view is always zero. Only changes made to real
2780 ** tables are counted.
2781 **
2782 ** Things are more complicated if the sqlite3_changes() function is
2783 ** executed while a trigger program is running. This may happen if the
2784 ** program uses the [changes() SQL function], or if some other callback
2785 ** function invokes sqlite3_changes() directly. Essentially:
2786 **
2787 ** <ul>
2788 ** <li> ^(Before entering a trigger program the value returned by
2789 ** sqlite3_changes() function is saved. After the trigger program
2790 ** has finished, the original value is restored.)^
2791 **
2792 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2793 ** statement sets the value returned by sqlite3_changes()
2794 ** upon completion as normal. Of course, this value will not include
2795 ** any changes performed by sub-triggers, as the sqlite3_changes()
2796 ** value will be saved and restored after each sub-trigger has run.)^
2797 ** </ul>
2798 **
2799 ** ^This means that if the changes() SQL function (or similar) is used
2800 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2801 ** returns the value as set when the calling statement began executing.
2802 ** ^If it is used by the second or subsequent such statement within a trigger
2803 ** program, the value returned reflects the number of rows modified by the
2804 ** previous INSERT, UPDATE or DELETE statement within the same trigger.
2805 **
2806 ** If a separate thread makes changes on the same database connection
2807 ** while [sqlite3_changes()] is running then the value returned
2808 ** is unpredictable and not meaningful.
2809 **
2810 ** See also:
2811 ** <ul>
2812 ** <li> the [sqlite3_total_changes()] interface
2813 ** <li> the [count_changes pragma]
2814 ** <li> the [changes() SQL function]
2815 ** <li> the [data_version pragma]
2816 ** </ul>
2817 */
2818 SQLITE_API int sqlite3_changes(sqlite3*);
2819 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2820
2821 /*
2822 ** CAPI3REF: Total Number Of Rows Modified
2823 ** METHOD: sqlite3
2824 **
2825 ** ^These functions return the total number of rows inserted, modified or
2826 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2827 ** since the database connection was opened, including those executed as
2828 ** part of trigger programs. The two functions are identical except for the
2829 ** type of the return value and that if the number of rows modified by the
2830 ** connection exceeds the maximum value supported by type "int", then
2831 ** the return value of sqlite3_total_changes() is undefined. ^Executing
2832 ** any other type of SQL statement does not affect the value returned by
2833 ** sqlite3_total_changes().
2834 **
2835 ** ^Changes made as part of [foreign key actions] are included in the
2836 ** count, but those made as part of REPLACE constraint resolution are
2837 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2838 ** are not counted.
2839 **
2840 ** The [sqlite3_total_changes(D)] interface only reports the number
2841 ** of rows that changed due to SQL statement run against database
2842 ** connection D. Any changes by other database connections are ignored.
2843 ** To detect changes against a database file from other database
2844 ** connections use the [PRAGMA data_version] command or the
2845 ** [SQLITE_FCNTL_DATA_VERSION] [file control].
2846 **
2847 ** If a separate thread makes changes on the same database connection
2848 ** while [sqlite3_total_changes()] is running then the value
2849 ** returned is unpredictable and not meaningful.
2850 **
2851 ** See also:
2852 ** <ul>
2853 ** <li> the [sqlite3_changes()] interface
2854 ** <li> the [count_changes pragma]
2855 ** <li> the [changes() SQL function]
2856 ** <li> the [data_version pragma]
2857 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2858 ** </ul>
2859 */
2860 SQLITE_API int sqlite3_total_changes(sqlite3*);
2861 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2862
2863 /*
2864 ** CAPI3REF: Interrupt A Long-Running Query
2865 ** METHOD: sqlite3
2866 **
2867 ** ^This function causes any pending database operation to abort and
2868 ** return at its earliest opportunity. This routine is typically
2869 ** called in response to a user action such as pressing "Cancel"
2870 ** or Ctrl-C where the user wants a long query operation to halt
2871 ** immediately.
2872 **
2873 ** ^It is safe to call this routine from a thread different from the
2874 ** thread that is currently running the database operation. But it
2875 ** is not safe to call this routine with a [database connection] that
2876 ** is closed or might close before sqlite3_interrupt() returns.
2877 **
2878 ** ^If an SQL operation is very nearly finished at the time when
2879 ** sqlite3_interrupt() is called, then it might not have an opportunity
2880 ** to be interrupted and might continue to completion.
2881 **
2882 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2883 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2884 ** that is inside an explicit transaction, then the entire transaction
2885 ** will be rolled back automatically.
2886 **
2887 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2888 ** SQL statements on [database connection] D complete. ^Any new SQL statements
2889 ** that are started after the sqlite3_interrupt() call and before the
2890 ** running statement count reaches zero are interrupted as if they had been
2891 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2892 ** that are started after the running statement count reaches zero are
2893 ** not effected by the sqlite3_interrupt().
2894 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2895 ** SQL statements is a no-op and has no effect on SQL statements
2896 ** that are started after the sqlite3_interrupt() call returns.
2897 **
2898 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2899 ** or not an interrupt is currently in effect for [database connection] D.
2900 ** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2901 */
2902 SQLITE_API void sqlite3_interrupt(sqlite3*);
2903 SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2904
2905 /*
2906 ** CAPI3REF: Determine If An SQL Statement Is Complete
2907 **
2908 ** These routines are useful during command-line input to determine if the
2909 ** currently entered text seems to form a complete SQL statement or
2910 ** if additional input is needed before sending the text into
2911 ** SQLite for parsing. ^These routines return 1 if the input string
2912 ** appears to be a complete SQL statement. ^A statement is judged to be
2913 ** complete if it ends with a semicolon token and is not a prefix of a
2914 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2915 ** string literals or quoted identifier names or comments are not
2916 ** independent tokens (they are part of the token in which they are
2917 ** embedded) and thus do not count as a statement terminator. ^Whitespace
2918 ** and comments that follow the final semicolon are ignored.
2919 **
2920 ** ^These routines return 0 if the statement is incomplete. ^If a
2921 ** memory allocation fails, then SQLITE_NOMEM is returned.
2922 **
2923 ** ^These routines do not parse the SQL statements thus
2924 ** will not detect syntactically incorrect SQL.
2925 **
2926 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2927 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2928 ** automatically by sqlite3_complete16(). If that initialization fails,
2929 ** then the return value from sqlite3_complete16() will be non-zero
2930 ** regardless of whether or not the input SQL is complete.)^
2931 **
2932 ** The input to [sqlite3_complete()] must be a zero-terminated
2933 ** UTF-8 string.
2934 **
2935 ** The input to [sqlite3_complete16()] must be a zero-terminated
2936 ** UTF-16 string in native byte order.
2937 */
2938 SQLITE_API int sqlite3_complete(const char *sql);
2939 SQLITE_API int sqlite3_complete16(const void *sql);
2940
2941 /*
2942 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2943 ** KEYWORDS: {busy-handler callback} {busy handler}
2944 ** METHOD: sqlite3
2945 **
2946 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2947 ** that might be invoked with argument P whenever
2948 ** an attempt is made to access a database table associated with
2949 ** [database connection] D when another thread
2950 ** or process has the table locked.
2951 ** The sqlite3_busy_handler() interface is used to implement
2952 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2953 **
2954 ** ^If the busy callback is NULL, then [SQLITE_BUSY]
2955 ** is returned immediately upon encountering the lock. ^If the busy callback
2956 ** is not NULL, then the callback might be invoked with two arguments.
2957 **
2958 ** ^The first argument to the busy handler is a copy of the void* pointer which
2959 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2960 ** the busy handler callback is the number of times that the busy handler has
2961 ** been invoked previously for the same locking event. ^If the
2962 ** busy callback returns 0, then no additional attempts are made to
2963 ** access the database and [SQLITE_BUSY] is returned
2964 ** to the application.
2965 ** ^If the callback returns non-zero, then another attempt
2966 ** is made to access the database and the cycle repeats.
2967 **
2968 ** The presence of a busy handler does not guarantee that it will be invoked
2969 ** when there is lock contention. ^If SQLite determines that invoking the busy
2970 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2971 ** to the application instead of invoking the
2972 ** busy handler.
2973 ** Consider a scenario where one process is holding a read lock that
2974 ** it is trying to promote to a reserved lock and
2975 ** a second process is holding a reserved lock that it is trying
2976 ** to promote to an exclusive lock. The first process cannot proceed
2977 ** because it is blocked by the second and the second process cannot
2978 ** proceed because it is blocked by the first. If both processes
2979 ** invoke the busy handlers, neither will make any progress. Therefore,
2980 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2981 ** will induce the first process to release its read lock and allow
2982 ** the second process to proceed.
2983 **
2984 ** ^The default busy callback is NULL.
2985 **
2986 ** ^(There can only be a single busy handler defined for each
2987 ** [database connection]. Setting a new busy handler clears any
2988 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2989 ** or evaluating [PRAGMA busy_timeout=N] will change the
2990 ** busy handler and thus clear any previously set busy handler.
2991 **
2992 ** The busy callback should not take any actions which modify the
2993 ** database connection that invoked the busy handler. In other words,
2994 ** the busy handler is not reentrant. Any such actions
2995 ** result in undefined behavior.
2996 **
2997 ** A busy handler must not close the database connection
2998 ** or [prepared statement] that invoked the busy handler.
2999 */
3000 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
3001
3002 /*
3003 ** CAPI3REF: Set A Busy Timeout
3004 ** METHOD: sqlite3
3005 **
3006 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
3007 ** for a specified amount of time when a table is locked. ^The handler
3008 ** will sleep multiple times until at least "ms" milliseconds of sleeping
3009 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
3010 ** the handler returns 0 which causes [sqlite3_step()] to return
3011 ** [SQLITE_BUSY].
3012 **
3013 ** ^Calling this routine with an argument less than or equal to zero
3014 ** turns off all busy handlers.
3015 **
3016 ** ^(There can only be a single busy handler for a particular
3017 ** [database connection] at any given moment. If another busy handler
3018 ** was defined (using [sqlite3_busy_handler()]) prior to calling
3019 ** this routine, that other busy handler is cleared.)^
3020 **
3021 ** See also: [PRAGMA busy_timeout]
3022 */
3023 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
3024
3025 /*
3026 ** CAPI3REF: Set the Setlk Timeout
3027 ** METHOD: sqlite3
3028 **
3029 ** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If
3030 ** the VFS supports blocking locks, it sets the timeout in ms used by
3031 ** eligible locks taken on wal mode databases by the specified database
3032 ** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does
3033 ** not support blocking locks, this function is a no-op.
3034 **
3035 ** Passing 0 to this function disables blocking locks altogether. Passing
3036 ** -1 to this function requests that the VFS blocks for a long time -
3037 ** indefinitely if possible. The results of passing any other negative value
3038 ** are undefined.
3039 **
3040 ** Internally, each SQLite database handle store two timeout values - the
3041 ** busy-timeout (used for rollback mode databases, or if the VFS does not
3042 ** support blocking locks) and the setlk-timeout (used for blocking locks
3043 ** on wal-mode databases). The sqlite3_busy_timeout() method sets both
3044 ** values, this function sets only the setlk-timeout value. Therefore,
3045 ** to configure separate busy-timeout and setlk-timeout values for a single
3046 ** database handle, call sqlite3_busy_timeout() followed by this function.
