1 /* 2 ** 2001 September 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 ** Provide the ability to override linkage features of the interface. 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 #ifndef SQLITE_API 52 # define SQLITE_API 53 #endif 54 #ifndef SQLITE_CDECL 55 # define SQLITE_CDECL 56 #endif 57 #ifndef SQLITE_APICALL 58 # define SQLITE_APICALL 59 #endif 60 #ifndef SQLITE_STDCALL 61 # define SQLITE_STDCALL SQLITE_APICALL 62 #endif 63 #ifndef SQLITE_CALLBACK 64 # define SQLITE_CALLBACK 65 #endif 66 #ifndef SQLITE_SYSAPI 67 # define SQLITE_SYSAPI 68 #endif 69 70 /* 71 ** These no-op macros are used in front of interfaces to mark those 72 ** interfaces as either deprecated or experimental. New applications 73 ** should not use deprecated interfaces - they are supported for backwards 74 ** compatibility only. Application writers should be aware that 75 ** experimental interfaces are subject to change in point releases. 76 ** 77 ** These macros used to resolve to various kinds of compiler magic that 78 ** would generate warning messages when they were used. But that 79 ** compiler magic ended up generating such a flurry of bug reports 80 ** that we have taken it all out and gone back to using simple 81 ** noop macros. 82 */ 83 #define SQLITE_DEPRECATED 84 #define SQLITE_EXPERIMENTAL 85 86 /* 87 ** Ensure these symbols were not defined by some previous header file. 88 */ 89 #ifdef SQLITE_VERSION 90 # undef SQLITE_VERSION 91 #endif 92 #ifdef SQLITE_VERSION_NUMBER 93 # undef SQLITE_VERSION_NUMBER 94 #endif 95 96 /* 97 ** CAPI3REF: Compile-Time Library Version Numbers 98 ** 99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100 ** evaluates to a string literal that is the SQLite version in the 101 ** format "X.Y.Z" where X is the major version number (always 3 for 102 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105 ** numbers used in [SQLITE_VERSION].)^ 106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107 ** be larger than the release from which it is derived. Either Y will 108 ** be held constant and Z will be incremented or else Y will be incremented 109 ** and Z will be reset to zero. 110 ** 111 ** Since version 3.6.18, SQLite source code has been stored in the 112 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 113 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 114 ** a string which identifies a particular check-in of SQLite 115 ** within its configuration management system. ^The SQLITE_SOURCE_ID 116 ** string contains the date and time of the check-in (UTC) and an SHA1 117 ** hash of the entire source tree. 118 ** 119 ** See also: [sqlite3_libversion()], 120 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 121 ** [sqlite_version()] and [sqlite_source_id()]. 122 */ 123 #define SQLITE_VERSION "3.14.1" 124 #define SQLITE_VERSION_NUMBER 3014001 125 #define SQLITE_SOURCE_ID "2016-08-11 18:53:32 a12d8059770df4bca59e321c266410344242bf7b" 126 127 /* 128 ** CAPI3REF: Run-Time Library Version Numbers 129 ** KEYWORDS: sqlite3_version, sqlite3_sourceid 130 ** 131 ** These interfaces provide the same information as the [SQLITE_VERSION], 132 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 133 ** but are associated with the library instead of the header file. ^(Cautious 134 ** programmers might include assert() statements in their application to 135 ** verify that values returned by these interfaces match the macros in 136 ** the header, and thus ensure that the application is 137 ** compiled with matching library and header files. 138 ** 139 ** <blockquote><pre> 140 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 141 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 142 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 143 ** </pre></blockquote>)^ 144 ** 145 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 146 ** macro. ^The sqlite3_libversion() function returns a pointer to the 147 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 148 ** function is provided for use in DLLs since DLL users usually do not have 149 ** direct access to string constants within the DLL. ^The 150 ** sqlite3_libversion_number() function returns an integer equal to 151 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 152 ** a pointer to a string constant whose value is the same as the 153 ** [SQLITE_SOURCE_ID] C preprocessor macro. 154 ** 155 ** See also: [sqlite_version()] and [sqlite_source_id()]. 156 */ 157 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 158 SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void); 159 SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void); 160 SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void); 161 162 /* 163 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 164 ** 165 ** ^The sqlite3_compileoption_used() function returns 0 or 1 166 ** indicating whether the specified option was defined at 167 ** compile time. ^The SQLITE_ prefix may be omitted from the 168 ** option name passed to sqlite3_compileoption_used(). 169 ** 170 ** ^The sqlite3_compileoption_get() function allows iterating 171 ** over the list of options that were defined at compile time by 172 ** returning the N-th compile time option string. ^If N is out of range, 173 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 174 ** prefix is omitted from any strings returned by 175 ** sqlite3_compileoption_get(). 176 ** 177 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 178 ** and sqlite3_compileoption_get() may be omitted by specifying the 179 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 180 ** 181 ** See also: SQL functions [sqlite_compileoption_used()] and 182 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 183 */ 184 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 185 SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName); 186 SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N); 187 #endif 188 189 /* 190 ** CAPI3REF: Test To See If The Library Is Threadsafe 191 ** 192 ** ^The sqlite3_threadsafe() function returns zero if and only if 193 ** SQLite was compiled with mutexing code omitted due to the 194 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 195 ** 196 ** SQLite can be compiled with or without mutexes. When 197 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 198 ** are enabled and SQLite is threadsafe. When the 199 ** [SQLITE_THREADSAFE] macro is 0, 200 ** the mutexes are omitted. Without the mutexes, it is not safe 201 ** to use SQLite concurrently from more than one thread. 202 ** 203 ** Enabling mutexes incurs a measurable performance penalty. 204 ** So if speed is of utmost importance, it makes sense to disable 205 ** the mutexes. But for maximum safety, mutexes should be enabled. 206 ** ^The default behavior is for mutexes to be enabled. 207 ** 208 ** This interface can be used by an application to make sure that the 209 ** version of SQLite that it is linking against was compiled with 210 ** the desired setting of the [SQLITE_THREADSAFE] macro. 211 ** 212 ** This interface only reports on the compile-time mutex setting 213 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 214 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 215 ** can be fully or partially disabled using a call to [sqlite3_config()] 216 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 217 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 218 ** sqlite3_threadsafe() function shows only the compile-time setting of 219 ** thread safety, not any run-time changes to that setting made by 220 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 221 ** is unchanged by calls to sqlite3_config().)^ 222 ** 223 ** See the [threading mode] documentation for additional information. 224 */ 225 SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void); 226 227 /* 228 ** CAPI3REF: Database Connection Handle 229 ** KEYWORDS: {database connection} {database connections} 230 ** 231 ** Each open SQLite database is represented by a pointer to an instance of 232 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 233 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 234 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 235 ** and [sqlite3_close_v2()] are its destructors. There are many other 236 ** interfaces (such as 237 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 238 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 239 ** sqlite3 object. 240 */ 241 typedef struct sqlite3 sqlite3; 242 243 /* 244 ** CAPI3REF: 64-Bit Integer Types 245 ** KEYWORDS: sqlite_int64 sqlite_uint64 246 ** 247 ** Because there is no cross-platform way to specify 64-bit integer types 248 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 249 ** 250 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 251 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 252 ** compatibility only. 253 ** 254 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 255 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 256 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 257 ** between 0 and +18446744073709551615 inclusive. 258 */ 259 #ifdef SQLITE_INT64_TYPE 260 typedef SQLITE_INT64_TYPE sqlite_int64; 261 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 262 #elif defined(_MSC_VER) || defined(__BORLANDC__) 263 typedef __int64 sqlite_int64; 264 typedef unsigned __int64 sqlite_uint64; 265 #else 266 typedef long long int sqlite_int64; 267 typedef unsigned long long int sqlite_uint64; 268 #endif 269 typedef sqlite_int64 sqlite3_int64; 270 typedef sqlite_uint64 sqlite3_uint64; 271 272 /* 273 ** If compiling for a processor that lacks floating point support, 274 ** substitute integer for floating-point. 275 */ 276 #ifdef SQLITE_OMIT_FLOATING_POINT 277 # define double sqlite3_int64 278 #endif 279 280 /* 281 ** CAPI3REF: Closing A Database Connection 282 ** DESTRUCTOR: sqlite3 283 ** 284 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 285 ** for the [sqlite3] object. 286 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 287 ** the [sqlite3] object is successfully destroyed and all associated 288 ** resources are deallocated. 289 ** 290 ** ^If the database connection is associated with unfinalized prepared 291 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 292 ** will leave the database connection open and return [SQLITE_BUSY]. 293 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 294 ** and/or unfinished sqlite3_backups, then the database connection becomes 295 ** an unusable "zombie" which will automatically be deallocated when the 296 ** last prepared statement is finalized or the last sqlite3_backup is 297 ** finished. The sqlite3_close_v2() interface is intended for use with 298 ** host languages that are garbage collected, and where the order in which 299 ** destructors are called is arbitrary. 300 ** 301 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 302 ** [sqlite3_blob_close | close] all [BLOB handles], and 303 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 304 ** with the [sqlite3] object prior to attempting to close the object. ^If 305 ** sqlite3_close_v2() is called on a [database connection] that still has 306 ** outstanding [prepared statements], [BLOB handles], and/or 307 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 308 ** of resources is deferred until all [prepared statements], [BLOB handles], 309 ** and [sqlite3_backup] objects are also destroyed. 310 ** 311 ** ^If an [sqlite3] object is destroyed while a transaction is open, 312 ** the transaction is automatically rolled back. 313 ** 314 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 315 ** must be either a NULL 316 ** pointer or an [sqlite3] object pointer obtained 317 ** from [sqlite3_open()], [sqlite3_open16()], or 318 ** [sqlite3_open_v2()], and not previously closed. 319 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 320 ** argument is a harmless no-op. 321 */ 322 SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*); 323 SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*); 324 325 /* 326 ** The type for a callback function. 327 ** This is legacy and deprecated. It is included for historical 328 ** compatibility and is not documented. 329 */ 330 typedef int (*sqlite3_callback)(void*,int,char**, char**); 331 332 /* 333 ** CAPI3REF: One-Step Query Execution Interface 334 ** METHOD: sqlite3 335 ** 336 ** The sqlite3_exec() interface is a convenience wrapper around 337 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 338 ** that allows an application to run multiple statements of SQL 339 ** without having to use a lot of C code. 340 ** 341 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 342 ** semicolon-separate SQL statements passed into its 2nd argument, 343 ** in the context of the [database connection] passed in as its 1st 344 ** argument. ^If the callback function of the 3rd argument to 345 ** sqlite3_exec() is not NULL, then it is invoked for each result row 346 ** coming out of the evaluated SQL statements. ^The 4th argument to 347 ** sqlite3_exec() is relayed through to the 1st argument of each 348 ** callback invocation. ^If the callback pointer to sqlite3_exec() 349 ** is NULL, then no callback is ever invoked and result rows are 350 ** ignored. 351 ** 352 ** ^If an error occurs while evaluating the SQL statements passed into 353 ** sqlite3_exec(), then execution of the current statement stops and 354 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 355 ** is not NULL then any error message is written into memory obtained 356 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 357 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 358 ** on error message strings returned through the 5th parameter of 359 ** sqlite3_exec() after the error message string is no longer needed. 360 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 361 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 362 ** NULL before returning. 363 ** 364 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 365 ** routine returns SQLITE_ABORT without invoking the callback again and 366 ** without running any subsequent SQL statements. 367 ** 368 ** ^The 2nd argument to the sqlite3_exec() callback function is the 369 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 370 ** callback is an array of pointers to strings obtained as if from 371 ** [sqlite3_column_text()], one for each column. ^If an element of a 372 ** result row is NULL then the corresponding string pointer for the 373 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 374 ** sqlite3_exec() callback is an array of pointers to strings where each 375 ** entry represents the name of corresponding result column as obtained 376 ** from [sqlite3_column_name()]. 377 ** 378 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 379 ** to an empty string, or a pointer that contains only whitespace and/or 380 ** SQL comments, then no SQL statements are evaluated and the database 381 ** is not changed. 382 ** 383 ** Restrictions: 384 ** 385 ** <ul> 386 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 387 ** is a valid and open [database connection]. 388 ** <li> The application must not close the [database connection] specified by 389 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 390 ** <li> The application must not modify the SQL statement text passed into 391 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 392 ** </ul> 393 */ 394 SQLITE_API int SQLITE_STDCALL sqlite3_exec( 395 sqlite3*, /* An open database */ 396 const char *sql, /* SQL to be evaluated */ 397 int (*callback)(void*,int,char**,char**), /* Callback function */ 398 void *, /* 1st argument to callback */ 399 char **errmsg /* Error msg written here */ 400 ); 401 402 /* 403 ** CAPI3REF: Result Codes 404 ** KEYWORDS: {result code definitions} 405 ** 406 ** Many SQLite functions return an integer result code from the set shown 407 ** here in order to indicate success or failure. 408 ** 409 ** New error codes may be added in future versions of SQLite. 410 ** 411 ** See also: [extended result code definitions] 412 */ 413 #define SQLITE_OK 0 /* Successful result */ 414 /* beginning-of-error-codes */ 415 #define SQLITE_ERROR 1 /* SQL error or missing database */ 416 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 417 #define SQLITE_PERM 3 /* Access permission denied */ 418 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 419 #define SQLITE_BUSY 5 /* The database file is locked */ 420 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 421 #define SQLITE_NOMEM 7 /* A malloc() failed */ 422 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 423 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 424 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 425 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 426 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 427 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 428 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 429 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 430 #define SQLITE_EMPTY 16 /* Database is empty */ 431 #define SQLITE_SCHEMA 17 /* The database schema changed */ 432 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 433 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 434 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 435 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 436 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 437 #define SQLITE_AUTH 23 /* Authorization denied */ 438 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 439 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 440 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 441 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 442 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 443 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 444 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 445 /* end-of-error-codes */ 446 447 /* 448 ** CAPI3REF: Extended Result Codes 449 ** KEYWORDS: {extended result code definitions} 450 ** 451 ** In its default configuration, SQLite API routines return one of 30 integer 452 ** [result codes]. However, experience has shown that many of 453 ** these result codes are too coarse-grained. They do not provide as 454 ** much information about problems as programmers might like. In an effort to 455 ** address this, newer versions of SQLite (version 3.3.8 and later) include 456 ** support for additional result codes that provide more detailed information 457 ** about errors. These [extended result codes] are enabled or disabled 458 ** on a per database connection basis using the 459 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 460 ** the most recent error can be obtained using 461 ** [sqlite3_extended_errcode()]. 462 */ 463 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 464 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 465 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 466 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 467 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 468 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 469 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 470 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 471 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 472 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 473 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 474 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 475 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 476 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 477 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 478 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 479 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 480 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 481 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 482 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 483 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 484 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 485 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 486 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 487 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 488 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 489 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 490 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 491 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 492 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 493 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 494 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 495 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 496 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 497 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 498 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 499 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 500 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 501 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 502 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 503 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 504 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 505 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 506 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 507 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 508 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 509 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 510 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 511 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 512 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 513 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 514 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 515 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 516 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 517 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 518 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 519 520 /* 521 ** CAPI3REF: Flags For File Open Operations 522 ** 523 ** These bit values are intended for use in the 524 ** 3rd parameter to the [sqlite3_open_v2()] interface and 525 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 526 */ 527 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 528 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 529 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 530 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 531 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 532 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 533 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 534 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 535 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 536 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 537 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 538 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 539 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 540 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 541 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 542 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 543 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 544 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 545 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 546 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 547 548 /* Reserved: 0x00F00000 */ 549 550 /* 551 ** CAPI3REF: Device Characteristics 552 ** 553 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 554 ** object returns an integer which is a vector of these 555 ** bit values expressing I/O characteristics of the mass storage 556 ** device that holds the file that the [sqlite3_io_methods] 557 ** refers to. 558 ** 559 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 560 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 561 ** mean that writes of blocks that are nnn bytes in size and 562 ** are aligned to an address which is an integer multiple of 563 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 564 ** that when data is appended to a file, the data is appended 565 ** first then the size of the file is extended, never the other 566 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 567 ** information is written to disk in the same order as calls 568 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 569 ** after reboot following a crash or power loss, the only bytes in a 570 ** file that were written at the application level might have changed 571 ** and that adjacent bytes, even bytes within the same sector are 572 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 573 ** flag indicate that a file cannot be deleted when open. The 574 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 575 ** read-only media and cannot be changed even by processes with 576 ** elevated privileges. 577 */ 578 #define SQLITE_IOCAP_ATOMIC 0x00000001 579 #define SQLITE_IOCAP_ATOMIC512 0x00000002 580 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 581 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 582 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 583 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 584 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 585 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 586 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 587 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 588 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 589 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 590 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 591 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 592 593 /* 594 ** CAPI3REF: File Locking Levels 595 ** 596 ** SQLite uses one of these integer values as the second 597 ** argument to calls it makes to the xLock() and xUnlock() methods 598 ** of an [sqlite3_io_methods] object. 599 */ 600 #define SQLITE_LOCK_NONE 0 601 #define SQLITE_LOCK_SHARED 1 602 #define SQLITE_LOCK_RESERVED 2 603 #define SQLITE_LOCK_PENDING 3 604 #define SQLITE_LOCK_EXCLUSIVE 4 605 606 /* 607 ** CAPI3REF: Synchronization Type Flags 608 ** 609 ** When SQLite invokes the xSync() method of an 610 ** [sqlite3_io_methods] object it uses a combination of 611 ** these integer values as the second argument. 612 ** 613 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 614 ** sync operation only needs to flush data to mass storage. Inode 615 ** information need not be flushed. If the lower four bits of the flag 616 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 617 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 618 ** to use Mac OS X style fullsync instead of fsync(). 619 ** 620 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 621 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 622 ** settings. The [synchronous pragma] determines when calls to the 623 ** xSync VFS method occur and applies uniformly across all platforms. 624 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 625 ** energetic or rigorous or forceful the sync operations are and 626 ** only make a difference on Mac OSX for the default SQLite code. 627 ** (Third-party VFS implementations might also make the distinction 628 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 629 ** operating systems natively supported by SQLite, only Mac OSX 630 ** cares about the difference.) 631 */ 632 #define SQLITE_SYNC_NORMAL 0x00002 633 #define SQLITE_SYNC_FULL 0x00003 634 #define SQLITE_SYNC_DATAONLY 0x00010 635 636 /* 637 ** CAPI3REF: OS Interface Open File Handle 638 ** 639 ** An [sqlite3_file] object represents an open file in the 640 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 641 ** implementations will 642 ** want to subclass this object by appending additional fields 643 ** for their own use. The pMethods entry is a pointer to an 644 ** [sqlite3_io_methods] object that defines methods for performing 645 ** I/O operations on the open file. 646 */ 647 typedef struct sqlite3_file sqlite3_file; 648 struct sqlite3_file { 649 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 650 }; 651 652 /* 653 ** CAPI3REF: OS Interface File Virtual Methods Object 654 ** 655 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 656 ** [sqlite3_file] object (or, more commonly, a subclass of the 657 ** [sqlite3_file] object) with a pointer to an instance of this object. 658 ** This object defines the methods used to perform various operations 659 ** against the open file represented by the [sqlite3_file] object. 660 ** 661 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 662 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 663 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 664 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 665 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 666 ** to NULL. 667 ** 668 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 669 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 670 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 671 ** flag may be ORed in to indicate that only the data of the file 672 ** and not its inode needs to be synced. 673 ** 674 ** The integer values to xLock() and xUnlock() are one of 675 ** <ul> 676 ** <li> [SQLITE_LOCK_NONE], 677 ** <li> [SQLITE_LOCK_SHARED], 678 ** <li> [SQLITE_LOCK_RESERVED], 679 ** <li> [SQLITE_LOCK_PENDING], or 680 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 681 ** </ul> 682 ** xLock() increases the lock. xUnlock() decreases the lock. 683 ** The xCheckReservedLock() method checks whether any database connection, 684 ** either in this process or in some other process, is holding a RESERVED, 685 ** PENDING, or EXCLUSIVE lock on the file. It returns true 686 ** if such a lock exists and false otherwise. 687 ** 688 ** The xFileControl() method is a generic interface that allows custom 689 ** VFS implementations to directly control an open file using the 690 ** [sqlite3_file_control()] interface. The second "op" argument is an 691 ** integer opcode. The third argument is a generic pointer intended to 692 ** point to a structure that may contain arguments or space in which to 693 ** write return values. Potential uses for xFileControl() might be 694 ** functions to enable blocking locks with timeouts, to change the 695 ** locking strategy (for example to use dot-file locks), to inquire 696 ** about the status of a lock, or to break stale locks. The SQLite 697 ** core reserves all opcodes less than 100 for its own use. 698 ** A [file control opcodes | list of opcodes] less than 100 is available. 699 ** Applications that define a custom xFileControl method should use opcodes 700 ** greater than 100 to avoid conflicts. VFS implementations should 701 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 702 ** recognize. 703 ** 704 ** The xSectorSize() method returns the sector size of the 705 ** device that underlies the file. The sector size is the 706 ** minimum write that can be performed without disturbing 707 ** other bytes in the file. The xDeviceCharacteristics() 708 ** method returns a bit vector describing behaviors of the 709 ** underlying device: 710 ** 711 ** <ul> 712 ** <li> [SQLITE_IOCAP_ATOMIC] 713 ** <li> [SQLITE_IOCAP_ATOMIC512] 714 ** <li> [SQLITE_IOCAP_ATOMIC1K] 715 ** <li> [SQLITE_IOCAP_ATOMIC2K] 716 ** <li> [SQLITE_IOCAP_ATOMIC4K] 717 ** <li> [SQLITE_IOCAP_ATOMIC8K] 718 ** <li> [SQLITE_IOCAP_ATOMIC16K] 719 ** <li> [SQLITE_IOCAP_ATOMIC32K] 720 ** <li> [SQLITE_IOCAP_ATOMIC64K] 721 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 722 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 723 ** </ul> 724 ** 725 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 726 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 727 ** mean that writes of blocks that are nnn bytes in size and 728 ** are aligned to an address which is an integer multiple of 729 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 730 ** that when data is appended to a file, the data is appended 731 ** first then the size of the file is extended, never the other 732 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 733 ** information is written to disk in the same order as calls 734 ** to xWrite(). 735 ** 736 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 737 ** in the unread portions of the buffer with zeros. A VFS that 738 ** fails to zero-fill short reads might seem to work. However, 739 ** failure to zero-fill short reads will eventually lead to 740 ** database corruption. 741 */ 742 typedef struct sqlite3_io_methods sqlite3_io_methods; 743 struct sqlite3_io_methods { 744 int iVersion; 745 int (*xClose)(sqlite3_file*); 746 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 747 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 748 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 749 int (*xSync)(sqlite3_file*, int flags); 750 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 751 int (*xLock)(sqlite3_file*, int); 752 int (*xUnlock)(sqlite3_file*, int); 753 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 754 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 755 int (*xSectorSize)(sqlite3_file*); 756 int (*xDeviceCharacteristics)(sqlite3_file*); 757 /* Methods above are valid for version 1 */ 758 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 759 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 760 void (*xShmBarrier)(sqlite3_file*); 761 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 762 /* Methods above are valid for version 2 */ 763 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 764 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 765 /* Methods above are valid for version 3 */ 766 /* Additional methods may be added in future releases */ 767 }; 768 769 /* 770 ** CAPI3REF: Standard File Control Opcodes 771 ** KEYWORDS: {file control opcodes} {file control opcode} 772 ** 773 ** These integer constants are opcodes for the xFileControl method 774 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 775 ** interface. 776 ** 777 ** <ul> 778 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 779 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 780 ** opcode causes the xFileControl method to write the current state of 781 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 782 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 783 ** into an integer that the pArg argument points to. This capability 784 ** is used during testing and is only available when the SQLITE_TEST 785 ** compile-time option is used. 786 ** 787 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 788 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 789 ** layer a hint of how large the database file will grow to be during the 790 ** current transaction. This hint is not guaranteed to be accurate but it 791 ** is often close. The underlying VFS might choose to preallocate database 792 ** file space based on this hint in order to help writes to the database 793 ** file run faster. 794 ** 795 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 796 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 797 ** extends and truncates the database file in chunks of a size specified 798 ** by the user. The fourth argument to [sqlite3_file_control()] should 799 ** point to an integer (type int) containing the new chunk-size to use 800 ** for the nominated database. Allocating database file space in large 801 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 802 ** improve performance on some systems. 803 ** 804 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 805 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 806 ** to the [sqlite3_file] object associated with a particular database 807 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 808 ** 809 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 810 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 811 ** to the [sqlite3_file] object associated with the journal file (either 812 ** the [rollback journal] or the [write-ahead log]) for a particular database 813 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 814 ** 815 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 816 ** No longer in use. 817 ** 818 ** <li>[[SQLITE_FCNTL_SYNC]] 819 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 820 ** sent to the VFS immediately before the xSync method is invoked on a 821 ** database file descriptor. Or, if the xSync method is not invoked 822 ** because the user has configured SQLite with 823 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 824 ** of the xSync method. In most cases, the pointer argument passed with 825 ** this file-control is NULL. However, if the database file is being synced 826 ** as part of a multi-database commit, the argument points to a nul-terminated 827 ** string containing the transactions master-journal file name. VFSes that 828 ** do not need this signal should silently ignore this opcode. Applications 829 ** should not call [sqlite3_file_control()] with this opcode as doing so may 830 ** disrupt the operation of the specialized VFSes that do require it. 831 ** 832 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 833 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 834 ** and sent to the VFS after a transaction has been committed immediately 835 ** but before the database is unlocked. VFSes that do not need this signal 836 ** should silently ignore this opcode. Applications should not call 837 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 838 ** operation of the specialized VFSes that do require it. 839 ** 840 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 841 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 842 ** retry counts and intervals for certain disk I/O operations for the 843 ** windows [VFS] in order to provide robustness in the presence of 844 ** anti-virus programs. By default, the windows VFS will retry file read, 845 ** file write, and file delete operations up to 10 times, with a delay 846 ** of 25 milliseconds before the first retry and with the delay increasing 847 ** by an additional 25 milliseconds with each subsequent retry. This 848 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 849 ** to be adjusted. The values are changed for all database connections 850 ** within the same process. The argument is a pointer to an array of two 851 ** integers where the first integer i the new retry count and the second 852 ** integer is the delay. If either integer is negative, then the setting 853 ** is not changed but instead the prior value of that setting is written 854 ** into the array entry, allowing the current retry settings to be 855 ** interrogated. The zDbName parameter is ignored. 856 ** 857 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 858 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 859 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 860 ** write ahead log and shared memory files used for transaction control 861 ** are automatically deleted when the latest connection to the database 862 ** closes. Setting persistent WAL mode causes those files to persist after 863 ** close. Persisting the files is useful when other processes that do not 864 ** have write permission on the directory containing the database file want 865 ** to read the database file, as the WAL and shared memory files must exist 866 ** in order for the database to be readable. The fourth parameter to 867 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 868 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 869 ** WAL mode. If the integer is -1, then it is overwritten with the current 870 ** WAL persistence setting. 871 ** 872 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 873 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 874 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 875 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 876 ** xDeviceCharacteristics methods. The fourth parameter to 877 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 878 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 879 ** mode. If the integer is -1, then it is overwritten with the current 880 ** zero-damage mode setting. 881 ** 882 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 883 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 884 ** a write transaction to indicate that, unless it is rolled back for some 885 ** reason, the entire database file will be overwritten by the current 886 ** transaction. This is used by VACUUM operations. 887 ** 888 ** <li>[[SQLITE_FCNTL_VFSNAME]] 889 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 890 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 891 ** final bottom-level VFS are written into memory obtained from 892 ** [sqlite3_malloc()] and the result is stored in the char* variable 893 ** that the fourth parameter of [sqlite3_file_control()] points to. 894 ** The caller is responsible for freeing the memory when done. As with 895 ** all file-control actions, there is no guarantee that this will actually 896 ** do anything. Callers should initialize the char* variable to a NULL 897 ** pointer in case this file-control is not implemented. This file-control 898 ** is intended for diagnostic use only. 899 ** 900 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 901 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 902 ** [VFSes] currently in use. ^(The argument X in 903 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 904 ** of type "[sqlite3_vfs] **". This opcodes will set *X 905 ** to a pointer to the top-level VFS.)^ 906 ** ^When there are multiple VFS shims in the stack, this opcode finds the 907 ** upper-most shim only. 908 ** 909 ** <li>[[SQLITE_FCNTL_PRAGMA]] 910 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 911 ** file control is sent to the open [sqlite3_file] object corresponding 912 ** to the database file to which the pragma statement refers. ^The argument 913 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 914 ** pointers to strings (char**) in which the second element of the array 915 ** is the name of the pragma and the third element is the argument to the 916 ** pragma or NULL if the pragma has no argument. ^The handler for an 917 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 918 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 919 ** or the equivalent and that string will become the result of the pragma or 920 ** the error message if the pragma fails. ^If the 921 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 922 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 923 ** file control returns [SQLITE_OK], then the parser assumes that the 924 ** VFS has handled the PRAGMA itself and the parser generates a no-op 925 ** prepared statement if result string is NULL, or that returns a copy 926 ** of the result string if the string is non-NULL. 927 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 928 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 929 ** that the VFS encountered an error while handling the [PRAGMA] and the 930 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 931 ** file control occurs at the beginning of pragma statement analysis and so 932 ** it is able to override built-in [PRAGMA] statements. 933 ** 934 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 935 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 936 ** file-control may be invoked by SQLite on the database file handle 937 ** shortly after it is opened in order to provide a custom VFS with access 938 ** to the connections busy-handler callback. The argument is of type (void **) 939 ** - an array of two (void *) values. The first (void *) actually points 940 ** to a function of type (int (*)(void *)). In order to invoke the connections 941 ** busy-handler, this function should be invoked with the second (void *) in 942 ** the array as the only argument. If it returns non-zero, then the operation 943 ** should be retried. If it returns zero, the custom VFS should abandon the 944 ** current operation. 945 ** 946 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 947 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 948 ** to have SQLite generate a 949 ** temporary filename using the same algorithm that is followed to generate 950 ** temporary filenames for TEMP tables and other internal uses. The 951 ** argument should be a char** which will be filled with the filename 952 ** written into memory obtained from [sqlite3_malloc()]. The caller should 953 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 954 ** 955 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 956 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 957 ** maximum number of bytes that will be used for memory-mapped I/O. 958 ** The argument is a pointer to a value of type sqlite3_int64 that 959 ** is an advisory maximum number of bytes in the file to memory map. The 960 ** pointer is overwritten with the old value. The limit is not changed if 961 ** the value originally pointed to is negative, and so the current limit 962 ** can be queried by passing in a pointer to a negative number. This 963 ** file-control is used internally to implement [PRAGMA mmap_size]. 964 ** 965 ** <li>[[SQLITE_FCNTL_TRACE]] 966 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 967 ** to the VFS about what the higher layers of the SQLite stack are doing. 968 ** This file control is used by some VFS activity tracing [shims]. 