3047 **
3048 ** Whenever the number of connections to a wal mode database falls from
3049 ** 1 to 0, the last connection takes an exclusive lock on the database,
3050 ** then checkpoints and deletes the wal file. While it is doing this, any
3051 ** new connection that tries to read from the database fails with an
3052 ** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is
3053 ** passed to this API, the new connection blocks until the exclusive lock
3054 ** has been released.
3055 */
3056 SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags);
3057
3058 /*
3059 ** CAPI3REF: Flags for sqlite3_setlk_timeout()
3060 */
3061 #define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01
3062
3063 /*
3064 ** CAPI3REF: Convenience Routines For Running Queries
3065 ** METHOD: sqlite3
3066 **
3067 ** This is a legacy interface that is preserved for backwards compatibility.
3068 ** Use of this interface is not recommended.
3069 **
3070 ** Definition: A <b>result table</b> is memory data structure created by the
3071 ** [sqlite3_get_table()] interface. A result table records the
3072 ** complete query results from one or more queries.
3073 **
3074 ** The table conceptually has a number of rows and columns. But
3075 ** these numbers are not part of the result table itself. These
3076 ** numbers are obtained separately. Let N be the number of rows
3077 ** and M be the number of columns.
3078 **
3079 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
3080 ** There are (N+1)*M elements in the array. The first M pointers point
3081 ** to zero-terminated strings that contain the names of the columns.
3082 ** The remaining entries all point to query results. NULL values result
3083 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
3084 ** string representation as returned by [sqlite3_column_text()].
3085 **
3086 ** A result table might consist of one or more memory allocations.
3087 ** It is not safe to pass a result table directly to [sqlite3_free()].
3088 ** A result table should be deallocated using [sqlite3_free_table()].
3089 **
3090 ** ^(As an example of the result table format, suppose a query result
3091 ** is as follows:
3092 **
3093 ** <blockquote><pre>
3094 ** Name | Age
3095 ** -----------------------
3096 ** Alice | 43
3097 ** Bob | 28
3098 ** Cindy | 21
3099 ** </pre></blockquote>
3100 **
3101 ** There are two columns (M==2) and three rows (N==3). Thus the
3102 ** result table has 8 entries. Suppose the result table is stored
3103 ** in an array named azResult. Then azResult holds this content:
3104 **
3105 ** <blockquote><pre>
3106 ** azResult&#91;0] = "Name";
3107 ** azResult&#91;1] = "Age";
3108 ** azResult&#91;2] = "Alice";
3109 ** azResult&#91;3] = "43";
3110 ** azResult&#91;4] = "Bob";
3111 ** azResult&#91;5] = "28";
3112 ** azResult&#91;6] = "Cindy";
3113 ** azResult&#91;7] = "21";
3114 ** </pre></blockquote>)^
3115 **
3116 ** ^The sqlite3_get_table() function evaluates one or more
3117 ** semicolon-separated SQL statements in the zero-terminated UTF-8
3118 ** string of its 2nd parameter and returns a result table to the
3119 ** pointer given in its 3rd parameter.
3120 **
3121 ** After the application has finished with the result from sqlite3_get_table(),
3122 ** it must pass the result table pointer to sqlite3_free_table() in order to
3123 ** release the memory that was malloced. Because of the way the
3124 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
3125 ** function must not try to call [sqlite3_free()] directly. Only
3126 ** [sqlite3_free_table()] is able to release the memory properly and safely.
3127 **
3128 ** The sqlite3_get_table() interface is implemented as a wrapper around
3129 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
3130 ** to any internal data structures of SQLite. It uses only the public
3131 ** interface defined here. As a consequence, errors that occur in the
3132 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
3133 ** reflected in subsequent calls to [sqlite3_errcode()] or
3134 ** [sqlite3_errmsg()].
3135 */
3136 SQLITE_API int sqlite3_get_table(
3137 sqlite3 *db, /* An open database */
3138 const char *zSql, /* SQL to be evaluated */
3139 char ***pazResult, /* Results of the query */
3140 int *pnRow, /* Number of result rows written here */
3141 int *pnColumn, /* Number of result columns written here */
3142 char **pzErrmsg /* Error msg written here */
3143 );
3144 SQLITE_API void sqlite3_free_table(char **result);
3145
3146 /*
3147 ** CAPI3REF: Formatted String Printing Functions
3148 **
3149 ** These routines are work-alikes of the "printf()" family of functions
3150 ** from the standard C library.
3151 ** These routines understand most of the common formatting options from
3152 ** the standard library printf()
3153 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
3154 ** See the [built-in printf()] documentation for details.
3155 **
3156 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
3157 ** results into memory obtained from [sqlite3_malloc64()].
3158 ** The strings returned by these two routines should be
3159 ** released by [sqlite3_free()]. ^Both routines return a
3160 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
3161 ** memory to hold the resulting string.
3162 **
3163 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
3164 ** the standard C library. The result is written into the
3165 ** buffer supplied as the second parameter whose size is given by
3166 ** the first parameter. Note that the order of the
3167 ** first two parameters is reversed from snprintf().)^ This is an
3168 ** historical accident that cannot be fixed without breaking
3169 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
3170 ** returns a pointer to its buffer instead of the number of
3171 ** characters actually written into the buffer.)^ We admit that
3172 ** the number of characters written would be a more useful return
3173 ** value but we cannot change the implementation of sqlite3_snprintf()
3174 ** now without breaking compatibility.
3175 **
3176 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
3177 ** guarantees that the buffer is always zero-terminated. ^The first
3178 ** parameter "n" is the total size of the buffer, including space for
3179 ** the zero terminator. So the longest string that can be completely
3180 ** written will be n-1 characters.
3181 **
3182 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
3183 **
3184 ** See also: [built-in printf()], [printf() SQL function]
3185 */
3186 SQLITE_API char *sqlite3_mprintf(const char*,...);
3187 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
3188 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
3189 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
3190
3191 /*
3192 ** CAPI3REF: Memory Allocation Subsystem
3193 **
3194 ** The SQLite core uses these three routines for all of its own
3195 ** internal memory allocation needs. "Core" in the previous sentence
3196 ** does not include operating-system specific [VFS] implementation. The
3197 ** Windows VFS uses native malloc() and free() for some operations.
3198 **
3199 ** ^The sqlite3_malloc() routine returns a pointer to a block
3200 ** of memory at least N bytes in length, where N is the parameter.
3201 ** ^If sqlite3_malloc() is unable to obtain sufficient free
3202 ** memory, it returns a NULL pointer. ^If the parameter N to
3203 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3204 ** a NULL pointer.
3205 **
3206 ** ^The sqlite3_malloc64(N) routine works just like
3207 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3208 ** of a signed 32-bit integer.
3209 **
3210 ** ^Calling sqlite3_free() with a pointer previously returned
3211 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3212 ** that it might be reused. ^The sqlite3_free() routine is
3213 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
3214 ** to sqlite3_free() is harmless. After being freed, memory
3215 ** should neither be read nor written. Even reading previously freed
3216 ** memory might result in a segmentation fault or other severe error.
3217 ** Memory corruption, a segmentation fault, or other severe error
3218 ** might result if sqlite3_free() is called with a non-NULL pointer that
3219 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3220 **
3221 ** ^The sqlite3_realloc(X,N) interface attempts to resize a
3222 ** prior memory allocation X to be at least N bytes.
3223 ** ^If the X parameter to sqlite3_realloc(X,N)
3224 ** is a NULL pointer then its behavior is identical to calling
3225 ** sqlite3_malloc(N).
3226 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3227 ** negative then the behavior is exactly the same as calling
3228 ** sqlite3_free(X).
3229 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3230 ** of at least N bytes in size or NULL if insufficient memory is available.
3231 ** ^If M is the size of the prior allocation, then min(N,M) bytes
3232 ** of the prior allocation are copied into the beginning of buffer returned
3233 ** by sqlite3_realloc(X,N) and the prior allocation is freed.
3234 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3235 ** prior allocation is not freed.
3236 **
3237 ** ^The sqlite3_realloc64(X,N) interfaces works the same as
3238 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3239 ** of a 32-bit signed integer.
3240 **
3241 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3242 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3243 ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3244 ** ^The value returned by sqlite3_msize(X) might be larger than the number
3245 ** of bytes requested when X was allocated. ^If X is a NULL pointer then
3246 ** sqlite3_msize(X) returns zero. If X points to something that is not
3247 ** the beginning of memory allocation, or if it points to a formerly
3248 ** valid memory allocation that has now been freed, then the behavior
3249 ** of sqlite3_msize(X) is undefined and possibly harmful.
3250 **
3251 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3252 ** sqlite3_malloc64(), and sqlite3_realloc64()
3253 ** is always aligned to at least an 8 byte boundary, or to a
3254 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3255 ** option is used.
3256 **
3257 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3258 ** must be either NULL or else pointers obtained from a prior
3259 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3260 ** not yet been released.
3261 **
3262 ** The application must not read or write any part of
3263 ** a block of memory after it has been released using
3264 ** [sqlite3_free()] or [sqlite3_realloc()].
3265 */
3266 SQLITE_API void *sqlite3_malloc(int);
3267 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3268 SQLITE_API void *sqlite3_realloc(void*, int);
3269 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3270 SQLITE_API void sqlite3_free(void*);
3271 SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3272
3273 /*
3274 ** CAPI3REF: Memory Allocator Statistics
3275 **
3276 ** SQLite provides these two interfaces for reporting on the status
3277 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3278 ** routines, which form the built-in memory allocation subsystem.
3279 **
3280 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
3281 ** of memory currently outstanding (malloced but not freed).
3282 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
3283 ** value of [sqlite3_memory_used()] since the high-water mark
3284 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
3285 ** [sqlite3_memory_highwater()] include any overhead
3286 ** added by SQLite in its implementation of [sqlite3_malloc()],
3287 ** but not overhead added by the any underlying system library
3288 ** routines that [sqlite3_malloc()] may call.
3289 **
3290 ** ^The memory high-water mark is reset to the current value of
3291 ** [sqlite3_memory_used()] if and only if the parameter to
3292 ** [sqlite3_memory_highwater()] is true. ^The value returned
3293 ** by [sqlite3_memory_highwater(1)] is the high-water mark
3294 ** prior to the reset.
3295 */
3296 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3297 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3298
3299 /*
3300 ** CAPI3REF: Pseudo-Random Number Generator
3301 **
3302 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3303 ** select random [ROWID | ROWIDs] when inserting new records into a table that
3304 ** already uses the largest possible [ROWID]. The PRNG is also used for
3305 ** the built-in random() and randomblob() SQL functions. This interface allows
3306 ** applications to access the same PRNG for other purposes.
3307 **
3308 ** ^A call to this routine stores N bytes of randomness into buffer P.
3309 ** ^The P parameter can be a NULL pointer.