969 ** The argument is a zero-terminated string. Higher layers in the 970 ** SQLite stack may generate instances of this file control if 971 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 972 ** 973 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 974 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 975 ** pointer to an integer and it writes a boolean into that integer depending 976 ** on whether or not the file has been renamed, moved, or deleted since it 977 ** was first opened. 978 ** 979 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 980 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 981 ** opcode causes the xFileControl method to swap the file handle with the one 982 ** pointed to by the pArg argument. This capability is used during testing 983 ** and only needs to be supported when SQLITE_TEST is defined. 984 ** 985 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 986 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 987 ** be advantageous to block on the next WAL lock if the lock is not immediately 988 ** available. The WAL subsystem issues this signal during rare 989 ** circumstances in order to fix a problem with priority inversion. 990 ** Applications should <em>not</em> use this file-control. 991 ** 992 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 993 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 994 ** VFS should return SQLITE_NOTFOUND for this opcode. 995 ** 996 ** <li>[[SQLITE_FCNTL_RBU]] 997 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 998 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 999 ** this opcode. 1000 ** </ul> 1001 */ 1002 #define SQLITE_FCNTL_LOCKSTATE 1 1003 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1004 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1005 #define SQLITE_FCNTL_LAST_ERRNO 4 1006 #define SQLITE_FCNTL_SIZE_HINT 5 1007 #define SQLITE_FCNTL_CHUNK_SIZE 6 1008 #define SQLITE_FCNTL_FILE_POINTER 7 1009 #define SQLITE_FCNTL_SYNC_OMITTED 8 1010 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1011 #define SQLITE_FCNTL_PERSIST_WAL 10 1012 #define SQLITE_FCNTL_OVERWRITE 11 1013 #define SQLITE_FCNTL_VFSNAME 12 1014 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1015 #define SQLITE_FCNTL_PRAGMA 14 1016 #define SQLITE_FCNTL_BUSYHANDLER 15 1017 #define SQLITE_FCNTL_TEMPFILENAME 16 1018 #define SQLITE_FCNTL_MMAP_SIZE 18 1019 #define SQLITE_FCNTL_TRACE 19 1020 #define SQLITE_FCNTL_HAS_MOVED 20 1021 #define SQLITE_FCNTL_SYNC 21 1022 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1023 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1024 #define SQLITE_FCNTL_WAL_BLOCK 24 1025 #define SQLITE_FCNTL_ZIPVFS 25 1026 #define SQLITE_FCNTL_RBU 26 1027 #define SQLITE_FCNTL_VFS_POINTER 27 1028 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1029 1030 /* deprecated names */ 1031 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1032 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1033 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1034 1035 1036 /* 1037 ** CAPI3REF: Mutex Handle 1038 ** 1039 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1040 ** abstract type for a mutex object. The SQLite core never looks 1041 ** at the internal representation of an [sqlite3_mutex]. It only 1042 ** deals with pointers to the [sqlite3_mutex] object. 1043 ** 1044 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1045 */ 1046 typedef struct sqlite3_mutex sqlite3_mutex; 1047 1048 /* 1049 ** CAPI3REF: Loadable Extension Thunk 1050 ** 1051 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1052 ** the third parameter to entry points of [loadable extensions]. This 1053 ** structure must be typedefed in order to work around compiler warnings 1054 ** on some platforms. 1055 */ 1056 typedef struct sqlite3_api_routines sqlite3_api_routines; 1057 1058 /* 1059 ** CAPI3REF: OS Interface Object 1060 ** 1061 ** An instance of the sqlite3_vfs object defines the interface between 1062 ** the SQLite core and the underlying operating system. The "vfs" 1063 ** in the name of the object stands for "virtual file system". See 1064 ** the [VFS | VFS documentation] for further information. 1065 ** 1066 ** The value of the iVersion field is initially 1 but may be larger in 1067 ** future versions of SQLite. Additional fields may be appended to this 1068 ** object when the iVersion value is increased. Note that the structure 1069 ** of the sqlite3_vfs object changes in the transaction between 1070 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1071 ** modified. 1072 ** 1073 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1074 ** structure used by this VFS. mxPathname is the maximum length of 1075 ** a pathname in this VFS. 1076 ** 1077 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1078 ** the pNext pointer. The [sqlite3_vfs_register()] 1079 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1080 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1081 ** searches the list. Neither the application code nor the VFS 1082 ** implementation should use the pNext pointer. 1083 ** 1084 ** The pNext field is the only field in the sqlite3_vfs 1085 ** structure that SQLite will ever modify. SQLite will only access 1086 ** or modify this field while holding a particular static mutex. 1087 ** The application should never modify anything within the sqlite3_vfs 1088 ** object once the object has been registered. 1089 ** 1090 ** The zName field holds the name of the VFS module. The name must 1091 ** be unique across all VFS modules. 1092 ** 1093 ** [[sqlite3_vfs.xOpen]] 1094 ** ^SQLite guarantees that the zFilename parameter to xOpen 1095 ** is either a NULL pointer or string obtained 1096 ** from xFullPathname() with an optional suffix added. 1097 ** ^If a suffix is added to the zFilename parameter, it will 1098 ** consist of a single "-" character followed by no more than 1099 ** 11 alphanumeric and/or "-" characters. 1100 ** ^SQLite further guarantees that 1101 ** the string will be valid and unchanged until xClose() is 1102 ** called. Because of the previous sentence, 1103 ** the [sqlite3_file] can safely store a pointer to the 1104 ** filename if it needs to remember the filename for some reason. 1105 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1106 ** must invent its own temporary name for the file. ^Whenever the 1107 ** xFilename parameter is NULL it will also be the case that the 1108 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1109 ** 1110 ** The flags argument to xOpen() includes all bits set in 1111 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1112 ** or [sqlite3_open16()] is used, then flags includes at least 1113 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1114 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1115 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1116 ** 1117 ** ^(SQLite will also add one of the following flags to the xOpen() 1118 ** call, depending on the object being opened: 1119 ** 1120 ** <ul> 1121 ** <li> [SQLITE_OPEN_MAIN_DB] 1122 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1123 ** <li> [SQLITE_OPEN_TEMP_DB] 1124 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1125 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1126 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1127 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1128 ** <li> [SQLITE_OPEN_WAL] 1129 ** </ul>)^ 1130 ** 1131 ** The file I/O implementation can use the object type flags to 1132 ** change the way it deals with files. For example, an application 1133 ** that does not care about crash recovery or rollback might make 1134 ** the open of a journal file a no-op. Writes to this journal would 1135 ** also be no-ops, and any attempt to read the journal would return 1136 ** SQLITE_IOERR. Or the implementation might recognize that a database 1137 ** file will be doing page-aligned sector reads and writes in a random 1138 ** order and set up its I/O subsystem accordingly. 1139 ** 1140 ** SQLite might also add one of the following flags to the xOpen method: 1141 ** 1142 ** <ul> 1143 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1144 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1145 ** </ul> 1146 ** 1147 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1148 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1149 ** will be set for TEMP databases and their journals, transient 1150 ** databases, and subjournals. 1151 ** 1152 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1153 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1154 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1155 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1156 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1157 ** be created, and that it is an error if it already exists. 1158 ** It is <i>not</i> used to indicate the file should be opened 1159 ** for exclusive access. 1160 ** 1161 ** ^At least szOsFile bytes of memory are allocated by SQLite 1162 ** to hold the [sqlite3_file] structure passed as the third 1163 ** argument to xOpen. The xOpen method does not have to 1164 ** allocate the structure; it should just fill it in. Note that 1165 ** the xOpen method must set the sqlite3_file.pMethods to either 1166 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1167 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1168 ** element will be valid after xOpen returns regardless of the success 1169 ** or failure of the xOpen call. 1170 ** 1171 ** [[sqlite3_vfs.xAccess]] 1172 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1173 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1174 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1175 ** to test whether a file is at least readable. The file can be a 1176 ** directory. 1177 ** 1178 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1179 ** output buffer xFullPathname. The exact size of the output buffer 1180 ** is also passed as a parameter to both methods. If the output buffer 1181 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1182 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1183 ** to prevent this by setting mxPathname to a sufficiently large value. 1184 ** 1185 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1186 ** interfaces are not strictly a part of the filesystem, but they are 1187 ** included in the VFS structure for completeness. 1188 ** The xRandomness() function attempts to return nBytes bytes 1189 ** of good-quality randomness into zOut. The return value is 1190 ** the actual number of bytes of randomness obtained. 1191 ** The xSleep() method causes the calling thread to sleep for at 1192 ** least the number of microseconds given. ^The xCurrentTime() 1193 ** method returns a Julian Day Number for the current date and time as 1194 ** a floating point value. 1195 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1196 ** Day Number multiplied by 86400000 (the number of milliseconds in 1197 ** a 24-hour day). 1198 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1199 ** date and time if that method is available (if iVersion is 2 or 1200 ** greater and the function pointer is not NULL) and will fall back 1201 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1202 ** 1203 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1204 ** are not used by the SQLite core. These optional interfaces are provided 1205 ** by some VFSes to facilitate testing of the VFS code. By overriding 1206 ** system calls with functions under its control, a test program can 1207 ** simulate faults and error conditions that would otherwise be difficult 1208 ** or impossible to induce. The set of system calls that can be overridden 1209 ** varies from one VFS to another, and from one version of the same VFS to the 1210 ** next. Applications that use these interfaces must be prepared for any 1211 ** or all of these interfaces to be NULL or for their behavior to change 1212 ** from one release to the next. Applications must not attempt to access 1213 ** any of these methods if the iVersion of the VFS is less than 3. 1214 */ 1215 typedef struct sqlite3_vfs sqlite3_vfs; 1216 typedef void (*sqlite3_syscall_ptr)(void); 1217 struct sqlite3_vfs { 1218 int iVersion; /* Structure version number (currently 3) */ 1219 int szOsFile; /* Size of subclassed sqlite3_file */ 1220 int mxPathname; /* Maximum file pathname length */ 1221 sqlite3_vfs *pNext; /* Next registered VFS */ 1222 const char *zName; /* Name of this virtual file system */ 1223 void *pAppData; /* Pointer to application-specific data */ 1224 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1225 int flags, int *pOutFlags); 1226 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1227 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1228 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1229 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1230 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1231 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1232 void (*xDlClose)(sqlite3_vfs*, void*); 1233 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1234 int (*xSleep)(sqlite3_vfs*, int microseconds); 1235 int (*xCurrentTime)(sqlite3_vfs*, double*); 1236 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1237 /* 1238 ** The methods above are in version 1 of the sqlite_vfs object 1239 ** definition. Those that follow are added in version 2 or later 1240 */ 1241 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1242 /* 1243 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1244 ** Those below are for version 3 and greater. 1245 */ 1246 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1247 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1248 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1249 /* 1250 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1251 ** New fields may be appended in future versions. The iVersion 1252 ** value will increment whenever this happens. 1253 */ 1254 }; 1255 1256 /* 1257 ** CAPI3REF: Flags for the xAccess VFS method 1258 ** 1259 ** These integer constants can be used as the third parameter to 1260 ** the xAccess method of an [sqlite3_vfs] object. They determine 1261 ** what kind of permissions the xAccess method is looking for. 1262 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1263 ** simply checks whether the file exists. 1264 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1265 ** checks whether the named directory is both readable and writable 1266 ** (in other words, if files can be added, removed, and renamed within 1267 ** the directory). 1268 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1269 ** [temp_store_directory pragma], though this could change in a future 1270 ** release of SQLite. 1271 ** With SQLITE_ACCESS_READ, the xAccess method 1272 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1273 ** currently unused, though it might be used in a future release of 1274 ** SQLite. 1275 */ 1276 #define SQLITE_ACCESS_EXISTS 0 1277 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1278 #define SQLITE_ACCESS_READ 2 /* Unused */ 1279 1280 /* 1281 ** CAPI3REF: Flags for the xShmLock VFS method 1282 ** 1283 ** These integer constants define the various locking operations 1284 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1285 ** following are the only legal combinations of flags to the 1286 ** xShmLock method: 1287 ** 1288 ** <ul> 1289 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1290 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1291 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1292 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1293 ** </ul> 1294 ** 1295 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1296 ** was given on the corresponding lock. 1297 ** 1298 ** The xShmLock method can transition between unlocked and SHARED or 1299 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1300 ** and EXCLUSIVE. 1301 */ 1302 #define SQLITE_SHM_UNLOCK 1 1303 #define SQLITE_SHM_LOCK 2 1304 #define SQLITE_SHM_SHARED 4 1305 #define SQLITE_SHM_EXCLUSIVE 8 1306 1307 /* 1308 ** CAPI3REF: Maximum xShmLock index 1309 ** 1310 ** The xShmLock method on [sqlite3_io_methods] may use values 1311 ** between 0 and this upper bound as its "offset" argument. 1312 ** The SQLite core will never attempt to acquire or release a 1313 ** lock outside of this range 1314 */ 1315 #define SQLITE_SHM_NLOCK 8 1316 1317 1318 /* 1319 ** CAPI3REF: Initialize The SQLite Library 1320 ** 1321 ** ^The sqlite3_initialize() routine initializes the 1322 ** SQLite library. ^The sqlite3_shutdown() routine 1323 ** deallocates any resources that were allocated by sqlite3_initialize(). 1324 ** These routines are designed to aid in process initialization and 1325 ** shutdown on embedded systems. Workstation applications using 1326 ** SQLite normally do not need to invoke either of these routines. 1327 ** 1328 ** A call to sqlite3_initialize() is an "effective" call if it is 1329 ** the first time sqlite3_initialize() is invoked during the lifetime of 1330 ** the process, or if it is the first time sqlite3_initialize() is invoked 1331 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1332 ** of sqlite3_initialize() does any initialization. All other calls 1333 ** are harmless no-ops.)^ 1334 ** 1335 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1336 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1337 ** an effective call to sqlite3_shutdown() does any deinitialization. 1338 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1339 ** 1340 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1341 ** is not. The sqlite3_shutdown() interface must only be called from a 1342 ** single thread. All open [database connections] must be closed and all 1343 ** other SQLite resources must be deallocated prior to invoking 1344 ** sqlite3_shutdown(). 1345 ** 1346 ** Among other things, ^sqlite3_initialize() will invoke 1347 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1348 ** will invoke sqlite3_os_end(). 1349 ** 1350 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1351 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1352 ** the library (perhaps it is unable to allocate a needed resource such 1353 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1354 ** 1355 ** ^The sqlite3_initialize() routine is called internally by many other 1356 ** SQLite interfaces so that an application usually does not need to 1357 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1358 ** calls sqlite3_initialize() so the SQLite library will be automatically 1359 ** initialized when [sqlite3_open()] is called if it has not be initialized 1360 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1361 ** compile-time option, then the automatic calls to sqlite3_initialize() 1362 ** are omitted and the application must call sqlite3_initialize() directly 1363 ** prior to using any other SQLite interface. For maximum portability, 1364 ** it is recommended that applications always invoke sqlite3_initialize() 1365 ** directly prior to using any other SQLite interface. Future releases 1366 ** of SQLite may require this. In other words, the behavior exhibited 1367 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1368 ** default behavior in some future release of SQLite. 1369 ** 1370 ** The sqlite3_os_init() routine does operating-system specific 1371 ** initialization of the SQLite library. The sqlite3_os_end() 1372 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1373 ** performed by these routines include allocation or deallocation 1374 ** of static resources, initialization of global variables, 1375 ** setting up a default [sqlite3_vfs] module, or setting up 1376 ** a default configuration using [sqlite3_config()]. 1377 ** 1378 ** The application should never invoke either sqlite3_os_init() 1379 ** or sqlite3_os_end() directly. The application should only invoke 1380 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1381 ** interface is called automatically by sqlite3_initialize() and 1382 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1383 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1384 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1385 ** When [custom builds | built for other platforms] 1386 ** (using the [SQLITE_OS_OTHER=1] compile-time 1387 ** option) the application must supply a suitable implementation for 1388 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1389 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1390 ** must return [SQLITE_OK] on success and some other [error code] upon 1391 ** failure. 1392 */ 1393 SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void); 1394 SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void); 1395 SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void); 1396 SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void); 1397 1398 /* 1399 ** CAPI3REF: Configuring The SQLite Library 1400 ** 1401 ** The sqlite3_config() interface is used to make global configuration 1402 ** changes to SQLite in order to tune SQLite to the specific needs of 1403 ** the application. The default configuration is recommended for most 1404 ** applications and so this routine is usually not necessary. It is 1405 ** provided to support rare applications with unusual needs. 1406 ** 1407 ** <b>The sqlite3_config() interface is not threadsafe. The application 1408 ** must ensure that no other SQLite interfaces are invoked by other 1409 ** threads while sqlite3_config() is running.</b> 1410 ** 1411 ** The sqlite3_config() interface 1412 ** may only be invoked prior to library initialization using 1413 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1414 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1415 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1416 ** Note, however, that ^sqlite3_config() can be called as part of the 1417 ** implementation of an application-defined [sqlite3_os_init()]. 1418 ** 1419 ** The first argument to sqlite3_config() is an integer 1420 ** [configuration option] that determines 1421 ** what property of SQLite is to be configured. Subsequent arguments 1422 ** vary depending on the [configuration option] 1423 ** in the first argument. 1424 ** 1425 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1426 ** ^If the option is unknown or SQLite is unable to set the option 1427 ** then this routine returns a non-zero [error code]. 1428 */ 1429 SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...); 1430 1431 /* 1432 ** CAPI3REF: Configure database connections 1433 ** METHOD: sqlite3 1434 ** 1435 ** The sqlite3_db_config() interface is used to make configuration 1436 ** changes to a [database connection]. The interface is similar to 1437 ** [sqlite3_config()] except that the changes apply to a single 1438 ** [database connection] (specified in the first argument). 1439 ** 1440 ** The second argument to sqlite3_db_config(D,V,...) is the 1441 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1442 ** that indicates what aspect of the [database connection] is being configured. 1443 ** Subsequent arguments vary depending on the configuration verb. 1444 ** 1445 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1446 ** the call is considered successful. 1447 */ 1448 SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...); 1449 1450 /* 1451 ** CAPI3REF: Memory Allocation Routines 1452 ** 1453 ** An instance of this object defines the interface between SQLite 1454 ** and low-level memory allocation routines. 1455 ** 1456 ** This object is used in only one place in the SQLite interface. 1457 ** A pointer to an instance of this object is the argument to 1458 ** [sqlite3_config()] when the configuration option is 1459 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1460 ** By creating an instance of this object 1461 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1462 ** during configuration, an application can specify an alternative 1463 ** memory allocation subsystem for SQLite to use for all of its 1464 ** dynamic memory needs. 1465 ** 1466 ** Note that SQLite comes with several [built-in memory allocators] 1467 ** that are perfectly adequate for the overwhelming majority of applications 1468 ** and that this object is only useful to a tiny minority of applications 1469 ** with specialized memory allocation requirements. This object is 1470 ** also used during testing of SQLite in order to specify an alternative 1471 ** memory allocator that simulates memory out-of-memory conditions in 1472 ** order to verify that SQLite recovers gracefully from such 1473 ** conditions. 1474 ** 1475 ** The xMalloc, xRealloc, and xFree methods must work like the 1476 ** malloc(), realloc() and free() functions from the standard C library. 1477 ** ^SQLite guarantees that the second argument to 1478 ** xRealloc is always a value returned by a prior call to xRoundup. 1479 ** 1480 ** xSize should return the allocated size of a memory allocation 1481 ** previously obtained from xMalloc or xRealloc. The allocated size 1482 ** is always at least as big as the requested size but may be larger. 1483 ** 1484 ** The xRoundup method returns what would be the allocated size of 1485 ** a memory allocation given a particular requested size. Most memory 1486 ** allocators round up memory allocations at least to the next multiple 1487 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1488 ** Every memory allocation request coming in through [sqlite3_malloc()] 1489 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1490 ** that causes the corresponding memory allocation to fail. 1491 ** 1492 ** The xInit method initializes the memory allocator. For example, 1493 ** it might allocate any require mutexes or initialize internal data 1494 ** structures. The xShutdown method is invoked (indirectly) by 1495 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1496 ** by xInit. The pAppData pointer is used as the only parameter to 1497 ** xInit and xShutdown. 1498 ** 1499 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1500 ** the xInit method, so the xInit method need not be threadsafe. The 1501 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1502 ** not need to be threadsafe either. For all other methods, SQLite 1503 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1504 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1505 ** it is by default) and so the methods are automatically serialized. 1506 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1507 ** methods must be threadsafe or else make their own arrangements for 1508 ** serialization. 1509 ** 1510 ** SQLite will never invoke xInit() more than once without an intervening 1511 ** call to xShutdown(). 1512 */ 1513 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1514 struct sqlite3_mem_methods { 1515 void *(*xMalloc)(int); /* Memory allocation function */ 1516 void (*xFree)(void*); /* Free a prior allocation */ 1517 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1518 int (*xSize)(void*); /* Return the size of an allocation */ 1519 int (*xRoundup)(int); /* Round up request size to allocation size */ 1520 int (*xInit)(void*); /* Initialize the memory allocator */ 1521 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1522 void *pAppData; /* Argument to xInit() and xShutdown() */ 1523 }; 1524 1525 /* 1526 ** CAPI3REF: Configuration Options 1527 ** KEYWORDS: {configuration option} 1528 ** 1529 ** These constants are the available integer configuration options that 1530 ** can be passed as the first argument to the [sqlite3_config()] interface. 1531 ** 1532 ** New configuration options may be added in future releases of SQLite. 1533 ** Existing configuration options might be discontinued. Applications 1534 ** should check the return code from [sqlite3_config()] to make sure that 1535 ** the call worked. The [sqlite3_config()] interface will return a 1536 ** non-zero [error code] if a discontinued or unsupported configuration option 1537 ** is invoked. 1538 ** 1539 ** <dl> 1540 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1541 ** <dd>There are no arguments to this option. ^This option sets the 1542 ** [threading mode] to Single-thread. In other words, it disables 1543 ** all mutexing and puts SQLite into a mode where it can only be used 1544 ** by a single thread. ^If SQLite is compiled with 1545 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1546 ** it is not possible to change the [threading mode] from its default 1547 ** value of Single-thread and so [sqlite3_config()] will return 1548 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1549 ** configuration option.</dd> 1550 ** 1551 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1552 ** <dd>There are no arguments to this option. ^This option sets the 1553 ** [threading mode] to Multi-thread. In other words, it disables 1554 ** mutexing on [database connection] and [prepared statement] objects. 1555 ** The application is responsible for serializing access to 1556 ** [database connections] and [prepared statements]. But other mutexes 1557 ** are enabled so that SQLite will be safe to use in a multi-threaded 1558 ** environment as long as no two threads attempt to use the same 1559 ** [database connection] at the same time. ^If SQLite is compiled with 1560 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1561 ** it is not possible to set the Multi-thread [threading mode] and 1562 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1563 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1564 ** 1565 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1566 ** <dd>There are no arguments to this option. ^This option sets the 1567 ** [threading mode] to Serialized. In other words, this option enables 1568 ** all mutexes including the recursive 1569 ** mutexes on [database connection] and [prepared statement] objects. 1570 ** In this mode (which is the default when SQLite is compiled with 1571 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1572 ** to [database connections] and [prepared statements] so that the 1573 ** application is free to use the same [database connection] or the 1574 ** same [prepared statement] in different threads at the same time. 1575 ** ^If SQLite is compiled with 1576 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1577 ** it is not possible to set the Serialized [threading mode] and 1578 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1579 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1580 ** 1581 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1582 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1583 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1584 ** The argument specifies 1585 ** alternative low-level memory allocation routines to be used in place of 1586 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1587 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1588 ** before the [sqlite3_config()] call returns.</dd> 1589 ** 1590 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1591 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1592 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1593 ** The [sqlite3_mem_methods] 1594 ** structure is filled with the currently defined memory allocation routines.)^ 1595 ** This option can be used to overload the default memory allocation 1596 ** routines with a wrapper that simulations memory allocation failure or 1597 ** tracks memory usage, for example. </dd> 1598 ** 1599 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1600 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1601 ** interpreted as a boolean, which enables or disables the collection of 1602 ** memory allocation statistics. ^(When memory allocation statistics are 1603 ** disabled, the following SQLite interfaces become non-operational: 1604 ** <ul> 1605 ** <li> [sqlite3_memory_used()] 1606 ** <li> [sqlite3_memory_highwater()] 1607 ** <li> [sqlite3_soft_heap_limit64()] 1608 ** <li> [sqlite3_status64()] 1609 ** </ul>)^ 1610 ** ^Memory allocation statistics are enabled by default unless SQLite is 1611 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1612 ** allocation statistics are disabled by default. 1613 ** </dd> 1614 ** 1615 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1616 ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1617 ** that SQLite can use for scratch memory. ^(There are three arguments 1618 ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1619 ** aligned memory buffer from which the scratch allocations will be 1620 ** drawn, the size of each scratch allocation (sz), 1621 ** and the maximum number of scratch allocations (N).)^ 1622 ** The first argument must be a pointer to an 8-byte aligned buffer 1623 ** of at least sz*N bytes of memory. 1624 ** ^SQLite will not use more than one scratch buffers per thread. 1625 ** ^SQLite will never request a scratch buffer that is more than 6 1626 ** times the database page size. 1627 ** ^If SQLite needs needs additional 1628 ** scratch memory beyond what is provided by this configuration option, then 1629 ** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1630 ** ^When the application provides any amount of scratch memory using 1631 ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1632 ** [sqlite3_malloc|heap allocations]. 1633 ** This can help [Robson proof|prevent memory allocation failures] due to heap 1634 ** fragmentation in low-memory embedded systems. 1635 ** </dd> 1636 ** 1637 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1638 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1639 ** that SQLite can use for the database page cache with the default page 1640 ** cache implementation. 1641 ** This configuration option is a no-op if an application-define page 1642 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1643 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1644 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1645 ** and the number of cache lines (N). 1646 ** The sz argument should be the size of the largest database page 1647 ** (a power of two between 512 and 65536) plus some extra bytes for each 1648 ** page header. ^The number of extra bytes needed by the page header 1649 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1650 ** ^It is harmless, apart from the wasted memory, 1651 ** for the sz parameter to be larger than necessary. The pMem 1652 ** argument must be either a NULL pointer or a pointer to an 8-byte 1653 ** aligned block of memory of at least sz*N bytes, otherwise 1654 ** subsequent behavior is undefined. 1655 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1656 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1657 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1658 ** is exhausted. 1659 ** ^If pMem is NULL and N is non-zero, then each database connection 1660 ** does an initial bulk allocation for page cache memory 1661 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1662 ** of -1024*N bytes if N is negative, . ^If additional 1663 ** page cache memory is needed beyond what is provided by the initial 1664 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1665 ** additional cache line. </dd> 1666 ** 1667 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1668 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1669 ** that SQLite will use for all of its dynamic memory allocation needs 1670 ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1671 ** [SQLITE_CONFIG_PAGECACHE]. 1672 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1673 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1674 ** [SQLITE_ERROR] if invoked otherwise. 1675 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1676 ** An 8-byte aligned pointer to the memory, 1677 ** the number of bytes in the memory buffer, and the minimum allocation size. 1678 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1679 ** to using its default memory allocator (the system malloc() implementation), 1680 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1681 ** memory pointer is not NULL then the alternative memory 1682 ** allocator is engaged to handle all of SQLites memory allocation needs. 1683 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1684 ** boundary or subsequent behavior of SQLite will be undefined. 1685 ** The minimum allocation size is capped at 2**12. Reasonable values 1686 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1687 ** 1688 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1689 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1690 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1691 ** The argument specifies alternative low-level mutex routines to be used 1692 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1693 ** the content of the [sqlite3_mutex_methods] structure before the call to 1694 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1695 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1696 ** the entire mutexing subsystem is omitted from the build and hence calls to 1697 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1698 ** return [SQLITE_ERROR].</dd> 1699 ** 1700 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1701 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1702 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1703 ** [sqlite3_mutex_methods] 1704 ** structure is filled with the currently defined mutex routines.)^ 1705 ** This option can be used to overload the default mutex allocation 1706 ** routines with a wrapper used to track mutex usage for performance 1707 ** profiling or testing, for example. ^If SQLite is compiled with 1708 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1709 ** the entire mutexing subsystem is omitted from the build and hence calls to 1710 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1711 ** return [SQLITE_ERROR].</dd> 1712 ** 1713 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1714 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1715 ** the default size of lookaside memory on each [database connection]. 1716 ** The first argument is the 1717 ** size of each lookaside buffer slot and the second is the number of 1718 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1719 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1720 ** option to [sqlite3_db_config()] can be used to change the lookaside 1721 ** configuration on individual connections.)^ </dd> 1722 ** 1723 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1724 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1725 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1726 ** the interface to a custom page cache implementation.)^ 1727 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1728 ** 1729 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1730 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1731 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1732 ** the current page cache implementation into that object.)^ </dd> 1733 ** 1734 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1735 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1736 ** global [error log]. 1737 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1738 ** function with a call signature of void(*)(void*,int,const char*), 1739 ** and a pointer to void. ^If the function pointer is not NULL, it is 1740 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1741 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1742 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1743 ** passed through as the first parameter to the application-defined logger 1744 ** function whenever that function is invoked. ^The second parameter to 1745 ** the logger function is a copy of the first parameter to the corresponding 1746 ** [sqlite3_log()] call and is intended to be a [result code] or an 1747 ** [extended result code]. ^The third parameter passed to the logger is 1748 ** log message after formatting via [sqlite3_snprintf()]. 1749 ** The SQLite logging interface is not reentrant; the logger function 1750 ** supplied by the application must not invoke any SQLite interface. 1751 ** In a multi-threaded application, the application-defined logger 1752 ** function must be threadsafe. </dd> 1753 ** 1754 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1755 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1756 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1757 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1758 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1759 ** [sqlite3_open16()] or 1760 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1761 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1762 ** connection is opened. ^If it is globally disabled, filenames are 1763 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1764 ** database connection is opened. ^(By default, URI handling is globally 1765 ** disabled. The default value may be changed by compiling with the 1766 ** [SQLITE_USE_URI] symbol defined.)^ 1767 ** 1768 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1769 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1770 ** argument which is interpreted as a boolean in order to enable or disable 1771 ** the use of covering indices for full table scans in the query optimizer. 1772 ** ^The default setting is determined 1773 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1774 ** if that compile-time option is omitted. 1775 ** The ability to disable the use of covering indices for full table scans 1776 ** is because some incorrectly coded legacy applications might malfunction 1777 ** when the optimization is enabled. Providing the ability to 1778 ** disable the optimization allows the older, buggy application code to work 1779 ** without change even with newer versions of SQLite. 1780 ** 1781 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1782 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1783 ** <dd> These options are obsolete and should not be used by new code. 1784 ** They are retained for backwards compatibility but are now no-ops. 1785 ** </dd> 1786 ** 1787 ** [[SQLITE_CONFIG_SQLLOG]] 1788 ** <dt>SQLITE_CONFIG_SQLLOG 1789 ** <dd>This option is only available if sqlite is compiled with the 1790 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1791 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1792 ** The second should be of type (void*). The callback is invoked by the library 1793 ** in three separate circumstances, identified by the value passed as the 1794 ** fourth parameter. If the fourth parameter is 0, then the database connection 1795 ** passed as the second argument has just been opened. The third argument 1796 ** points to a buffer containing the name of the main database file. If the 1797 ** fourth parameter is 1, then the SQL statement that the third parameter 1798 ** points to has just been executed. Or, if the fourth parameter is 2, then 1799 ** the connection being passed as the second parameter is being closed. The 1800 ** third parameter is passed NULL In this case. An example of using this 1801 ** configuration option can be seen in the "test_sqllog.c" source file in 1802 ** the canonical SQLite source tree.</dd> 1803 ** 1804 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1805 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1806 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1807 ** that are the default mmap size limit (the default setting for 1808 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1809 ** ^The default setting can be overridden by each database connection using 1810 ** either the [PRAGMA mmap_size] command, or by using the 1811 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1812 ** will be silently truncated if necessary so that it does not exceed the 1813 ** compile-time maximum mmap size set by the 1814 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1815 ** ^If either argument to this option is negative, then that argument is 1816 ** changed to its compile-time default. 1817 ** 1818 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1819 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1820 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1821 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1822 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1823 ** that specifies the maximum size of the created heap. 1824 ** 1825 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1826 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1827 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1828 ** is a pointer to an integer and writes into that integer the number of extra 1829 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1830 ** The amount of extra space required can change depending on the compiler, 1831 ** target platform, and SQLite version. 1832 ** 1833 ** [[SQLITE_CONFIG_PMASZ]] 1834 ** <dt>SQLITE_CONFIG_PMASZ 1835 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1836 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1837 ** sorter to that integer. The default minimum PMA Size is set by the 1838 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1839 ** to help with sort operations when multithreaded sorting 1840 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1841 ** to be sorted exceeds the page size times the minimum of the 1842 ** [PRAGMA cache_size] setting and this value. 1843 ** 1844 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1845 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1846 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1847 ** becomes the [statement journal] spill-to-disk threshold. 1848 ** [Statement journals] are held in memory until their size (in bytes) 1849 ** exceeds this threshold, at which point they are written to disk. 1850 ** Or if the threshold is -1, statement journals are always held 1851 ** exclusively in memory. 1852 ** Since many statement journals never become large, setting the spill 1853 ** threshold to a value such as 64KiB can greatly reduce the amount of 1854 ** I/O required to support statement rollback. 1855 ** The default value for this setting is controlled by the 1856 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1857 ** </dl> 1858 */ 1859 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1860 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1861 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1862 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1863 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1864 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1865 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1866 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1867 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1868 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1869 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1870 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1871 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1872 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1873 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1874 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1875 #define SQLITE_CONFIG_URI 17 /* int */ 1876 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1877 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1878 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1879 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1880 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1881 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1882 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1883 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1884 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1885 1886 /* 1887 ** CAPI3REF: Database Connection Configuration Options 1888 ** 1889 ** These constants are the available integer configuration options that 1890 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1891 ** 1892 ** New configuration options may be added in future releases of SQLite. 1893 ** Existing configuration options might be discontinued. Applications 1894 ** should check the return code from [sqlite3_db_config()] to make sure that 1895 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1896 ** non-zero [error code] if a discontinued or unsupported configuration option 1897 ** is invoked. 1898 ** 1899 ** <dl> 1900 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1901 ** <dd> ^This option takes three additional arguments that determine the 1902 ** [lookaside memory allocator] configuration for the [database connection]. 1903 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1904 ** pointer to a memory buffer to use for lookaside memory. 1905 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1906 ** may be NULL in which case SQLite will allocate the 1907 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1908 ** size of each lookaside buffer slot. ^The third argument is the number of 1909 ** slots. The size of the buffer in the first argument must be greater than 1910 ** or equal to the product of the second and third arguments. The buffer 1911 ** must be aligned to an 8-byte boundary. ^If the second argument to 1912 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1913 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1914 ** configuration for a database connection can only be changed when that 1915 ** connection is not currently using lookaside memory, or in other words 1916 ** when the "current value" returned by 1917 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1918 ** Any attempt to change the lookaside memory configuration when lookaside 1919 ** memory is in use leaves the configuration unchanged and returns 1920 ** [SQLITE_BUSY].)^</dd> 1921 ** 1922 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1923 ** <dd> ^This option is used to enable or disable the enforcement of 1924 ** [foreign key constraints]. There should be two additional arguments. 1925 ** The first argument is an integer which is 0 to disable FK enforcement, 1926 ** positive to enable FK enforcement or negative to leave FK enforcement 1927 ** unchanged. The second parameter is a pointer to an integer into which 1928 ** is written 0 or 1 to indicate whether FK enforcement is off or on 1929 ** following this call. The second parameter may be a NULL pointer, in 1930 ** which case the FK enforcement setting is not reported back. </dd> 1931 ** 1932 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1933 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1934 ** There should be two additional arguments. 1935 ** The first argument is an integer which is 0 to disable triggers, 1936 ** positive to enable triggers or negative to leave the setting unchanged. 1937 ** The second parameter is a pointer to an integer into which 1938 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1939 ** following this call. The second parameter may be a NULL pointer, in 1940 ** which case the trigger setting is not reported back. </dd> 1941 ** 1942 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 1943 ** <dd> ^This option is used to enable or disable the two-argument 1944 ** version of the [fts3_tokenizer()] function which is part of the 1945 ** [FTS3] full-text search engine extension. 1946 ** There should be two additional arguments. 1947 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 1948 ** positive to enable fts3_tokenizer() or negative to leave the setting 1949 ** unchanged. 1950 ** The second parameter is a pointer to an integer into which 1951 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 1952 ** following this call. The second parameter may be a NULL pointer, in 1953 ** which case the new setting is not reported back. </dd> 1954 ** 1955 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 1956 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 1957 ** interface independently of the [load_extension()] SQL function. 1958 ** The [sqlite3_enable_load_extension()] API enables or disables both the 1959 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 1960 ** There should be two additional arguments. 1961 ** When the first argument to this interface is 1, then only the C-API is 1962 ** enabled and the SQL function remains disabled. If the first argument to 1963 ** this interface is 0, then both the C-API and the SQL function are disabled. 1964 ** If the first argument is -1, then no changes are made to state of either the 1965 ** C-API or the SQL function. 1966 ** The second parameter is a pointer to an integer into which 1967 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 1968 ** is disabled or enabled following this call. The second parameter may 1969 ** be a NULL pointer, in which case the new setting is not reported back. 1970 ** </dd> 1971 ** 1972 ** </dl> 1973 */ 1974 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1975 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1976 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1977 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 1978 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 1979 1980 1981 /* 1982 ** CAPI3REF: Enable Or Disable Extended Result Codes 1983 ** METHOD: sqlite3 1984 ** 1985 ** ^The sqlite3_extended_result_codes() routine enables or disables the 1986 ** [extended result codes] feature of SQLite. ^The extended result 1987 ** codes are disabled by default for historical compatibility. 1988 */ 1989 SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff); 1990 1991 /* 1992 ** CAPI3REF: Last Insert Rowid 1993 ** METHOD: sqlite3 1994 ** 1995 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1996 ** has a unique 64-bit signed 1997 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1998 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1999 ** names are not also used by explicitly declared columns. ^If 2000 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2001 ** is another alias for the rowid. 2002 ** 2003 ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 2004 ** most recent successful [INSERT] into a rowid table or [virtual table] 2005 ** on database connection D. 2006 ** ^Inserts into [WITHOUT ROWID] tables are not recorded. 2007 ** ^If no successful [INSERT]s into rowid tables 2008 ** have ever occurred on the database connection D, 2009 ** then sqlite3_last_insert_rowid(D) returns zero. 2010 ** 2011 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 2012 ** method, then this routine will return the [rowid] of the inserted 2013 ** row as long as the trigger or virtual table method is running. 2014 ** But once the trigger or virtual table method ends, the value returned 2015 ** by this routine reverts to what it was before the trigger or virtual 2016 ** table method began.)^ 2017 ** 2018 ** ^An [INSERT] that fails due to a constraint violation is not a 2019 ** successful [INSERT] and does not change the value returned by this 2020 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2021 ** and INSERT OR ABORT make no changes to the return value of this 2022 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2023 ** encounters a constraint violation, it does not fail. The 2024 ** INSERT continues to completion after deleting rows that caused 2025 ** the constraint problem so INSERT OR REPLACE will always change 2026 ** the return value of this interface.)^ 2027 ** 2028 ** ^For the purposes of this routine, an [INSERT] is considered to 2029 ** be successful even if it is subsequently rolled back. 2030 ** 2031 ** This function is accessible to SQL statements via the 2032 ** [last_insert_rowid() SQL function]. 2033 ** 2034 ** If a separate thread performs a new [INSERT] on the same 2035 ** database connection while the [sqlite3_last_insert_rowid()] 2036 ** function is running and thus changes the last insert [rowid], 2037 ** then the value returned by [sqlite3_last_insert_rowid()] is 2038 ** unpredictable and might not equal either the old or the new 2039 ** last insert [rowid]. 2040 */ 2041 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*); 2042 2043 /* 2044 ** CAPI3REF: Count The Number Of Rows Modified 2045 ** METHOD: sqlite3 2046 ** 2047 ** ^This function returns the number of rows modified, inserted or 2048 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2049 ** statement on the database connection specified by the only parameter. 2050 ** ^Executing any other type of SQL statement does not modify the value 2051 ** returned by this function. 2052 ** 2053 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2054 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2055 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2056 ** 2057 ** Changes to a view that are intercepted by 2058 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2059 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2060 ** DELETE statement run on a view is always zero. Only changes made to real 2061 ** tables are counted. 2062 ** 2063 ** Things are more complicated if the sqlite3_changes() function is 2064 ** executed while a trigger program is running. This may happen if the 2065 ** program uses the [changes() SQL function], or if some other callback 2066 ** function invokes sqlite3_changes() directly. Essentially: 2067 ** 2068 ** <ul> 2069 ** <li> ^(Before entering a trigger program the value returned by 2070 ** sqlite3_changes() function is saved. After the trigger program 2071 ** has finished, the original value is restored.)^ 2072 ** 2073 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2074 ** statement sets the value returned by sqlite3_changes() 2075 ** upon completion as normal. Of course, this value will not include 2076 ** any changes performed by sub-triggers, as the sqlite3_changes() 2077 ** value will be saved and restored after each sub-trigger has run.)^ 2078 ** </ul> 2079 ** 2080 ** ^This means that if the changes() SQL function (or similar) is used 2081 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2082 ** returns the value as set when the calling statement began executing. 2083 ** ^If it is used by the second or subsequent such statement within a trigger 2084 ** program, the value returned reflects the number of rows modified by the 2085 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2086 ** 2087 ** See also the [sqlite3_total_changes()] interface, the 2088 ** [count_changes pragma], and the [changes() SQL function]. 2089 ** 2090 ** If a separate thread makes changes on the same database connection 2091 ** while [sqlite3_changes()] is running then the value returned 2092 ** is unpredictable and not meaningful. 2093 */ 2094 SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*); 2095 2096 /* 2097 ** CAPI3REF: Total Number Of Rows Modified 2098 ** METHOD: sqlite3 2099 ** 2100 ** ^This function returns the total number of rows inserted, modified or 2101 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2102 ** since the database connection was opened, including those executed as 2103 ** part of trigger programs. ^Executing any other type of SQL statement 2104 ** does not affect the value returned by sqlite3_total_changes(). 2105 ** 2106 ** ^Changes made as part of [foreign key actions] are included in the 2107 ** count, but those made as part of REPLACE constraint resolution are 2108 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2109 ** are not counted. 2110 ** 2111 ** See also the [sqlite3_changes()] interface, the 2112 ** [count_changes pragma], and the [total_changes() SQL function]. 2113 ** 2114 ** If a separate thread makes changes on the same database connection 2115 ** while [sqlite3_total_changes()] is running then the value 2116 ** returned is unpredictable and not meaningful. 2117 */ 2118 SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*); 2119 2120 /* 2121 ** CAPI3REF: Interrupt A Long-Running Query 2122 ** METHOD: sqlite3 2123 ** 2124 ** ^This function causes any pending database operation to abort and 2125 ** return at its earliest opportunity. This routine is typically 2126 ** called in response to a user action such as pressing "Cancel" 2127 ** or Ctrl-C where the user wants a long query operation to halt 2128 ** immediately. 2129 ** 2130 ** ^It is safe to call this routine from a thread different from the 2131 ** thread that is currently running the database operation. But it 2132 ** is not safe to call this routine with a [database connection] that 2133 ** is closed or might close before sqlite3_interrupt() returns. 2134 ** 2135 ** ^If an SQL operation is very nearly finished at the time when 2136 ** sqlite3_interrupt() is called, then it might not have an opportunity 2137 ** to be interrupted and might continue to completion. 2138 ** 2139 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2140 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2141 ** that is inside an explicit transaction, then the entire transaction 2142 ** will be rolled back automatically. 2143 ** 2144 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2145 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2146 ** that are started after the sqlite3_interrupt() call and before the 2147 ** running statements reaches zero are interrupted as if they had been 2148 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2149 ** that are started after the running statement count reaches zero are 2150 ** not effected by the sqlite3_interrupt(). 2151 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2152 ** SQL statements is a no-op and has no effect on SQL statements 2153 ** that are started after the sqlite3_interrupt() call returns. 2154 ** 2155 ** If the database connection closes while [sqlite3_interrupt()] 2156 ** is running then bad things will likely happen. 2157 */ 2158 SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*); 2159 2160 /* 2161 ** CAPI3REF: Determine If An SQL Statement Is Complete 2162 ** 2163 ** These routines are useful during command-line input to determine if the 2164 ** currently entered text seems to form a complete SQL statement or 2165 ** if additional input is needed before sending the text into 2166 ** SQLite for parsing. ^These routines return 1 if the input string 2167 ** appears to be a complete SQL statement. ^A statement is judged to be 2168 ** complete if it ends with a semicolon token and is not a prefix of a 2169 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2170 ** string literals or quoted identifier names or comments are not 2171 ** independent tokens (they are part of the token in which they are 2172 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2173 ** and comments that follow the final semicolon are ignored. 2174 ** 2175 ** ^These routines return 0 if the statement is incomplete. ^If a 2176 ** memory allocation fails, then SQLITE_NOMEM is returned. 2177 ** 2178 ** ^These routines do not parse the SQL statements thus 2179 ** will not detect syntactically incorrect SQL. 2180 ** 2181 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2182 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2183 ** automatically by sqlite3_complete16(). If that initialization fails, 2184 ** then the return value from sqlite3_complete16() will be non-zero 2185 ** regardless of whether or not the input SQL is complete.)^ 2186 ** 2187 ** The input to [sqlite3_complete()] must be a zero-terminated 2188 ** UTF-8 string. 2189 ** 2190 ** The input to [sqlite3_complete16()] must be a zero-terminated 2191 ** UTF-16 string in native byte order. 2192 */ 2193 SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql); 2194 SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql); 2195 2196 /* 2197 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2198 ** KEYWORDS: {busy-handler callback} {busy handler} 2199 ** METHOD: sqlite3 2200 ** 2201 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2202 ** that might be invoked with argument P whenever 2203 ** an attempt is made to access a database table associated with 2204 ** [database connection] D when another thread 2205 ** or process has the table locked. 2206 ** The sqlite3_busy_handler() interface is used to implement 2207 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2208 ** 2209 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2210 ** is returned immediately upon encountering the lock. ^If the busy callback 2211 ** is not NULL, then the callback might be invoked with two arguments. 2212 ** 2213 ** ^The first argument to the busy handler is a copy of the void* pointer which 2214 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2215 ** the busy handler callback is the number of times that the busy handler has 2216 ** been invoked previously for the same locking event. ^If the 2217 ** busy callback returns 0, then no additional attempts are made to 2218 ** access the database and [SQLITE_BUSY] is returned 2219 ** to the application. 2220 ** ^If the callback returns non-zero, then another attempt 2221 ** is made to access the database and the cycle repeats. 2222 ** 2223 ** The presence of a busy handler does not guarantee that it will be invoked 2224 ** when there is lock contention. ^If SQLite determines that invoking the busy 2225 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2226 ** to the application instead of invoking the 2227 ** busy handler. 2228 ** Consider a scenario where one process is holding a read lock that 2229 ** it is trying to promote to a reserved lock and 2230 ** a second process is holding a reserved lock that it is trying 2231 ** to promote to an exclusive lock. The first process cannot proceed 2232 ** because it is blocked by the second and the second process cannot 2233 ** proceed because it is blocked by the first. If both processes 2234 ** invoke the busy handlers, neither will make any progress. Therefore, 2235 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2236 ** will induce the first process to release its read lock and allow 2237 ** the second process to proceed. 2238 ** 2239 ** ^The default busy callback is NULL. 2240 ** 2241 ** ^(There can only be a single busy handler defined for each 2242 ** [database connection]. Setting a new busy handler clears any 2243 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2244 ** or evaluating [PRAGMA busy_timeout=N] will change the 2245 ** busy handler and thus clear any previously set busy handler. 2246 ** 2247 ** The busy callback should not take any actions which modify the 2248 ** database connection that invoked the busy handler. In other words, 2249 ** the busy handler is not reentrant. Any such actions 2250 ** result in undefined behavior. 2251 ** 2252 ** A busy handler must not close the database connection 2253 ** or [prepared statement] that invoked the busy handler. 2254 */ 2255 SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2256 2257 /* 2258 ** CAPI3REF: Set A Busy Timeout 2259 ** METHOD: sqlite3 2260 ** 2261 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2262 ** for a specified amount of time when a table is locked. ^The handler 2263 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2264 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2265 ** the handler returns 0 which causes [sqlite3_step()] to return 2266 ** [SQLITE_BUSY]. 2267 ** 2268 ** ^Calling this routine with an argument less than or equal to zero 2269 ** turns off all busy handlers. 2270 ** 2271 ** ^(There can only be a single busy handler for a particular 2272 ** [database connection] at any given moment. If another busy handler 2273 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2274 ** this routine, that other busy handler is cleared.)^ 2275 ** 2276 ** See also: [PRAGMA busy_timeout] 2277 */ 2278 SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms); 2279 2280 /* 2281 ** CAPI3REF: Convenience Routines For Running Queries 2282 ** METHOD: sqlite3 2283 ** 2284 ** This is a legacy interface that is preserved for backwards compatibility. 2285 ** Use of this interface is not recommended. 2286 ** 2287 ** Definition: A <b>result table</b> is memory data structure created by the 2288 ** [sqlite3_get_table()] interface. A result table records the 2289 ** complete query results from one or more queries. 2290 ** 2291 ** The table conceptually has a number of rows and columns. But 2292 ** these numbers are not part of the result table itself. These 2293 ** numbers are obtained separately. Let N be the number of rows 2294 ** and M be the number of columns. 2295 ** 2296 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2297 ** There are (N+1)*M elements in the array. The first M pointers point 2298 ** to zero-terminated strings that contain the names of the columns. 2299 ** The remaining entries all point to query results. NULL values result 2300 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2301 ** string representation as returned by [sqlite3_column_text()]. 2302 ** 2303 ** A result table might consist of one or more memory allocations. 2304 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2305 ** A result table should be deallocated using [sqlite3_free_table()]. 2306 ** 2307 ** ^(As an example of the result table format, suppose a query result 2308 ** is as follows: 2309 ** 2310 ** <blockquote><pre> 2311 ** Name | Age 2312 ** ----------------------- 2313 ** Alice | 43 2314 ** Bob | 28 2315 ** Cindy | 21 2316 ** </pre></blockquote> 2317 ** 2318 ** There are two column (M==2) and three rows (N==3). Thus the 2319 ** result table has 8 entries. Suppose the result table is stored 2320 ** in an array names azResult. Then azResult holds this content: 2321 ** 2322 ** <blockquote><pre> 2323 ** azResult[0] = "Name"; 2324 ** azResult[1] = "Age"; 2325 ** azResult[2] = "Alice"; 2326 ** azResult[3] = "43"; 2327 ** azResult[4] = "Bob"; 2328 ** azResult[5] = "28"; 2329 ** azResult[6] = "Cindy"; 2330 ** azResult[7] = "21"; 2331 ** </pre></blockquote>)^ 2332 ** 2333 ** ^The sqlite3_get_table() function evaluates one or more 2334 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2335 ** string of its 2nd parameter and returns a result table to the 2336 ** pointer given in its 3rd parameter. 2337 ** 2338 ** After the application has finished with the result from sqlite3_get_table(), 2339 ** it must pass the result table pointer to sqlite3_free_table() in order to 2340 ** release the memory that was malloced. Because of the way the 2341 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2342 ** function must not try to call [sqlite3_free()] directly. Only 2343 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2344 ** 2345 ** The sqlite3_get_table() interface is implemented as a wrapper around 2346 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2347 ** to any internal data structures of SQLite. It uses only the public 2348 ** interface defined here. As a consequence, errors that occur in the 2349 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2350 ** reflected in subsequent calls to [sqlite3_errcode()] or 2351 ** [sqlite3_errmsg()]. 2352 */ 2353 SQLITE_API int SQLITE_STDCALL sqlite3_get_table( 2354 sqlite3 *db, /* An open database */ 2355 const char *zSql, /* SQL to be evaluated */ 2356 char ***pazResult, /* Results of the query */ 2357 int *pnRow, /* Number of result rows written here */ 2358 int *pnColumn, /* Number of result columns written here */ 2359 char **pzErrmsg /* Error msg written here */ 2360 ); 2361 SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result); 2362 2363 /* 2364 ** CAPI3REF: Formatted String Printing Functions 2365 ** 2366 ** These routines are work-alikes of the "printf()" family of functions 2367 ** from the standard C library. 2368 ** These routines understand most of the common K&R formatting options, 2369 ** plus some additional non-standard formats, detailed below. 2370 ** Note that some of the more obscure formatting options from recent 2371 ** C-library standards are omitted from this implementation. 2372 ** 2373 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2374 ** results into memory obtained from [sqlite3_malloc()]. 2375 ** The strings returned by these two routines should be 2376 ** released by [sqlite3_free()]. ^Both routines return a 2377 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2378 ** memory to hold the resulting string. 2379 ** 2380 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2381 ** the standard C library. The result is written into the 2382 ** buffer supplied as the second parameter whose size is given by 2383 ** the first parameter. Note that the order of the 2384 ** first two parameters is reversed from snprintf().)^ This is an 2385 ** historical accident that cannot be fixed without breaking 2386 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2387 ** returns a pointer to its buffer instead of the number of 2388 ** characters actually written into the buffer.)^ We admit that 2389 ** the number of characters written would be a more useful return 2390 ** value but we cannot change the implementation of sqlite3_snprintf() 2391 ** now without breaking compatibility. 2392 ** 2393 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2394 ** guarantees that the buffer is always zero-terminated. ^The first 2395 ** parameter "n" is the total size of the buffer, including space for 2396 ** the zero terminator. So the longest string that can be completely 2397 ** written will be n-1 characters. 2398 ** 2399 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2400 ** 2401 ** These routines all implement some additional formatting 2402 ** options that are useful for constructing SQL statements. 2403 ** All of the usual printf() formatting options apply. In addition, there 2404 ** is are "%q", "%Q", "%w" and "%z" options. 2405 ** 2406 ** ^(The %q option works like %s in that it substitutes a nul-terminated 2407 ** string from the argument list. But %q also doubles every '\'' character. 2408 ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2409 ** character it escapes that character and allows it to be inserted into 2410 ** the string. 2411 ** 2412 ** For example, assume the string variable zText contains text as follows: 2413 ** 2414 ** <blockquote><pre> 2415 ** char *zText = "It's a happy day!"; 2416 ** </pre></blockquote> 2417 ** 2418 ** One can use this text in an SQL statement as follows: 2419 ** 2420 ** <blockquote><pre> 2421 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2422 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2423 ** sqlite3_free(zSQL); 2424 ** </pre></blockquote> 2425 ** 2426 ** Because the %q format string is used, the '\'' character in zText 2427 ** is escaped and the SQL generated is as follows: 2428 ** 2429 ** <blockquote><pre> 2430 ** INSERT INTO table1 VALUES('It''s a happy day!') 2431 ** </pre></blockquote> 2432 ** 2433 ** This is correct. Had we used %s instead of %q, the generated SQL 2434 ** would have looked like this: 2435 ** 2436 ** <blockquote><pre> 2437 ** INSERT INTO table1 VALUES('It's a happy day!'); 2438 ** </pre></blockquote> 2439 ** 2440 ** This second example is an SQL syntax error. As a general rule you should 2441 ** always use %q instead of %s when inserting text into a string literal. 2442 ** 2443 ** ^(The %Q option works like %q except it also adds single quotes around 2444 ** the outside of the total string. Additionally, if the parameter in the 2445 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2446 ** single quotes).)^ So, for example, one could say: 2447 ** 2448 ** <blockquote><pre> 2449 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2450 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2451 ** sqlite3_free(zSQL); 2452 ** </pre></blockquote> 2453 ** 2454 ** The code above will render a correct SQL statement in the zSQL 2455 ** variable even if the zText variable is a NULL pointer. 2456 ** 2457 ** ^(The "%w" formatting option is like "%q" except that it expects to 2458 ** be contained within double-quotes instead of single quotes, and it 2459 ** escapes the double-quote character instead of the single-quote 2460 ** character.)^ The "%w" formatting option is intended for safely inserting 2461 ** table and column names into a constructed SQL statement. 2462 ** 2463 ** ^(The "%z" formatting option works like "%s" but with the 2464 ** addition that after the string has been read and copied into 2465 ** the result, [sqlite3_free()] is called on the input string.)^ 2466 */ 2467 SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...); 2468 SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list); 2469 SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...); 2470 SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list); 2471 2472 /* 2473 ** CAPI3REF: Memory Allocation Subsystem 2474 ** 2475 ** The SQLite core uses these three routines for all of its own 2476 ** internal memory allocation needs. "Core" in the previous sentence 2477 ** does not include operating-system specific VFS implementation. The 2478 ** Windows VFS uses native malloc() and free() for some operations. 2479 ** 2480 ** ^The sqlite3_malloc() routine returns a pointer to a block 2481 ** of memory at least N bytes in length, where N is the parameter. 2482 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2483 ** memory, it returns a NULL pointer. ^If the parameter N to 2484 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2485 ** a NULL pointer. 2486 ** 2487 ** ^The sqlite3_malloc64(N) routine works just like 2488 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2489 ** of a signed 32-bit integer. 2490 ** 2491 ** ^Calling sqlite3_free() with a pointer previously returned 2492 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2493 ** that it might be reused. ^The sqlite3_free() routine is 2494 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2495 ** to sqlite3_free() is harmless. After being freed, memory 2496 ** should neither be read nor written. Even reading previously freed 2497 ** memory might result in a segmentation fault or other severe error. 2498 ** Memory corruption, a segmentation fault, or other severe error 2499 ** might result if sqlite3_free() is called with a non-NULL pointer that 2500 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2501 ** 2502 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2503 ** prior memory allocation X to be at least N bytes. 2504 ** ^If the X parameter to sqlite3_realloc(X,N) 2505 ** is a NULL pointer then its behavior is identical to calling 2506 ** sqlite3_malloc(N). 2507 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2508 ** negative then the behavior is exactly the same as calling 2509 ** sqlite3_free(X). 2510 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2511 ** of at least N bytes in size or NULL if insufficient memory is available. 2512 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2513 ** of the prior allocation are copied into the beginning of buffer returned 2514 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2515 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2516 ** prior allocation is not freed. 2517 ** 2518 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2519 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2520 ** of a 32-bit signed integer. 2521 ** 2522 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2523 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2524 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2525 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2526 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2527 ** sqlite3_msize(X) returns zero. If X points to something that is not 2528 ** the beginning of memory allocation, or if it points to a formerly 2529 ** valid memory allocation that has now been freed, then the behavior 2530 ** of sqlite3_msize(X) is undefined and possibly harmful. 2531 ** 2532 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2533 ** sqlite3_malloc64(), and sqlite3_realloc64() 2534 ** is always aligned to at least an 8 byte boundary, or to a 2535 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2536 ** option is used. 2537 ** 2538 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2539 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2540 ** implementation of these routines to be omitted. That capability 2541 ** is no longer provided. Only built-in memory allocators can be used. 2542 ** 2543 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2544 ** the system malloc() and free() directly when converting 2545 ** filenames between the UTF-8 encoding used by SQLite 2546 ** and whatever filename encoding is used by the particular Windows 2547 ** installation. Memory allocation errors were detected, but 2548 ** they were reported back as [SQLITE_CANTOPEN] or 2549 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2550 ** 2551 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2552 ** must be either NULL or else pointers obtained from a prior 2553 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2554 ** not yet been released. 2555 ** 2556 ** The application must not read or write any part of 2557 ** a block of memory after it has been released using 2558 ** [sqlite3_free()] or [sqlite3_realloc()]. 2559 */ 2560 SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int); 2561 SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64); 2562 SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int); 2563 SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64); 2564 SQLITE_API void SQLITE_STDCALL sqlite3_free(void*); 2565 SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*); 2566 2567 /* 2568 ** CAPI3REF: Memory Allocator Statistics 2569 ** 2570 ** SQLite provides these two interfaces for reporting on the status 2571 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2572 ** routines, which form the built-in memory allocation subsystem. 2573 ** 2574 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2575 ** of memory currently outstanding (malloced but not freed). 2576 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2577 ** value of [sqlite3_memory_used()] since the high-water mark 2578 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2579 ** [sqlite3_memory_highwater()] include any overhead 2580 ** added by SQLite in its implementation of [sqlite3_malloc()], 2581 ** but not overhead added by the any underlying system library 2582 ** routines that [sqlite3_malloc()] may call. 2583 ** 2584 ** ^The memory high-water mark is reset to the current value of 2585 ** [sqlite3_memory_used()] if and only if the parameter to 2586 ** [sqlite3_memory_highwater()] is true. ^The value returned 2587 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2588 ** prior to the reset. 2589 */ 2590 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void); 2591 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag); 2592 2593 /* 2594 ** CAPI3REF: Pseudo-Random Number Generator 2595 ** 2596 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2597 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2598 ** already uses the largest possible [ROWID]. The PRNG is also used for 2599 ** the build-in random() and randomblob() SQL functions. This interface allows 2600 ** applications to access the same PRNG for other purposes. 2601 ** 2602 ** ^A call to this routine stores N bytes of randomness into buffer P. 2603 ** ^The P parameter can be a NULL pointer. 2604 ** 2605 ** ^If this routine has not been previously called or if the previous 2606 ** call had N less than one or a NULL pointer for P, then the PRNG is 2607 ** seeded using randomness obtained from the xRandomness method of 2608 ** the default [sqlite3_vfs] object. 2609 ** ^If the previous call to this routine had an N of 1 or more and a 2610 ** non-NULL P then the pseudo-randomness is generated 2611 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2612 ** method. 2613 */ 2614 SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P); 2615 2616 /* 2617 ** CAPI3REF: Compile-Time Authorization Callbacks 2618 ** METHOD: sqlite3 2619 ** 2620 ** ^This routine registers an authorizer callback with a particular 2621 ** [database connection], supplied in the first argument. 2622 ** ^The authorizer callback is invoked as SQL statements are being compiled 2623 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2624 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2625 ** points during the compilation process, as logic is being created 2626 ** to perform various actions, the authorizer callback is invoked to 2627 ** see if those actions are allowed. ^The authorizer callback should 2628 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2629 ** specific action but allow the SQL statement to continue to be 2630 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2631 ** rejected with an error. ^If the authorizer callback returns 2632 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2633 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2634 ** the authorizer will fail with an error message. 2635 ** 2636 ** When the callback returns [SQLITE_OK], that means the operation 2637 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2638 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2639 ** authorizer will fail with an error message explaining that 2640 ** access is denied. 2641 ** 2642 ** ^The first parameter to the authorizer callback is a copy of the third 2643 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2644 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2645 ** the particular action to be authorized. ^The third through sixth parameters 2646 ** to the callback are zero-terminated strings that contain additional 2647 ** details about the action to be authorized. 2648 ** 2649 ** ^If the action code is [SQLITE_READ] 2650 ** and the callback returns [SQLITE_IGNORE] then the 2651 ** [prepared statement] statement is constructed to substitute 2652 ** a NULL value in place of the table column that would have 2653 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2654 ** return can be used to deny an untrusted user access to individual 2655 ** columns of a table. 2656 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2657 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2658 ** [truncate optimization] is disabled and all rows are deleted individually. 2659 ** 2660 ** An authorizer is used when [sqlite3_prepare | preparing] 2661 ** SQL statements from an untrusted source, to ensure that the SQL statements 2662 ** do not try to access data they are not allowed to see, or that they do not 2663 ** try to execute malicious statements that damage the database. For 2664 ** example, an application may allow a user to enter arbitrary 2665 ** SQL queries for evaluation by a database. But the application does 2666 ** not want the user to be able to make arbitrary changes to the 2667 ** database. An authorizer could then be put in place while the 2668 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2669 ** disallows everything except [SELECT] statements. 2670 ** 2671 ** Applications that need to process SQL from untrusted sources 2672 ** might also consider lowering resource limits using [sqlite3_limit()] 2673 ** and limiting database size using the [max_page_count] [PRAGMA] 2674 ** in addition to using an authorizer. 2675 ** 2676 ** ^(Only a single authorizer can be in place on a database connection 2677 ** at a time. Each call to sqlite3_set_authorizer overrides the 2678 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2679 ** The authorizer is disabled by default. 2680 ** 2681 ** The authorizer callback must not do anything that will modify 2682 ** the database connection that invoked the authorizer callback. 2683 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2684 ** database connections for the meaning of "modify" in this paragraph. 2685 ** 2686 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2687 ** statement might be re-prepared during [sqlite3_step()] due to a 2688 ** schema change. Hence, the application should ensure that the 2689 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2690 ** 2691 ** ^Note that the authorizer callback is invoked only during 2692 ** [sqlite3_prepare()] or its variants. Authorization is not 2693 ** performed during statement evaluation in [sqlite3_step()], unless 2694 ** as stated in the previous paragraph, sqlite3_step() invokes 2695 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2696 */ 2697 SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer( 2698 sqlite3*, 2699 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2700 void *pUserData 2701 ); 2702 2703 /* 2704 ** CAPI3REF: Authorizer Return Codes 2705 ** 2706 ** The [sqlite3_set_authorizer | authorizer callback function] must 2707 ** return either [SQLITE_OK] or one of these two constants in order 2708 ** to signal SQLite whether or not the action is permitted. See the 2709 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2710 ** information. 2711 ** 2712 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2713 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2714 */ 2715 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2716 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2717 2718 /* 2719 ** CAPI3REF: Authorizer Action Codes 2720 ** 2721 ** The [sqlite3_set_authorizer()] interface registers a callback function 2722 ** that is invoked to authorize certain SQL statement actions. The 2723 ** second parameter to the callback is an integer code that specifies 2724 ** what action is being authorized. These are the integer action codes that 2725 ** the authorizer callback may be passed. 2726 ** 2727 ** These action code values signify what kind of operation is to be 2728 ** authorized. The 3rd and 4th parameters to the authorization 2729 ** callback function will be parameters or NULL depending on which of these 2730 ** codes is used as the second parameter. ^(The 5th parameter to the 2731 ** authorizer callback is the name of the database ("main", "temp", 2732 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2733 ** is the name of the inner-most trigger or view that is responsible for 2734 ** the access attempt or NULL if this access attempt is directly from 2735 ** top-level SQL code. 2736 */ 2737 /******************************************* 3rd ************ 4th ***********/ 2738 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2739 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2740 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2741 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2742 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2743 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2744 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2745 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2746 #define SQLITE_DELETE 9 /* Table Name NULL */ 2747 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2748 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2749 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2750 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2751 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2752 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2753 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2754 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2755 #define SQLITE_INSERT 18 /* Table Name NULL */ 2756 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2757 #define SQLITE_READ 20 /* Table Name Column Name */ 2758 #define SQLITE_SELECT 21 /* NULL NULL */ 2759 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2760 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2761 #define SQLITE_ATTACH 24 /* Filename NULL */ 2762 #define SQLITE_DETACH 25 /* Database Name NULL */ 2763 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2764 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2765 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2766 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2767 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2768 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2769 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2770 #define SQLITE_COPY 0 /* No longer used */ 2771 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2772 2773 /* 2774 ** CAPI3REF: Tracing And Profiling Functions 2775 ** METHOD: sqlite3 2776 ** 2777 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2778 ** instead of the routines described here. 2779 ** 2780 ** These routines register callback functions that can be used for 2781 ** tracing and profiling the execution of SQL statements. 