3310 **
3311 ** ^If this routine has not been previously called or if the previous
3312 ** call had N less than one or a NULL pointer for P, then the PRNG is
3313 ** seeded using randomness obtained from the xRandomness method of
3314 ** the default [sqlite3_vfs] object.
3315 ** ^If the previous call to this routine had an N of 1 or more and a
3316 ** non-NULL P then the pseudo-randomness is generated
3317 ** internally and without recourse to the [sqlite3_vfs] xRandomness
3318 ** method.
3319 */
3320 SQLITE_API void sqlite3_randomness(int N, void *P);
3321
3322 /*
3323 ** CAPI3REF: Compile-Time Authorization Callbacks
3324 ** METHOD: sqlite3
3325 ** KEYWORDS: {authorizer callback}
3326 **
3327 ** ^This routine registers an authorizer callback with a particular
3328 ** [database connection], supplied in the first argument.
3329 ** ^The authorizer callback is invoked as SQL statements are being compiled
3330 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3331 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3332 ** and [sqlite3_prepare16_v3()]. ^At various
3333 ** points during the compilation process, as logic is being created
3334 ** to perform various actions, the authorizer callback is invoked to
3335 ** see if those actions are allowed. ^The authorizer callback should
3336 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3337 ** specific action but allow the SQL statement to continue to be
3338 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3339 ** rejected with an error. ^If the authorizer callback returns
3340 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3341 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3342 ** the authorizer will fail with an error message.
3343 **
3344 ** When the callback returns [SQLITE_OK], that means the operation
3345 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
3346 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
3347 ** authorizer will fail with an error message explaining that
3348 ** access is denied.
3349 **
3350 ** ^The first parameter to the authorizer callback is a copy of the third
3351 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3352 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
3353 ** the particular action to be authorized. ^The third through sixth parameters
3354 ** to the callback are either NULL pointers or zero-terminated strings
3355 ** that contain additional details about the action to be authorized.
3356 ** Applications must always be prepared to encounter a NULL pointer in any
3357 ** of the third through the sixth parameters of the authorization callback.
3358 **
3359 ** ^If the action code is [SQLITE_READ]
3360 ** and the callback returns [SQLITE_IGNORE] then the
3361 ** [prepared statement] statement is constructed to substitute
3362 ** a NULL value in place of the table column that would have
3363 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3364 ** return can be used to deny an untrusted user access to individual
3365 ** columns of a table.
3366 ** ^When a table is referenced by a [SELECT] but no column values are
3367 ** extracted from that table (for example in a query like
3368 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3369 ** is invoked once for that table with a column name that is an empty string.
3370 ** ^If the action code is [SQLITE_DELETE] and the callback returns
3371 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3372 ** [truncate optimization] is disabled and all rows are deleted individually.
3373 **
3374 ** An authorizer is used when [sqlite3_prepare | preparing]
3375 ** SQL statements from an untrusted source, to ensure that the SQL statements
3376 ** do not try to access data they are not allowed to see, or that they do not
3377 ** try to execute malicious statements that damage the database. For
3378 ** example, an application may allow a user to enter arbitrary
3379 ** SQL queries for evaluation by a database. But the application does
3380 ** not want the user to be able to make arbitrary changes to the
3381 ** database. An authorizer could then be put in place while the
3382 ** user-entered SQL is being [sqlite3_prepare | prepared] that
3383 ** disallows everything except [SELECT] statements.
3384 **
3385 ** Applications that need to process SQL from untrusted sources
3386 ** might also consider lowering resource limits using [sqlite3_limit()]
3387 ** and limiting database size using the [max_page_count] [PRAGMA]
3388 ** in addition to using an authorizer.
3389 **
3390 ** ^(Only a single authorizer can be in place on a database connection
3391 ** at a time. Each call to sqlite3_set_authorizer overrides the
3392 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3393 ** The authorizer is disabled by default.
3394 **
3395 ** The authorizer callback must not do anything that will modify
3396 ** the database connection that invoked the authorizer callback.
3397 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3398 ** database connections for the meaning of "modify" in this paragraph.
3399 **
3400 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3401 ** statement might be re-prepared during [sqlite3_step()] due to a
3402 ** schema change. Hence, the application should ensure that the
3403 ** correct authorizer callback remains in place during the [sqlite3_step()].
3404 **
3405 ** ^Note that the authorizer callback is invoked only during
3406 ** [sqlite3_prepare()] or its variants. Authorization is not
3407 ** performed during statement evaluation in [sqlite3_step()], unless
3408 ** as stated in the previous paragraph, sqlite3_step() invokes
3409 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3410 */
3411 SQLITE_API int sqlite3_set_authorizer(
3412 sqlite3*,
3413 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3414 void *pUserData
3415 );
3416
3417 /*
3418 ** CAPI3REF: Authorizer Return Codes
3419 **
3420 ** The [sqlite3_set_authorizer | authorizer callback function] must
3421 ** return either [SQLITE_OK] or one of these two constants in order
3422 ** to signal SQLite whether or not the action is permitted. See the
3423 ** [sqlite3_set_authorizer | authorizer documentation] for additional
3424 ** information.
3425 **
3426 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3427 ** returned from the [sqlite3_vtab_on_conflict()] interface.
3428 */
3429 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3430 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3431
3432 /*
3433 ** CAPI3REF: Authorizer Action Codes
3434 **
3435 ** The [sqlite3_set_authorizer()] interface registers a callback function
3436 ** that is invoked to authorize certain SQL statement actions. The
3437 ** second parameter to the callback is an integer code that specifies
3438 ** what action is being authorized. These are the integer action codes that
3439 ** the authorizer callback may be passed.
3440 **
3441 ** These action code values signify what kind of operation is to be
3442 ** authorized. The 3rd and 4th parameters to the authorization
3443 ** callback function will be parameters or NULL depending on which of these
3444 ** codes is used as the second parameter. ^(The 5th parameter to the
3445 ** authorizer callback is the name of the database ("main", "temp",
3446 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3447 ** is the name of the inner-most trigger or view that is responsible for
3448 ** the access attempt or NULL if this access attempt is directly from
3449 ** top-level SQL code.
3450 */
3451 /******************************************* 3rd ************ 4th ***********/
3452 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3453 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3454 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3455 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3456 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3457 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3458 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3459 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3460 #define SQLITE_DELETE 9 /* Table Name NULL */
3461 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3462 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3463 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3464 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3465 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3466 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3467 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3468 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
3469 #define SQLITE_INSERT 18 /* Table Name NULL */
3470 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3471 #define SQLITE_READ 20 /* Table Name Column Name */
3472 #define SQLITE_SELECT 21 /* NULL NULL */
3473 #define SQLITE_TRANSACTION 22 /* Operation NULL */
3474 #define SQLITE_UPDATE 23 /* Table Name Column Name */
3475 #define SQLITE_ATTACH 24 /* Filename NULL */
3476 #define SQLITE_DETACH 25 /* Database Name NULL */
3477 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3478 #define SQLITE_REINDEX 27 /* Index Name NULL */
3479 #define SQLITE_ANALYZE 28 /* Table Name NULL */
3480 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3481 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3482 #define SQLITE_FUNCTION 31 /* NULL Function Name */
3483 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3484 #define SQLITE_COPY 0 /* No longer used */
3485 #define SQLITE_RECURSIVE 33 /* NULL NULL */
3486
3487 /*
3488 ** CAPI3REF: Deprecated Tracing And Profiling Functions
3489 ** DEPRECATED
3490 **
3491 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3492 ** instead of the routines described here.
3493 **
3494 ** These routines register callback functions that can be used for
3495 ** tracing and profiling the execution of SQL statements.
3496 **
3497 ** ^The callback function registered by sqlite3_trace() is invoked at
3498 ** various times when an SQL statement is being run by [sqlite3_step()].
3499 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3500 ** SQL statement text as the statement first begins executing.
3501 ** ^(Additional sqlite3_trace() callbacks might occur
3502 ** as each triggered subprogram is entered. The callbacks for triggers
3503 ** contain a UTF-8 SQL comment that identifies the trigger.)^
3504 **
3505 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3506 ** the length of [bound parameter] expansion in the output of sqlite3_trace().
3507 **
3508 ** ^The callback function registered by sqlite3_profile() is invoked
3509 ** as each SQL statement finishes. ^The profile callback contains
3510 ** the original statement text and an estimate of wall-clock time
3511 ** of how long that statement took to run. ^The profile callback
3512 ** time is in units of nanoseconds, however the current implementation
3513 ** is only capable of millisecond resolution so the six least significant
3514 ** digits in the time are meaningless. Future versions of SQLite
3515 ** might provide greater resolution on the profiler callback. Invoking
3516 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3517 ** profile callback.
3518 */
3519 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3520 void(*xTrace)(void*,const char*), void*);
3521 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3522 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3523
3524 /*
3525 ** CAPI3REF: SQL Trace Event Codes
3526 ** KEYWORDS: SQLITE_TRACE
3527 **
3528 ** These constants identify classes of events that can be monitored
3529 ** using the [sqlite3_trace_v2()] tracing logic. The M argument
3530 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3531 ** the following constants. ^The first argument to the trace callback
3532 ** is one of the following constants.
3533 **
3534 ** New tracing constants may be added in future releases.
3535 **
3536 ** ^A trace callback has four arguments: xCallback(T,C,P,X).
3537 ** ^The T argument is one of the integer type codes above.
3538 ** ^The C argument is a copy of the context pointer passed in as the
3539 ** fourth argument to [sqlite3_trace_v2()].
3540 ** The P and X arguments are pointers whose meanings depend on T.
3541 **
3542 ** <dl>
3543 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3544 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3545 ** first begins running and possibly at other times during the
3546 ** execution of the prepared statement, such as at the start of each
3547 ** trigger subprogram. ^The P argument is a pointer to the
3548 ** [prepared statement]. ^The X argument is a pointer to a string which
3549 ** is the unexpanded SQL text of the prepared statement or an SQL comment
3550 ** that indicates the invocation of a trigger. ^The callback can compute
3551 ** the same text that would have been returned by the legacy [sqlite3_trace()]
3552 ** interface by using the X argument when X begins with "--" and invoking
3553 ** [sqlite3_expanded_sql(P)] otherwise.
3554 **
3555 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3556 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3557 ** information as is provided by the [sqlite3_profile()] callback.
3558 ** ^The P argument is a pointer to the [prepared statement] and the
3559 ** X argument points to a 64-bit integer which is approximately
3560 ** the number of nanoseconds that the prepared statement took to run.
3561 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3562 **
3563 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3564 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3565 ** statement generates a single row of result.
3566 ** ^The P argument is a pointer to the [prepared statement] and the
3567 ** X argument is unused.
3568 **
3569 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3570 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3571 ** connection closes.
3572 ** ^The P argument is a pointer to the [database connection] object
3573 ** and the X argument is unused.