2782 ** 2783 ** ^The callback function registered by sqlite3_trace() is invoked at 2784 ** various times when an SQL statement is being run by [sqlite3_step()]. 2785 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2786 ** SQL statement text as the statement first begins executing. 2787 ** ^(Additional sqlite3_trace() callbacks might occur 2788 ** as each triggered subprogram is entered. The callbacks for triggers 2789 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2790 ** 2791 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2792 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2793 ** 2794 ** ^The callback function registered by sqlite3_profile() is invoked 2795 ** as each SQL statement finishes. ^The profile callback contains 2796 ** the original statement text and an estimate of wall-clock time 2797 ** of how long that statement took to run. ^The profile callback 2798 ** time is in units of nanoseconds, however the current implementation 2799 ** is only capable of millisecond resolution so the six least significant 2800 ** digits in the time are meaningless. Future versions of SQLite 2801 ** might provide greater resolution on the profiler callback. The 2802 ** sqlite3_profile() function is considered experimental and is 2803 ** subject to change in future versions of SQLite. 2804 */ 2805 SQLITE_API SQLITE_DEPRECATED void *SQLITE_STDCALL sqlite3_trace(sqlite3*, 2806 void(*xTrace)(void*,const char*), void*); 2807 SQLITE_API SQLITE_DEPRECATED void *SQLITE_STDCALL sqlite3_profile(sqlite3*, 2808 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2809 2810 /* 2811 ** CAPI3REF: SQL Trace Event Codes 2812 ** KEYWORDS: SQLITE_TRACE 2813 ** 2814 ** These constants identify classes of events that can be monitored 2815 ** using the [sqlite3_trace_v2()] tracing logic. The third argument 2816 ** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of 2817 ** the following constants. ^The first argument to the trace callback 2818 ** is one of the following constants. 2819 ** 2820 ** New tracing constants may be added in future releases. 2821 ** 2822 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 2823 ** ^The T argument is one of the integer type codes above. 2824 ** ^The C argument is a copy of the context pointer passed in as the 2825 ** fourth argument to [sqlite3_trace_v2()]. 2826 ** The P and X arguments are pointers whose meanings depend on T. 2827 ** 2828 ** <dl> 2829 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2830 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2831 ** first begins running and possibly at other times during the 2832 ** execution of the prepared statement, such as at the start of each 2833 ** trigger subprogram. ^The P argument is a pointer to the 2834 ** [prepared statement]. ^The X argument is a pointer to a string which 2835 ** is the unexpanded SQL text of the prepared statement or an SQL comment 2836 ** that indicates the invocation of a trigger. ^The callback can compute 2837 ** the same text that would have been returned by the legacy [sqlite3_trace()] 2838 ** interface by using the X argument when X begins with "--" and invoking 2839 ** [sqlite3_expanded_sql(P)] otherwise. 2840 ** 2841 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2842 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2843 ** information as is provided by the [sqlite3_profile()] callback. 2844 ** ^The P argument is a pointer to the [prepared statement] and the 2845 ** X argument points to a 64-bit integer which is the estimated of 2846 ** the number of nanosecond that the prepared statement took to run. 2847 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2848 ** 2849 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2850 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2851 ** statement generates a single row of result. 2852 ** ^The P argument is a pointer to the [prepared statement] and the 2853 ** X argument is unused. 2854 ** 2855 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2856 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2857 ** connection closes. 2858 ** ^The P argument is a pointer to the [database connection] object 2859 ** and the X argument is unused. 2860 ** </dl> 2861 */ 2862 #define SQLITE_TRACE_STMT 0x01 2863 #define SQLITE_TRACE_PROFILE 0x02 2864 #define SQLITE_TRACE_ROW 0x04 2865 #define SQLITE_TRACE_CLOSE 0x08 2866 2867 /* 2868 ** CAPI3REF: SQL Trace Hook 2869 ** METHOD: sqlite3 2870 ** 2871 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2872 ** function X against [database connection] D, using property mask M 2873 ** and context pointer P. ^If the X callback is 2874 ** NULL or if the M mask is zero, then tracing is disabled. The 2875 ** M argument should be the bitwise OR-ed combination of 2876 ** zero or more [SQLITE_TRACE] constants. 2877 ** 2878 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 2879 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 2880 ** 2881 ** ^The X callback is invoked whenever any of the events identified by 2882 ** mask M occur. ^The integer return value from the callback is currently 2883 ** ignored, though this may change in future releases. Callback 2884 ** implementations should return zero to ensure future compatibility. 2885 ** 2886 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 2887 ** ^The T argument is one of the [SQLITE_TRACE] 2888 ** constants to indicate why the callback was invoked. 2889 ** ^The C argument is a copy of the context pointer. 2890 ** The P and X arguments are pointers whose meanings depend on T. 2891 ** 2892 ** The sqlite3_trace_v2() interface is intended to replace the legacy 2893 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 2894 ** are deprecated. 2895 */ 2896 SQLITE_API int SQLITE_STDCALL sqlite3_trace_v2( 2897 sqlite3*, 2898 unsigned uMask, 2899 int(*xCallback)(unsigned,void*,void*,void*), 2900 void *pCtx 2901 ); 2902 2903 /* 2904 ** CAPI3REF: Query Progress Callbacks 2905 ** METHOD: sqlite3 2906 ** 2907 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2908 ** function X to be invoked periodically during long running calls to 2909 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2910 ** database connection D. An example use for this 2911 ** interface is to keep a GUI updated during a large query. 2912 ** 2913 ** ^The parameter P is passed through as the only parameter to the 2914 ** callback function X. ^The parameter N is the approximate number of 2915 ** [virtual machine instructions] that are evaluated between successive 2916 ** invocations of the callback X. ^If N is less than one then the progress 2917 ** handler is disabled. 2918 ** 2919 ** ^Only a single progress handler may be defined at one time per 2920 ** [database connection]; setting a new progress handler cancels the 2921 ** old one. ^Setting parameter X to NULL disables the progress handler. 2922 ** ^The progress handler is also disabled by setting N to a value less 2923 ** than 1. 2924 ** 2925 ** ^If the progress callback returns non-zero, the operation is 2926 ** interrupted. This feature can be used to implement a 2927 ** "Cancel" button on a GUI progress dialog box. 2928 ** 2929 ** The progress handler callback must not do anything that will modify 2930 ** the database connection that invoked the progress handler. 2931 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2932 ** database connections for the meaning of "modify" in this paragraph. 2933 ** 2934 */ 2935 SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2936 2937 /* 2938 ** CAPI3REF: Opening A New Database Connection 2939 ** CONSTRUCTOR: sqlite3 2940 ** 2941 ** ^These routines open an SQLite database file as specified by the 2942 ** filename argument. ^The filename argument is interpreted as UTF-8 for 2943 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2944 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 2945 ** returned in *ppDb, even if an error occurs. The only exception is that 2946 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2947 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2948 ** object.)^ ^(If the database is opened (and/or created) successfully, then 2949 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2950 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2951 ** an English language description of the error following a failure of any 2952 ** of the sqlite3_open() routines. 2953 ** 2954 ** ^The default encoding will be UTF-8 for databases created using 2955 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2956 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 2957 ** 2958 ** Whether or not an error occurs when it is opened, resources 2959 ** associated with the [database connection] handle should be released by 2960 ** passing it to [sqlite3_close()] when it is no longer required. 2961 ** 2962 ** The sqlite3_open_v2() interface works like sqlite3_open() 2963 ** except that it accepts two additional parameters for additional control 2964 ** over the new database connection. ^(The flags parameter to 2965 ** sqlite3_open_v2() can take one of 2966 ** the following three values, optionally combined with the 2967 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2968 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2969 ** 2970 ** <dl> 2971 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2972 ** <dd>The database is opened in read-only mode. If the database does not 2973 ** already exist, an error is returned.</dd>)^ 2974 ** 2975 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2976 ** <dd>The database is opened for reading and writing if possible, or reading 2977 ** only if the file is write protected by the operating system. In either 2978 ** case the database must already exist, otherwise an error is returned.</dd>)^ 2979 ** 2980 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2981 ** <dd>The database is opened for reading and writing, and is created if 2982 ** it does not already exist. This is the behavior that is always used for 2983 ** sqlite3_open() and sqlite3_open16().</dd>)^ 2984 ** </dl> 2985 ** 2986 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 2987 ** combinations shown above optionally combined with other 2988 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2989 ** then the behavior is undefined. 2990 ** 2991 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2992 ** opens in the multi-thread [threading mode] as long as the single-thread 2993 ** mode has not been set at compile-time or start-time. ^If the 2994 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2995 ** in the serialized [threading mode] unless single-thread was 2996 ** previously selected at compile-time or start-time. 2997 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2998 ** eligible to use [shared cache mode], regardless of whether or not shared 2999 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3000 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3001 ** participate in [shared cache mode] even if it is enabled. 3002 ** 3003 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3004 ** [sqlite3_vfs] object that defines the operating system interface that 3005 ** the new database connection should use. ^If the fourth parameter is 3006 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3007 ** 3008 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3009 ** is created for the connection. ^This in-memory database will vanish when 3010 ** the database connection is closed. Future versions of SQLite might 3011 ** make use of additional special filenames that begin with the ":" character. 3012 ** It is recommended that when a database filename actually does begin with 3013 ** a ":" character you should prefix the filename with a pathname such as 3014 ** "./" to avoid ambiguity. 3015 ** 3016 ** ^If the filename is an empty string, then a private, temporary 3017 ** on-disk database will be created. ^This private database will be 3018 ** automatically deleted as soon as the database connection is closed. 3019 ** 3020 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3021 ** 3022 ** ^If [URI filename] interpretation is enabled, and the filename argument 3023 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3024 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3025 ** set in the fourth argument to sqlite3_open_v2(), or if it has 3026 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3027 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3028 ** As of SQLite version 3.7.7, URI filename interpretation is turned off 3029 ** by default, but future releases of SQLite might enable URI filename 3030 ** interpretation by default. See "[URI filenames]" for additional 3031 ** information. 3032 ** 3033 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3034 ** authority, then it must be either an empty string or the string 3035 ** "localhost". ^If the authority is not an empty string or "localhost", an 3036 ** error is returned to the caller. ^The fragment component of a URI, if 3037 ** present, is ignored. 3038 ** 3039 ** ^SQLite uses the path component of the URI as the name of the disk file 3040 ** which contains the database. ^If the path begins with a '/' character, 3041 ** then it is interpreted as an absolute path. ^If the path does not begin 3042 ** with a '/' (meaning that the authority section is omitted from the URI) 3043 ** then the path is interpreted as a relative path. 3044 ** ^(On windows, the first component of an absolute path 3045 ** is a drive specification (e.g. "C:").)^ 3046 ** 3047 ** [[core URI query parameters]] 3048 ** The query component of a URI may contain parameters that are interpreted 3049 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3050 ** SQLite and its built-in [VFSes] interpret the 3051 ** following query parameters: 3052 ** 3053 ** <ul> 3054 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3055 ** a VFS object that provides the operating system interface that should 3056 ** be used to access the database file on disk. ^If this option is set to 3057 ** an empty string the default VFS object is used. ^Specifying an unknown 3058 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3059 ** present, then the VFS specified by the option takes precedence over 3060 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3061 ** 3062 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3063 ** "rwc", or "memory". Attempting to set it to any other value is 3064 ** an error)^. 3065 ** ^If "ro" is specified, then the database is opened for read-only 3066 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3067 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3068 ** "rw", then the database is opened for read-write (but not create) 3069 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3070 ** been set. ^Value "rwc" is equivalent to setting both 3071 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3072 ** set to "memory" then a pure [in-memory database] that never reads 3073 ** or writes from disk is used. ^It is an error to specify a value for 3074 ** the mode parameter that is less restrictive than that specified by 3075 ** the flags passed in the third parameter to sqlite3_open_v2(). 3076 ** 3077 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3078 ** "private". ^Setting it to "shared" is equivalent to setting the 3079 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3080 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3081 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3082 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3083 ** a URI filename, its value overrides any behavior requested by setting 3084 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3085 ** 3086 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3087 ** [powersafe overwrite] property does or does not apply to the 3088 ** storage media on which the database file resides. 3089 ** 3090 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3091 ** which if set disables file locking in rollback journal modes. This 3092 ** is useful for accessing a database on a filesystem that does not 3093 ** support locking. Caution: Database corruption might result if two 3094 ** or more processes write to the same database and any one of those 3095 ** processes uses nolock=1. 3096 ** 3097 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3098 ** parameter that indicates that the database file is stored on 3099 ** read-only media. ^When immutable is set, SQLite assumes that the 3100 ** database file cannot be changed, even by a process with higher 3101 ** privilege, and so the database is opened read-only and all locking 3102 ** and change detection is disabled. Caution: Setting the immutable 3103 ** property on a database file that does in fact change can result 3104 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3105 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3106 ** 3107 ** </ul> 3108 ** 3109 ** ^Specifying an unknown parameter in the query component of a URI is not an 3110 ** error. Future versions of SQLite might understand additional query 3111 ** parameters. See "[query parameters with special meaning to SQLite]" for 3112 ** additional information. 3113 ** 3114 ** [[URI filename examples]] <h3>URI filename examples</h3> 3115 ** 3116 ** <table border="1" align=center cellpadding=5> 3117 ** <tr><th> URI filenames <th> Results 3118 ** <tr><td> file:data.db <td> 3119 ** Open the file "data.db" in the current directory. 3120 ** <tr><td> file:/home/fred/data.db<br> 3121 ** file:///home/fred/data.db <br> 3122 ** file://localhost/home/fred/data.db <br> <td> 3123 ** Open the database file "/home/fred/data.db". 3124 ** <tr><td> file://darkstar/home/fred/data.db <td> 3125 ** An error. "darkstar" is not a recognized authority. 3126 ** <tr><td style="white-space:nowrap"> 3127 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3128 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3129 ** C:. Note that the %20 escaping in this example is not strictly 3130 ** necessary - space characters can be used literally 3131 ** in URI filenames. 3132 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3133 ** Open file "data.db" in the current directory for read-only access. 3134 ** Regardless of whether or not shared-cache mode is enabled by 3135 ** default, use a private cache. 3136 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3137 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3138 ** that uses dot-files in place of posix advisory locking. 3139 ** <tr><td> file:data.db?mode=readonly <td> 3140 ** An error. "readonly" is not a valid option for the "mode" parameter. 3141 ** </table> 3142 ** 3143 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3144 ** query components of a URI. A hexadecimal escape sequence consists of a 3145 ** percent sign - "%" - followed by exactly two hexadecimal digits 3146 ** specifying an octet value. ^Before the path or query components of a 3147 ** URI filename are interpreted, they are encoded using UTF-8 and all 3148 ** hexadecimal escape sequences replaced by a single byte containing the 3149 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3150 ** the results are undefined. 3151 ** 3152 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3153 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3154 ** codepage is currently defined. Filenames containing international 3155 ** characters must be converted to UTF-8 prior to passing them into 3156 ** sqlite3_open() or sqlite3_open_v2(). 3157 ** 3158 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3159 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3160 ** features that require the use of temporary files may fail. 3161 ** 3162 ** See also: [sqlite3_temp_directory] 3163 */ 3164 SQLITE_API int SQLITE_STDCALL sqlite3_open( 3165 const char *filename, /* Database filename (UTF-8) */ 3166 sqlite3 **ppDb /* OUT: SQLite db handle */ 3167 ); 3168 SQLITE_API int SQLITE_STDCALL sqlite3_open16( 3169 const void *filename, /* Database filename (UTF-16) */ 3170 sqlite3 **ppDb /* OUT: SQLite db handle */ 3171 ); 3172 SQLITE_API int SQLITE_STDCALL sqlite3_open_v2( 3173 const char *filename, /* Database filename (UTF-8) */ 3174 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3175 int flags, /* Flags */ 3176 const char *zVfs /* Name of VFS module to use */ 3177 ); 3178 3179 /* 3180 ** CAPI3REF: Obtain Values For URI Parameters 3181 ** 3182 ** These are utility routines, useful to VFS implementations, that check 3183 ** to see if a database file was a URI that contained a specific query 3184 ** parameter, and if so obtains the value of that query parameter. 3185 ** 3186 ** If F is the database filename pointer passed into the xOpen() method of 3187 ** a VFS implementation when the flags parameter to xOpen() has one or 3188 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3189 ** P is the name of the query parameter, then 3190 ** sqlite3_uri_parameter(F,P) returns the value of the P 3191 ** parameter if it exists or a NULL pointer if P does not appear as a 3192 ** query parameter on F. If P is a query parameter of F 3193 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3194 ** a pointer to an empty string. 3195 ** 3196 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3197 ** parameter and returns true (1) or false (0) according to the value 3198 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3199 ** value of query parameter P is one of "yes", "true", or "on" in any 3200 ** case or if the value begins with a non-zero number. The 3201 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3202 ** query parameter P is one of "no", "false", or "off" in any case or 3203 ** if the value begins with a numeric zero. If P is not a query 3204 ** parameter on F or if the value of P is does not match any of the 3205 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3206 ** 3207 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3208 ** 64-bit signed integer and returns that integer, or D if P does not 3209 ** exist. If the value of P is something other than an integer, then 3210 ** zero is returned. 3211 ** 3212 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3213 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3214 ** is not a database file pathname pointer that SQLite passed into the xOpen 3215 ** VFS method, then the behavior of this routine is undefined and probably 3216 ** undesirable. 3217 */ 3218 SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3219 SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3220 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3221 3222 3223 /* 3224 ** CAPI3REF: Error Codes And Messages 3225 ** METHOD: sqlite3 3226 ** 3227 ** ^If the most recent sqlite3_* API call associated with 3228 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3229 ** returns the numeric [result code] or [extended result code] for that 3230 ** API call. 3231 ** If the most recent API call was successful, 3232 ** then the return value from sqlite3_errcode() is undefined. 3233 ** ^The sqlite3_extended_errcode() 3234 ** interface is the same except that it always returns the 3235 ** [extended result code] even when extended result codes are 3236 ** disabled. 3237 ** 3238 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3239 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3240 ** ^(Memory to hold the error message string is managed internally. 3241 ** The application does not need to worry about freeing the result. 3242 ** However, the error string might be overwritten or deallocated by 3243 ** subsequent calls to other SQLite interface functions.)^ 3244 ** 3245 ** ^The sqlite3_errstr() interface returns the English-language text 3246 ** that describes the [result code], as UTF-8. 3247 ** ^(Memory to hold the error message string is managed internally 3248 ** and must not be freed by the application)^. 3249 ** 3250 ** When the serialized [threading mode] is in use, it might be the 3251 ** case that a second error occurs on a separate thread in between 3252 ** the time of the first error and the call to these interfaces. 3253 ** When that happens, the second error will be reported since these 3254 ** interfaces always report the most recent result. To avoid 3255 ** this, each thread can obtain exclusive use of the [database connection] D 3256 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3257 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3258 ** all calls to the interfaces listed here are completed. 3259 ** 3260 ** If an interface fails with SQLITE_MISUSE, that means the interface 3261 ** was invoked incorrectly by the application. In that case, the 3262 ** error code and message may or may not be set. 3263 */ 3264 SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db); 3265 SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db); 3266 SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*); 3267 SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*); 3268 SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int); 3269 3270 /* 3271 ** CAPI3REF: Prepared Statement Object 3272 ** KEYWORDS: {prepared statement} {prepared statements} 3273 ** 3274 ** An instance of this object represents a single SQL statement that 3275 ** has been compiled into binary form and is ready to be evaluated. 3276 ** 3277 ** Think of each SQL statement as a separate computer program. The 3278 ** original SQL text is source code. A prepared statement object 3279 ** is the compiled object code. All SQL must be converted into a 3280 ** prepared statement before it can be run. 3281 ** 3282 ** The life-cycle of a prepared statement object usually goes like this: 3283 ** 3284 ** <ol> 3285 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3286 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3287 ** interfaces. 3288 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3289 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3290 ** to step 2. Do this zero or more times. 3291 ** <li> Destroy the object using [sqlite3_finalize()]. 3292 ** </ol> 3293 */ 3294 typedef struct sqlite3_stmt sqlite3_stmt; 3295 3296 /* 3297 ** CAPI3REF: Run-time Limits 3298 ** METHOD: sqlite3 3299 ** 3300 ** ^(This interface allows the size of various constructs to be limited 3301 ** on a connection by connection basis. The first parameter is the 3302 ** [database connection] whose limit is to be set or queried. The 3303 ** second parameter is one of the [limit categories] that define a 3304 ** class of constructs to be size limited. The third parameter is the 3305 ** new limit for that construct.)^ 3306 ** 3307 ** ^If the new limit is a negative number, the limit is unchanged. 3308 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3309 ** [limits | hard upper bound] 3310 ** set at compile-time by a C preprocessor macro called 3311 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3312 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3313 ** ^Attempts to increase a limit above its hard upper bound are 3314 ** silently truncated to the hard upper bound. 3315 ** 3316 ** ^Regardless of whether or not the limit was changed, the 3317 ** [sqlite3_limit()] interface returns the prior value of the limit. 3318 ** ^Hence, to find the current value of a limit without changing it, 3319 ** simply invoke this interface with the third parameter set to -1. 3320 ** 3321 ** Run-time limits are intended for use in applications that manage 3322 ** both their own internal database and also databases that are controlled 3323 ** by untrusted external sources. An example application might be a 3324 ** web browser that has its own databases for storing history and 3325 ** separate databases controlled by JavaScript applications downloaded 3326 ** off the Internet. The internal databases can be given the 3327 ** large, default limits. Databases managed by external sources can 3328 ** be given much smaller limits designed to prevent a denial of service 3329 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3330 ** interface to further control untrusted SQL. The size of the database 3331 ** created by an untrusted script can be contained using the 3332 ** [max_page_count] [PRAGMA]. 3333 ** 3334 ** New run-time limit categories may be added in future releases. 3335 */ 3336 SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal); 3337 3338 /* 3339 ** CAPI3REF: Run-Time Limit Categories 3340 ** KEYWORDS: {limit category} {*limit categories} 3341 ** 3342 ** These constants define various performance limits 3343 ** that can be lowered at run-time using [sqlite3_limit()]. 3344 ** The synopsis of the meanings of the various limits is shown below. 3345 ** Additional information is available at [limits | Limits in SQLite]. 3346 ** 3347 ** <dl> 3348 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3349 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3350 ** 3351 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3352 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3353 ** 3354 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3355 ** <dd>The maximum number of columns in a table definition or in the 3356 ** result set of a [SELECT] or the maximum number of columns in an index 3357 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3358 ** 3359 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3360 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3361 ** 3362 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3363 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3364 ** 3365 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3366 ** <dd>The maximum number of instructions in a virtual machine program 3367 ** used to implement an SQL statement. This limit is not currently 3368 ** enforced, though that might be added in some future release of 3369 ** SQLite.</dd>)^ 3370 ** 3371 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3372 ** <dd>The maximum number of arguments on a function.</dd>)^ 3373 ** 3374 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3375 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3376 ** 3377 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3378 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3379 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3380 ** [GLOB] operators.</dd>)^ 3381 ** 3382 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3383 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3384 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3385 ** 3386 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3387 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3388 ** 3389 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3390 ** <dd>The maximum number of auxiliary worker threads that a single 3391 ** [prepared statement] may start.</dd>)^ 3392 ** </dl> 3393 */ 3394 #define SQLITE_LIMIT_LENGTH 0 3395 #define SQLITE_LIMIT_SQL_LENGTH 1 3396 #define SQLITE_LIMIT_COLUMN 2 3397 #define SQLITE_LIMIT_EXPR_DEPTH 3 3398 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3399 #define SQLITE_LIMIT_VDBE_OP 5 3400 #define SQLITE_LIMIT_FUNCTION_ARG 6 3401 #define SQLITE_LIMIT_ATTACHED 7 3402 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3403 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3404 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3405 #define SQLITE_LIMIT_WORKER_THREADS 11 3406 3407 /* 3408 ** CAPI3REF: Compiling An SQL Statement 3409 ** KEYWORDS: {SQL statement compiler} 3410 ** METHOD: sqlite3 3411 ** CONSTRUCTOR: sqlite3_stmt 3412 ** 3413 ** To execute an SQL query, it must first be compiled into a byte-code 3414 ** program using one of these routines. 3415 ** 3416 ** The first argument, "db", is a [database connection] obtained from a 3417 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3418 ** [sqlite3_open16()]. The database connection must not have been closed. 3419 ** 3420 ** The second argument, "zSql", is the statement to be compiled, encoded 3421 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3422 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3423 ** use UTF-16. 3424 ** 3425 ** ^If the nByte argument is negative, then zSql is read up to the 3426 ** first zero terminator. ^If nByte is positive, then it is the 3427 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3428 ** statement is generated. 3429 ** If the caller knows that the supplied string is nul-terminated, then 3430 ** there is a small performance advantage to passing an nByte parameter that 3431 ** is the number of bytes in the input string <i>including</i> 3432 ** the nul-terminator. 3433 ** 3434 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3435 ** past the end of the first SQL statement in zSql. These routines only 3436 ** compile the first statement in zSql, so *pzTail is left pointing to 3437 ** what remains uncompiled. 3438 ** 3439 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3440 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3441 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3442 ** string or a comment) then *ppStmt is set to NULL. 3443 ** The calling procedure is responsible for deleting the compiled 3444 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3445 ** ppStmt may not be NULL. 3446 ** 3447 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3448 ** otherwise an [error code] is returned. 3449 ** 3450 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3451 ** recommended for all new programs. The two older interfaces are retained 3452 ** for backwards compatibility, but their use is discouraged. 3453 ** ^In the "v2" interfaces, the prepared statement 3454 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3455 ** original SQL text. This causes the [sqlite3_step()] interface to 3456 ** behave differently in three ways: 3457 ** 3458 ** <ol> 3459 ** <li> 3460 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3461 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3462 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3463 ** retries will occur before sqlite3_step() gives up and returns an error. 3464 ** </li> 3465 ** 3466 ** <li> 3467 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3468 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3469 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3470 ** and the application would have to make a second call to [sqlite3_reset()] 3471 ** in order to find the underlying cause of the problem. With the "v2" prepare 3472 ** interfaces, the underlying reason for the error is returned immediately. 3473 ** </li> 3474 ** 3475 ** <li> 3476 ** ^If the specific value bound to [parameter | host parameter] in the 3477 ** WHERE clause might influence the choice of query plan for a statement, 3478 ** then the statement will be automatically recompiled, as if there had been 3479 ** a schema change, on the first [sqlite3_step()] call following any change 3480 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3481 ** ^The specific value of WHERE-clause [parameter] might influence the 3482 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3483 ** or [GLOB] operator or if the parameter is compared to an indexed column 3484 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3485 ** </li> 3486 ** </ol> 3487 */ 3488 SQLITE_API int SQLITE_STDCALL sqlite3_prepare( 3489 sqlite3 *db, /* Database handle */ 3490 const char *zSql, /* SQL statement, UTF-8 encoded */ 3491 int nByte, /* Maximum length of zSql in bytes. */ 3492 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3493 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3494 ); 3495 SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2( 3496 sqlite3 *db, /* Database handle */ 3497 const char *zSql, /* SQL statement, UTF-8 encoded */ 3498 int nByte, /* Maximum length of zSql in bytes. */ 3499 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3500 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3501 ); 3502 SQLITE_API int SQLITE_STDCALL sqlite3_prepare16( 3503 sqlite3 *db, /* Database handle */ 3504 const void *zSql, /* SQL statement, UTF-16 encoded */ 3505 int nByte, /* Maximum length of zSql in bytes. */ 3506 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3507 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3508 ); 3509 SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2( 3510 sqlite3 *db, /* Database handle */ 3511 const void *zSql, /* SQL statement, UTF-16 encoded */ 3512 int nByte, /* Maximum length of zSql in bytes. */ 3513 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3514 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3515 ); 3516 3517 /* 3518 ** CAPI3REF: Retrieving Statement SQL 3519 ** METHOD: sqlite3_stmt 3520 ** 3521 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3522 ** SQL text used to create [prepared statement] P if P was 3523 ** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3524 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3525 ** string containing the SQL text of prepared statement P with 3526 ** [bound parameters] expanded. 3527 ** 3528 ** ^(For example, if a prepared statement is created using the SQL 3529 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3530 ** and parameter :xyz is unbound, then sqlite3_sql() will return 3531 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3532 ** will return "SELECT 2345,NULL".)^ 3533 ** 3534 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3535 ** is available to hold the result, or if the result would exceed the 3536 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3537 ** 3538 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3539 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3540 ** option causes sqlite3_expanded_sql() to always return NULL. 3541 ** 3542 ** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3543 ** automatically freed when the prepared statement is finalized. 3544 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3545 ** is obtained from [sqlite3_malloc()] and must be free by the application 3546 ** by passing it to [sqlite3_free()]. 3547 */ 3548 SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt); 3549 SQLITE_API char *SQLITE_STDCALL sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3550 3551 /* 3552 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3553 ** METHOD: sqlite3_stmt 3554 ** 3555 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3556 ** and only if the [prepared statement] X makes no direct changes to 3557 ** the content of the database file. 3558 ** 3559 ** Note that [application-defined SQL functions] or 3560 ** [virtual tables] might change the database indirectly as a side effect. 3561 ** ^(For example, if an application defines a function "eval()" that 3562 ** calls [sqlite3_exec()], then the following SQL statement would 3563 ** change the database file through side-effects: 3564 ** 3565 ** <blockquote><pre> 3566 ** SELECT eval('DELETE FROM t1') FROM t2; 3567 ** </pre></blockquote> 3568 ** 3569 ** But because the [SELECT] statement does not change the database file 3570 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3571 ** 3572 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3573 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3574 ** since the statements themselves do not actually modify the database but 3575 ** rather they control the timing of when other statements modify the 3576 ** database. ^The [ATTACH] and [DETACH] statements also cause 3577 ** sqlite3_stmt_readonly() to return true since, while those statements 3578 ** change the configuration of a database connection, they do not make 3579 ** changes to the content of the database files on disk. 3580 */ 3581 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3582 3583 /* 3584 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3585 ** METHOD: sqlite3_stmt 3586 ** 3587 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3588 ** [prepared statement] S has been stepped at least once using 3589 ** [sqlite3_step(S)] but has neither run to completion (returned 3590 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3591 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3592 ** interface returns false if S is a NULL pointer. If S is not a 3593 ** NULL pointer and is not a pointer to a valid [prepared statement] 3594 ** object, then the behavior is undefined and probably undesirable. 3595 ** 3596 ** This interface can be used in combination [sqlite3_next_stmt()] 3597 ** to locate all prepared statements associated with a database 3598 ** connection that are in need of being reset. This can be used, 3599 ** for example, in diagnostic routines to search for prepared 3600 ** statements that are holding a transaction open. 3601 */ 3602 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*); 3603 3604 /* 3605 ** CAPI3REF: Dynamically Typed Value Object 3606 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3607 ** 3608 ** SQLite uses the sqlite3_value object to represent all values 3609 ** that can be stored in a database table. SQLite uses dynamic typing 3610 ** for the values it stores. ^Values stored in sqlite3_value objects 3611 ** can be integers, floating point values, strings, BLOBs, or NULL. 3612 ** 3613 ** An sqlite3_value object may be either "protected" or "unprotected". 3614 ** Some interfaces require a protected sqlite3_value. Other interfaces 3615 ** will accept either a protected or an unprotected sqlite3_value. 3616 ** Every interface that accepts sqlite3_value arguments specifies 3617 ** whether or not it requires a protected sqlite3_value. The 3618 ** [sqlite3_value_dup()] interface can be used to construct a new 3619 ** protected sqlite3_value from an unprotected sqlite3_value. 3620 ** 3621 ** The terms "protected" and "unprotected" refer to whether or not 3622 ** a mutex is held. An internal mutex is held for a protected 3623 ** sqlite3_value object but no mutex is held for an unprotected 3624 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3625 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3626 ** or if SQLite is run in one of reduced mutex modes 3627 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3628 ** then there is no distinction between protected and unprotected 3629 ** sqlite3_value objects and they can be used interchangeably. However, 3630 ** for maximum code portability it is recommended that applications 3631 ** still make the distinction between protected and unprotected 3632 ** sqlite3_value objects even when not strictly required. 3633 ** 3634 ** ^The sqlite3_value objects that are passed as parameters into the 3635 ** implementation of [application-defined SQL functions] are protected. 3636 ** ^The sqlite3_value object returned by 3637 ** [sqlite3_column_value()] is unprotected. 3638 ** Unprotected sqlite3_value objects may only be used with 3639 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3640 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3641 ** interfaces require protected sqlite3_value objects. 3642 */ 3643 typedef struct Mem sqlite3_value; 3644 3645 /* 3646 ** CAPI3REF: SQL Function Context Object 3647 ** 3648 ** The context in which an SQL function executes is stored in an 3649 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3650 ** is always first parameter to [application-defined SQL functions]. 3651 ** The application-defined SQL function implementation will pass this 3652 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3653 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3654 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3655 ** and/or [sqlite3_set_auxdata()]. 3656 */ 3657 typedef struct sqlite3_context sqlite3_context; 3658 3659 /* 3660 ** CAPI3REF: Binding Values To Prepared Statements 3661 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3662 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3663 ** METHOD: sqlite3_stmt 3664 ** 3665 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3666 ** literals may be replaced by a [parameter] that matches one of following 3667 ** templates: 3668 ** 3669 ** <ul> 3670 ** <li> ? 