3574 ** </dl>
3575 */
3576 #define SQLITE_TRACE_STMT 0x01
3577 #define SQLITE_TRACE_PROFILE 0x02
3578 #define SQLITE_TRACE_ROW 0x04
3579 #define SQLITE_TRACE_CLOSE 0x08
3580
3581 /*
3582 ** CAPI3REF: SQL Trace Hook
3583 ** METHOD: sqlite3
3584 **
3585 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3586 ** function X against [database connection] D, using property mask M
3587 ** and context pointer P. ^If the X callback is
3588 ** NULL or if the M mask is zero, then tracing is disabled. The
3589 ** M argument should be the bitwise OR-ed combination of
3590 ** zero or more [SQLITE_TRACE] constants.
3591 **
3592 ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3593 ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3594 ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3595 ** database connection may have at most one trace callback.
3596 **
3597 ** ^The X callback is invoked whenever any of the events identified by
3598 ** mask M occur. ^The integer return value from the callback is currently
3599 ** ignored, though this may change in future releases. Callback
3600 ** implementations should return zero to ensure future compatibility.
3601 **
3602 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3603 ** ^The T argument is one of the [SQLITE_TRACE]
3604 ** constants to indicate why the callback was invoked.
3605 ** ^The C argument is a copy of the context pointer.
3606 ** The P and X arguments are pointers whose meanings depend on T.
3607 **
3608 ** The sqlite3_trace_v2() interface is intended to replace the legacy
3609 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3610 ** are deprecated.
3611 */
3612 SQLITE_API int sqlite3_trace_v2(
3613 sqlite3*,
3614 unsigned uMask,
3615 int(*xCallback)(unsigned,void*,void*,void*),
3616 void *pCtx
3617 );
3618
3619 /*
3620 ** CAPI3REF: Query Progress Callbacks
3621 ** METHOD: sqlite3
3622 **
3623 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3624 ** function X to be invoked periodically during long running calls to
3625 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3626 ** database connection D. An example use for this
3627 ** interface is to keep a GUI updated during a large query.
3628 **
3629 ** ^The parameter P is passed through as the only parameter to the
3630 ** callback function X. ^The parameter N is the approximate number of
3631 ** [virtual machine instructions] that are evaluated between successive
3632 ** invocations of the callback X. ^If N is less than one then the progress
3633 ** handler is disabled.
3634 **
3635 ** ^Only a single progress handler may be defined at one time per
3636 ** [database connection]; setting a new progress handler cancels the
3637 ** old one. ^Setting parameter X to NULL disables the progress handler.
3638 ** ^The progress handler is also disabled by setting N to a value less
3639 ** than 1.
3640 **
3641 ** ^If the progress callback returns non-zero, the operation is
3642 ** interrupted. This feature can be used to implement a
3643 ** "Cancel" button on a GUI progress dialog box.
3644 **
3645 ** The progress handler callback must not do anything that will modify
3646 ** the database connection that invoked the progress handler.
3647 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3648 ** database connections for the meaning of "modify" in this paragraph.
3649 **
3650 ** The progress handler callback would originally only be invoked from the
3651 ** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3652 ** and similar because those routines might force a reparse of the schema
3653 ** which involves running the bytecode engine. However, beginning with
3654 ** SQLite version 3.41.0, the progress handler callback might also be
3655 ** invoked directly from [sqlite3_prepare()] while analyzing and generating
3656 ** code for complex queries.
3657 */
3658 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3659
3660 /*
3661 ** CAPI3REF: Opening A New Database Connection
3662 ** CONSTRUCTOR: sqlite3
3663 **
3664 ** ^These routines open an SQLite database file as specified by the
3665 ** filename argument. ^The filename argument is interpreted as UTF-8 for
3666 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3667 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
3668 ** returned in *ppDb, even if an error occurs. The only exception is that
3669 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3670 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3671 ** object.)^ ^(If the database is opened (and/or created) successfully, then
3672 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3673 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3674 ** an English language description of the error following a failure of any
3675 ** of the sqlite3_open() routines.
3676 **
3677 ** ^The default encoding will be UTF-8 for databases created using
3678 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3679 ** created using sqlite3_open16() will be UTF-16 in the native byte order.
3680 **
3681 ** Whether or not an error occurs when it is opened, resources
3682 ** associated with the [database connection] handle should be released by
3683 ** passing it to [sqlite3_close()] when it is no longer required.
3684 **
3685 ** The sqlite3_open_v2() interface works like sqlite3_open()
3686 ** except that it accepts two additional parameters for additional control
3687 ** over the new database connection. ^(The flags parameter to
3688 ** sqlite3_open_v2() must include, at a minimum, one of the following
3689 ** three flag combinations:)^
3690 **
3691 ** <dl>
3692 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3693 ** <dd>The database is opened in read-only mode. If the database does
3694 ** not already exist, an error is returned.</dd>)^
3695 **
3696 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3697 ** <dd>The database is opened for reading and writing if possible, or
3698 ** reading only if the file is write protected by the operating
3699 ** system. In either case the database must already exist, otherwise
3700 ** an error is returned. For historical reasons, if opening in
3701 ** read-write mode fails due to OS-level permissions, an attempt is
3702 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3703 ** used to determine whether the database is actually
3704 ** read-write.</dd>)^
3705 **
3706 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3707 ** <dd>The database is opened for reading and writing, and is created if
3708 ** it does not already exist. This is the behavior that is always used for
3709 ** sqlite3_open() and sqlite3_open16().</dd>)^
3710 ** </dl>
3711 **
3712 ** In addition to the required flags, the following optional flags are
3713 ** also supported:
3714 **
3715 ** <dl>
3716 ** ^(<dt>[SQLITE_OPEN_URI]</dt>
3717 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3718 **
3719 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3720 ** <dd>The database will be opened as an in-memory database. The database
3721 ** is named by the "filename" argument for the purposes of cache-sharing,
3722 ** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3723 ** </dd>)^
3724 **
3725 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3726 ** <dd>The new database connection will use the "multi-thread"
3727 ** [threading mode].)^ This means that separate threads are allowed
3728 ** to use SQLite at the same time, as long as each thread is using
3729 ** a different [database connection].
3730 **
3731 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3732 ** <dd>The new database connection will use the "serialized"
3733 ** [threading mode].)^ This means the multiple threads can safely
3734 ** attempt to use the same database connection at the same time.
3735 ** (Mutexes will block any actual concurrency, but in this mode
3736 ** there is no harm in trying.)
3737 **
3738 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3739 ** <dd>The database is opened [shared cache] enabled, overriding
3740 ** the default shared cache setting provided by
3741 ** [sqlite3_enable_shared_cache()].)^
3742 ** The [use of shared cache mode is discouraged] and hence shared cache
3743 ** capabilities may be omitted from many builds of SQLite. In such cases,
3744 ** this option is a no-op.
3745 **
3746 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3747 ** <dd>The database is opened [shared cache] disabled, overriding
3748 ** the default shared cache setting provided by
3749 ** [sqlite3_enable_shared_cache()].)^
3750 **
3751 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3752 ** <dd>The database connection comes up in "extended result code mode".
3753 ** In other words, the database behaves as if
3754 ** [sqlite3_extended_result_codes(db,1)] were called on the database
3755 ** connection as soon as the connection is created. In addition to setting
3756 ** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3757 ** to return an extended result code.</dd>
3758 **
3759 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3760 ** <dd>The database filename is not allowed to contain a symbolic link</dd>
3761 ** </dl>)^
3762 **
3763 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
3764 ** required combinations shown above optionally combined with other
3765 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3766 ** then the behavior is undefined. Historic versions of SQLite
3767 ** have silently ignored surplus bits in the flags parameter to
3768 ** sqlite3_open_v2(), however that behavior might not be carried through
3769 ** into future versions of SQLite and so applications should not rely
3770 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3771 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3772 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3773 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3774 ** by sqlite3_open_v2().
3775 **
3776 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3777 ** [sqlite3_vfs] object that defines the operating system interface that
3778 ** the new database connection should use. ^If the fourth parameter is
3779 ** a NULL pointer then the default [sqlite3_vfs] object is used.
3780 **
3781 ** ^If the filename is ":memory:", then a private, temporary in-memory database
3782 ** is created for the connection. ^This in-memory database will vanish when
3783 ** the database connection is closed. Future versions of SQLite might
3784 ** make use of additional special filenames that begin with the ":" character.
3785 ** It is recommended that when a database filename actually does begin with
3786 ** a ":" character you should prefix the filename with a pathname such as
3787 ** "./" to avoid ambiguity.
3788 **
3789 ** ^If the filename is an empty string, then a private, temporary
3790 ** on-disk database will be created. ^This private database will be
3791 ** automatically deleted as soon as the database connection is closed.
3792 **
3793 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3794 **
3795 ** ^If [URI filename] interpretation is enabled, and the filename argument
3796 ** begins with "file:", then the filename is interpreted as a URI. ^URI
3797 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3798 ** set in the third argument to sqlite3_open_v2(), or if it has
3799 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3800 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3801 ** URI filename interpretation is turned off
3802 ** by default, but future releases of SQLite might enable URI filename
3803 ** interpretation by default. See "[URI filenames]" for additional
3804 ** information.
3805 **
3806 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3807 ** authority, then it must be either an empty string or the string
3808 ** "localhost". ^If the authority is not an empty string or "localhost", an
3809 ** error is returned to the caller. ^The fragment component of a URI, if
3810 ** present, is ignored.
3811 **
3812 ** ^SQLite uses the path component of the URI as the name of the disk file
3813 ** which contains the database. ^If the path begins with a '/' character,
3814 ** then it is interpreted as an absolute path. ^If the path does not begin
3815 ** with a '/' (meaning that the authority section is omitted from the URI)
3816 ** then the path is interpreted as a relative path.
3817 ** ^(On windows, the first component of an absolute path
3818 ** is a drive specification (e.g. "C:").)^
3819 **
3820 ** [[core URI query parameters]]
3821 ** The query component of a URI may contain parameters that are interpreted
3822 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
3823 ** SQLite and its built-in [VFSes] interpret the
3824 ** following query parameters:
3825 **
3826 ** <ul>
3827 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3828 ** a VFS object that provides the operating system interface that should
3829 ** be used to access the database file on disk. ^If this option is set to
3830 ** an empty string the default VFS object is used. ^Specifying an unknown
3831 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3832 ** present, then the VFS specified by the option takes precedence over
3833 ** the value passed as the fourth parameter to sqlite3_open_v2().
3834 **
3835 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3836 ** "rwc", or "memory". Attempting to set it to any other value is
3837 ** an error)^.
3838 ** ^If "ro" is specified, then the database is opened for read-only
3839 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3840 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3841 ** "rw", then the database is opened for read-write (but not create)
3842 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3843 ** been set. ^Value "rwc" is equivalent to setting both
3844 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3845 ** set to "memory" then a pure [in-memory database] that never reads
3846 ** or writes from disk is used. ^It is an error to specify a value for
3847 ** the mode parameter that is less restrictive than that specified by
3848 ** the flags passed in the third parameter to sqlite3_open_v2().
3849 **
3850 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3851 ** "private". ^Setting it to "shared" is equivalent to setting the
3852 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3853 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3854 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3855 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3856 ** a URI filename, its value overrides any behavior requested by setting
3857 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3858 **
3859 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3860 ** [powersafe overwrite] property does or does not apply to the
3861 ** storage media on which the database file resides.