3671 ** <li> ?NNN 3672 ** <li> :VVV 3673 ** <li> @VVV 3674 ** <li> $VVV 3675 ** </ul> 3676 ** 3677 ** In the templates above, NNN represents an integer literal, 3678 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3679 ** parameters (also called "host parameter names" or "SQL parameters") 3680 ** can be set using the sqlite3_bind_*() routines defined here. 3681 ** 3682 ** ^The first argument to the sqlite3_bind_*() routines is always 3683 ** a pointer to the [sqlite3_stmt] object returned from 3684 ** [sqlite3_prepare_v2()] or its variants. 3685 ** 3686 ** ^The second argument is the index of the SQL parameter to be set. 3687 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3688 ** SQL parameter is used more than once, second and subsequent 3689 ** occurrences have the same index as the first occurrence. 3690 ** ^The index for named parameters can be looked up using the 3691 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3692 ** for "?NNN" parameters is the value of NNN. 3693 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3694 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3695 ** 3696 ** ^The third argument is the value to bind to the parameter. 3697 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3698 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3699 ** is ignored and the end result is the same as sqlite3_bind_null(). 3700 ** 3701 ** ^(In those routines that have a fourth argument, its value is the 3702 ** number of bytes in the parameter. To be clear: the value is the 3703 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3704 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3705 ** is negative, then the length of the string is 3706 ** the number of bytes up to the first zero terminator. 3707 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3708 ** the behavior is undefined. 3709 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3710 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3711 ** that parameter must be the byte offset 3712 ** where the NUL terminator would occur assuming the string were NUL 3713 ** terminated. If any NUL characters occur at byte offsets less than 3714 ** the value of the fourth parameter then the resulting string value will 3715 ** contain embedded NULs. The result of expressions involving strings 3716 ** with embedded NULs is undefined. 3717 ** 3718 ** ^The fifth argument to the BLOB and string binding interfaces 3719 ** is a destructor used to dispose of the BLOB or 3720 ** string after SQLite has finished with it. ^The destructor is called 3721 ** to dispose of the BLOB or string even if the call to bind API fails. 3722 ** ^If the fifth argument is 3723 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3724 ** information is in static, unmanaged space and does not need to be freed. 3725 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3726 ** SQLite makes its own private copy of the data immediately, before 3727 ** the sqlite3_bind_*() routine returns. 3728 ** 3729 ** ^The sixth argument to sqlite3_bind_text64() must be one of 3730 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3731 ** to specify the encoding of the text in the third parameter. If 3732 ** the sixth argument to sqlite3_bind_text64() is not one of the 3733 ** allowed values shown above, or if the text encoding is different 3734 ** from the encoding specified by the sixth parameter, then the behavior 3735 ** is undefined. 3736 ** 3737 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3738 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3739 ** (just an integer to hold its size) while it is being processed. 3740 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3741 ** content is later written using 3742 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3743 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3744 ** 3745 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3746 ** for the [prepared statement] or with a prepared statement for which 3747 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3748 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3749 ** routine is passed a [prepared statement] that has been finalized, the 3750 ** result is undefined and probably harmful. 3751 ** 3752 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3753 ** ^Unbound parameters are interpreted as NULL. 3754 ** 3755 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3756 ** [error code] if anything goes wrong. 3757 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3758 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3759 ** [SQLITE_MAX_LENGTH]. 3760 ** ^[SQLITE_RANGE] is returned if the parameter 3761 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3762 ** 3763 ** See also: [sqlite3_bind_parameter_count()], 3764 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3765 */ 3766 SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3767 SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3768 void(*)(void*)); 3769 SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double); 3770 SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int); 3771 SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3772 SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int); 3773 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3774 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3775 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3776 void(*)(void*), unsigned char encoding); 3777 SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3778 SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3779 SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3780 3781 /* 3782 ** CAPI3REF: Number Of SQL Parameters 3783 ** METHOD: sqlite3_stmt 3784 ** 3785 ** ^This routine can be used to find the number of [SQL parameters] 3786 ** in a [prepared statement]. SQL parameters are tokens of the 3787 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3788 ** placeholders for values that are [sqlite3_bind_blob | bound] 3789 ** to the parameters at a later time. 3790 ** 3791 ** ^(This routine actually returns the index of the largest (rightmost) 3792 ** parameter. For all forms except ?NNN, this will correspond to the 3793 ** number of unique parameters. If parameters of the ?NNN form are used, 3794 ** there may be gaps in the list.)^ 3795 ** 3796 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3797 ** [sqlite3_bind_parameter_name()], and 3798 ** [sqlite3_bind_parameter_index()]. 3799 */ 3800 SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*); 3801 3802 /* 3803 ** CAPI3REF: Name Of A Host Parameter 3804 ** METHOD: sqlite3_stmt 3805 ** 3806 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3807 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3808 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3809 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3810 ** respectively. 3811 ** In other words, the initial ":" or "$" or "@" or "?" 3812 ** is included as part of the name.)^ 3813 ** ^Parameters of the form "?" without a following integer have no name 3814 ** and are referred to as "nameless" or "anonymous parameters". 3815 ** 3816 ** ^The first host parameter has an index of 1, not 0. 3817 ** 3818 ** ^If the value N is out of range or if the N-th parameter is 3819 ** nameless, then NULL is returned. ^The returned string is 3820 ** always in UTF-8 encoding even if the named parameter was 3821 ** originally specified as UTF-16 in [sqlite3_prepare16()] or 3822 ** [sqlite3_prepare16_v2()]. 3823 ** 3824 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3825 ** [sqlite3_bind_parameter_count()], and 3826 ** [sqlite3_bind_parameter_index()]. 3827 */ 3828 SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3829 3830 /* 3831 ** CAPI3REF: Index Of A Parameter With A Given Name 3832 ** METHOD: sqlite3_stmt 3833 ** 3834 ** ^Return the index of an SQL parameter given its name. ^The 3835 ** index value returned is suitable for use as the second 3836 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3837 ** is returned if no matching parameter is found. ^The parameter 3838 ** name must be given in UTF-8 even if the original statement 3839 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3840 ** 3841 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3842 ** [sqlite3_bind_parameter_count()], and 3843 ** [sqlite3_bind_parameter_name()]. 3844 */ 3845 SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3846 3847 /* 3848 ** CAPI3REF: Reset All Bindings On A Prepared Statement 3849 ** METHOD: sqlite3_stmt 3850 ** 3851 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3852 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3853 ** ^Use this routine to reset all host parameters to NULL. 3854 */ 3855 SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*); 3856 3857 /* 3858 ** CAPI3REF: Number Of Columns In A Result Set 3859 ** METHOD: sqlite3_stmt 3860 ** 3861 ** ^Return the number of columns in the result set returned by the 3862 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3863 ** statement that does not return data (for example an [UPDATE]). 3864 ** 3865 ** See also: [sqlite3_data_count()] 3866 */ 3867 SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt); 3868 3869 /* 3870 ** CAPI3REF: Column Names In A Result Set 3871 ** METHOD: sqlite3_stmt 3872 ** 3873 ** ^These routines return the name assigned to a particular column 3874 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3875 ** interface returns a pointer to a zero-terminated UTF-8 string 3876 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 3877 ** UTF-16 string. ^The first parameter is the [prepared statement] 3878 ** that implements the [SELECT] statement. ^The second parameter is the 3879 ** column number. ^The leftmost column is number 0. 3880 ** 3881 ** ^The returned string pointer is valid until either the [prepared statement] 3882 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3883 ** reprepared by the first call to [sqlite3_step()] for a particular run 3884 ** or until the next call to 3885 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3886 ** 3887 ** ^If sqlite3_malloc() fails during the processing of either routine 3888 ** (for example during a conversion from UTF-8 to UTF-16) then a 3889 ** NULL pointer is returned. 3890 ** 3891 ** ^The name of a result column is the value of the "AS" clause for 3892 ** that column, if there is an AS clause. If there is no AS clause 3893 ** then the name of the column is unspecified and may change from 3894 ** one release of SQLite to the next. 3895 */ 3896 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N); 3897 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N); 3898 3899 /* 3900 ** CAPI3REF: Source Of Data In A Query Result 3901 ** METHOD: sqlite3_stmt 3902 ** 3903 ** ^These routines provide a means to determine the database, table, and 3904 ** table column that is the origin of a particular result column in 3905 ** [SELECT] statement. 3906 ** ^The name of the database or table or column can be returned as 3907 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3908 ** the database name, the _table_ routines return the table name, and 3909 ** the origin_ routines return the column name. 3910 ** ^The returned string is valid until the [prepared statement] is destroyed 3911 ** using [sqlite3_finalize()] or until the statement is automatically 3912 ** reprepared by the first call to [sqlite3_step()] for a particular run 3913 ** or until the same information is requested 3914 ** again in a different encoding. 3915 ** 3916 ** ^The names returned are the original un-aliased names of the 3917 ** database, table, and column. 3918 ** 3919 ** ^The first argument to these interfaces is a [prepared statement]. 3920 ** ^These functions return information about the Nth result column returned by 3921 ** the statement, where N is the second function argument. 3922 ** ^The left-most column is column 0 for these routines. 3923 ** 3924 ** ^If the Nth column returned by the statement is an expression or 3925 ** subquery and is not a column value, then all of these functions return 3926 ** NULL. ^These routine might also return NULL if a memory allocation error 3927 ** occurs. ^Otherwise, they return the name of the attached database, table, 3928 ** or column that query result column was extracted from. 3929 ** 3930 ** ^As with all other SQLite APIs, those whose names end with "16" return 3931 ** UTF-16 encoded strings and the other functions return UTF-8. 3932 ** 3933 ** ^These APIs are only available if the library was compiled with the 3934 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3935 ** 3936 ** If two or more threads call one or more of these routines against the same 3937 ** prepared statement and column at the same time then the results are 3938 ** undefined. 3939 ** 3940 ** If two or more threads call one or more 3941 ** [sqlite3_column_database_name | column metadata interfaces] 3942 ** for the same [prepared statement] and result column 3943 ** at the same time then the results are undefined. 3944 */ 3945 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int); 3946 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int); 3947 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int); 3948 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int); 3949 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int); 3950 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int); 3951 3952 /* 3953 ** CAPI3REF: Declared Datatype Of A Query Result 3954 ** METHOD: sqlite3_stmt 3955 ** 3956 ** ^(The first parameter is a [prepared statement]. 3957 ** If this statement is a [SELECT] statement and the Nth column of the 3958 ** returned result set of that [SELECT] is a table column (not an 3959 ** expression or subquery) then the declared type of the table 3960 ** column is returned.)^ ^If the Nth column of the result set is an 3961 ** expression or subquery, then a NULL pointer is returned. 3962 ** ^The returned string is always UTF-8 encoded. 3963 ** 3964 ** ^(For example, given the database schema: 3965 ** 3966 ** CREATE TABLE t1(c1 VARIANT); 3967 ** 3968 ** and the following statement to be compiled: 3969 ** 3970 ** SELECT c1 + 1, c1 FROM t1; 3971 ** 3972 ** this routine would return the string "VARIANT" for the second result 3973 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3974 ** 3975 ** ^SQLite uses dynamic run-time typing. ^So just because a column 3976 ** is declared to contain a particular type does not mean that the 3977 ** data stored in that column is of the declared type. SQLite is 3978 ** strongly typed, but the typing is dynamic not static. ^Type 3979 ** is associated with individual values, not with the containers 3980 ** used to hold those values. 3981 */ 3982 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int); 3983 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int); 3984 3985 /* 3986 ** CAPI3REF: Evaluate An SQL Statement 3987 ** METHOD: sqlite3_stmt 3988 ** 3989 ** After a [prepared statement] has been prepared using either 3990 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3991 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3992 ** must be called one or more times to evaluate the statement. 3993 ** 3994 ** The details of the behavior of the sqlite3_step() interface depend 3995 ** on whether the statement was prepared using the newer "v2" interface 3996 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3997 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3998 ** new "v2" interface is recommended for new applications but the legacy 3999 ** interface will continue to be supported. 4000 ** 4001 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4002 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4003 ** ^With the "v2" interface, any of the other [result codes] or 4004 ** [extended result codes] might be returned as well. 4005 ** 4006 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4007 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4008 ** or occurs outside of an explicit transaction, then you can retry the 4009 ** statement. If the statement is not a [COMMIT] and occurs within an 4010 ** explicit transaction then you should rollback the transaction before 4011 ** continuing. 4012 ** 4013 ** ^[SQLITE_DONE] means that the statement has finished executing 4014 ** successfully. sqlite3_step() should not be called again on this virtual 4015 ** machine without first calling [sqlite3_reset()] to reset the virtual 4016 ** machine back to its initial state. 4017 ** 4018 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4019 ** is returned each time a new row of data is ready for processing by the 4020 ** caller. The values may be accessed using the [column access functions]. 4021 ** sqlite3_step() is called again to retrieve the next row of data. 4022 ** 4023 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4024 ** violation) has occurred. sqlite3_step() should not be called again on 4025 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4026 ** ^With the legacy interface, a more specific error code (for example, 4027 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4028 ** can be obtained by calling [sqlite3_reset()] on the 4029 ** [prepared statement]. ^In the "v2" interface, 4030 ** the more specific error code is returned directly by sqlite3_step(). 4031 ** 4032 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4033 ** Perhaps it was called on a [prepared statement] that has 4034 ** already been [sqlite3_finalize | finalized] or on one that had 4035 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4036 ** be the case that the same database connection is being used by two or 4037 ** more threads at the same moment in time. 4038 ** 4039 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4040 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4041 ** other than [SQLITE_ROW] before any subsequent invocation of 4042 ** sqlite3_step(). Failure to reset the prepared statement using 4043 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4044 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 4045 ** calling [sqlite3_reset()] automatically in this circumstance rather 4046 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4047 ** break because any application that ever receives an SQLITE_MISUSE error 4048 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4049 ** can be used to restore the legacy behavior. 4050 ** 4051 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4052 ** API always returns a generic error code, [SQLITE_ERROR], following any 4053 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4054 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4055 ** specific [error codes] that better describes the error. 4056 ** We admit that this is a goofy design. The problem has been fixed 4057 ** with the "v2" interface. If you prepare all of your SQL statements 4058 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 4059 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4060 ** then the more specific [error codes] are returned directly 4061 ** by sqlite3_step(). The use of the "v2" interface is recommended. 4062 */ 4063 SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*); 4064 4065 /* 4066 ** CAPI3REF: Number of columns in a result set 4067 ** METHOD: sqlite3_stmt 4068 ** 4069 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4070 ** current row of the result set of [prepared statement] P. 4071 ** ^If prepared statement P does not have results ready to return 4072 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4073 ** interfaces) then sqlite3_data_count(P) returns 0. 4074 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4075 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4076 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4077 ** will return non-zero if previous call to [sqlite3_step](P) returned 4078 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4079 ** where it always returns zero since each step of that multi-step 4080 ** pragma returns 0 columns of data. 4081 ** 4082 ** See also: [sqlite3_column_count()] 4083 */ 4084 SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt); 4085 4086 /* 4087 ** CAPI3REF: Fundamental Datatypes 4088 ** KEYWORDS: SQLITE_TEXT 4089 ** 4090 ** ^(Every value in SQLite has one of five fundamental datatypes: 4091 ** 4092 ** <ul> 4093 ** <li> 64-bit signed integer 4094 ** <li> 64-bit IEEE floating point number 4095 ** <li> string 4096 ** <li> BLOB 4097 ** <li> NULL 4098 ** </ul>)^ 4099 ** 4100 ** These constants are codes for each of those types. 4101 ** 4102 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4103 ** for a completely different meaning. Software that links against both 4104 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4105 ** SQLITE_TEXT. 4106 */ 4107 #define SQLITE_INTEGER 1 4108 #define SQLITE_FLOAT 2 4109 #define SQLITE_BLOB 4 4110 #define SQLITE_NULL 5 4111 #ifdef SQLITE_TEXT 4112 # undef SQLITE_TEXT 4113 #else 4114 # define SQLITE_TEXT 3 4115 #endif 4116 #define SQLITE3_TEXT 3 4117 4118 /* 4119 ** CAPI3REF: Result Values From A Query 4120 ** KEYWORDS: {column access functions} 4121 ** METHOD: sqlite3_stmt 4122 ** 4123 ** ^These routines return information about a single column of the current 4124 ** result row of a query. ^In every case the first argument is a pointer 4125 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4126 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4127 ** and the second argument is the index of the column for which information 4128 ** should be returned. ^The leftmost column of the result set has the index 0. 4129 ** ^The number of columns in the result can be determined using 4130 ** [sqlite3_column_count()]. 4131 ** 4132 ** If the SQL statement does not currently point to a valid row, or if the 4133 ** column index is out of range, the result is undefined. 4134 ** These routines may only be called when the most recent call to 4135 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4136 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4137 ** If any of these routines are called after [sqlite3_reset()] or 4138 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4139 ** something other than [SQLITE_ROW], the results are undefined. 4140 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4141 ** are called from a different thread while any of these routines 4142 ** are pending, then the results are undefined. 4143 ** 4144 ** ^The sqlite3_column_type() routine returns the 4145 ** [SQLITE_INTEGER | datatype code] for the initial data type 4146 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4147 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 4148 ** returned by sqlite3_column_type() is only meaningful if no type 4149 ** conversions have occurred as described below. After a type conversion, 4150 ** the value returned by sqlite3_column_type() is undefined. Future 4151 ** versions of SQLite may change the behavior of sqlite3_column_type() 4152 ** following a type conversion. 4153 ** 4154 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4155 ** routine returns the number of bytes in that BLOB or string. 4156 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4157 ** the string to UTF-8 and then returns the number of bytes. 4158 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4159 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4160 ** the number of bytes in that string. 4161 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4162 ** 4163 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4164 ** routine returns the number of bytes in that BLOB or string. 4165 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4166 ** the string to UTF-16 and then returns the number of bytes. 4167 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4168 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4169 ** the number of bytes in that string. 4170 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4171 ** 4172 ** ^The values returned by [sqlite3_column_bytes()] and 4173 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4174 ** of the string. ^For clarity: the values returned by 4175 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4176 ** bytes in the string, not the number of characters. 4177 ** 4178 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4179 ** even empty strings, are always zero-terminated. ^The return 4180 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4181 ** 4182 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4183 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4184 ** an unprotected sqlite3_value object may only be used safely with 4185 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4186 ** If the [unprotected sqlite3_value] object returned by 4187 ** [sqlite3_column_value()] is used in any other way, including calls 4188 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4189 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4190 ** 4191 ** These routines attempt to convert the value where appropriate. ^For 4192 ** example, if the internal representation is FLOAT and a text result 4193 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4194 ** conversion automatically. ^(The following table details the conversions 4195 ** that are applied: 4196 ** 4197 ** <blockquote> 4198 ** <table border="1"> 4199 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4200 ** 4201 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4202 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4203 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4204 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4205 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4206 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4207 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4208 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4209 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4210 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4211 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4212 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4213 ** <tr><td> TEXT <td> BLOB <td> No change 4214 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4215 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4216 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4217 ** </table> 4218 ** </blockquote>)^ 4219 ** 4220 ** Note that when type conversions occur, pointers returned by prior 4221 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4222 ** sqlite3_column_text16() may be invalidated. 4223 ** Type conversions and pointer invalidations might occur 4224 ** in the following cases: 4225 ** 4226 ** <ul> 4227 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4228 ** sqlite3_column_text16() is called. A zero-terminator might 4229 ** need to be added to the string.</li> 4230 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4231 ** sqlite3_column_text16() is called. The content must be converted 4232 ** to UTF-16.</li> 4233 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4234 ** sqlite3_column_text() is called. The content must be converted 4235 ** to UTF-8.</li> 4236 ** </ul> 4237 ** 4238 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4239 ** not invalidate a prior pointer, though of course the content of the buffer 4240 ** that the prior pointer references will have been modified. Other kinds 4241 ** of conversion are done in place when it is possible, but sometimes they 4242 ** are not possible and in those cases prior pointers are invalidated. 4243 ** 4244 ** The safest policy is to invoke these routines 4245 ** in one of the following ways: 4246 ** 4247 ** <ul> 4248 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4249 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4250 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4251 ** </ul> 4252 ** 4253 ** In other words, you should call sqlite3_column_text(), 4254 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4255 ** into the desired format, then invoke sqlite3_column_bytes() or 4256 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4257 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4258 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4259 ** with calls to sqlite3_column_bytes(). 4260 ** 4261 ** ^The pointers returned are valid until a type conversion occurs as 4262 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4263 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4264 ** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4265 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4266 ** [sqlite3_free()]. 4267 ** 4268 ** ^(If a memory allocation error occurs during the evaluation of any 4269 ** of these routines, a default value is returned. The default value 4270 ** is either the integer 0, the floating point number 0.0, or a NULL 4271 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 4272 ** [SQLITE_NOMEM].)^ 4273 */ 4274 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol); 4275 SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4276 SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4277 SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol); 4278 SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol); 4279 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol); 4280 SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol); 4281 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol); 4282 SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol); 4283 SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol); 4284 4285 /* 4286 ** CAPI3REF: Destroy A Prepared Statement Object 4287 ** DESTRUCTOR: sqlite3_stmt 4288 ** 4289 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4290 ** ^If the most recent evaluation of the statement encountered no errors 4291 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4292 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4293 ** sqlite3_finalize(S) returns the appropriate [error code] or 4294 ** [extended error code]. 4295 ** 4296 ** ^The sqlite3_finalize(S) routine can be called at any point during 4297 ** the life cycle of [prepared statement] S: 4298 ** before statement S is ever evaluated, after 4299 ** one or more calls to [sqlite3_reset()], or after any call 4300 ** to [sqlite3_step()] regardless of whether or not the statement has 4301 ** completed execution. 4302 ** 4303 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4304 ** 4305 ** The application must finalize every [prepared statement] in order to avoid 4306 ** resource leaks. It is a grievous error for the application to try to use 4307 ** a prepared statement after it has been finalized. Any use of a prepared 4308 ** statement after it has been finalized can result in undefined and 4309 ** undesirable behavior such as segfaults and heap corruption. 4310 */ 4311 SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt); 4312 4313 /* 4314 ** CAPI3REF: Reset A Prepared Statement Object 4315 ** METHOD: sqlite3_stmt 4316 ** 4317 ** The sqlite3_reset() function is called to reset a [prepared statement] 4318 ** object back to its initial state, ready to be re-executed. 4319 ** ^Any SQL statement variables that had values bound to them using 4320 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4321 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4322 ** 4323 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4324 ** back to the beginning of its program. 4325 ** 4326 ** ^If the most recent call to [sqlite3_step(S)] for the 4327 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4328 ** or if [sqlite3_step(S)] has never before been called on S, 4329 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4330 ** 4331 ** ^If the most recent call to [sqlite3_step(S)] for the 4332 ** [prepared statement] S indicated an error, then 4333 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4334 ** 4335 ** ^The [sqlite3_reset(S)] interface does not change the values 4336 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4337 */ 4338 SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt); 4339 4340 /* 4341 ** CAPI3REF: Create Or Redefine SQL Functions 4342 ** KEYWORDS: {function creation routines} 4343 ** KEYWORDS: {application-defined SQL function} 4344 ** KEYWORDS: {application-defined SQL functions} 4345 ** METHOD: sqlite3 4346 ** 4347 ** ^These functions (collectively known as "function creation routines") 4348 ** are used to add SQL functions or aggregates or to redefine the behavior 4349 ** of existing SQL functions or aggregates. The only differences between 4350 ** these routines are the text encoding expected for 4351 ** the second parameter (the name of the function being created) 4352 ** and the presence or absence of a destructor callback for 4353 ** the application data pointer. 4354 ** 4355 ** ^The first parameter is the [database connection] to which the SQL 4356 ** function is to be added. ^If an application uses more than one database 4357 ** connection then application-defined SQL functions must be added 4358 ** to each database connection separately. 4359 ** 4360 ** ^The second parameter is the name of the SQL function to be created or 4361 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4362 ** representation, exclusive of the zero-terminator. ^Note that the name 4363 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4364 ** ^Any attempt to create a function with a longer name 4365 ** will result in [SQLITE_MISUSE] being returned. 4366 ** 4367 ** ^The third parameter (nArg) 4368 ** is the number of arguments that the SQL function or 4369 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4370 ** aggregate may take any number of arguments between 0 and the limit 4371 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4372 ** parameter is less than -1 or greater than 127 then the behavior is 4373 ** undefined. 4374 ** 4375 ** ^The fourth parameter, eTextRep, specifies what 4376 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4377 ** its parameters. The application should set this parameter to 4378 ** [SQLITE_UTF16LE] if the function implementation invokes 4379 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4380 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4381 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4382 ** otherwise. ^The same SQL function may be registered multiple times using 4383 ** different preferred text encodings, with different implementations for 4384 ** each encoding. 4385 ** ^When multiple implementations of the same function are available, SQLite 4386 ** will pick the one that involves the least amount of data conversion. 4387 ** 4388 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4389 ** to signal that the function will always return the same result given 4390 ** the same inputs within a single SQL statement. Most SQL functions are 4391 ** deterministic. The built-in [random()] SQL function is an example of a 4392 ** function that is not deterministic. The SQLite query planner is able to 4393 ** perform additional optimizations on deterministic functions, so use 4394 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4395 ** 4396 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4397 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4398 ** 4399 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4400 ** pointers to C-language functions that implement the SQL function or 4401 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4402 ** callback only; NULL pointers must be passed as the xStep and xFinal 4403 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4404 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4405 ** SQL function or aggregate, pass NULL pointers for all three function 4406 ** callbacks. 4407 ** 4408 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4409 ** then it is destructor for the application data pointer. 4410 ** The destructor is invoked when the function is deleted, either by being 4411 ** overloaded or when the database connection closes.)^ 4412 ** ^The destructor is also invoked if the call to 4413 ** sqlite3_create_function_v2() fails. 4414 ** ^When the destructor callback of the tenth parameter is invoked, it 4415 ** is passed a single argument which is a copy of the application data 4416 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4417 ** 4418 ** ^It is permitted to register multiple implementations of the same 4419 ** functions with the same name but with either differing numbers of 4420 ** arguments or differing preferred text encodings. ^SQLite will use 4421 ** the implementation that most closely matches the way in which the 4422 ** SQL function is used. ^A function implementation with a non-negative 4423 ** nArg parameter is a better match than a function implementation with 4424 ** a negative nArg. ^A function where the preferred text encoding 4425 ** matches the database encoding is a better 4426 ** match than a function where the encoding is different. 4427 ** ^A function where the encoding difference is between UTF16le and UTF16be 4428 ** is a closer match than a function where the encoding difference is 4429 ** between UTF8 and UTF16. 4430 ** 4431 ** ^Built-in functions may be overloaded by new application-defined functions. 4432 ** 4433 ** ^An application-defined function is permitted to call other 4434 ** SQLite interfaces. However, such calls must not 4435 ** close the database connection nor finalize or reset the prepared 4436 ** statement in which the function is running. 4437 */ 4438 SQLITE_API int SQLITE_STDCALL sqlite3_create_function( 4439 sqlite3 *db, 4440 const char *zFunctionName, 4441 int nArg, 4442 int eTextRep, 4443 void *pApp, 4444 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4445 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4446 void (*xFinal)(sqlite3_context*) 4447 ); 4448 SQLITE_API int SQLITE_STDCALL sqlite3_create_function16( 4449 sqlite3 *db, 4450 const void *zFunctionName, 4451 int nArg, 4452 int eTextRep, 4453 void *pApp, 4454 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4455 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4456 void (*xFinal)(sqlite3_context*) 4457 ); 4458 SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2( 4459 sqlite3 *db, 4460 const char *zFunctionName, 4461 int nArg, 4462 int eTextRep, 4463 void *pApp, 4464 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4465 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4466 void (*xFinal)(sqlite3_context*), 4467 void(*xDestroy)(void*) 4468 ); 4469 4470 /* 4471 ** CAPI3REF: Text Encodings 4472 ** 4473 ** These constant define integer codes that represent the various 4474 ** text encodings supported by SQLite. 4475 */ 4476 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4477 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4478 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4479 #define SQLITE_UTF16 4 /* Use native byte order */ 4480 #define SQLITE_ANY 5 /* Deprecated */ 4481 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4482 4483 /* 4484 ** CAPI3REF: Function Flags 4485 ** 4486 ** These constants may be ORed together with the 4487 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4488 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4489 ** [sqlite3_create_function_v2()]. 4490 */ 4491 #define SQLITE_DETERMINISTIC 0x800 4492 4493 /* 4494 ** CAPI3REF: Deprecated Functions 4495 ** DEPRECATED 4496 ** 4497 ** These functions are [deprecated]. In order to maintain 4498 ** backwards compatibility with older code, these functions continue 4499 ** to be supported. However, new applications should avoid 4500 ** the use of these functions. To encourage programmers to avoid 4501 ** these functions, we will not explain what they do. 4502 */ 4503 #ifndef SQLITE_OMIT_DEPRECATED 4504 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*); 4505 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*); 4506 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4507 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void); 4508 SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void); 4509 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4510 void*,sqlite3_int64); 4511 #endif 4512 4513 /* 4514 ** CAPI3REF: Obtaining SQL Values 4515 ** METHOD: sqlite3_value 4516 ** 4517 ** The C-language implementation of SQL functions and aggregates uses 4518 ** this set of interface routines to access the parameter values on 4519 ** the function or aggregate. 4520 ** 4521 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4522 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4523 ** define callbacks that implement the SQL functions and aggregates. 4524 ** The 3rd parameter to these callbacks is an array of pointers to 4525 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4526 ** each parameter to the SQL function. These routines are used to 4527 ** extract values from the [sqlite3_value] objects. 4528 ** 4529 ** These routines work only with [protected sqlite3_value] objects. 4530 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4531 ** object results in undefined behavior. 4532 ** 4533 ** ^These routines work just like the corresponding [column access functions] 4534 ** except that these routines take a single [protected sqlite3_value] object 4535 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4536 ** 4537 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4538 ** in the native byte-order of the host machine. ^The 4539 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4540 ** extract UTF-16 strings as big-endian and little-endian respectively. 4541 ** 4542 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4543 ** numeric affinity to the value. This means that an attempt is 4544 ** made to convert the value to an integer or floating point. If 4545 ** such a conversion is possible without loss of information (in other 4546 ** words, if the value is a string that looks like a number) 4547 ** then the conversion is performed. Otherwise no conversion occurs. 4548 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4549 ** 4550 ** Please pay particular attention to the fact that the pointer returned 4551 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4552 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4553 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4554 ** or [sqlite3_value_text16()]. 4555 ** 4556 ** These routines must be called from the same thread as 4557 ** the SQL function that supplied the [sqlite3_value*] parameters. 4558 */ 4559 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*); 4560 SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*); 4561 SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*); 4562 SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*); 4563 SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*); 4564 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*); 4565 SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*); 4566 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*); 4567 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*); 4568 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*); 4569 SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*); 4570 SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*); 4571 4572 /* 4573 ** CAPI3REF: Finding The Subtype Of SQL Values 4574 ** METHOD: sqlite3_value 4575 ** 4576 ** The sqlite3_value_subtype(V) function returns the subtype for 4577 ** an [application-defined SQL function] argument V. The subtype 4578 ** information can be used to pass a limited amount of context from 4579 ** one SQL function to another. Use the [sqlite3_result_subtype()] 4580 ** routine to set the subtype for the return value of an SQL function. 4581 ** 4582 ** SQLite makes no use of subtype itself. It merely passes the subtype 4583 ** from the result of one [application-defined SQL function] into the 4584 ** input of another. 4585 */ 4586 SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value*); 4587 4588 /* 4589 ** CAPI3REF: Copy And Free SQL Values 4590 ** METHOD: sqlite3_value 4591 ** 4592 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4593 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4594 ** is a [protected sqlite3_value] object even if the input is not. 4595 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4596 ** memory allocation fails. 4597 ** 4598 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4599 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4600 ** then sqlite3_value_free(V) is a harmless no-op. 4601 */ 4602 SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value*); 4603 SQLITE_API void SQLITE_STDCALL sqlite3_value_free(sqlite3_value*); 4604 4605 /* 4606 ** CAPI3REF: Obtain Aggregate Function Context 4607 ** METHOD: sqlite3_context 4608 ** 4609 ** Implementations of aggregate SQL functions use this 4610 ** routine to allocate memory for storing their state. 4611 ** 4612 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4613 ** for a particular aggregate function, SQLite 4614 ** allocates N of memory, zeroes out that memory, and returns a pointer 4615 ** to the new memory. ^On second and subsequent calls to 4616 ** sqlite3_aggregate_context() for the same aggregate function instance, 4617 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4618 ** called once for each invocation of the xStep callback and then one 4619 ** last time when the xFinal callback is invoked. ^(When no rows match 4620 ** an aggregate query, the xStep() callback of the aggregate function 4621 ** implementation is never called and xFinal() is called exactly once. 4622 ** In those cases, sqlite3_aggregate_context() might be called for the 4623 ** first time from within xFinal().)^ 4624 ** 4625 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4626 ** when first called if N is less than or equal to zero or if a memory 4627 ** allocate error occurs. 4628 ** 4629 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4630 ** determined by the N parameter on first successful call. Changing the 4631 ** value of N in subsequent call to sqlite3_aggregate_context() within 4632 ** the same aggregate function instance will not resize the memory 4633 ** allocation.)^ Within the xFinal callback, it is customary to set 4634 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4635 ** pointless memory allocations occur. 4636 ** 4637 ** ^SQLite automatically frees the memory allocated by 4638 ** sqlite3_aggregate_context() when the aggregate query concludes. 4639 ** 4640 ** The first parameter must be a copy of the 4641 ** [sqlite3_context | SQL function context] that is the first parameter 4642 ** to the xStep or xFinal callback routine that implements the aggregate 4643 ** function. 4644 ** 4645 ** This routine must be called from the same thread in which 4646 ** the aggregate SQL function is running. 4647 */ 4648 SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4649 4650 /* 4651 ** CAPI3REF: User Data For Functions 4652 ** METHOD: sqlite3_context 4653 ** 4654 ** ^The sqlite3_user_data() interface returns a copy of 4655 ** the pointer that was the pUserData parameter (the 5th parameter) 4656 ** of the [sqlite3_create_function()] 4657 ** and [sqlite3_create_function16()] routines that originally 4658 ** registered the application defined function. 4659 ** 4660 ** This routine must be called from the same thread in which 4661 ** the application-defined function is running. 4662 */ 4663 SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*); 4664 4665 /* 4666 ** CAPI3REF: Database Connection For Functions 4667 ** METHOD: sqlite3_context 4668 ** 4669 ** ^The sqlite3_context_db_handle() interface returns a copy of 4670 ** the pointer to the [database connection] (the 1st parameter) 4671 ** of the [sqlite3_create_function()] 4672 ** and [sqlite3_create_function16()] routines that originally 4673 ** registered the application defined function. 4674 */ 4675 SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*); 4676 4677 /* 4678 ** CAPI3REF: Function Auxiliary Data 4679 ** METHOD: sqlite3_context 4680 ** 4681 ** These functions may be used by (non-aggregate) SQL functions to 4682 ** associate metadata with argument values. If the same value is passed to 4683 ** multiple invocations of the same SQL function during query execution, under 4684 ** some circumstances the associated metadata may be preserved. An example 4685 ** of where this might be useful is in a regular-expression matching 4686 ** function. The compiled version of the regular expression can be stored as 4687 ** metadata associated with the pattern string. 4688 ** Then as long as the pattern string remains the same, 4689 ** the compiled regular expression can be reused on multiple 4690 ** invocations of the same function. 4691 ** 4692 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4693 ** associated by the sqlite3_set_auxdata() function with the Nth argument 4694 ** value to the application-defined function. ^If there is no metadata 4695 ** associated with the function argument, this sqlite3_get_auxdata() interface 4696 ** returns a NULL pointer. 4697 ** 4698 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4699 ** argument of the application-defined function. ^Subsequent 4700 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4701 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4702 ** NULL if the metadata has been discarded. 4703 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4704 ** SQLite will invoke the destructor function X with parameter P exactly 4705 ** once, when the metadata is discarded. 4706 ** SQLite is free to discard the metadata at any time, including: <ul> 4707 ** <li> ^(when the corresponding function parameter changes)^, or 4708 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4709 ** SQL statement)^, or 4710 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 4711 ** parameter)^, or 4712 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 4713 ** allocation error occurs.)^ </ul> 4714 ** 4715 ** Note the last bullet in particular. The destructor X in 4716 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4717 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4718 ** should be called near the end of the function implementation and the 4719 ** function implementation should not make any use of P after 4720 ** sqlite3_set_auxdata() has been called. 4721 ** 4722 ** ^(In practice, metadata is preserved between function calls for 4723 ** function parameters that are compile-time constants, including literal 4724 ** values and [parameters] and expressions composed from the same.)^ 4725 ** 4726 ** These routines must be called from the same thread in which 4727 ** the SQL function is running. 4728 */ 4729 SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N); 4730 SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4731 4732 4733 /* 4734 ** CAPI3REF: Constants Defining Special Destructor Behavior 4735 ** 4736 ** These are special values for the destructor that is passed in as the 4737 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4738 ** argument is SQLITE_STATIC, it means that the content pointer is constant 4739 ** and will never change. It does not need to be destroyed. ^The 4740 ** SQLITE_TRANSIENT value means that the content will likely change in 4741 ** the near future and that SQLite should make its own private copy of 4742 ** the content before returning. 4743 ** 4744 ** The typedef is necessary to work around problems in certain 4745 ** C++ compilers. 4746 */ 4747 typedef void (*sqlite3_destructor_type)(void*); 4748 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 4749 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4750 4751 /* 4752 ** CAPI3REF: Setting The Result Of An SQL Function 4753 ** METHOD: sqlite3_context 4754 ** 4755 ** These routines are used by the xFunc or xFinal callbacks that 4756 ** implement SQL functions and aggregates. See 4757 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 4758 ** for additional information. 4759 ** 4760 ** These functions work very much like the [parameter binding] family of 4761 ** functions used to bind values to host parameters in prepared statements. 4762 ** Refer to the [SQL parameter] documentation for additional information. 4763 ** 4764 ** ^The sqlite3_result_blob() interface sets the result from 4765 ** an application-defined function to be the BLOB whose content is pointed 4766 ** to by the second parameter and which is N bytes long where N is the 4767 ** third parameter. 4768 ** 4769 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4770 ** interfaces set the result of the application-defined function to be 4771 ** a BLOB containing all zero bytes and N bytes in size. 4772 ** 4773 ** ^The sqlite3_result_double() interface sets the result from 4774 ** an application-defined function to be a floating point value specified 4775 ** by its 2nd argument. 4776 ** 4777 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4778 ** cause the implemented SQL function to throw an exception. 4779 ** ^SQLite uses the string pointed to by the 4780 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4781 ** as the text of an error message. ^SQLite interprets the error 4782 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 4783 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 4784 ** byte order. ^If the third parameter to sqlite3_result_error() 4785 ** or sqlite3_result_error16() is negative then SQLite takes as the error 4786 ** message all text up through the first zero character. 4787 ** ^If the third parameter to sqlite3_result_error() or 4788 ** sqlite3_result_error16() is non-negative then SQLite takes that many 4789 ** bytes (not characters) from the 2nd parameter as the error message. 4790 ** ^The sqlite3_result_error() and sqlite3_result_error16() 4791 ** routines make a private copy of the error message text before 4792 ** they return. Hence, the calling function can deallocate or 4793 ** modify the text after they return without harm. 4794 ** ^The sqlite3_result_error_code() function changes the error code 4795 ** returned by SQLite as a result of an error in a function. ^By default, 4796 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4797 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4798 ** 4799 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4800 ** error indicating that a string or BLOB is too long to represent. 4801 ** 4802 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4803 ** error indicating that a memory allocation failed. 4804 ** 4805 ** ^The sqlite3_result_int() interface sets the return value 4806 ** of the application-defined function to be the 32-bit signed integer 4807 ** value given in the 2nd argument. 4808 ** ^The sqlite3_result_int64() interface sets the return value 4809 ** of the application-defined function to be the 64-bit signed integer 4810 ** value given in the 2nd argument. 4811 ** 4812 ** ^The sqlite3_result_null() interface sets the return value 4813 ** of the application-defined function to be NULL. 4814 ** 4815 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 4816 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4817 ** set the return value of the application-defined function to be 4818 ** a text string which is represented as UTF-8, UTF-16 native byte order, 4819 ** UTF-16 little endian, or UTF-16 big endian, respectively. 4820 ** ^The sqlite3_result_text64() interface sets the return value of an 4821 ** application-defined function to be a text string in an encoding 4822 ** specified by the fifth (and last) parameter, which must be one 4823 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4824 ** ^SQLite takes the text result from the application from 4825 ** the 2nd parameter of the sqlite3_result_text* interfaces. 4826 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4827 ** is negative, then SQLite takes result text from the 2nd parameter 4828 ** through the first zero character. 4829 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4830 ** is non-negative, then as many bytes (not characters) of the text 4831 ** pointed to by the 2nd parameter are taken as the application-defined 4832 ** function result. If the 3rd parameter is non-negative, then it 4833 ** must be the byte offset into the string where the NUL terminator would 4834 ** appear if the string where NUL terminated. If any NUL characters occur 4835 ** in the string at a byte offset that is less than the value of the 3rd 4836 ** parameter, then the resulting string will contain embedded NULs and the 4837 ** result of expressions operating on strings with embedded NULs is undefined. 4838 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4839 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4840 ** function as the destructor on the text or BLOB result when it has 4841 ** finished using that result. 4842 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4843 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4844 ** assumes that the text or BLOB result is in constant space and does not 4845 ** copy the content of the parameter nor call a destructor on the content 4846 ** when it has finished using that result. 4847 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4848 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4849 ** then SQLite makes a copy of the result into space obtained from 4850 ** from [sqlite3_malloc()] before it returns. 4851 ** 4852 ** ^The sqlite3_result_value() interface sets the result of 4853 ** the application-defined function to be a copy of the 4854 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4855 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4856 ** so that the [sqlite3_value] specified in the parameter may change or 4857 ** be deallocated after sqlite3_result_value() returns without harm. 4858 ** ^A [protected sqlite3_value] object may always be used where an 4859 ** [unprotected sqlite3_value] object is required, so either 4860 ** kind of [sqlite3_value] object can be used with this interface. 4861 ** 4862 ** If these routines are called from within the different thread 4863 ** than the one containing the application-defined function that received 4864 ** the [sqlite3_context] pointer, the results are undefined. 4865 */ 4866 SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4867 SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*, 4868 sqlite3_uint64,void(*)(void*)); 4869 SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double); 4870 SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int); 4871 SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int); 4872 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*); 4873 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*); 4874 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int); 4875 SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int); 4876 SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4877 SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*); 4878 SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4879 SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4880 void(*)(void*), unsigned char encoding); 4881 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4882 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4883 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4884 SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4885 SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n); 4886 SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4887 4888 4889 /* 4890 ** CAPI3REF: Setting The Subtype Of An SQL Function 4891 ** METHOD: sqlite3_context 4892 ** 4893 ** The sqlite3_result_subtype(C,T) function causes the subtype of 4894 ** the result from the [application-defined SQL function] with 4895 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 4896 ** of the subtype T are preserved in current versions of SQLite; 4897 ** higher order bits are discarded. 4898 ** The number of subtype bytes preserved by SQLite might increase 4899 ** in future releases of SQLite. 4900 */ 4901 SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context*,unsigned int); 4902 4903 /* 4904 ** CAPI3REF: Define New Collating Sequences 4905 ** METHOD: sqlite3 4906 ** 4907 ** ^These functions add, remove, or modify a [collation] associated 4908 ** with the [database connection] specified as the first argument. 4909 ** 4910 ** ^The name of the collation is a UTF-8 string 4911 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4912 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4913 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4914 ** considered to be the same name. 4915 ** 4916 ** ^(The third argument (eTextRep) must be one of the constants: 4917 ** <ul> 4918 ** <li> [SQLITE_UTF8], 4919 ** <li> [SQLITE_UTF16LE], 4920 ** <li> [SQLITE_UTF16BE], 4921 ** <li> [SQLITE_UTF16], or 4922 ** <li> [SQLITE_UTF16_ALIGNED]. 4923 ** </ul>)^ 4924 ** ^The eTextRep argument determines the encoding of strings passed 4925 ** to the collating function callback, xCallback. 4926 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4927 ** force strings to be UTF16 with native byte order. 4928 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4929 ** on an even byte address. 4930 ** 4931 ** ^The fourth argument, pArg, is an application data pointer that is passed 4932 ** through as the first argument to the collating function callback. 4933 ** 4934 ** ^The fifth argument, xCallback, is a pointer to the collating function. 4935 ** ^Multiple collating functions can be registered using the same name but 4936 ** with different eTextRep parameters and SQLite will use whichever 4937 ** function requires the least amount of data transformation. 4938 ** ^If the xCallback argument is NULL then the collating function is 4939 ** deleted. ^When all collating functions having the same name are deleted, 4940 ** that collation is no longer usable. 4941 ** 4942 ** ^The collating function callback is invoked with a copy of the pArg 4943 ** application data pointer and with two strings in the encoding specified 4944 ** by the eTextRep argument. The collating function must return an 4945 ** integer that is negative, zero, or positive 4946 ** if the first string is less than, equal to, or greater than the second, 4947 ** respectively. A collating function must always return the same answer 4948 ** given the same inputs. If two or more collating functions are registered 4949 ** to the same collation name (using different eTextRep values) then all 4950 ** must give an equivalent answer when invoked with equivalent strings. 4951 ** The collating function must obey the following properties for all 4952 ** strings A, B, and C: 4953 ** 4954 ** <ol> 4955 ** <li> If A==B then B==A. 4956 ** <li> If A==B and B==C then A==C. 4957 ** <li> If A<B THEN B>A. 4958 ** <li> If A<B and B<C then A<C. 4959 ** </ol> 4960 ** 4961 ** If a collating function fails any of the above constraints and that 4962 ** collating function is registered and used, then the behavior of SQLite 4963 ** is undefined. 4964 ** 4965 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4966 ** with the addition that the xDestroy callback is invoked on pArg when 4967 ** the collating function is deleted. 4968 ** ^Collating functions are deleted when they are overridden by later 4969 ** calls to the collation creation functions or when the 4970 ** [database connection] is closed using [sqlite3_close()]. 4971 ** 4972 ** ^The xDestroy callback is <u>not</u> called if the 4973 ** sqlite3_create_collation_v2() function fails. Applications that invoke 4974 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4975 ** check the return code and dispose of the application data pointer 4976 ** themselves rather than expecting SQLite to deal with it for them. 4977 ** This is different from every other SQLite interface. The inconsistency 4978 ** is unfortunate but cannot be changed without breaking backwards 4979 ** compatibility. 4980 ** 4981 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4982 */ 4983 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation( 4984 sqlite3*, 4985 const char *zName, 4986 int eTextRep, 4987 void *pArg, 4988 int(*xCompare)(void*,int,const void*,int,const void*) 4989 ); 4990 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2( 4991 sqlite3*, 4992 const char *zName, 4993 int eTextRep, 4994 void *pArg, 4995 int(*xCompare)(void*,int,const void*,int,const void*), 4996 void(*xDestroy)(void*) 4997 ); 4998 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16( 4999 sqlite3*, 5000 const void *zName, 5001 int eTextRep, 5002 void *pArg, 5003 int(*xCompare)(void*,int,const void*,int,const void*) 5004 ); 5005 5006 /* 5007 ** CAPI3REF: Collation Needed Callbacks 5008 ** METHOD: sqlite3 5009 ** 5010 ** ^To avoid having to register all collation sequences before a database 5011 ** can be used, a single callback function may be registered with the 5012 ** [database connection] to be invoked whenever an undefined collation 5013 ** sequence is required. 5014 ** 5015 ** ^If the function is registered using the sqlite3_collation_needed() API, 5016 ** then it is passed the names of undefined collation sequences as strings 5017 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5018 ** the names are passed as UTF-16 in machine native byte order. 5019 ** ^A call to either function replaces the existing collation-needed callback. 5020 ** 5021 ** ^(When the callback is invoked, the first argument passed is a copy 5022 ** of the second argument to sqlite3_collation_needed() or 5023 ** sqlite3_collation_needed16(). The second argument is the database 5024 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5025 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5026 ** sequence function required. The fourth parameter is the name of the 5027 ** required collation sequence.)^ 5028 ** 5029 ** The callback function should register the desired collation using 5030 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5031 ** [sqlite3_create_collation_v2()]. 5032 */ 5033 SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed( 5034 sqlite3*, 5035 void*, 5036 void(*)(void*,sqlite3*,int eTextRep,const char*) 5037 ); 5038 SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16( 5039 sqlite3*, 5040 void*, 5041 void(*)(void*,sqlite3*,int eTextRep,const void*) 5042 ); 5043 5044 #ifdef SQLITE_HAS_CODEC 5045 /* 5046 ** Specify the key for an encrypted database. This routine should be 5047 ** called right after sqlite3_open(). 5048 ** 5049 ** The code to implement this API is not available in the public release 5050 ** of SQLite. 5051 */ 5052 SQLITE_API int SQLITE_STDCALL sqlite3_key( 5053 sqlite3 *db, /* Database to be rekeyed */ 5054 const void *pKey, int nKey /* The key */ 5055 ); 5056 SQLITE_API int SQLITE_STDCALL sqlite3_key_v2( 5057 sqlite3 *db, /* Database to be rekeyed */ 5058 const char *zDbName, /* Name of the database */ 5059 const void *pKey, int nKey /* The key */ 5060 ); 5061 5062 /* 5063 ** Change the key on an open database. If the current database is not 5064 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5065 ** database is decrypted. 5066 ** 5067 ** The code to implement this API is not available in the public release 5068 ** of SQLite. 5069 */ 5070 SQLITE_API int SQLITE_STDCALL sqlite3_rekey( 5071 sqlite3 *db, /* Database to be rekeyed */ 5072 const void *pKey, int nKey /* The new key */ 5073 ); 5074 SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2( 5075 sqlite3 *db, /* Database to be rekeyed */ 5076 const char *zDbName, /* Name of the database */ 5077 const void *pKey, int nKey /* The new key */ 5078 ); 5079 5080 /* 5081 ** Specify the activation key for a SEE database. Unless 5082 ** activated, none of the SEE routines will work. 5083 */ 5084 SQLITE_API void SQLITE_STDCALL sqlite3_activate_see( 5085 const char *zPassPhrase /* Activation phrase */ 5086 ); 5087 #endif 5088 5089 #ifdef SQLITE_ENABLE_CEROD 5090 /* 5091 ** Specify the activation key for a CEROD database. Unless 5092 ** activated, none of the CEROD routines will work. 5093 */ 5094 SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod( 5095 const char *zPassPhrase /* Activation phrase */ 5096 ); 5097 #endif 5098 5099 /* 5100 ** CAPI3REF: Suspend Execution For A Short Time 5101 ** 5102 ** The sqlite3_sleep() function causes the current thread to suspend execution 5103 ** for at least a number of milliseconds specified in its parameter. 5104 ** 5105 ** If the operating system does not support sleep requests with 5106 ** millisecond time resolution, then the time will be rounded up to 5107 ** the nearest second. The number of milliseconds of sleep actually 5108 ** requested from the operating system is returned. 5109 ** 5110 ** ^SQLite implements this interface by calling the xSleep() 5111 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5112 ** of the default VFS is not implemented correctly, or not implemented at 5113 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5114 ** in the previous paragraphs. 5115 */ 5116 SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int); 5117 5118 /* 5119 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5120 ** 5121 ** ^(If this global variable is made to point to a string which is 5122 ** the name of a folder (a.k.a. directory), then all temporary files 5123 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5124 ** will be placed in that directory.)^ ^If this variable 5125 ** is a NULL pointer, then SQLite performs a search for an appropriate 5126 ** temporary file directory. 5127 ** 5128 ** Applications are strongly discouraged from using this global variable. 5129 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5130 ** But for all other platforms, it is highly recommended that applications 5131 ** neither read nor write this variable. This global variable is a relic 5132 ** that exists for backwards compatibility of legacy applications and should 5133 ** be avoided in new projects. 5134 ** 5135 ** It is not safe to read or modify this variable in more than one 5136 ** thread at a time. It is not safe to read or modify this variable 5137 ** if a [database connection] is being used at the same time in a separate 5138 ** thread. 5139 ** It is intended that this variable be set once 5140 ** as part of process initialization and before any SQLite interface 5141 ** routines have been called and that this variable remain unchanged 5142 ** thereafter. 5143 ** 5144 ** ^The [temp_store_directory pragma] may modify this variable and cause 5145 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5146 ** the [temp_store_directory pragma] always assumes that any string 5147 ** that this variable points to is held in memory obtained from 5148 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5149 ** using [sqlite3_free]. 5150 ** Hence, if this variable is modified directly, either it should be 5151 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5152 ** or else the use of the [temp_store_directory pragma] should be avoided. 5153 ** Except when requested by the [temp_store_directory pragma], SQLite 5154 ** does not free the memory that sqlite3_temp_directory points to. If 5155 ** the application wants that memory to be freed, it must do 5156 ** so itself, taking care to only do so after all [database connection] 5157 ** objects have been destroyed. 5158 ** 5159 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5160 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5161 ** features that require the use of temporary files may fail. Here is an 5162 ** example of how to do this using C++ with the Windows Runtime: 5163 ** 5164 ** <blockquote><pre> 5165 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5166 ** TemporaryFolder->Path->Data(); 5167 ** char zPathBuf[MAX_PATH + 1]; 5168 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5169 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5170 ** NULL, NULL); 5171 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5172 ** </pre></blockquote> 5173 */ 5174 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5175 5176 /* 5177 ** CAPI3REF: Name Of The Folder Holding Database Files 5178 ** 5179 ** ^(If this global variable is made to point to a string which is 5180 ** the name of a folder (a.k.a. directory), then all database files 5181 ** specified with a relative pathname and created or accessed by 5182 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5183 ** to be relative to that directory.)^ ^If this variable is a NULL 5184 ** pointer, then SQLite assumes that all database files specified 5185 ** with a relative pathname are relative to the current directory 5186 ** for the process. Only the windows VFS makes use of this global 5187 ** variable; it is ignored by the unix VFS. 5188 ** 5189 ** Changing the value of this variable while a database connection is 5190 ** open can result in a corrupt database. 5191 ** 5192 ** It is not safe to read or modify this variable in more than one 5193 ** thread at a time. It is not safe to read or modify this variable 5194 ** if a [database connection] is being used at the same time in a separate 5195 ** thread. 5196 ** It is intended that this variable be set once 5197 ** as part of process initialization and before any SQLite interface 5198 ** routines have been called and that this variable remain unchanged 5199 ** thereafter. 5200 ** 5201 ** ^The [data_store_directory pragma] may modify this variable and cause 5202 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5203 ** the [data_store_directory pragma] always assumes that any string 5204 ** that this variable points to is held in memory obtained from 5205 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5206 ** using [sqlite3_free]. 5207 ** Hence, if this variable is modified directly, either it should be 5208 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5209 ** or else the use of the [data_store_directory pragma] should be avoided. 5210 */ 5211 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5212 5213 /* 5214 ** CAPI3REF: Test For Auto-Commit Mode 5215 ** KEYWORDS: {autocommit mode} 5216 ** METHOD: sqlite3 5217 ** 5218 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5219 ** zero if the given database connection is or is not in autocommit mode, 5220 ** respectively. ^Autocommit mode is on by default. 5221 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5222 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5223 ** 5224 ** If certain kinds of errors occur on a statement within a multi-statement 5225 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5226 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5227 ** transaction might be rolled back automatically. The only way to 5228 ** find out whether SQLite automatically rolled back the transaction after 5229 ** an error is to use this function. 5230 ** 5231 ** If another thread changes the autocommit status of the database 5232 ** connection while this routine is running, then the return value 5233 ** is undefined. 5234 */ 5235 SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*); 5236 5237 /* 5238 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5239 ** METHOD: sqlite3_stmt 5240 ** 5241 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5242 ** to which a [prepared statement] belongs. ^The [database connection] 5243 ** returned by sqlite3_db_handle is the same [database connection] 5244 ** that was the first argument 5245 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5246 ** create the statement in the first place. 5247 */ 5248 SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*); 5249 5250 /* 5251 ** CAPI3REF: Return The Filename For A Database Connection 5252 ** METHOD: sqlite3 5253 ** 5254 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5255 ** associated with database N of connection D. ^The main database file 5256 ** has the name "main". If there is no attached database N on the database 5257 ** connection D, or if database N is a temporary or in-memory database, then 5258 ** a NULL pointer is returned. 5259 ** 5260 ** ^The filename returned by this function is the output of the 5261 ** xFullPathname method of the [VFS]. ^In other words, the filename 5262 ** will be an absolute pathname, even if the filename used 5263 ** to open the database originally was a URI or relative pathname. 5264 */ 5265 SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5266 5267 /* 5268 ** CAPI3REF: Determine if a database is read-only 5269 ** METHOD: sqlite3 5270 ** 5271 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5272 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5273 ** the name of a database on connection D. 5274 */ 5275 SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5276 5277 /* 5278 ** CAPI3REF: Find the next prepared statement 5279 ** METHOD: sqlite3 5280 ** 5281 ** ^This interface returns a pointer to the next [prepared statement] after 5282 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5283 ** then this interface returns a pointer to the first prepared statement 5284 ** associated with the database connection pDb. ^If no prepared statement 5285 ** satisfies the conditions of this routine, it returns NULL. 5286 ** 5287 ** The [database connection] pointer D in a call to 5288 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5289 ** connection and in particular must not be a NULL pointer. 5290 */ 5291 SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5292 5293 /* 5294 ** CAPI3REF: Commit And Rollback Notification Callbacks 5295 ** METHOD: sqlite3 5296 ** 5297 ** ^The sqlite3_commit_hook() interface registers a callback 5298 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5299 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5300 ** for the same database connection is overridden. 5301 ** ^The sqlite3_rollback_hook() interface registers a callback 5302 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5303 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5304 ** for the same database connection is overridden. 5305 ** ^The pArg argument is passed through to the callback. 5306 ** ^If the callback on a commit hook function returns non-zero, 5307 ** then the commit is converted into a rollback. 5308 ** 5309 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5310 ** return the P argument from the previous call of the same function 5311 ** on the same [database connection] D, or NULL for 5312 ** the first call for each function on D. 5313 ** 5314 ** The commit and rollback hook callbacks are not reentrant. 5315 ** The callback implementation must not do anything that will modify 5316 ** the database connection that invoked the callback. Any actions 5317 ** to modify the database connection must be deferred until after the 5318 ** completion of the [sqlite3_step()] call that triggered the commit 5319 ** or rollback hook in the first place. 5320 ** Note that running any other SQL statements, including SELECT statements, 5321 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5322 ** the database connections for the meaning of "modify" in this paragraph. 5323 ** 5324 ** ^Registering a NULL function disables the callback. 5325 ** 5326 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5327 ** operation is allowed to continue normally. ^If the commit hook 5328 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5329 ** ^The rollback hook is invoked on a rollback that results from a commit 5330 ** hook returning non-zero, just as it would be with any other rollback. 5331 ** 5332 ** ^For the purposes of this API, a transaction is said to have been 5333 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5334 ** an error or constraint causes an implicit rollback to occur. 5335 ** ^The rollback callback is not invoked if a transaction is 5336 ** automatically rolled back because the database connection is closed. 5337 ** 5338 ** See also the [sqlite3_update_hook()] interface. 5339 */ 5340 SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5341 SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5342 5343 /* 5344 ** CAPI3REF: Data Change Notification Callbacks 5345 ** METHOD: sqlite3 5346 ** 5347 ** ^The sqlite3_update_hook() interface registers a callback function 5348 ** with the [database connection] identified by the first argument 5349 ** to be invoked whenever a row is updated, inserted or deleted in 5350 ** a [rowid table]. 5351 ** ^Any callback set by a previous call to this function 5352 ** for the same database connection is overridden. 5353 ** 5354 ** ^The second argument is a pointer to the function to invoke when a 5355 ** row is updated, inserted or deleted in a rowid table. 5356 ** ^The first argument to the callback is a copy of the third argument 5357 ** to sqlite3_update_hook(). 5358 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5359 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5360 ** to be invoked. 5361 ** ^The third and fourth arguments to the callback contain pointers to the 5362 ** database and table name containing the affected row. 5363 ** ^The final callback parameter is the [rowid] of the row. 5364 ** ^In the case of an update, this is the [rowid] after the update takes place. 5365 ** 5366 ** ^(The update hook is not invoked when internal system tables are 5367 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5368 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5369 ** 5370 ** ^In the current implementation, the update hook 5371 ** is not invoked when duplication rows are deleted because of an 5372 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5373 ** invoked when rows are deleted using the [truncate optimization]. 5374 ** The exceptions defined in this paragraph might change in a future 5375 ** release of SQLite. 5376 ** 5377 ** The update hook implementation must not do anything that will modify 5378 ** the database connection that invoked the update hook. Any actions 5379 ** to modify the database connection must be deferred until after the 5380 ** completion of the [sqlite3_step()] call that triggered the update hook. 5381 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5382 ** database connections for the meaning of "modify" in this paragraph. 5383 ** 5384 ** ^The sqlite3_update_hook(D,C,P) function 5385 ** returns the P argument from the previous call 5386 ** on the same [database connection] D, or NULL for 5387 ** the first call on D. 5388 ** 5389 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5390 ** and [sqlite3_preupdate_hook()] interfaces. 5391 */ 5392 SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook( 5393 sqlite3*, 5394 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5395 void* 5396 ); 5397 5398 /* 5399 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5400 ** 5401 ** ^(This routine enables or disables the sharing of the database cache 5402 ** and schema data structures between [database connection | connections] 5403 ** to the same database. Sharing is enabled if the argument is true 5404 ** and disabled if the argument is false.)^ 5405 ** 5406 ** ^Cache sharing is enabled and disabled for an entire process. 5407 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5408 ** sharing was enabled or disabled for each thread separately. 5409 ** 5410 ** ^(The cache sharing mode set by this interface effects all subsequent 5411 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5412 ** Existing database connections continue use the sharing mode 5413 ** that was in effect at the time they were opened.)^ 5414 ** 5415 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5416 ** successfully. An [error code] is returned otherwise.)^ 5417 ** 5418 ** ^Shared cache is disabled by default. But this might change in 5419 ** future releases of SQLite. Applications that care about shared 5420 ** cache setting should set it explicitly. 5421 ** 5422 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5423 ** and will always return SQLITE_MISUSE. On those systems, 5424 ** shared cache mode should be enabled per-database connection via 5425 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5426 ** 5427 ** This interface is threadsafe on processors where writing a 5428 ** 32-bit integer is atomic. 5429 ** 5430 ** See Also: [SQLite Shared-Cache Mode] 5431 */ 5432 SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int); 5433 5434 /* 5435 ** CAPI3REF: Attempt To Free Heap Memory 5436 ** 5437 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5438 ** of heap memory by deallocating non-essential memory allocations 5439 ** held by the database library. Memory used to cache database 5440 ** pages to improve performance is an example of non-essential memory. 5441 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5442 ** which might be more or less than the amount requested. 5443 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5444 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5445 ** 5446 ** See also: [sqlite3_db_release_memory()] 5447 */ 5448 SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int); 5449 5450 /* 5451 ** CAPI3REF: Free Memory Used By A Database Connection 5452 ** METHOD: sqlite3 5453 ** 5454 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5455 ** memory as possible from database connection D. Unlike the 5456 ** [sqlite3_release_memory()] interface, this interface is in effect even 5457 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5458 ** omitted. 5459 ** 5460 ** See also: [sqlite3_release_memory()] 5461 */ 5462 SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*); 5463 5464 /* 5465 ** CAPI3REF: Impose A Limit On Heap Size 5466 ** 5467 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5468 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5469 ** ^SQLite strives to keep heap memory utilization below the soft heap 5470 ** limit by reducing the number of pages held in the page cache 5471 ** as heap memory usages approaches the limit. 5472 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5473 ** below the limit, it will exceed the limit rather than generate 5474 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5475 ** is advisory only. 5476 ** 5477 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5478 ** the soft heap limit prior to the call, or negative in the case of an 5479 ** error. ^If the argument N is negative 5480 ** then no change is made to the soft heap limit. Hence, the current 5481 ** size of the soft heap limit can be determined by invoking 5482 ** sqlite3_soft_heap_limit64() with a negative argument. 5483 ** 5484 ** ^If the argument N is zero then the soft heap limit is disabled. 5485 ** 5486 ** ^(The soft heap limit is not enforced in the current implementation 5487 ** if one or more of following conditions are true: 5488 ** 5489 ** <ul> 5490 ** <li> The soft heap limit is set to zero. 5491 ** <li> Memory accounting is disabled using a combination of the 5492 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5493 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5494 ** <li> An alternative page cache implementation is specified using 5495 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5496 ** <li> The page cache allocates from its own memory pool supplied 5497 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5498 ** from the heap. 5499 ** </ul>)^ 5500 ** 5501 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5502 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5503 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5504 ** the soft heap limit is enforced on every memory allocation. Without 5505 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5506 ** when memory is allocated by the page cache. Testing suggests that because 5507 ** the page cache is the predominate memory user in SQLite, most 5508 ** applications will achieve adequate soft heap limit enforcement without 5509 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5510 ** 5511 ** The circumstances under which SQLite will enforce the soft heap limit may 5512 ** changes in future releases of SQLite. 5513 */ 5514 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N); 5515 5516 /* 5517 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5518 ** DEPRECATED 5519 ** 5520 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5521 ** interface. This routine is provided for historical compatibility 5522 ** only. All new applications should use the 5523 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5524 */ 5525 SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N); 5526 5527 5528 /* 5529 ** CAPI3REF: Extract Metadata About A Column Of A Table 5530 ** METHOD: sqlite3 5531 ** 5532 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5533 ** information about column C of table T in database D 5534 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5535 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 5536 ** the final five arguments with appropriate values if the specified 5537 ** column exists. ^The sqlite3_table_column_metadata() interface returns 5538 ** SQLITE_ERROR and if the specified column does not exist. 5539 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5540 ** NULL pointer, then this routine simply checks for the existence of the 5541 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5542 ** does not. 5543 ** 5544 ** ^The column is identified by the second, third and fourth parameters to 5545 ** this function. ^(The second parameter is either the name of the database 5546 ** (i.e. "main", "temp", or an attached database) containing the specified 5547 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5548 ** for the table using the same algorithm used by the database engine to 5549 ** resolve unqualified table references. 5550 ** 5551 ** ^The third and fourth parameters to this function are the table and column 5552 ** name of the desired column, respectively. 5553 ** 5554 ** ^Metadata is returned by writing to the memory locations passed as the 5th 5555 ** and subsequent parameters to this function. ^Any of these arguments may be 5556 ** NULL, in which case the corresponding element of metadata is omitted. 5557 ** 5558 ** ^(<blockquote> 5559 ** <table border="1"> 5560 ** <tr><th> Parameter <th> Output<br>Type <th> Description 5561 ** 5562 ** <tr><td> 5th <td> const char* <td> Data type 5563 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5564 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5565 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5566 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5567 ** </table> 5568 ** </blockquote>)^ 5569 ** 5570 ** ^The memory pointed to by the character pointers returned for the 5571 ** declaration type and collation sequence is valid until the next 5572 ** call to any SQLite API function. 5573 ** 5574 ** ^If the specified table is actually a view, an [error code] is returned. 