3862 **
3863 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3864 ** which if set disables file locking in rollback journal modes. This
3865 ** is useful for accessing a database on a filesystem that does not
3866 ** support locking. Caution: Database corruption might result if two
3867 ** or more processes write to the same database and any one of those
3868 ** processes uses nolock=1.
3869 **
3870 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3871 ** parameter that indicates that the database file is stored on
3872 ** read-only media. ^When immutable is set, SQLite assumes that the
3873 ** database file cannot be changed, even by a process with higher
3874 ** privilege, and so the database is opened read-only and all locking
3875 ** and change detection is disabled. Caution: Setting the immutable
3876 ** property on a database file that does in fact change can result
3877 ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3878 ** See also: [SQLITE_IOCAP_IMMUTABLE].
3879 **
3880 ** </ul>
3881 **
3882 ** ^Specifying an unknown parameter in the query component of a URI is not an
3883 ** error. Future versions of SQLite might understand additional query
3884 ** parameters. See "[query parameters with special meaning to SQLite]" for
3885 ** additional information.
3886 **
3887 ** [[URI filename examples]] <h3>URI filename examples</h3>
3888 **
3889 ** <table border="1" align=center cellpadding=5>
3890 ** <tr><th> URI filenames <th> Results
3891 ** <tr><td> file:data.db <td>
3892 ** Open the file "data.db" in the current directory.
3893 ** <tr><td> file:/home/fred/data.db<br>
3894 ** file:///home/fred/data.db <br>
3895 ** file://localhost/home/fred/data.db <br> <td>
3896 ** Open the database file "/home/fred/data.db".
3897 ** <tr><td> file://darkstar/home/fred/data.db <td>
3898 ** An error. "darkstar" is not a recognized authority.
3899 ** <tr><td style="white-space:nowrap">
3900 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3901 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3902 ** C:. Note that the %20 escaping in this example is not strictly
3903 ** necessary - space characters can be used literally
3904 ** in URI filenames.
3905 ** <tr><td> file:data.db?mode=ro&cache=private <td>
3906 ** Open file "data.db" in the current directory for read-only access.
3907 ** Regardless of whether or not shared-cache mode is enabled by
3908 ** default, use a private cache.
3909 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3910 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3911 ** that uses dot-files in place of posix advisory locking.
3912 ** <tr><td> file:data.db?mode=readonly <td>
3913 ** An error. "readonly" is not a valid option for the "mode" parameter.
3914 ** Use "ro" instead: "file:data.db?mode=ro".
3915 ** </table>
3916 **
3917 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3918 ** query components of a URI. A hexadecimal escape sequence consists of a
3919 ** percent sign - "%" - followed by exactly two hexadecimal digits
3920 ** specifying an octet value. ^Before the path or query components of a
3921 ** URI filename are interpreted, they are encoded using UTF-8 and all
3922 ** hexadecimal escape sequences replaced by a single byte containing the
3923 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3924 ** the results are undefined.
3925 **
3926 ** <b>Note to Windows users:</b> The encoding used for the filename argument
3927 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3928 ** codepage is currently defined. Filenames containing international
3929 ** characters must be converted to UTF-8 prior to passing them into
3930 ** sqlite3_open() or sqlite3_open_v2().
3931 **
3932 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3933 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3934 ** features that require the use of temporary files may fail.
3935 **
3936 ** See also: [sqlite3_temp_directory]
3937 */
3938 SQLITE_API int sqlite3_open(
3939 const char *filename, /* Database filename (UTF-8) */
3940 sqlite3 **ppDb /* OUT: SQLite db handle */
3941 );
3942 SQLITE_API int sqlite3_open16(
3943 const void *filename, /* Database filename (UTF-16) */
3944 sqlite3 **ppDb /* OUT: SQLite db handle */
3945 );
3946 SQLITE_API int sqlite3_open_v2(
3947 const char *filename, /* Database filename (UTF-8) */
3948 sqlite3 **ppDb, /* OUT: SQLite db handle */
3949 int flags, /* Flags */
3950 const char *zVfs /* Name of VFS module to use */
3951 );
3952
3953 /*
3954 ** CAPI3REF: Obtain Values For URI Parameters
3955 **
3956 ** These are utility routines, useful to [VFS|custom VFS implementations],
3957 ** that check if a database file was a URI that contained a specific query
3958 ** parameter, and if so obtains the value of that query parameter.
3959 **
3960 ** The first parameter to these interfaces (hereafter referred to
3961 ** as F) must be one of:
3962 ** <ul>
3963 ** <li> A database filename pointer created by the SQLite core and
3964 ** passed into the xOpen() method of a VFS implementation, or
3965 ** <li> A filename obtained from [sqlite3_db_filename()], or
3966 ** <li> A new filename constructed using [sqlite3_create_filename()].
3967 ** </ul>
3968 ** If the F parameter is not one of the above, then the behavior is
3969 ** undefined and probably undesirable. Older versions of SQLite were
3970 ** more tolerant of invalid F parameters than newer versions.
3971 **
3972 ** If F is a suitable filename (as described in the previous paragraph)
3973 ** and if P is the name of the query parameter, then
3974 ** sqlite3_uri_parameter(F,P) returns the value of the P
3975 ** parameter if it exists or a NULL pointer if P does not appear as a
3976 ** query parameter on F. If P is a query parameter of F and it
3977 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3978 ** a pointer to an empty string.
3979 **
3980 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3981 ** parameter and returns true (1) or false (0) according to the value
3982 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3983 ** value of query parameter P is one of "yes", "true", or "on" in any
3984 ** case or if the value begins with a non-zero number. The
3985 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3986 ** query parameter P is one of "no", "false", or "off" in any case or
3987 ** if the value begins with a numeric zero. If P is not a query
3988 ** parameter on F or if the value of P does not match any of the
3989 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3990 **
3991 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3992 ** 64-bit signed integer and returns that integer, or D if P does not
3993 ** exist. If the value of P is something other than an integer, then
3994 ** zero is returned.
3995 **
3996 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3997 ** the value) of the N-th query parameter for filename F, or a NULL
3998 ** pointer if N is less than zero or greater than the number of query
3999 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain
4000 ** the name of the first query parameter, 1 for the second parameter, and
4001 ** so forth.
4002 **
4003 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
4004 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
4005 ** is not a database file pathname pointer that the SQLite core passed
4006 ** into the xOpen VFS method, then the behavior of this routine is undefined
4007 ** and probably undesirable.
4008 **
4009 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
4010 ** parameter can also be the name of a rollback journal file or WAL file
4011 ** in addition to the main database file. Prior to version 3.31.0, these
4012 ** routines would only work if F was the name of the main database file.
4013 ** When the F parameter is the name of the rollback journal or WAL file,
4014 ** it has access to all the same query parameters as were found on the
4015 ** main database file.
4016 **
4017 ** See the [URI filename] documentation for additional information.
4018 */
4019 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
4020 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
4021 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
4022 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
4023
4024 /*
4025 ** CAPI3REF: Translate filenames
4026 **
4027 ** These routines are available to [VFS|custom VFS implementations] for
4028 ** translating filenames between the main database file, the journal file,
4029 ** and the WAL file.
4030 **
4031 ** If F is the name of an sqlite database file, journal file, or WAL file
4032 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
4033 ** returns the name of the corresponding database file.
4034 **
4035 ** If F is the name of an sqlite database file, journal file, or WAL file
4036 ** passed by the SQLite core into the VFS, or if F is a database filename
4037 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
4038 ** returns the name of the corresponding rollback journal file.
4039 **
4040 ** If F is the name of an sqlite database file, journal file, or WAL file
4041 ** that was passed by the SQLite core into the VFS, or if F is a database
4042 ** filename obtained from [sqlite3_db_filename()], then
4043 ** sqlite3_filename_wal(F) returns the name of the corresponding
4044 ** WAL file.
4045 **
4046 ** In all of the above, if F is not the name of a database, journal or WAL
4047 ** filename passed into the VFS from the SQLite core and F is not the
4048 ** return value from [sqlite3_db_filename()], then the result is
4049 ** undefined and is likely a memory access violation.
4050 */
4051 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
4052 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
4053 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
4054
4055 /*
4056 ** CAPI3REF: Database File Corresponding To A Journal
4057 **
4058 ** ^If X is the name of a rollback or WAL-mode journal file that is
4059 ** passed into the xOpen method of [sqlite3_vfs], then
4060 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
4061 ** object that represents the main database file.
4062 **
4063 ** This routine is intended for use in custom [VFS] implementations
4064 ** only. It is not a general-purpose interface.
4065 ** The argument sqlite3_file_object(X) must be a filename pointer that
4066 ** has been passed into [sqlite3_vfs].xOpen method where the
4067 ** flags parameter to xOpen contains one of the bits
4068 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
4069 ** of this routine results in undefined and probably undesirable
4070 ** behavior.
4071 */
4072 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
4073
4074 /*
4075 ** CAPI3REF: Create and Destroy VFS Filenames
4076 **
4077 ** These interfaces are provided for use by [VFS shim] implementations and
4078 ** are not useful outside of that context.
4079 **
4080 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
4081 ** database filename D with corresponding journal file J and WAL file W and
4082 ** an array P of N URI Key/Value pairs. The result from
4083 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
4084 ** is safe to pass to routines like:
4085 ** <ul>
4086 ** <li> [sqlite3_uri_parameter()],
4087 ** <li> [sqlite3_uri_boolean()],
4088 ** <li> [sqlite3_uri_int64()],
4089 ** <li> [sqlite3_uri_key()],
4090 ** <li> [sqlite3_filename_database()],
4091 ** <li> [sqlite3_filename_journal()], or
4092 ** <li> [sqlite3_filename_wal()].
4093 ** </ul>
4094 ** If a memory allocation error occurs, sqlite3_create_filename() might
4095 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
4096 ** must be released by a corresponding call to sqlite3_free_filename(Y).
4097 **
4098 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
4099 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds
4100 ** to a key and value for a query parameter. The P parameter may be a NULL
4101 ** pointer if N is zero. None of the 2*N pointers in the P array may be
4102 ** NULL pointers and key pointers should not be empty strings.
4103 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
4104 ** be NULL pointers, though they can be empty strings.
4105 **
4106 ** The sqlite3_free_filename(Y) routine releases a memory allocation
4107 ** previously obtained from sqlite3_create_filename(). Invoking
4108 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
4109 **
4110 ** If the Y parameter to sqlite3_free_filename(Y) is anything other
4111 ** than a NULL pointer or a pointer previously acquired from
4112 ** sqlite3_create_filename(), then bad things such as heap
4113 ** corruption or segfaults may occur. The value Y should not be
4114 ** used again after sqlite3_free_filename(Y) has been called. This means
4115 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
4116 ** then the corresponding [sqlite3_module.xClose() method should also be
4117 ** invoked prior to calling sqlite3_free_filename(Y).