5575 ** 5576 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5577 ** is not a [WITHOUT ROWID] table and an 5578 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5579 ** parameters are set for the explicitly declared column. ^(If there is no 5580 ** [INTEGER PRIMARY KEY] column, then the outputs 5581 ** for the [rowid] are set as follows: 5582 ** 5583 ** <pre> 5584 ** data type: "INTEGER" 5585 ** collation sequence: "BINARY" 5586 ** not null: 0 5587 ** primary key: 1 5588 ** auto increment: 0 5589 ** </pre>)^ 5590 ** 5591 ** ^This function causes all database schemas to be read from disk and 5592 ** parsed, if that has not already been done, and returns an error if 5593 ** any errors are encountered while loading the schema. 5594 */ 5595 SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata( 5596 sqlite3 *db, /* Connection handle */ 5597 const char *zDbName, /* Database name or NULL */ 5598 const char *zTableName, /* Table name */ 5599 const char *zColumnName, /* Column name */ 5600 char const **pzDataType, /* OUTPUT: Declared data type */ 5601 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5602 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5603 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5604 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5605 ); 5606 5607 /* 5608 ** CAPI3REF: Load An Extension 5609 ** METHOD: sqlite3 5610 ** 5611 ** ^This interface loads an SQLite extension library from the named file. 5612 ** 5613 ** ^The sqlite3_load_extension() interface attempts to load an 5614 ** [SQLite extension] library contained in the file zFile. If 5615 ** the file cannot be loaded directly, attempts are made to load 5616 ** with various operating-system specific extensions added. 5617 ** So for example, if "samplelib" cannot be loaded, then names like 5618 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5619 ** be tried also. 5620 ** 5621 ** ^The entry point is zProc. 5622 ** ^(zProc may be 0, in which case SQLite will try to come up with an 5623 ** entry point name on its own. It first tries "sqlite3_extension_init". 5624 ** If that does not work, it constructs a name "sqlite3_X_init" where the 5625 ** X is consists of the lower-case equivalent of all ASCII alphabetic 5626 ** characters in the filename from the last "/" to the first following 5627 ** "." and omitting any initial "lib".)^ 5628 ** ^The sqlite3_load_extension() interface returns 5629 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5630 ** ^If an error occurs and pzErrMsg is not 0, then the 5631 ** [sqlite3_load_extension()] interface shall attempt to 5632 ** fill *pzErrMsg with error message text stored in memory 5633 ** obtained from [sqlite3_malloc()]. The calling function 5634 ** should free this memory by calling [sqlite3_free()]. 5635 ** 5636 ** ^Extension loading must be enabled using 5637 ** [sqlite3_enable_load_extension()] or 5638 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5639 ** prior to calling this API, 5640 ** otherwise an error will be returned. 5641 ** 5642 ** <b>Security warning:</b> It is recommended that the 5643 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5644 ** interface. The use of the [sqlite3_enable_load_extension()] interface 5645 ** should be avoided. This will keep the SQL function [load_extension()] 5646 ** disabled and prevent SQL injections from giving attackers 5647 ** access to extension loading capabilities. 5648 ** 5649 ** See also the [load_extension() SQL function]. 5650 */ 5651 SQLITE_API int SQLITE_STDCALL sqlite3_load_extension( 5652 sqlite3 *db, /* Load the extension into this database connection */ 5653 const char *zFile, /* Name of the shared library containing extension */ 5654 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5655 char **pzErrMsg /* Put error message here if not 0 */ 5656 ); 5657 5658 /* 5659 ** CAPI3REF: Enable Or Disable Extension Loading 5660 ** METHOD: sqlite3 5661 ** 5662 ** ^So as not to open security holes in older applications that are 5663 ** unprepared to deal with [extension loading], and as a means of disabling 5664 ** [extension loading] while evaluating user-entered SQL, the following API 5665 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5666 ** 5667 ** ^Extension loading is off by default. 5668 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5669 ** to turn extension loading on and call it with onoff==0 to turn 5670 ** it back off again. 5671 ** 5672 ** ^This interface enables or disables both the C-API 5673 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5674 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5675 ** to enable or disable only the C-API.)^ 5676 ** 5677 ** <b>Security warning:</b> It is recommended that extension loading 5678 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5679 ** rather than this interface, so the [load_extension()] SQL function 5680 ** remains disabled. This will prevent SQL injections from giving attackers 5681 ** access to extension loading capabilities. 5682 */ 5683 SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5684 5685 /* 5686 ** CAPI3REF: Automatically Load Statically Linked Extensions 5687 ** 5688 ** ^This interface causes the xEntryPoint() function to be invoked for 5689 ** each new [database connection] that is created. The idea here is that 5690 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5691 ** that is to be automatically loaded into all new database connections. 5692 ** 5693 ** ^(Even though the function prototype shows that xEntryPoint() takes 5694 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5695 ** arguments and expects an integer result as if the signature of the 5696 ** entry point where as follows: 5697 ** 5698 ** <blockquote><pre> 5699 ** int xEntryPoint( 5700 ** sqlite3 *db, 5701 ** const char **pzErrMsg, 5702 ** const struct sqlite3_api_routines *pThunk 5703 ** ); 5704 ** </pre></blockquote>)^ 5705 ** 5706 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5707 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5708 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5709 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5710 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5711 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5712 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5713 ** 5714 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5715 ** on the list of automatic extensions is a harmless no-op. ^No entry point 5716 ** will be called more than once for each database connection that is opened. 5717 ** 5718 ** See also: [sqlite3_reset_auto_extension()] 5719 ** and [sqlite3_cancel_auto_extension()] 5720 */ 5721 SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void(*xEntryPoint)(void)); 5722 5723 /* 5724 ** CAPI3REF: Cancel Automatic Extension Loading 5725 ** 5726 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5727 ** initialization routine X that was registered using a prior call to 5728 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5729 ** routine returns 1 if initialization routine X was successfully 5730 ** unregistered and it returns 0 if X was not on the list of initialization 5731 ** routines. 5732 */ 5733 SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 5734 5735 /* 5736 ** CAPI3REF: Reset Automatic Extension Loading 5737 ** 5738 ** ^This interface disables all automatic extensions previously 5739 ** registered using [sqlite3_auto_extension()]. 5740 */ 5741 SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void); 5742 5743 /* 5744 ** The interface to the virtual-table mechanism is currently considered 5745 ** to be experimental. The interface might change in incompatible ways. 5746 ** If this is a problem for you, do not use the interface at this time. 5747 ** 5748 ** When the virtual-table mechanism stabilizes, we will declare the 5749 ** interface fixed, support it indefinitely, and remove this comment. 5750 */ 5751 5752 /* 5753 ** Structures used by the virtual table interface 5754 */ 5755 typedef struct sqlite3_vtab sqlite3_vtab; 5756 typedef struct sqlite3_index_info sqlite3_index_info; 5757 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5758 typedef struct sqlite3_module sqlite3_module; 5759 5760 /* 5761 ** CAPI3REF: Virtual Table Object 5762 ** KEYWORDS: sqlite3_module {virtual table module} 5763 ** 5764 ** This structure, sometimes called a "virtual table module", 5765 ** defines the implementation of a [virtual tables]. 5766 ** This structure consists mostly of methods for the module. 5767 ** 5768 ** ^A virtual table module is created by filling in a persistent 5769 ** instance of this structure and passing a pointer to that instance 5770 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5771 ** ^The registration remains valid until it is replaced by a different 5772 ** module or until the [database connection] closes. The content 5773 ** of this structure must not change while it is registered with 5774 ** any database connection. 5775 */ 5776 struct sqlite3_module { 5777 int iVersion; 5778 int (*xCreate)(sqlite3*, void *pAux, 5779 int argc, const char *const*argv, 5780 sqlite3_vtab **ppVTab, char**); 5781 int (*xConnect)(sqlite3*, void *pAux, 5782 int argc, const char *const*argv, 5783 sqlite3_vtab **ppVTab, char**); 5784 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5785 int (*xDisconnect)(sqlite3_vtab *pVTab); 5786 int (*xDestroy)(sqlite3_vtab *pVTab); 5787 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5788 int (*xClose)(sqlite3_vtab_cursor*); 5789 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5790 int argc, sqlite3_value **argv); 5791 int (*xNext)(sqlite3_vtab_cursor*); 5792 int (*xEof)(sqlite3_vtab_cursor*); 5793 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5794 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5795 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5796 int (*xBegin)(sqlite3_vtab *pVTab); 5797 int (*xSync)(sqlite3_vtab *pVTab); 5798 int (*xCommit)(sqlite3_vtab *pVTab); 5799 int (*xRollback)(sqlite3_vtab *pVTab); 5800 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5801 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5802 void **ppArg); 5803 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5804 /* The methods above are in version 1 of the sqlite_module object. Those 5805 ** below are for version 2 and greater. */ 5806 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5807 int (*xRelease)(sqlite3_vtab *pVTab, int); 5808 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5809 }; 5810 5811 /* 5812 ** CAPI3REF: Virtual Table Indexing Information 5813 ** KEYWORDS: sqlite3_index_info 5814 ** 5815 ** The sqlite3_index_info structure and its substructures is used as part 5816 ** of the [virtual table] interface to 5817 ** pass information into and receive the reply from the [xBestIndex] 5818 ** method of a [virtual table module]. The fields under **Inputs** are the 5819 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 5820 ** results into the **Outputs** fields. 5821 ** 5822 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 5823 ** 5824 ** <blockquote>column OP expr</blockquote> 5825 ** 5826 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5827 ** stored in aConstraint[].op using one of the 5828 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5829 ** ^(The index of the column is stored in 5830 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5831 ** expr on the right-hand side can be evaluated (and thus the constraint 5832 ** is usable) and false if it cannot.)^ 5833 ** 5834 ** ^The optimizer automatically inverts terms of the form "expr OP column" 5835 ** and makes other simplifications to the WHERE clause in an attempt to 5836 ** get as many WHERE clause terms into the form shown above as possible. 5837 ** ^The aConstraint[] array only reports WHERE clause terms that are 5838 ** relevant to the particular virtual table being queried. 5839 ** 5840 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5841 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 5842 ** 5843 ** The colUsed field indicates which columns of the virtual table may be 5844 ** required by the current scan. Virtual table columns are numbered from 5845 ** zero in the order in which they appear within the CREATE TABLE statement 5846 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5847 ** the corresponding bit is set within the colUsed mask if the column may be 5848 ** required by SQLite. If the table has at least 64 columns and any column 5849 ** to the right of the first 63 is required, then bit 63 of colUsed is also 5850 ** set. In other words, column iCol may be required if the expression 5851 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5852 ** non-zero. 5853 ** 5854 ** The [xBestIndex] method must fill aConstraintUsage[] with information 5855 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 5856 ** the right-hand side of the corresponding aConstraint[] is evaluated 5857 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5858 ** is true, then the constraint is assumed to be fully handled by the 5859 ** virtual table and is not checked again by SQLite.)^ 5860 ** 5861 ** ^The idxNum and idxPtr values are recorded and passed into the 5862 ** [xFilter] method. 5863 ** ^[sqlite3_free()] is used to free idxPtr if and only if 5864 ** needToFreeIdxPtr is true. 5865 ** 5866 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5867 ** the correct order to satisfy the ORDER BY clause so that no separate 5868 ** sorting step is required. 5869 ** 5870 ** ^The estimatedCost value is an estimate of the cost of a particular 5871 ** strategy. A cost of N indicates that the cost of the strategy is similar 5872 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 5873 ** indicates that the expense of the operation is similar to that of a 5874 ** binary search on a unique indexed field of an SQLite table with N rows. 5875 ** 5876 ** ^The estimatedRows value is an estimate of the number of rows that 5877 ** will be returned by the strategy. 5878 ** 5879 ** The xBestIndex method may optionally populate the idxFlags field with a 5880 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5881 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5882 ** assumes that the strategy may visit at most one row. 5883 ** 5884 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5885 ** SQLite also assumes that if a call to the xUpdate() method is made as 5886 ** part of the same statement to delete or update a virtual table row and the 5887 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5888 ** any database changes. In other words, if the xUpdate() returns 5889 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5890 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5891 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5892 ** the xUpdate method are automatically rolled back by SQLite. 5893 ** 5894 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5895 ** structure for SQLite version 3.8.2. If a virtual table extension is 5896 ** used with an SQLite version earlier than 3.8.2, the results of attempting 5897 ** to read or write the estimatedRows field are undefined (but are likely 5898 ** to included crashing the application). The estimatedRows field should 5899 ** therefore only be used if [sqlite3_libversion_number()] returns a 5900 ** value greater than or equal to 3008002. Similarly, the idxFlags field 5901 ** was added for version 3.9.0. It may therefore only be used if 5902 ** sqlite3_libversion_number() returns a value greater than or equal to 5903 ** 3009000. 5904 */ 5905 struct sqlite3_index_info { 5906 /* Inputs */ 5907 int nConstraint; /* Number of entries in aConstraint */ 5908 struct sqlite3_index_constraint { 5909 int iColumn; /* Column constrained. -1 for ROWID */ 5910 unsigned char op; /* Constraint operator */ 5911 unsigned char usable; /* True if this constraint is usable */ 5912 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5913 } *aConstraint; /* Table of WHERE clause constraints */ 5914 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5915 struct sqlite3_index_orderby { 5916 int iColumn; /* Column number */ 5917 unsigned char desc; /* True for DESC. False for ASC. */ 5918 } *aOrderBy; /* The ORDER BY clause */ 5919 /* Outputs */ 5920 struct sqlite3_index_constraint_usage { 5921 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5922 unsigned char omit; /* Do not code a test for this constraint */ 5923 } *aConstraintUsage; 5924 int idxNum; /* Number used to identify the index */ 5925 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5926 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5927 int orderByConsumed; /* True if output is already ordered */ 5928 double estimatedCost; /* Estimated cost of using this index */ 5929 /* Fields below are only available in SQLite 3.8.2 and later */ 5930 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5931 /* Fields below are only available in SQLite 3.9.0 and later */ 5932 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 5933 /* Fields below are only available in SQLite 3.10.0 and later */ 5934 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 5935 }; 5936 5937 /* 5938 ** CAPI3REF: Virtual Table Scan Flags 5939 */ 5940 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 5941 5942 /* 5943 ** CAPI3REF: Virtual Table Constraint Operator Codes 5944 ** 5945 ** These macros defined the allowed values for the 5946 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 5947 ** an operator that is part of a constraint term in the wHERE clause of 5948 ** a query that uses a [virtual table]. 5949 */ 5950 #define SQLITE_INDEX_CONSTRAINT_EQ 2 5951 #define SQLITE_INDEX_CONSTRAINT_GT 4 5952 #define SQLITE_INDEX_CONSTRAINT_LE 8 5953 #define SQLITE_INDEX_CONSTRAINT_LT 16 5954 #define SQLITE_INDEX_CONSTRAINT_GE 32 5955 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 5956 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 5957 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 5958 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 5959 5960 /* 5961 ** CAPI3REF: Register A Virtual Table Implementation 5962 ** METHOD: sqlite3 5963 ** 5964 ** ^These routines are used to register a new [virtual table module] name. 5965 ** ^Module names must be registered before 5966 ** creating a new [virtual table] using the module and before using a 5967 ** preexisting [virtual table] for the module. 5968 ** 5969 ** ^The module name is registered on the [database connection] specified 5970 ** by the first parameter. ^The name of the module is given by the 5971 ** second parameter. ^The third parameter is a pointer to 5972 ** the implementation of the [virtual table module]. ^The fourth 5973 ** parameter is an arbitrary client data pointer that is passed through 5974 ** into the [xCreate] and [xConnect] methods of the virtual table module 5975 ** when a new virtual table is be being created or reinitialized. 5976 ** 5977 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5978 ** is a pointer to a destructor for the pClientData. ^SQLite will 5979 ** invoke the destructor function (if it is not NULL) when SQLite 5980 ** no longer needs the pClientData pointer. ^The destructor will also 5981 ** be invoked if the call to sqlite3_create_module_v2() fails. 5982 ** ^The sqlite3_create_module() 5983 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 5984 ** destructor. 5985 */ 5986 SQLITE_API int SQLITE_STDCALL sqlite3_create_module( 5987 sqlite3 *db, /* SQLite connection to register module with */ 5988 const char *zName, /* Name of the module */ 5989 const sqlite3_module *p, /* Methods for the module */ 5990 void *pClientData /* Client data for xCreate/xConnect */ 5991 ); 5992 SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2( 5993 sqlite3 *db, /* SQLite connection to register module with */ 5994 const char *zName, /* Name of the module */ 5995 const sqlite3_module *p, /* Methods for the module */ 5996 void *pClientData, /* Client data for xCreate/xConnect */ 5997 void(*xDestroy)(void*) /* Module destructor function */ 5998 ); 5999 6000 /* 6001 ** CAPI3REF: Virtual Table Instance Object 6002 ** KEYWORDS: sqlite3_vtab 6003 ** 6004 ** Every [virtual table module] implementation uses a subclass 6005 ** of this object to describe a particular instance 6006 ** of the [virtual table]. Each subclass will 6007 ** be tailored to the specific needs of the module implementation. 6008 ** The purpose of this superclass is to define certain fields that are 6009 ** common to all module implementations. 6010 ** 6011 ** ^Virtual tables methods can set an error message by assigning a 6012 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6013 ** take care that any prior string is freed by a call to [sqlite3_free()] 6014 ** prior to assigning a new string to zErrMsg. ^After the error message 6015 ** is delivered up to the client application, the string will be automatically 6016 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6017 */ 6018 struct sqlite3_vtab { 6019 const sqlite3_module *pModule; /* The module for this virtual table */ 6020 int nRef; /* Number of open cursors */ 6021 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6022 /* Virtual table implementations will typically add additional fields */ 6023 }; 6024 6025 /* 6026 ** CAPI3REF: Virtual Table Cursor Object 6027 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6028 ** 6029 ** Every [virtual table module] implementation uses a subclass of the 6030 ** following structure to describe cursors that point into the 6031 ** [virtual table] and are used 6032 ** to loop through the virtual table. Cursors are created using the 6033 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6034 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6035 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6036 ** of the module. Each module implementation will define 6037 ** the content of a cursor structure to suit its own needs. 6038 ** 6039 ** This superclass exists in order to define fields of the cursor that 6040 ** are common to all implementations. 6041 */ 6042 struct sqlite3_vtab_cursor { 6043 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6044 /* Virtual table implementations will typically add additional fields */ 6045 }; 6046 6047 /* 6048 ** CAPI3REF: Declare The Schema Of A Virtual Table 6049 ** 6050 ** ^The [xCreate] and [xConnect] methods of a 6051 ** [virtual table module] call this interface 6052 ** to declare the format (the names and datatypes of the columns) of 6053 ** the virtual tables they implement. 6054 */ 6055 SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6056 6057 /* 6058 ** CAPI3REF: Overload A Function For A Virtual Table 6059 ** METHOD: sqlite3 6060 ** 6061 ** ^(Virtual tables can provide alternative implementations of functions 6062 ** using the [xFindFunction] method of the [virtual table module]. 6063 ** But global versions of those functions 6064 ** must exist in order to be overloaded.)^ 6065 ** 6066 ** ^(This API makes sure a global version of a function with a particular 6067 ** name and number of parameters exists. If no such function exists 6068 ** before this API is called, a new function is created.)^ ^The implementation 6069 ** of the new function always causes an exception to be thrown. So 6070 ** the new function is not good for anything by itself. Its only 6071 ** purpose is to be a placeholder function that can be overloaded 6072 ** by a [virtual table]. 6073 */ 6074 SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6075 6076 /* 6077 ** The interface to the virtual-table mechanism defined above (back up 6078 ** to a comment remarkably similar to this one) is currently considered 6079 ** to be experimental. The interface might change in incompatible ways. 6080 ** If this is a problem for you, do not use the interface at this time. 6081 ** 6082 ** When the virtual-table mechanism stabilizes, we will declare the 6083 ** interface fixed, support it indefinitely, and remove this comment. 6084 */ 6085 6086 /* 6087 ** CAPI3REF: A Handle To An Open BLOB 6088 ** KEYWORDS: {BLOB handle} {BLOB handles} 6089 ** 6090 ** An instance of this object represents an open BLOB on which 6091 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6092 ** ^Objects of this type are created by [sqlite3_blob_open()] 6093 ** and destroyed by [sqlite3_blob_close()]. 6094 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6095 ** can be used to read or write small subsections of the BLOB. 6096 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6097 */ 6098 typedef struct sqlite3_blob sqlite3_blob; 6099 6100 /* 6101 ** CAPI3REF: Open A BLOB For Incremental I/O 6102 ** METHOD: sqlite3 6103 ** CONSTRUCTOR: sqlite3_blob 6104 ** 6105 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6106 ** in row iRow, column zColumn, table zTable in database zDb; 6107 ** in other words, the same BLOB that would be selected by: 6108 ** 6109 ** <pre> 6110 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6111 ** </pre>)^ 6112 ** 6113 ** ^(Parameter zDb is not the filename that contains the database, but 6114 ** rather the symbolic name of the database. For attached databases, this is 6115 ** the name that appears after the AS keyword in the [ATTACH] statement. 6116 ** For the main database file, the database name is "main". For TEMP 6117 ** tables, the database name is "temp".)^ 6118 ** 6119 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 6120 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 6121 ** read-only access. 6122 ** 6123 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6124 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6125 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6126 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6127 ** on *ppBlob after this function it returns. 6128 ** 6129 ** This function fails with SQLITE_ERROR if any of the following are true: 6130 ** <ul> 6131 ** <li> ^(Database zDb does not exist)^, 6132 ** <li> ^(Table zTable does not exist within database zDb)^, 6133 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6134 ** <li> ^(Column zColumn does not exist)^, 6135 ** <li> ^(Row iRow is not present in the table)^, 6136 ** <li> ^(The specified column of row iRow contains a value that is not 6137 ** a TEXT or BLOB value)^, 6138 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6139 ** constraint and the blob is being opened for read/write access)^, 6140 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6141 ** column zColumn is part of a [child key] definition and the blob is 6142 ** being opened for read/write access)^. 6143 ** </ul> 6144 ** 6145 ** ^Unless it returns SQLITE_MISUSE, this function sets the 6146 ** [database connection] error code and message accessible via 6147 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6148 ** 6149 ** 6150 ** ^(If the row that a BLOB handle points to is modified by an 6151 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6152 ** then the BLOB handle is marked as "expired". 6153 ** This is true if any column of the row is changed, even a column 6154 ** other than the one the BLOB handle is open on.)^ 6155 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6156 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6157 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 6158 ** rolled back by the expiration of the BLOB. Such changes will eventually 6159 ** commit if the transaction continues to completion.)^ 6160 ** 6161 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6162 ** the opened blob. ^The size of a blob may not be changed by this 6163 ** interface. Use the [UPDATE] SQL command to change the size of a 6164 ** blob. 6165 ** 6166 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6167 ** and the built-in [zeroblob] SQL function may be used to create a 6168 ** zero-filled blob to read or write using the incremental-blob interface. 6169 ** 6170 ** To avoid a resource leak, every open [BLOB handle] should eventually 6171 ** be released by a call to [sqlite3_blob_close()]. 6172 */ 6173 SQLITE_API int SQLITE_STDCALL sqlite3_blob_open( 6174 sqlite3*, 6175 const char *zDb, 6176 const char *zTable, 6177 const char *zColumn, 6178 sqlite3_int64 iRow, 6179 int flags, 6180 sqlite3_blob **ppBlob 6181 ); 6182 6183 /* 6184 ** CAPI3REF: Move a BLOB Handle to a New Row 6185 ** METHOD: sqlite3_blob 6186 ** 6187 ** ^This function is used to move an existing blob handle so that it points 6188 ** to a different row of the same database table. ^The new row is identified 6189 ** by the rowid value passed as the second argument. Only the row can be 6190 ** changed. ^The database, table and column on which the blob handle is open 6191 ** remain the same. Moving an existing blob handle to a new row can be 6192 ** faster than closing the existing handle and opening a new one. 6193 ** 6194 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6195 ** it must exist and there must be either a blob or text value stored in 6196 ** the nominated column.)^ ^If the new row is not present in the table, or if 6197 ** it does not contain a blob or text value, or if another error occurs, an 6198 ** SQLite error code is returned and the blob handle is considered aborted. 6199 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6200 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6201 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6202 ** always returns zero. 6203 ** 6204 ** ^This function sets the database handle error code and message. 6205 */ 6206 SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6207 6208 /* 6209 ** CAPI3REF: Close A BLOB Handle 6210 ** DESTRUCTOR: sqlite3_blob 6211 ** 6212 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6213 ** unconditionally. Even if this routine returns an error code, the 6214 ** handle is still closed.)^ 6215 ** 6216 ** ^If the blob handle being closed was opened for read-write access, and if 6217 ** the database is in auto-commit mode and there are no other open read-write 6218 ** blob handles or active write statements, the current transaction is 6219 ** committed. ^If an error occurs while committing the transaction, an error 6220 ** code is returned and the transaction rolled back. 6221 ** 6222 ** Calling this function with an argument that is not a NULL pointer or an 6223 ** open blob handle results in undefined behaviour. ^Calling this routine 6224 ** with a null pointer (such as would be returned by a failed call to 6225 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6226 ** is passed a valid open blob handle, the values returned by the 6227 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6228 */ 6229 SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *); 6230 6231 /* 6232 ** CAPI3REF: Return The Size Of An Open BLOB 6233 ** METHOD: sqlite3_blob 6234 ** 6235 ** ^Returns the size in bytes of the BLOB accessible via the 6236 ** successfully opened [BLOB handle] in its only argument. ^The 6237 ** incremental blob I/O routines can only read or overwriting existing 6238 ** blob content; they cannot change the size of a blob. 6239 ** 6240 ** This routine only works on a [BLOB handle] which has been created 6241 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6242 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6243 ** to this routine results in undefined and probably undesirable behavior. 6244 */ 6245 SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *); 6246 6247 /* 6248 ** CAPI3REF: Read Data From A BLOB Incrementally 6249 ** METHOD: sqlite3_blob 6250 ** 6251 ** ^(This function is used to read data from an open [BLOB handle] into a 6252 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6253 ** from the open BLOB, starting at offset iOffset.)^ 6254 ** 6255 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6256 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6257 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6258 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6259 ** can be determined using the [sqlite3_blob_bytes()] interface. 6260 ** 6261 ** ^An attempt to read from an expired [BLOB handle] fails with an 6262 ** error code of [SQLITE_ABORT]. 6263 ** 6264 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6265 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6266 ** 6267 ** This routine only works on a [BLOB handle] which has been created 6268 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6269 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6270 ** to this routine results in undefined and probably undesirable behavior. 6271 ** 6272 ** See also: [sqlite3_blob_write()]. 6273 */ 6274 SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6275 6276 /* 6277 ** CAPI3REF: Write Data Into A BLOB Incrementally 6278 ** METHOD: sqlite3_blob 6279 ** 6280 ** ^(This function is used to write data into an open [BLOB handle] from a 6281 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6282 ** into the open BLOB, starting at offset iOffset.)^ 6283 ** 6284 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6285 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6286 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6287 ** [database connection] error code and message accessible via 6288 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6289 ** 6290 ** ^If the [BLOB handle] passed as the first argument was not opened for 6291 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6292 ** this function returns [SQLITE_READONLY]. 6293 ** 6294 ** This function may only modify the contents of the BLOB; it is 6295 ** not possible to increase the size of a BLOB using this API. 6296 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6297 ** [SQLITE_ERROR] is returned and no data is written. The size of the 6298 ** BLOB (and hence the maximum value of N+iOffset) can be determined 6299 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6300 ** than zero [SQLITE_ERROR] is returned and no data is written. 6301 ** 6302 ** ^An attempt to write to an expired [BLOB handle] fails with an 6303 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6304 ** before the [BLOB handle] expired are not rolled back by the 6305 ** expiration of the handle, though of course those changes might 6306 ** have been overwritten by the statement that expired the BLOB handle 6307 ** or by other independent statements. 6308 ** 6309 ** This routine only works on a [BLOB handle] which has been created 6310 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6311 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6312 ** to this routine results in undefined and probably undesirable behavior. 6313 ** 6314 ** See also: [sqlite3_blob_read()]. 6315 */ 6316 SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6317 6318 /* 6319 ** CAPI3REF: Virtual File System Objects 6320 ** 6321 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6322 ** that SQLite uses to interact 6323 ** with the underlying operating system. Most SQLite builds come with a 6324 ** single default VFS that is appropriate for the host computer. 6325 ** New VFSes can be registered and existing VFSes can be unregistered. 6326 ** The following interfaces are provided. 6327 ** 6328 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6329 ** ^Names are case sensitive. 6330 ** ^Names are zero-terminated UTF-8 strings. 6331 ** ^If there is no match, a NULL pointer is returned. 6332 ** ^If zVfsName is NULL then the default VFS is returned. 6333 ** 6334 ** ^New VFSes are registered with sqlite3_vfs_register(). 6335 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6336 ** ^The same VFS can be registered multiple times without injury. 6337 ** ^To make an existing VFS into the default VFS, register it again 6338 ** with the makeDflt flag set. If two different VFSes with the 6339 ** same name are registered, the behavior is undefined. If a 6340 ** VFS is registered with a name that is NULL or an empty string, 6341 ** then the behavior is undefined. 6342 ** 6343 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6344 ** ^(If the default VFS is unregistered, another VFS is chosen as 6345 ** the default. The choice for the new VFS is arbitrary.)^ 6346 */ 6347 SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName); 6348 SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6349 SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*); 6350 6351 /* 6352 ** CAPI3REF: Mutexes 6353 ** 6354 ** The SQLite core uses these routines for thread 6355 ** synchronization. Though they are intended for internal 6356 ** use by SQLite, code that links against SQLite is 6357 ** permitted to use any of these routines. 6358 ** 6359 ** The SQLite source code contains multiple implementations 6360 ** of these mutex routines. An appropriate implementation 6361 ** is selected automatically at compile-time. The following 6362 ** implementations are available in the SQLite core: 6363 ** 6364 ** <ul> 6365 ** <li> SQLITE_MUTEX_PTHREADS 6366 ** <li> SQLITE_MUTEX_W32 6367 ** <li> SQLITE_MUTEX_NOOP 6368 ** </ul> 6369 ** 6370 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6371 ** that does no real locking and is appropriate for use in 6372 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6373 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6374 ** and Windows. 6375 ** 6376 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6377 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6378 ** implementation is included with the library. In this case the 6379 ** application must supply a custom mutex implementation using the 6380 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6381 ** before calling sqlite3_initialize() or any other public sqlite3_ 6382 ** function that calls sqlite3_initialize(). 6383 ** 6384 ** ^The sqlite3_mutex_alloc() routine allocates a new 6385 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6386 ** routine returns NULL if it is unable to allocate the requested 6387 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6388 ** integer constants: 6389 ** 6390 ** <ul> 6391 ** <li> SQLITE_MUTEX_FAST 6392 ** <li> SQLITE_MUTEX_RECURSIVE 6393 ** <li> SQLITE_MUTEX_STATIC_MASTER 6394 ** <li> SQLITE_MUTEX_STATIC_MEM 6395 ** <li> SQLITE_MUTEX_STATIC_OPEN 6396 ** <li> SQLITE_MUTEX_STATIC_PRNG 6397 ** <li> SQLITE_MUTEX_STATIC_LRU 6398 ** <li> SQLITE_MUTEX_STATIC_PMEM 6399 ** <li> SQLITE_MUTEX_STATIC_APP1 6400 ** <li> SQLITE_MUTEX_STATIC_APP2 6401 ** <li> SQLITE_MUTEX_STATIC_APP3 6402 ** <li> SQLITE_MUTEX_STATIC_VFS1 6403 ** <li> SQLITE_MUTEX_STATIC_VFS2 6404 ** <li> SQLITE_MUTEX_STATIC_VFS3 6405 ** </ul> 6406 ** 6407 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6408 ** cause sqlite3_mutex_alloc() to create 6409 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6410 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6411 ** The mutex implementation does not need to make a distinction 6412 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6413 ** not want to. SQLite will only request a recursive mutex in 6414 ** cases where it really needs one. If a faster non-recursive mutex 6415 ** implementation is available on the host platform, the mutex subsystem 6416 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6417 ** 6418 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6419 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6420 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6421 ** used by the current version of SQLite. Future versions of SQLite 6422 ** may add additional static mutexes. Static mutexes are for internal 6423 ** use by SQLite only. Applications that use SQLite mutexes should 6424 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6425 ** SQLITE_MUTEX_RECURSIVE. 6426 ** 6427 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6428 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6429 ** returns a different mutex on every call. ^For the static 6430 ** mutex types, the same mutex is returned on every call that has 6431 ** the same type number. 6432 ** 6433 ** ^The sqlite3_mutex_free() routine deallocates a previously 6434 ** allocated dynamic mutex. Attempting to deallocate a static 6435 ** mutex results in undefined behavior. 6436 ** 6437 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6438 ** to enter a mutex. ^If another thread is already within the mutex, 6439 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6440 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6441 ** upon successful entry. ^(Mutexes created using 6442 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6443 ** In such cases, the 6444 ** mutex must be exited an equal number of times before another thread 6445 ** can enter.)^ If the same thread tries to enter any mutex other 6446 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6447 ** 6448 ** ^(Some systems (for example, Windows 95) do not support the operation 6449 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6450 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6451 ** sqlite3_mutex_try() as an optimization so this is acceptable 6452 ** behavior.)^ 6453 ** 6454 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6455 ** previously entered by the same thread. The behavior 6456 ** is undefined if the mutex is not currently entered by the 6457 ** calling thread or is not currently allocated. 6458 ** 6459 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6460 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6461 ** behave as no-ops. 6462 ** 6463 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6464 */ 6465 SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int); 6466 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*); 6467 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*); 6468 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*); 6469 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*); 6470 6471 /* 6472 ** CAPI3REF: Mutex Methods Object 6473 ** 6474 ** An instance of this structure defines the low-level routines 6475 ** used to allocate and use mutexes. 6476 ** 6477 ** Usually, the default mutex implementations provided by SQLite are 6478 ** sufficient, however the application has the option of substituting a custom 6479 ** implementation for specialized deployments or systems for which SQLite 6480 ** does not provide a suitable implementation. In this case, the application 6481 ** creates and populates an instance of this structure to pass 6482 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6483 ** Additionally, an instance of this structure can be used as an 6484 ** output variable when querying the system for the current mutex 6485 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6486 ** 6487 ** ^The xMutexInit method defined by this structure is invoked as 6488 ** part of system initialization by the sqlite3_initialize() function. 6489 ** ^The xMutexInit routine is called by SQLite exactly once for each 6490 ** effective call to [sqlite3_initialize()]. 6491 ** 6492 ** ^The xMutexEnd method defined by this structure is invoked as 6493 ** part of system shutdown by the sqlite3_shutdown() function. The 6494 ** implementation of this method is expected to release all outstanding 6495 ** resources obtained by the mutex methods implementation, especially 6496 ** those obtained by the xMutexInit method. ^The xMutexEnd() 6497 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6498 ** 6499 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6500 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6501 ** xMutexNotheld) implement the following interfaces (respectively): 6502 ** 6503 ** <ul> 6504 ** <li> [sqlite3_mutex_alloc()] </li> 6505 ** <li> [sqlite3_mutex_free()] </li> 6506 ** <li> [sqlite3_mutex_enter()] </li> 6507 ** <li> [sqlite3_mutex_try()] </li> 6508 ** <li> [sqlite3_mutex_leave()] </li> 6509 ** <li> [sqlite3_mutex_held()] </li> 6510 ** <li> [sqlite3_mutex_notheld()] </li> 6511 ** </ul>)^ 6512 ** 6513 ** The only difference is that the public sqlite3_XXX functions enumerated 6514 ** above silently ignore any invocations that pass a NULL pointer instead 6515 ** of a valid mutex handle. The implementations of the methods defined 6516 ** by this structure are not required to handle this case, the results 6517 ** of passing a NULL pointer instead of a valid mutex handle are undefined 6518 ** (i.e. it is acceptable to provide an implementation that segfaults if 6519 ** it is passed a NULL pointer). 6520 ** 6521 ** The xMutexInit() method must be threadsafe. It must be harmless to 6522 ** invoke xMutexInit() multiple times within the same process and without 6523 ** intervening calls to xMutexEnd(). Second and subsequent calls to 6524 ** xMutexInit() must be no-ops. 6525 ** 6526 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6527 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6528 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6529 ** memory allocation for a fast or recursive mutex. 6530 ** 6531 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6532 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6533 ** If xMutexInit fails in any way, it is expected to clean up after itself 6534 ** prior to returning. 6535 */ 6536 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6537 struct sqlite3_mutex_methods { 6538 int (*xMutexInit)(void); 6539 int (*xMutexEnd)(void); 6540 sqlite3_mutex *(*xMutexAlloc)(int); 6541 void (*xMutexFree)(sqlite3_mutex *); 6542 void (*xMutexEnter)(sqlite3_mutex *); 6543 int (*xMutexTry)(sqlite3_mutex *); 6544 void (*xMutexLeave)(sqlite3_mutex *); 6545 int (*xMutexHeld)(sqlite3_mutex *); 6546 int (*xMutexNotheld)(sqlite3_mutex *); 6547 }; 6548 6549 /* 6550 ** CAPI3REF: Mutex Verification Routines 6551 ** 6552 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6553 ** are intended for use inside assert() statements. The SQLite core 6554 ** never uses these routines except inside an assert() and applications 6555 ** are advised to follow the lead of the core. The SQLite core only 6556 ** provides implementations for these routines when it is compiled 6557 ** with the SQLITE_DEBUG flag. External mutex implementations 6558 ** are only required to provide these routines if SQLITE_DEBUG is 6559 ** defined and if NDEBUG is not defined. 