4118 */
4119 SQLITE_API sqlite3_filename sqlite3_create_filename(
4120 const char *zDatabase,
4121 const char *zJournal,
4122 const char *zWal,
4123 int nParam,
4124 const char **azParam
4125 );
4126 SQLITE_API void sqlite3_free_filename(sqlite3_filename);
4127
4128 /*
4129 ** CAPI3REF: Error Codes And Messages
4130 ** METHOD: sqlite3
4131 **
4132 ** ^If the most recent sqlite3_* API call associated with
4133 ** [database connection] D failed, then the sqlite3_errcode(D) interface
4134 ** returns the numeric [result code] or [extended result code] for that
4135 ** API call.
4136 ** ^The sqlite3_extended_errcode()
4137 ** interface is the same except that it always returns the
4138 ** [extended result code] even when extended result codes are
4139 ** disabled.
4140 **
4141 ** The values returned by sqlite3_errcode() and/or
4142 ** sqlite3_extended_errcode() might change with each API call.
4143 ** Except, there are some interfaces that are guaranteed to never
4144 ** change the value of the error code. The error-code preserving
4145 ** interfaces include the following:
4146 **
4147 ** <ul>
4148 ** <li> sqlite3_errcode()
4149 ** <li> sqlite3_extended_errcode()
4150 ** <li> sqlite3_errmsg()
4151 ** <li> sqlite3_errmsg16()
4152 ** <li> sqlite3_error_offset()
4153 ** </ul>
4154 **
4155 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
4156 ** text that describes the error, as either UTF-8 or UTF-16 respectively,
4157 ** or NULL if no error message is available.
4158 ** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
4159 ** ^(Memory to hold the error message string is managed internally.
4160 ** The application does not need to worry about freeing the result.
4161 ** However, the error string might be overwritten or deallocated by
4162 ** subsequent calls to other SQLite interface functions.)^
4163 **
4164 ** ^The sqlite3_errstr(E) interface returns the English-language text
4165 ** that describes the [result code] E, as UTF-8, or NULL if E is not an
4166 ** result code for which a text error message is available.
4167 ** ^(Memory to hold the error message string is managed internally
4168 ** and must not be freed by the application)^.
4169 **
4170 ** ^If the most recent error references a specific token in the input
4171 ** SQL, the sqlite3_error_offset() interface returns the byte offset
4172 ** of the start of that token. ^The byte offset returned by
4173 ** sqlite3_error_offset() assumes that the input SQL is UTF8.
4174 ** ^If the most recent error does not reference a specific token in the input
4175 ** SQL, then the sqlite3_error_offset() function returns -1.
4176 **
4177 ** When the serialized [threading mode] is in use, it might be the
4178 ** case that a second error occurs on a separate thread in between
4179 ** the time of the first error and the call to these interfaces.
4180 ** When that happens, the second error will be reported since these
4181 ** interfaces always report the most recent result. To avoid
4182 ** this, each thread can obtain exclusive use of the [database connection] D
4183 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
4184 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
4185 ** all calls to the interfaces listed here are completed.
4186 **
4187 ** If an interface fails with SQLITE_MISUSE, that means the interface
4188 ** was invoked incorrectly by the application. In that case, the
4189 ** error code and message may or may not be set.
4190 */
4191 SQLITE_API int sqlite3_errcode(sqlite3 *db);
4192 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
4193 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
4194 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
4195 SQLITE_API const char *sqlite3_errstr(int);
4196 SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4197
4198 /*
4199 ** CAPI3REF: Prepared Statement Object
4200 ** KEYWORDS: {prepared statement} {prepared statements}
4201 **
4202 ** An instance of this object represents a single SQL statement that
4203 ** has been compiled into binary form and is ready to be evaluated.
4204 **
4205 ** Think of each SQL statement as a separate computer program. The
4206 ** original SQL text is source code. A prepared statement object
4207 ** is the compiled object code. All SQL must be converted into a
4208 ** prepared statement before it can be run.
4209 **
4210 ** The life-cycle of a prepared statement object usually goes like this:
4211 **
4212 ** <ol>
4213 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4214 ** <li> Bind values to [parameters] using the sqlite3_bind_*()
4215 ** interfaces.
4216 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4217 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4218 ** to step 2. Do this zero or more times.
4219 ** <li> Destroy the object using [sqlite3_finalize()].
4220 ** </ol>
4221 */
4222 typedef struct sqlite3_stmt sqlite3_stmt;
4223
4224 /*
4225 ** CAPI3REF: Run-time Limits
4226 ** METHOD: sqlite3
4227 **
4228 ** ^(This interface allows the size of various constructs to be limited
4229 ** on a connection by connection basis. The first parameter is the
4230 ** [database connection] whose limit is to be set or queried. The
4231 ** second parameter is one of the [limit categories] that define a
4232 ** class of constructs to be size limited. The third parameter is the
4233 ** new limit for that construct.)^
4234 **
4235 ** ^If the new limit is a negative number, the limit is unchanged.
4236 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4237 ** [limits | hard upper bound]
4238 ** set at compile-time by a C preprocessor macro called
4239 ** [limits | SQLITE_MAX_<i>NAME</i>].
4240 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4241 ** ^Attempts to increase a limit above its hard upper bound are
4242 ** silently truncated to the hard upper bound.
4243 **
4244 ** ^Regardless of whether or not the limit was changed, the
4245 ** [sqlite3_limit()] interface returns the prior value of the limit.
4246 ** ^Hence, to find the current value of a limit without changing it,
4247 ** simply invoke this interface with the third parameter set to -1.
4248 **
4249 ** Run-time limits are intended for use in applications that manage
4250 ** both their own internal database and also databases that are controlled
4251 ** by untrusted external sources. An example application might be a
4252 ** web browser that has its own databases for storing history and
4253 ** separate databases controlled by JavaScript applications downloaded
4254 ** off the Internet. The internal databases can be given the
4255 ** large, default limits. Databases managed by external sources can
4256 ** be given much smaller limits designed to prevent a denial of service
4257 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4258 ** interface to further control untrusted SQL. The size of the database
4259 ** created by an untrusted script can be contained using the
4260 ** [max_page_count] [PRAGMA].
4261 **
4262 ** New run-time limit categories may be added in future releases.
4263 */
4264 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4265
4266 /*
4267 ** CAPI3REF: Run-Time Limit Categories
4268 ** KEYWORDS: {limit category} {*limit categories}
4269 **
4270 ** These constants define various performance limits
4271 ** that can be lowered at run-time using [sqlite3_limit()].
4272 ** The synopsis of the meanings of the various limits is shown below.
4273 ** Additional information is available at [limits | Limits in SQLite].
4274 **
4275 ** <dl>
4276 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4277 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4278 **
4279 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4280 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4281 **
4282 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4283 ** <dd>The maximum number of columns in a table definition or in the
4284 ** result set of a [SELECT] or the maximum number of columns in an index
4285 ** or in an ORDER BY or GROUP BY clause.</dd>)^
4286 **
4287 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4288 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4289 **
4290 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4291 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4292 **
4293 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4294 ** <dd>The maximum number of instructions in a virtual machine program
4295 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4296 ** the equivalent tries to allocate space for more than this many opcodes
4297 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4298 **
4299 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4300 ** <dd>The maximum number of arguments on a function.</dd>)^
4301 **
4302 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4303 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4304 **
4305 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4306 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4307 ** <dd>The maximum length of the pattern argument to the [LIKE] or
4308 ** [GLOB] operators.</dd>)^
4309 **
4310 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4311 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4312 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4313 **
4314 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4315 ** <dd>The maximum depth of recursion for triggers.</dd>)^
4316 **
4317 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4318 ** <dd>The maximum number of auxiliary worker threads that a single
4319 ** [prepared statement] may start.</dd>)^
4320 ** </dl>
4321 */
4322 #define SQLITE_LIMIT_LENGTH 0
4323 #define SQLITE_LIMIT_SQL_LENGTH 1
4324 #define SQLITE_LIMIT_COLUMN 2
4325 #define SQLITE_LIMIT_EXPR_DEPTH 3
4326 #define SQLITE_LIMIT_COMPOUND_SELECT 4
4327 #define SQLITE_LIMIT_VDBE_OP 5
4328 #define SQLITE_LIMIT_FUNCTION_ARG 6
4329 #define SQLITE_LIMIT_ATTACHED 7
4330 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4331 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
4332 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
4333 #define SQLITE_LIMIT_WORKER_THREADS 11
4334
4335 /*
4336 ** CAPI3REF: Prepare Flags
4337 **
4338 ** These constants define various flags that can be passed into
4339 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4340 ** [sqlite3_prepare16_v3()] interfaces.
4341 **
4342 ** New flags may be added in future releases of SQLite.
4343 **
4344 ** <dl>
4345 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4346 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4347 ** that the prepared statement will be retained for a long time and
4348 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4349 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4350 ** be used just once or at most a few times and then destroyed using
4351 ** [sqlite3_finalize()] relatively soon. The current implementation acts
4352 ** on this hint by avoiding the use of [lookaside memory] so as not to
4353 ** deplete the limited store of lookaside memory. Future versions of
4354 ** SQLite may act on this hint differently.
4355 **
4356 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4357 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4358 ** to be required for any prepared statement that wanted to use the
4359 ** [sqlite3_normalized_sql()] interface. However, the
4360 ** [sqlite3_normalized_sql()] interface is now available to all
4361 ** prepared statements, regardless of whether or not they use this
4362 ** flag.
4363 **
4364 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4365 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4366 ** to return an error (error code SQLITE_ERROR) if the statement uses
4367 ** any virtual tables.
4368 **
4369 ** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt>
4370 ** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler
4371 ** errors from being sent to the error log defined by
4372 ** [SQLITE_CONFIG_LOG]. This can be used, for example, to do test
4373 ** compiles to see if some SQL syntax is well-formed, without generating
4374 ** messages on the global error log when it is not. If the test compile
4375 ** fails, the sqlite3_prepare_v3() call returns the same error indications
4376 ** with or without this flag; it just omits the call to [sqlite3_log()] that
4377 ** logs the error.
4378 ** </dl>
4379 */
4380 #define SQLITE_PREPARE_PERSISTENT 0x01
4381 #define SQLITE_PREPARE_NORMALIZE 0x02
4382 #define SQLITE_PREPARE_NO_VTAB 0x04
4383 #define SQLITE_PREPARE_DONT_LOG 0x10
4384
4385 /*
4386 ** CAPI3REF: Compiling An SQL Statement
4387 ** KEYWORDS: {SQL statement compiler}
4388 ** METHOD: sqlite3
4389 ** CONSTRUCTOR: sqlite3_stmt
4390 **
4391 ** To execute an SQL statement, it must first be compiled into a byte-code
4392 ** program using one of these routines. Or, in other words, these routines
4393 ** are constructors for the [prepared statement] object.
4394 **
4395 ** The preferred routine to use is [sqlite3_prepare_v2()]. The
4396 ** [sqlite3_prepare()] interface is legacy and should be avoided.
4397 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4398 ** for special purposes.
4399 **
4400 ** The use of the UTF-8 interfaces is preferred, as SQLite currently
4401 ** does all parsing using UTF-8. The UTF-16 interfaces are provided
4402 ** as a convenience. The UTF-16 interfaces work by converting the
4403 ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4404 **
4405 ** The first argument, "db", is a [database connection] obtained from a
4406 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4407 ** [sqlite3_open16()]. The database connection must not have been closed.
4408 **
4409 ** The second argument, "zSql", is the statement to be compiled, encoded
4410 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4411 ** and sqlite3_prepare_v3()
4412 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4413 ** and sqlite3_prepare16_v3() use UTF-16.
4414 **
4415 ** ^If the nByte argument is negative, then zSql is read up to the
4416 ** first zero terminator. ^If nByte is positive, then it is the maximum
4417 ** number of bytes read from zSql. When nByte is positive, zSql is read
4418 ** up to the first zero terminator or until the nByte bytes have been read,
4419 ** whichever comes first. ^If nByte is zero, then no prepared
4420 ** statement is generated.
4421 ** If the caller knows that the supplied string is nul-terminated, then
4422 ** there is a small performance advantage to passing an nByte parameter that
4423 ** is the number of bytes in the input string <i>including</i>
4424 ** the nul-terminator.
4425 ** Note that nByte measure the length of the input in bytes, not
4426 ** characters, even for the UTF-16 interfaces.
4427 **
4428 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4429 ** past the end of the first SQL statement in zSql. These routines only
4430 ** compile the first statement in zSql, so *pzTail is left pointing to
4431 ** what remains uncompiled.
4432 **
4433 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4434 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4435 ** to NULL. ^If the input text contains no SQL (if the input is an empty
4436 ** string or a comment) then *ppStmt is set to NULL.
4437 ** The calling procedure is responsible for deleting the compiled
4438 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
4439 ** ppStmt may not be NULL.
4440 **
4441 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4442 ** otherwise an [error code] is returned.
4443 **
4444 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4445 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4446 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4447 ** are retained for backwards compatibility, but their use is discouraged.
4448 ** ^In the "vX" interfaces, the prepared statement
4449 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
4450 ** original SQL text. This causes the [sqlite3_step()] interface to
4451 ** behave differently in three ways:
4452 **
4453 ** <ol>
4454 ** <li>
4455 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4456 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
4457 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4458 ** retries will occur before sqlite3_step() gives up and returns an error.
4459 ** </li>
4460 **
4461 ** <li>
4462 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4463 ** [error codes] or [extended error codes]. ^The legacy behavior was that
4464 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4465 ** and the application would have to make a second call to [sqlite3_reset()]
4466 ** in order to find the underlying cause of the problem. With the "v2" prepare
4467 ** interfaces, the underlying reason for the error is returned immediately.
4468 ** </li>
4469 **
4470 ** <li>
4471 ** ^If the specific value bound to a [parameter | host parameter] in the
4472 ** WHERE clause might influence the choice of query plan for a statement,
4473 ** then the statement will be automatically recompiled, as if there had been
4474 ** a schema change, on the first [sqlite3_step()] call following any change
4475 ** to the [sqlite3_bind_text | bindings] of that [parameter].
4476 ** ^The specific value of a WHERE-clause [parameter] might influence the
4477 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
4478 ** or [GLOB] operator or if the parameter is compared to an indexed column
4479 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4480 ** </li>
4481 ** </ol>
4482 **
4483 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4484 ** the extra prepFlags parameter, which is a bit array consisting of zero or
4485 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4486 ** sqlite3_prepare_v2() interface works exactly the same as
4487 ** sqlite3_prepare_v3() with a zero prepFlags parameter.
4488 */
4489 SQLITE_API int sqlite3_prepare(
4490 sqlite3 *db, /* Database handle */
4491 const char *zSql, /* SQL statement, UTF-8 encoded */
4492 int nByte, /* Maximum length of zSql in bytes. */
4493 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4494 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4495 );
4496 SQLITE_API int sqlite3_prepare_v2(
4497 sqlite3 *db, /* Database handle */
4498 const char *zSql, /* SQL statement, UTF-8 encoded */
4499 int nByte, /* Maximum length of zSql in bytes. */
4500 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4501 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4502 );
4503 SQLITE_API int sqlite3_prepare_v3(
4504 sqlite3 *db, /* Database handle */
4505 const char *zSql, /* SQL statement, UTF-8 encoded */
4506 int nByte, /* Maximum length of zSql in bytes. */
4507 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4508 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4509 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4510 );
4511 SQLITE_API int sqlite3_prepare16(
4512 sqlite3 *db, /* Database handle */
4513 const void *zSql, /* SQL statement, UTF-16 encoded */
4514 int nByte, /* Maximum length of zSql in bytes. */
4515 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4516 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4517 );
4518 SQLITE_API int sqlite3_prepare16_v2(
4519 sqlite3 *db, /* Database handle */
4520 const void *zSql, /* SQL statement, UTF-16 encoded */
4521 int nByte, /* Maximum length of zSql in bytes. */
4522 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4523 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4524 );
4525 SQLITE_API int sqlite3_prepare16_v3(
4526 sqlite3 *db, /* Database handle */
4527 const void *zSql, /* SQL statement, UTF-16 encoded */
4528 int nByte, /* Maximum length of zSql in bytes. */
4529 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4530 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4531 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4532 );
4533
4534 /*
4535 ** CAPI3REF: Retrieving Statement SQL
4536 ** METHOD: sqlite3_stmt
4537 **
4538 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4539 ** SQL text used to create [prepared statement] P if P was
4540 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4541 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4542 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4543 ** string containing the SQL text of prepared statement P with
4544 ** [bound parameters] expanded.
4545 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4546 ** string containing the normalized SQL text of prepared statement P. The
4547 ** semantics used to normalize a SQL statement are unspecified and subject
4548 ** to change. At a minimum, literal values will be replaced with suitable
4549 ** placeholders.
4550 **
4551 ** ^(For example, if a prepared statement is created using the SQL
4552 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4553 ** and parameter :xyz is unbound, then sqlite3_sql() will return
4554 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4555 ** will return "SELECT 2345,NULL".)^
4556 **
4557 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4558 ** is available to hold the result, or if the result would exceed the
4559 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4560 **
4561 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4562 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4563 ** option causes sqlite3_expanded_sql() to always return NULL.
4564 **
4565 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4566 ** are managed by SQLite and are automatically freed when the prepared
4567 ** statement is finalized.
4568 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4569 ** is obtained from [sqlite3_malloc()] and must be freed by the application
4570 ** by passing it to [sqlite3_free()].
4571 **
4572 ** ^The sqlite3_normalized_sql() interface is only available if
4573 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4574 */
4575 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4576 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4577 #ifdef SQLITE_ENABLE_NORMALIZE
4578 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4579 #endif
4580
4581 /*
4582 ** CAPI3REF: Determine If An SQL Statement Writes The Database
4583 ** METHOD: sqlite3_stmt
4584 **
4585 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4586 ** and only if the [prepared statement] X makes no direct changes to
4587 ** the content of the database file.
4588 **
4589 ** Note that [application-defined SQL functions] or
4590 ** [virtual tables] might change the database indirectly as a side effect.
4591 ** ^(For example, if an application defines a function "eval()" that
4592 ** calls [sqlite3_exec()], then the following SQL statement would
4593 ** change the database file through side-effects:
4594 **
4595 ** <blockquote><pre>
4596 ** SELECT eval('DELETE FROM t1') FROM t2;
4597 ** </pre></blockquote>
4598 **
4599 ** But because the [SELECT] statement does not change the database file
4600 ** directly, sqlite3_stmt_readonly() would still return true.)^
4601 **
4602 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4603 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4604 ** since the statements themselves do not actually modify the database but
4605 ** rather they control the timing of when other statements modify the
4606 ** database. ^The [ATTACH] and [DETACH] statements also cause
4607 ** sqlite3_stmt_readonly() to return true since, while those statements
4608 ** change the configuration of a database connection, they do not make
4609 ** changes to the content of the database files on disk.
4610 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4611 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4612 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4613 ** sqlite3_stmt_readonly() returns false for those commands.
4614 **
4615 ** ^This routine returns false if there is any possibility that the
4616 ** statement might change the database file. ^A false return does
4617 ** not guarantee that the statement will change the database file.
4618 ** ^For example, an UPDATE statement might have a WHERE clause that
4619 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4620 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4621 ** read-only no-op if the table already exists, but
4622 ** sqlite3_stmt_readonly() still returns false for such a statement.
4623 **
4624 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4625 ** statement, then sqlite3_stmt_readonly(X) returns the same value as
4626 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4627 */
4628 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4629
4630 /*
4631 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4632 ** METHOD: sqlite3_stmt
4633 **
4634 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4635 ** prepared statement S is an EXPLAIN statement, or 2 if the
4636 ** statement S is an EXPLAIN QUERY PLAN.
4637 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4638 ** an ordinary statement or a NULL pointer.
4639 */
4640 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4641
4642 /*
4643 ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4644 ** METHOD: sqlite3_stmt
4645 **
4646 ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4647 ** setting for [prepared statement] S. If E is zero, then S becomes
4648 ** a normal prepared statement. If E is 1, then S behaves as if
4649 ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4650 ** its SQL text began with "[EXPLAIN QUERY PLAN]".
4651 **
4652 ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4653 ** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4654 ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4655 **
4656 ** Because of the potential need to reprepare, a call to
4657 ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4658 ** reprepared because it was created using [sqlite3_prepare()] instead of
4659 ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4660 ** hence has no saved SQL text with which to reprepare.
4661 **
4662 ** Changing the explain setting for a prepared statement does not change
4663 ** the original SQL text for the statement. Hence, if the SQL text originally
4664 ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4665 ** is called to convert the statement into an ordinary statement, the EXPLAIN
4666 ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4667 ** output, even though the statement now acts like a normal SQL statement.
4668 **
4669 ** This routine returns SQLITE_OK if the explain mode is successfully
4670 ** changed, or an error code if the explain mode could not be changed.
4671 ** The explain mode cannot be changed while a statement is active.
4672 ** Hence, it is good practice to call [sqlite3_reset(S)]
4673 ** immediately prior to calling sqlite3_stmt_explain(S,E).
4674 */
4675 SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4676
4677 /*
4678 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4679 ** METHOD: sqlite3_stmt
4680 **
4681 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4682 ** [prepared statement] S has been stepped at least once using
4683 ** [sqlite3_step(S)] but has neither run to completion (returned
4684 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4685 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4686 ** interface returns false if S is a NULL pointer. If S is not a
4687 ** NULL pointer and is not a pointer to a valid [prepared statement]
4688 ** object, then the behavior is undefined and probably undesirable.
4689 **
4690 ** This interface can be used in combination [sqlite3_next_stmt()]
4691 ** to locate all prepared statements associated with a database
4692 ** connection that are in need of being reset. This can be used,
4693 ** for example, in diagnostic routines to search for prepared
4694 ** statements that are holding a transaction open.
4695 */
4696 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4697
4698 /*
4699 ** CAPI3REF: Dynamically Typed Value Object
4700 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4701 **
4702 ** SQLite uses the sqlite3_value object to represent all values
4703 ** that can be stored in a database table. SQLite uses dynamic typing
4704 ** for the values it stores. ^Values stored in sqlite3_value objects
4705 ** can be integers, floating point values, strings, BLOBs, or NULL.
4706 **
4707 ** An sqlite3_value object may be either "protected" or "unprotected".
4708 ** Some interfaces require a protected sqlite3_value. Other interfaces
4709 ** will accept either a protected or an unprotected sqlite3_value.
4710 ** Every interface that accepts sqlite3_value arguments specifies
4711 ** whether or not it requires a protected sqlite3_value. The
4712 ** [sqlite3_value_dup()] interface can be used to construct a new
4713 ** protected sqlite3_value from an unprotected sqlite3_value.
4714 **
4715 ** The terms "protected" and "unprotected" refer to whether or not
4716 ** a mutex is held. An internal mutex is held for a protected
4717 ** sqlite3_value object but no mutex is held for an unprotected
4718 ** sqlite3_value object. If SQLite is compiled to be single-threaded
4719 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4720 ** or if SQLite is run in one of reduced mutex modes
4721 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4722 ** then there is no distinction between protected and unprotected
4723 ** sqlite3_value objects and they can be used interchangeably. However,
4724 ** for maximum code portability it is recommended that applications
4725 ** still make the distinction between protected and unprotected
4726 ** sqlite3_value objects even when not strictly required.
4727 **
4728 ** ^The sqlite3_value objects that are passed as parameters into the
4729 ** implementation of [application-defined SQL functions] are protected.
4730 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4731 ** are protected.
4732 ** ^The sqlite3_value object returned by
4733 ** [sqlite3_column_value()] is unprotected.
4734 ** Unprotected sqlite3_value objects may only be used as arguments
4735 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4736 ** [sqlite3_value_dup()].
4737 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
4738 ** interfaces require protected sqlite3_value objects.
4739 */
4740 typedef struct sqlite3_value sqlite3_value;
4741
4742 /*
4743 ** CAPI3REF: SQL Function Context Object
4744 **
4745 ** The context in which an SQL function executes is stored in an
4746 ** sqlite3_context object. ^A pointer to an sqlite3_context object
4747 ** is always first parameter to [application-defined SQL functions].
4748 ** The application-defined SQL function implementation will pass this
4749 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4750 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4751 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4752 ** and/or [sqlite3_set_auxdata()].
4753 */
4754 typedef struct sqlite3_context sqlite3_context;
4755
4756 /*
4757 ** CAPI3REF: Binding Values To Prepared Statements
4758 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4759 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4760 ** METHOD: sqlite3_stmt
4761 **
4762 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4763 ** literals may be replaced by a [parameter] that matches one of the following
4764 ** templates:
4765 **
4766 ** <ul>
4767 ** <li> ?
4768 ** <li> ?NNN
4769 ** <li> :VVV
4770 ** <li> @VVV
4771 ** <li> $VVV
4772 ** </ul>
4773 **
4774 ** In the templates above, NNN represents an integer literal,
4775 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
4776 ** parameters (also called "host parameter names" or "SQL parameters")
4777 ** can be set using the sqlite3_bind_*() routines defined here.
4778 **
4779 ** ^The first argument to the sqlite3_bind_*() routines is always
4780 ** a pointer to the [sqlite3_stmt] object returned from
4781 ** [sqlite3_prepare_v2()] or its variants.
4782 **
4783 ** ^The second argument is the index of the SQL parameter to be set.
4784 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
4785 ** SQL parameter is used more than once, second and subsequent
4786 ** occurrences have the same index as the first occurrence.
4787 ** ^The index for named parameters can be looked up using the
4788 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
4789 ** for "?NNN" parameters is the value of NNN.
4790 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
4791 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4792 **
4793 ** ^The third argument is the value to bind to the parameter.
4794 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4795 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4796 ** is ignored and the end result is the same as sqlite3_bind_null().
4797 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4798 ** it should be a pointer to well-formed UTF8 text.
4799 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4800 ** it should be a pointer to well-formed UTF16 text.
4801 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4802 ** it should be a pointer to a well-formed unicode string that is
4803 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4804 ** otherwise.
4805 **
4806 ** [[byte-order determination rules]] ^The byte-order of
4807 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4808 ** found in the first character, which is removed, or in the absence of a BOM
4809 ** the byte order is the native byte order of the host
4810 ** machine for sqlite3_bind_text16() or the byte order specified in
4811 ** the 6th parameter for sqlite3_bind_text64().)^
4812 ** ^If UTF16 input text contains invalid unicode
4813 ** characters, then SQLite might change those invalid characters
4814 ** into the unicode replacement character: U+FFFD.
4815 **
4816 ** ^(In those routines that have a fourth argument, its value is the
4817 ** number of bytes in the parameter. To be clear: the value is the
4818 ** number of <u>bytes</u> in the value, not the number of characters.)^
4819 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4820 ** is negative, then the length of the string is
4821 ** the number of bytes up to the first zero terminator.
4822 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
4823 ** the behavior is undefined.
4824 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4825 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4826 ** that parameter must be the byte offset
4827 ** where the NUL terminator would occur assuming the string were NUL
4828 ** terminated. If any NUL characters occur at byte offsets less than
4829 ** the value of the fourth parameter then the resulting string value will
4830 ** contain embedded NULs. The result of expressions involving strings
4831 ** with embedded NULs is undefined.
4832 **
4833 ** ^The fifth argument to the BLOB and string binding interfaces controls
4834 ** or indicates the lifetime of the object referenced by the third parameter.
4835 ** These three options exist:
4836 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4837 ** with it may be passed. ^It is called to dispose of the BLOB or string even
4838 ** if the call to the bind API fails, except the destructor is not called if
4839 ** the third parameter is a NULL pointer or the fourth parameter is negative.
4840 ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4841 ** the application remains responsible for disposing of the object. ^In this
4842 ** case, the object and the provided pointer to it must remain valid until
4843 ** either the prepared statement is finalized or the same SQL parameter is
4844 ** bound to something else, whichever occurs sooner.
4845 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4846 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4847 ** object and pointer to it must remain valid until then. ^SQLite will then
4848 ** manage the lifetime of its private copy.
4849 **
4850 ** ^The sixth argument to sqlite3_bind_text64() must be one of
4851 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4852 ** to specify the encoding of the text in the third parameter. If
4853 ** the sixth argument to sqlite3_bind_text64() is not one of the
4854 ** allowed values shown above, or if the text encoding is different
4855 ** from the encoding specified by the sixth parameter, then the behavior
4856 ** is undefined.
4857 **
4858 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4859 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4860 ** (just an integer to hold its size) while it is being processed.
4861 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
4862 ** content is later written using
4863 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
4864 ** ^A negative value for the zeroblob results in a zero-length BLOB.
4865 **
4866 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4867 ** [prepared statement] S to have an SQL value of NULL, but to also be
4868 ** associated with the pointer P of type T. ^D is either a NULL pointer or
4869 ** a pointer to a destructor function for P. ^SQLite will invoke the
4870 ** destructor D with a single argument of P when it is finished using
4871 ** P. The T parameter should be a static string, preferably a string
4872 ** literal. The sqlite3_bind_pointer() routine is part of the
4873 ** [pointer passing interface] added for SQLite 3.20.0.
4874 **
4875 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4876 ** for the [prepared statement] or with a prepared statement for which
4877 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4878 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4879 ** routine is passed a [prepared statement] that has been finalized, the
4880 ** result is undefined and probably harmful.
4881 **
4882 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4883 ** ^Unbound parameters are interpreted as NULL.
4884 **
4885 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4886 ** [error code] if anything goes wrong.
4887 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4888 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4889 ** [SQLITE_MAX_LENGTH].
4890 ** ^[SQLITE_RANGE] is returned if the parameter
4891 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4892 **
4893 ** See also: [sqlite3_bind_parameter_count()],
4894 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4895 */
4896 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4897 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4898 void(*)(void*));
4899 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4900 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4901 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4902 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4903 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4904 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4905 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4906 void(*)(void*), unsigned char encoding);
4907 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4908 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4909 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4910 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4911
4912 /*
4913 ** CAPI3REF: Number Of SQL Parameters
4914 ** METHOD: sqlite3_stmt
4915 **
4916 ** ^This routine can be used to find the number of [SQL parameters]
4917 ** in a [prepared statement]. SQL parameters are tokens of the
4918 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4919 ** placeholders for values that are [sqlite3_bind_blob | bound]
4920 ** to the parameters at a later time.
4921 **
4922 ** ^(This routine actually returns the index of the largest (rightmost)
4923 ** parameter. For all forms except ?NNN, this will correspond to the
4924 ** number of unique parameters. If parameters of the ?NNN form are used,
4925 ** there may be gaps in the list.)^
4926 **
4927 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4928 ** [sqlite3_bind_parameter_name()], and
4929 ** [sqlite3_bind_parameter_index()].
4930 */
4931 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4932
4933 /*
4934 ** CAPI3REF: Name Of A Host Parameter
4935 ** METHOD: sqlite3_stmt
4936 **
4937 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
4938 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
4939 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4940 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4941 ** respectively.
4942 ** In other words, the initial ":" or "$" or "@" or "?"
4943 ** is included as part of the name.)^
4944 ** ^Parameters of the form "?" without a following integer have no name
4945 ** and are referred to as "nameless" or "anonymous parameters".
4946 **
4947 ** ^The first host parameter has an index of 1, not 0.
4948 **
4949 ** ^If the value N is out of range or if the N-th parameter is
4950 ** nameless, then NULL is returned. ^The returned string is
4951 ** always in UTF-8 encoding even if the named parameter was
4952 ** originally specified as UTF-16 in [sqlite3_prepare16()],
4953 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4954 **
4955 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4956 ** [sqlite3_bind_parameter_count()], and
4957 ** [sqlite3_bind_parameter_index()].
4958 */
4959 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4960
4961 /*
4962 ** CAPI3REF: Index Of A Parameter With A Given Name
4963 ** METHOD: sqlite3_stmt
4964 **
4965 ** ^Return the index of an SQL parameter given its name. ^The
4966 ** index value returned is suitable for use as the second
4967 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4968 ** is returned if no matching parameter is found. ^The parameter
4969 ** name must be given in UTF-8 even if the original statement
4970 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4971 ** [sqlite3_prepare16_v3()].
4972 **
4973 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4974 ** [sqlite3_bind_parameter_count()], and
4975 ** [sqlite3_bind_parameter_name()].
4976 */
4977 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4978
4979 /*
4980 ** CAPI3REF: Reset All Bindings On A Prepared Statement
4981 ** METHOD: sqlite3_stmt
4982 **
4983 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4984 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4985 ** ^Use this routine to reset all host parameters to NULL.
4986 */
4987 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4988
4989 /*
4990 ** CAPI3REF: Number Of Columns In A Result Set
4991 ** METHOD: sqlite3_stmt
4992 **
4993 ** ^Return the number of columns in the result set returned by the
4994 ** [prepared statement]. ^If this routine returns 0, that means the
4995 ** [prepared statement] returns no data (for example an [UPDATE]).
4996 ** ^However, just because this routine returns a positive number does not
4997 ** mean that one or more rows of data will be returned. ^A SELECT statement
4998 ** will always have a positive sqlite3_column_count() but depending on the
4999 ** WHERE clause constraints and the table content, it might return no rows.
5000 **
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