6560 ** 6561 ** These routines should return true if the mutex in their argument 6562 ** is held or not held, respectively, by the calling thread. 6563 ** 6564 ** The implementation is not required to provide versions of these 6565 ** routines that actually work. If the implementation does not provide working 6566 ** versions of these routines, it should at least provide stubs that always 6567 ** return true so that one does not get spurious assertion failures. 6568 ** 6569 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 6570 ** the routine should return 1. This seems counter-intuitive since 6571 ** clearly the mutex cannot be held if it does not exist. But 6572 ** the reason the mutex does not exist is because the build is not 6573 ** using mutexes. And we do not want the assert() containing the 6574 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6575 ** the appropriate thing to do. The sqlite3_mutex_notheld() 6576 ** interface should also return 1 when given a NULL pointer. 6577 */ 6578 #ifndef NDEBUG 6579 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*); 6580 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*); 6581 #endif 6582 6583 /* 6584 ** CAPI3REF: Mutex Types 6585 ** 6586 ** The [sqlite3_mutex_alloc()] interface takes a single argument 6587 ** which is one of these integer constants. 6588 ** 6589 ** The set of static mutexes may change from one SQLite release to the 6590 ** next. Applications that override the built-in mutex logic must be 6591 ** prepared to accommodate additional static mutexes. 6592 */ 6593 #define SQLITE_MUTEX_FAST 0 6594 #define SQLITE_MUTEX_RECURSIVE 1 6595 #define SQLITE_MUTEX_STATIC_MASTER 2 6596 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6597 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6598 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6599 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6600 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6601 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6602 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6603 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6604 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6605 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6606 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6607 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6608 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6609 6610 /* 6611 ** CAPI3REF: Retrieve the mutex for a database connection 6612 ** METHOD: sqlite3 6613 ** 6614 ** ^This interface returns a pointer the [sqlite3_mutex] object that 6615 ** serializes access to the [database connection] given in the argument 6616 ** when the [threading mode] is Serialized. 6617 ** ^If the [threading mode] is Single-thread or Multi-thread then this 6618 ** routine returns a NULL pointer. 6619 */ 6620 SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*); 6621 6622 /* 6623 ** CAPI3REF: Low-Level Control Of Database Files 6624 ** METHOD: sqlite3 6625 ** 6626 ** ^The [sqlite3_file_control()] interface makes a direct call to the 6627 ** xFileControl method for the [sqlite3_io_methods] object associated 6628 ** with a particular database identified by the second argument. ^The 6629 ** name of the database is "main" for the main database or "temp" for the 6630 ** TEMP database, or the name that appears after the AS keyword for 6631 ** databases that are added using the [ATTACH] SQL command. 6632 ** ^A NULL pointer can be used in place of "main" to refer to the 6633 ** main database file. 6634 ** ^The third and fourth parameters to this routine 6635 ** are passed directly through to the second and third parameters of 6636 ** the xFileControl method. ^The return value of the xFileControl 6637 ** method becomes the return value of this routine. 6638 ** 6639 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6640 ** a pointer to the underlying [sqlite3_file] object to be written into 6641 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6642 ** case is a short-circuit path which does not actually invoke the 6643 ** underlying sqlite3_io_methods.xFileControl method. 6644 ** 6645 ** ^If the second parameter (zDbName) does not match the name of any 6646 ** open database file, then SQLITE_ERROR is returned. ^This error 6647 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6648 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6649 ** also return SQLITE_ERROR. There is no way to distinguish between 6650 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6651 ** xFileControl method. 6652 ** 6653 ** See also: [SQLITE_FCNTL_LOCKSTATE] 6654 */ 6655 SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6656 6657 /* 6658 ** CAPI3REF: Testing Interface 6659 ** 6660 ** ^The sqlite3_test_control() interface is used to read out internal 6661 ** state of SQLite and to inject faults into SQLite for testing 6662 ** purposes. ^The first parameter is an operation code that determines 6663 ** the number, meaning, and operation of all subsequent parameters. 6664 ** 6665 ** This interface is not for use by applications. It exists solely 6666 ** for verifying the correct operation of the SQLite library. Depending 6667 ** on how the SQLite library is compiled, this interface might not exist. 6668 ** 6669 ** The details of the operation codes, their meanings, the parameters 6670 ** they take, and what they do are all subject to change without notice. 6671 ** Unlike most of the SQLite API, this function is not guaranteed to 6672 ** operate consistently from one release to the next. 6673 */ 6674 SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...); 6675 6676 /* 6677 ** CAPI3REF: Testing Interface Operation Codes 6678 ** 6679 ** These constants are the valid operation code parameters used 6680 ** as the first argument to [sqlite3_test_control()]. 6681 ** 6682 ** These parameters and their meanings are subject to change 6683 ** without notice. These values are for testing purposes only. 6684 ** Applications should not use any of these parameters or the 6685 ** [sqlite3_test_control()] interface. 6686 */ 6687 #define SQLITE_TESTCTRL_FIRST 5 6688 #define SQLITE_TESTCTRL_PRNG_SAVE 5 6689 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 6690 #define SQLITE_TESTCTRL_PRNG_RESET 7 6691 #define SQLITE_TESTCTRL_BITVEC_TEST 8 6692 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 6693 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6694 #define SQLITE_TESTCTRL_PENDING_BYTE 11 6695 #define SQLITE_TESTCTRL_ASSERT 12 6696 #define SQLITE_TESTCTRL_ALWAYS 13 6697 #define SQLITE_TESTCTRL_RESERVE 14 6698 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6699 #define SQLITE_TESTCTRL_ISKEYWORD 16 6700 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6701 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6702 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6703 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6704 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6705 #define SQLITE_TESTCTRL_BYTEORDER 22 6706 #define SQLITE_TESTCTRL_ISINIT 23 6707 #define SQLITE_TESTCTRL_SORTER_MMAP 24 6708 #define SQLITE_TESTCTRL_IMPOSTER 25 6709 #define SQLITE_TESTCTRL_LAST 25 6710 6711 /* 6712 ** CAPI3REF: SQLite Runtime Status 6713 ** 6714 ** ^These interfaces are used to retrieve runtime status information 6715 ** about the performance of SQLite, and optionally to reset various 6716 ** highwater marks. ^The first argument is an integer code for 6717 ** the specific parameter to measure. ^(Recognized integer codes 6718 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 6719 ** ^The current value of the parameter is returned into *pCurrent. 6720 ** ^The highest recorded value is returned in *pHighwater. ^If the 6721 ** resetFlag is true, then the highest record value is reset after 6722 ** *pHighwater is written. ^(Some parameters do not record the highest 6723 ** value. For those parameters 6724 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6725 ** ^(Other parameters record only the highwater mark and not the current 6726 ** value. For these latter parameters nothing is written into *pCurrent.)^ 6727 ** 6728 ** ^The sqlite3_status() and sqlite3_status64() routines return 6729 ** SQLITE_OK on success and a non-zero [error code] on failure. 6730 ** 6731 ** If either the current value or the highwater mark is too large to 6732 ** be represented by a 32-bit integer, then the values returned by 6733 ** sqlite3_status() are undefined. 6734 ** 6735 ** See also: [sqlite3_db_status()] 6736 */ 6737 SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6738 SQLITE_API int SQLITE_STDCALL sqlite3_status64( 6739 int op, 6740 sqlite3_int64 *pCurrent, 6741 sqlite3_int64 *pHighwater, 6742 int resetFlag 6743 ); 6744 6745 6746 /* 6747 ** CAPI3REF: Status Parameters 6748 ** KEYWORDS: {status parameters} 6749 ** 6750 ** These integer constants designate various run-time status parameters 6751 ** that can be returned by [sqlite3_status()]. 6752 ** 6753 ** <dl> 6754 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6755 ** <dd>This parameter is the current amount of memory checked out 6756 ** using [sqlite3_malloc()], either directly or indirectly. The 6757 ** figure includes calls made to [sqlite3_malloc()] by the application 6758 ** and internal memory usage by the SQLite library. Scratch memory 6759 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6760 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6761 ** this parameter. The amount returned is the sum of the allocation 6762 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6763 ** 6764 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6765 ** <dd>This parameter records the largest memory allocation request 6766 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6767 ** internal equivalents). Only the value returned in the 6768 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6769 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6770 ** 6771 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6772 ** <dd>This parameter records the number of separate memory allocations 6773 ** currently checked out.</dd>)^ 6774 ** 6775 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6776 ** <dd>This parameter returns the number of pages used out of the 6777 ** [pagecache memory allocator] that was configured using 6778 ** [SQLITE_CONFIG_PAGECACHE]. The 6779 ** value returned is in pages, not in bytes.</dd>)^ 6780 ** 6781 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6782 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6783 ** <dd>This parameter returns the number of bytes of page cache 6784 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6785 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 6786 ** returned value includes allocations that overflowed because they 6787 ** where too large (they were larger than the "sz" parameter to 6788 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6789 ** no space was left in the page cache.</dd>)^ 6790 ** 6791 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6792 ** <dd>This parameter records the largest memory allocation request 6793 ** handed to [pagecache memory allocator]. Only the value returned in the 6794 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6795 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6796 ** 6797 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6798 ** <dd>This parameter returns the number of allocations used out of the 6799 ** [scratch memory allocator] configured using 6800 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6801 ** in bytes. Since a single thread may only have one scratch allocation 6802 ** outstanding at time, this parameter also reports the number of threads 6803 ** using scratch memory at the same time.</dd>)^ 6804 ** 6805 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6806 ** <dd>This parameter returns the number of bytes of scratch memory 6807 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6808 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6809 ** returned include overflows because the requested allocation was too 6810 ** larger (that is, because the requested allocation was larger than the 6811 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6812 ** slots were available. 6813 ** </dd>)^ 6814 ** 6815 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6816 ** <dd>This parameter records the largest memory allocation request 6817 ** handed to [scratch memory allocator]. Only the value returned in the 6818 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6819 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6820 ** 6821 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6822 ** <dd>The *pHighwater parameter records the deepest parser stack. 6823 ** The *pCurrent value is undefined. The *pHighwater value is only 6824 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6825 ** </dl> 6826 ** 6827 ** New status parameters may be added from time to time. 6828 */ 6829 #define SQLITE_STATUS_MEMORY_USED 0 6830 #define SQLITE_STATUS_PAGECACHE_USED 1 6831 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6832 #define SQLITE_STATUS_SCRATCH_USED 3 6833 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6834 #define SQLITE_STATUS_MALLOC_SIZE 5 6835 #define SQLITE_STATUS_PARSER_STACK 6 6836 #define SQLITE_STATUS_PAGECACHE_SIZE 7 6837 #define SQLITE_STATUS_SCRATCH_SIZE 8 6838 #define SQLITE_STATUS_MALLOC_COUNT 9 6839 6840 /* 6841 ** CAPI3REF: Database Connection Status 6842 ** METHOD: sqlite3 6843 ** 6844 ** ^This interface is used to retrieve runtime status information 6845 ** about a single [database connection]. ^The first argument is the 6846 ** database connection object to be interrogated. ^The second argument 6847 ** is an integer constant, taken from the set of 6848 ** [SQLITE_DBSTATUS options], that 6849 ** determines the parameter to interrogate. The set of 6850 ** [SQLITE_DBSTATUS options] is likely 6851 ** to grow in future releases of SQLite. 6852 ** 6853 ** ^The current value of the requested parameter is written into *pCur 6854 ** and the highest instantaneous value is written into *pHiwtr. ^If 6855 ** the resetFlg is true, then the highest instantaneous value is 6856 ** reset back down to the current value. 6857 ** 6858 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6859 ** non-zero [error code] on failure. 6860 ** 6861 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6862 */ 6863 SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6864 6865 /* 6866 ** CAPI3REF: Status Parameters for database connections 6867 ** KEYWORDS: {SQLITE_DBSTATUS options} 6868 ** 6869 ** These constants are the available integer "verbs" that can be passed as 6870 ** the second argument to the [sqlite3_db_status()] interface. 6871 ** 6872 ** New verbs may be added in future releases of SQLite. Existing verbs 6873 ** might be discontinued. Applications should check the return code from 6874 ** [sqlite3_db_status()] to make sure that the call worked. 6875 ** The [sqlite3_db_status()] interface will return a non-zero error code 6876 ** if a discontinued or unsupported verb is invoked. 6877 ** 6878 ** <dl> 6879 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6880 ** <dd>This parameter returns the number of lookaside memory slots currently 6881 ** checked out.</dd>)^ 6882 ** 6883 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6884 ** <dd>This parameter returns the number malloc attempts that were 6885 ** satisfied using lookaside memory. Only the high-water value is meaningful; 6886 ** the current value is always zero.)^ 6887 ** 6888 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6889 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6890 ** <dd>This parameter returns the number malloc attempts that might have 6891 ** been satisfied using lookaside memory but failed due to the amount of 6892 ** memory requested being larger than the lookaside slot size. 6893 ** Only the high-water value is meaningful; 6894 ** the current value is always zero.)^ 6895 ** 6896 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6897 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6898 ** <dd>This parameter returns the number malloc attempts that might have 6899 ** been satisfied using lookaside memory but failed due to all lookaside 6900 ** memory already being in use. 6901 ** Only the high-water value is meaningful; 6902 ** the current value is always zero.)^ 6903 ** 6904 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6905 ** <dd>This parameter returns the approximate number of bytes of heap 6906 ** memory used by all pager caches associated with the database connection.)^ 6907 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6908 ** 6909 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 6910 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 6911 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 6912 ** pager cache is shared between two or more connections the bytes of heap 6913 ** memory used by that pager cache is divided evenly between the attached 6914 ** connections.)^ In other words, if none of the pager caches associated 6915 ** with the database connection are shared, this request returns the same 6916 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 6917 ** shared, the value returned by this call will be smaller than that returned 6918 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 6919 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 6920 ** 6921 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6922 ** <dd>This parameter returns the approximate number of bytes of heap 6923 ** memory used to store the schema for all databases associated 6924 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6925 ** ^The full amount of memory used by the schemas is reported, even if the 6926 ** schema memory is shared with other database connections due to 6927 ** [shared cache mode] being enabled. 6928 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6929 ** 6930 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6931 ** <dd>This parameter returns the approximate number of bytes of heap 6932 ** and lookaside memory used by all prepared statements associated with 6933 ** the database connection.)^ 6934 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6935 ** </dd> 6936 ** 6937 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6938 ** <dd>This parameter returns the number of pager cache hits that have 6939 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6940 ** is always 0. 6941 ** </dd> 6942 ** 6943 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6944 ** <dd>This parameter returns the number of pager cache misses that have 6945 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6946 ** is always 0. 6947 ** </dd> 6948 ** 6949 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6950 ** <dd>This parameter returns the number of dirty cache entries that have 6951 ** been written to disk. Specifically, the number of pages written to the 6952 ** wal file in wal mode databases, or the number of pages written to the 6953 ** database file in rollback mode databases. Any pages written as part of 6954 ** transaction rollback or database recovery operations are not included. 6955 ** If an IO or other error occurs while writing a page to disk, the effect 6956 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6957 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6958 ** </dd> 6959 ** 6960 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6961 ** <dd>This parameter returns zero for the current value if and only if 6962 ** all foreign key constraints (deferred or immediate) have been 6963 ** resolved.)^ ^The highwater mark is always 0. 6964 ** </dd> 6965 ** </dl> 6966 */ 6967 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6968 #define SQLITE_DBSTATUS_CACHE_USED 1 6969 #define SQLITE_DBSTATUS_SCHEMA_USED 2 6970 #define SQLITE_DBSTATUS_STMT_USED 3 6971 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6972 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6973 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6974 #define SQLITE_DBSTATUS_CACHE_HIT 7 6975 #define SQLITE_DBSTATUS_CACHE_MISS 8 6976 #define SQLITE_DBSTATUS_CACHE_WRITE 9 6977 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 6978 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 6979 #define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ 6980 6981 6982 /* 6983 ** CAPI3REF: Prepared Statement Status 6984 ** METHOD: sqlite3_stmt 6985 ** 6986 ** ^(Each prepared statement maintains various 6987 ** [SQLITE_STMTSTATUS counters] that measure the number 6988 ** of times it has performed specific operations.)^ These counters can 6989 ** be used to monitor the performance characteristics of the prepared 6990 ** statements. For example, if the number of table steps greatly exceeds 6991 ** the number of table searches or result rows, that would tend to indicate 6992 ** that the prepared statement is using a full table scan rather than 6993 ** an index. 6994 ** 6995 ** ^(This interface is used to retrieve and reset counter values from 6996 ** a [prepared statement]. The first argument is the prepared statement 6997 ** object to be interrogated. The second argument 6998 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6999 ** to be interrogated.)^ 7000 ** ^The current value of the requested counter is returned. 7001 ** ^If the resetFlg is true, then the counter is reset to zero after this 7002 ** interface call returns. 7003 ** 7004 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7005 */ 7006 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7007 7008 /* 7009 ** CAPI3REF: Status Parameters for prepared statements 7010 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7011 ** 7012 ** These preprocessor macros define integer codes that name counter 7013 ** values associated with the [sqlite3_stmt_status()] interface. 7014 ** The meanings of the various counters are as follows: 7015 ** 7016 ** <dl> 7017 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7018 ** <dd>^This is the number of times that SQLite has stepped forward in 7019 ** a table as part of a full table scan. Large numbers for this counter 7020 ** may indicate opportunities for performance improvement through 7021 ** careful use of indices.</dd> 7022 ** 7023 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7024 ** <dd>^This is the number of sort operations that have occurred. 7025 ** A non-zero value in this counter may indicate an opportunity to 7026 ** improvement performance through careful use of indices.</dd> 7027 ** 7028 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7029 ** <dd>^This is the number of rows inserted into transient indices that 7030 ** were created automatically in order to help joins run faster. 7031 ** A non-zero value in this counter may indicate an opportunity to 7032 ** improvement performance by adding permanent indices that do not 7033 ** need to be reinitialized each time the statement is run.</dd> 7034 ** 7035 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7036 ** <dd>^This is the number of virtual machine operations executed 7037 ** by the prepared statement if that number is less than or equal 7038 ** to 2147483647. The number of virtual machine operations can be 7039 ** used as a proxy for the total work done by the prepared statement. 7040 ** If the number of virtual machine operations exceeds 2147483647 7041 ** then the value returned by this statement status code is undefined. 7042 ** </dd> 7043 ** </dl> 7044 */ 7045 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7046 #define SQLITE_STMTSTATUS_SORT 2 7047 #define SQLITE_STMTSTATUS_AUTOINDEX 3 7048 #define SQLITE_STMTSTATUS_VM_STEP 4 7049 7050 /* 7051 ** CAPI3REF: Custom Page Cache Object 7052 ** 7053 ** The sqlite3_pcache type is opaque. It is implemented by 7054 ** the pluggable module. The SQLite core has no knowledge of 7055 ** its size or internal structure and never deals with the 7056 ** sqlite3_pcache object except by holding and passing pointers 7057 ** to the object. 7058 ** 7059 ** See [sqlite3_pcache_methods2] for additional information. 7060 */ 7061 typedef struct sqlite3_pcache sqlite3_pcache; 7062 7063 /* 7064 ** CAPI3REF: Custom Page Cache Object 7065 ** 7066 ** The sqlite3_pcache_page object represents a single page in the 7067 ** page cache. The page cache will allocate instances of this 7068 ** object. Various methods of the page cache use pointers to instances 7069 ** of this object as parameters or as their return value. 7070 ** 7071 ** See [sqlite3_pcache_methods2] for additional information. 7072 */ 7073 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7074 struct sqlite3_pcache_page { 7075 void *pBuf; /* The content of the page */ 7076 void *pExtra; /* Extra information associated with the page */ 7077 }; 7078 7079 /* 7080 ** CAPI3REF: Application Defined Page Cache. 7081 ** KEYWORDS: {page cache} 7082 ** 7083 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7084 ** register an alternative page cache implementation by passing in an 7085 ** instance of the sqlite3_pcache_methods2 structure.)^ 7086 ** In many applications, most of the heap memory allocated by 7087 ** SQLite is used for the page cache. 7088 ** By implementing a 7089 ** custom page cache using this API, an application can better control 7090 ** the amount of memory consumed by SQLite, the way in which 7091 ** that memory is allocated and released, and the policies used to 7092 ** determine exactly which parts of a database file are cached and for 7093 ** how long. 7094 ** 7095 ** The alternative page cache mechanism is an 7096 ** extreme measure that is only needed by the most demanding applications. 7097 ** The built-in page cache is recommended for most uses. 7098 ** 7099 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7100 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7101 ** the application may discard the parameter after the call to 7102 ** [sqlite3_config()] returns.)^ 7103 ** 7104 ** [[the xInit() page cache method]] 7105 ** ^(The xInit() method is called once for each effective 7106 ** call to [sqlite3_initialize()])^ 7107 ** (usually only once during the lifetime of the process). ^(The xInit() 7108 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7109 ** The intent of the xInit() method is to set up global data structures 7110 ** required by the custom page cache implementation. 7111 ** ^(If the xInit() method is NULL, then the 7112 ** built-in default page cache is used instead of the application defined 7113 ** page cache.)^ 7114 ** 7115 ** [[the xShutdown() page cache method]] 7116 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7117 ** It can be used to clean up 7118 ** any outstanding resources before process shutdown, if required. 7119 ** ^The xShutdown() method may be NULL. 7120 ** 7121 ** ^SQLite automatically serializes calls to the xInit method, 7122 ** so the xInit method need not be threadsafe. ^The 7123 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 7124 ** not need to be threadsafe either. All other methods must be threadsafe 7125 ** in multithreaded applications. 7126 ** 7127 ** ^SQLite will never invoke xInit() more than once without an intervening 7128 ** call to xShutdown(). 7129 ** 7130 ** [[the xCreate() page cache methods]] 7131 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 7132 ** SQLite will typically create one cache instance for each open database file, 7133 ** though this is not guaranteed. ^The 7134 ** first parameter, szPage, is the size in bytes of the pages that must 7135 ** be allocated by the cache. ^szPage will always a power of two. ^The 7136 ** second parameter szExtra is a number of bytes of extra storage 7137 ** associated with each page cache entry. ^The szExtra parameter will 7138 ** a number less than 250. SQLite will use the 7139 ** extra szExtra bytes on each page to store metadata about the underlying 7140 ** database page on disk. The value passed into szExtra depends 7141 ** on the SQLite version, the target platform, and how SQLite was compiled. 7142 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7143 ** created will be used to cache database pages of a file stored on disk, or 7144 ** false if it is used for an in-memory database. The cache implementation 7145 ** does not have to do anything special based with the value of bPurgeable; 7146 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7147 ** never invoke xUnpin() except to deliberately delete a page. 7148 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7149 ** false will always have the "discard" flag set to true. 7150 ** ^Hence, a cache created with bPurgeable false will 7151 ** never contain any unpinned pages. 7152 ** 7153 ** [[the xCachesize() page cache method]] 7154 ** ^(The xCachesize() method may be called at any time by SQLite to set the 7155 ** suggested maximum cache-size (number of pages stored by) the cache 7156 ** instance passed as the first argument. This is the value configured using 7157 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7158 ** parameter, the implementation is not required to do anything with this 7159 ** value; it is advisory only. 7160 ** 7161 ** [[the xPagecount() page cache methods]] 7162 ** The xPagecount() method must return the number of pages currently 7163 ** stored in the cache, both pinned and unpinned. 7164 ** 7165 ** [[the xFetch() page cache methods]] 7166 ** The xFetch() method locates a page in the cache and returns a pointer to 7167 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7168 ** The pBuf element of the returned sqlite3_pcache_page object will be a 7169 ** pointer to a buffer of szPage bytes used to store the content of a 7170 ** single database page. The pExtra element of sqlite3_pcache_page will be 7171 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 7172 ** for each entry in the page cache. 7173 ** 7174 ** The page to be fetched is determined by the key. ^The minimum key value 7175 ** is 1. After it has been retrieved using xFetch, the page is considered 7176 ** to be "pinned". 7177 ** 7178 ** If the requested page is already in the page cache, then the page cache 7179 ** implementation must return a pointer to the page buffer with its content 7180 ** intact. If the requested page is not already in the cache, then the 7181 ** cache implementation should use the value of the createFlag 7182 ** parameter to help it determined what action to take: 7183 ** 7184 ** <table border=1 width=85% align=center> 7185 ** <tr><th> createFlag <th> Behavior when page is not already in cache 7186 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7187 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7188 ** Otherwise return NULL. 7189 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7190 ** NULL if allocating a new page is effectively impossible. 7191 ** </table> 7192 ** 7193 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7194 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 7195 ** failed.)^ In between the to xFetch() calls, SQLite may 7196 ** attempt to unpin one or more cache pages by spilling the content of 7197 ** pinned pages to disk and synching the operating system disk cache. 7198 ** 7199 ** [[the xUnpin() page cache method]] 7200 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7201 ** as its second argument. If the third parameter, discard, is non-zero, 7202 ** then the page must be evicted from the cache. 7203 ** ^If the discard parameter is 7204 ** zero, then the page may be discarded or retained at the discretion of 7205 ** page cache implementation. ^The page cache implementation 7206 ** may choose to evict unpinned pages at any time. 7207 ** 7208 ** The cache must not perform any reference counting. A single 7209 ** call to xUnpin() unpins the page regardless of the number of prior calls 7210 ** to xFetch(). 7211 ** 7212 ** [[the xRekey() page cache methods]] 7213 ** The xRekey() method is used to change the key value associated with the 7214 ** page passed as the second argument. If the cache 7215 ** previously contains an entry associated with newKey, it must be 7216 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7217 ** to be pinned. 7218 ** 7219 ** When SQLite calls the xTruncate() method, the cache must discard all 7220 ** existing cache entries with page numbers (keys) greater than or equal 7221 ** to the value of the iLimit parameter passed to xTruncate(). If any 7222 ** of these pages are pinned, they are implicitly unpinned, meaning that 7223 ** they can be safely discarded. 7224 ** 7225 ** [[the xDestroy() page cache method]] 7226 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7227 ** All resources associated with the specified cache should be freed. ^After 7228 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7229 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7230 ** functions. 7231 ** 7232 ** [[the xShrink() page cache method]] 7233 ** ^SQLite invokes the xShrink() method when it wants the page cache to 7234 ** free up as much of heap memory as possible. The page cache implementation 7235 ** is not obligated to free any memory, but well-behaved implementations should 7236 ** do their best. 7237 */ 7238 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7239 struct sqlite3_pcache_methods2 { 7240 int iVersion; 7241 void *pArg; 7242 int (*xInit)(void*); 7243 void (*xShutdown)(void*); 7244 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7245 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7246 int (*xPagecount)(sqlite3_pcache*); 7247 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7248 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7249 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7250 unsigned oldKey, unsigned newKey); 7251 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7252 void (*xDestroy)(sqlite3_pcache*); 7253 void (*xShrink)(sqlite3_pcache*); 7254 }; 7255 7256 /* 7257 ** This is the obsolete pcache_methods object that has now been replaced 7258 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7259 ** retained in the header file for backwards compatibility only. 7260 */ 7261 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7262 struct sqlite3_pcache_methods { 7263 void *pArg; 7264 int (*xInit)(void*); 7265 void (*xShutdown)(void*); 7266 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7267 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7268 int (*xPagecount)(sqlite3_pcache*); 7269 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7270 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7271 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7272 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7273 void (*xDestroy)(sqlite3_pcache*); 7274 }; 7275 7276 7277 /* 7278 ** CAPI3REF: Online Backup Object 7279 ** 7280 ** The sqlite3_backup object records state information about an ongoing 7281 ** online backup operation. ^The sqlite3_backup object is created by 7282 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 7283 ** [sqlite3_backup_finish()]. 7284 ** 7285 ** See Also: [Using the SQLite Online Backup API] 7286 */ 7287 typedef struct sqlite3_backup sqlite3_backup; 7288 7289 /* 7290 ** CAPI3REF: Online Backup API. 7291 ** 7292 ** The backup API copies the content of one database into another. 7293 ** It is useful either for creating backups of databases or 7294 ** for copying in-memory databases to or from persistent files. 7295 ** 7296 ** See Also: [Using the SQLite Online Backup API] 7297 ** 7298 ** ^SQLite holds a write transaction open on the destination database file 7299 ** for the duration of the backup operation. 7300 ** ^The source database is read-locked only while it is being read; 7301 ** it is not locked continuously for the entire backup operation. 7302 ** ^Thus, the backup may be performed on a live source database without 7303 ** preventing other database connections from 7304 ** reading or writing to the source database while the backup is underway. 7305 ** 7306 ** ^(To perform a backup operation: 7307 ** <ol> 7308 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7309 ** backup, 7310 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7311 ** the data between the two databases, and finally 7312 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7313 ** associated with the backup operation. 7314 ** </ol>)^ 7315 ** There should be exactly one call to sqlite3_backup_finish() for each 7316 ** successful call to sqlite3_backup_init(). 7317 ** 7318 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7319 ** 7320 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7321 ** [database connection] associated with the destination database 7322 ** and the database name, respectively. 7323 ** ^The database name is "main" for the main database, "temp" for the 7324 ** temporary database, or the name specified after the AS keyword in 7325 ** an [ATTACH] statement for an attached database. 7326 ** ^The S and M arguments passed to 7327 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7328 ** and database name of the source database, respectively. 7329 ** ^The source and destination [database connections] (parameters S and D) 7330 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7331 ** an error. 7332 ** 7333 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7334 ** there is already a read or read-write transaction open on the 7335 ** destination database. 7336 ** 7337 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7338 ** returned and an error code and error message are stored in the 7339 ** destination [database connection] D. 7340 ** ^The error code and message for the failed call to sqlite3_backup_init() 7341 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7342 ** [sqlite3_errmsg16()] functions. 7343 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 7344 ** [sqlite3_backup] object. 7345 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7346 ** sqlite3_backup_finish() functions to perform the specified backup 7347 ** operation. 7348 ** 7349 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7350 ** 7351 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7352 ** the source and destination databases specified by [sqlite3_backup] object B. 7353 ** ^If N is negative, all remaining source pages are copied. 7354 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7355 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 7356 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7357 ** from source to destination, then it returns [SQLITE_DONE]. 7358 ** ^If an error occurs while running sqlite3_backup_step(B,N), 7359 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 7360 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7361 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7362 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7363 ** 7364 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7365 ** <ol> 7366 ** <li> the destination database was opened read-only, or 7367 ** <li> the destination database is using write-ahead-log journaling 7368 ** and the destination and source page sizes differ, or 7369 ** <li> the destination database is an in-memory database and the 7370 ** destination and source page sizes differ. 7371 ** </ol>)^ 7372 ** 7373 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7374 ** the [sqlite3_busy_handler | busy-handler function] 7375 ** is invoked (if one is specified). ^If the 7376 ** busy-handler returns non-zero before the lock is available, then 7377 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7378 ** sqlite3_backup_step() can be retried later. ^If the source 7379 ** [database connection] 7380 ** is being used to write to the source database when sqlite3_backup_step() 7381 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7382 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 7383 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7384 ** [SQLITE_READONLY] is returned, then 7385 ** there is no point in retrying the call to sqlite3_backup_step(). These 7386 ** errors are considered fatal.)^ The application must accept 7387 ** that the backup operation has failed and pass the backup operation handle 7388 ** to the sqlite3_backup_finish() to release associated resources. 7389 ** 7390 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7391 ** on the destination file. ^The exclusive lock is not released until either 7392 ** sqlite3_backup_finish() is called or the backup operation is complete 7393 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7394 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 7395 ** lasts for the duration of the sqlite3_backup_step() call. 7396 ** ^Because the source database is not locked between calls to 7397 ** sqlite3_backup_step(), the source database may be modified mid-way 7398 ** through the backup process. ^If the source database is modified by an 7399 ** external process or via a database connection other than the one being 7400 ** used by the backup operation, then the backup will be automatically 7401 ** restarted by the next call to sqlite3_backup_step(). ^If the source 7402 ** database is modified by the using the same database connection as is used 7403 ** by the backup operation, then the backup database is automatically 7404 ** updated at the same time. 7405 ** 7406 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7407 ** 7408 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7409 ** application wishes to abandon the backup operation, the application 7410 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7411 ** ^The sqlite3_backup_finish() interfaces releases all 7412 ** resources associated with the [sqlite3_backup] object. 7413 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7414 ** active write-transaction on the destination database is rolled back. 7415 ** The [sqlite3_backup] object is invalid 7416 ** and may not be used following a call to sqlite3_backup_finish(). 7417 ** 7418 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7419 ** sqlite3_backup_step() errors occurred, regardless or whether or not 7420 ** sqlite3_backup_step() completed. 7421 ** ^If an out-of-memory condition or IO error occurred during any prior 7422 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7423 ** sqlite3_backup_finish() returns the corresponding [error code]. 7424 ** 7425 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7426 ** is not a permanent error and does not affect the return value of 7427 ** sqlite3_backup_finish(). 7428 ** 7429 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7430 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7431 ** 7432 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 7433 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7434 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7435 ** in the source database at the conclusion of the most recent 7436 ** sqlite3_backup_step(). 7437 ** ^(The values returned by these functions are only updated by 7438 ** sqlite3_backup_step(). If the source database is modified in a way that 7439 ** changes the size of the source database or the number of pages remaining, 7440 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 7441 ** and sqlite3_backup_remaining() until after the next 7442 ** sqlite3_backup_step().)^ 7443 ** 7444 ** <b>Concurrent Usage of Database Handles</b> 7445 ** 7446 ** ^The source [database connection] may be used by the application for other 7447 ** purposes while a backup operation is underway or being initialized. 7448 ** ^If SQLite is compiled and configured to support threadsafe database 7449 ** connections, then the source database connection may be used concurrently 7450 ** from within other threads. 7451 ** 7452 ** However, the application must guarantee that the destination 7453 ** [database connection] is not passed to any other API (by any thread) after 7454 ** sqlite3_backup_init() is called and before the corresponding call to 7455 ** sqlite3_backup_finish(). SQLite does not currently check to see 7456 ** if the application incorrectly accesses the destination [database connection] 7457 ** and so no error code is reported, but the operations may malfunction 7458 ** nevertheless. Use of the destination database connection while a 7459 ** backup is in progress might also also cause a mutex deadlock. 7460 ** 7461 ** If running in [shared cache mode], the application must 7462 ** guarantee that the shared cache used by the destination database 7463 ** is not accessed while the backup is running. In practice this means 7464 ** that the application must guarantee that the disk file being 7465 ** backed up to is not accessed by any connection within the process, 7466 ** not just the specific connection that was passed to sqlite3_backup_init(). 7467 ** 7468 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7469 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7470 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7471 ** APIs are not strictly speaking threadsafe. If they are invoked at the 7472 ** same time as another thread is invoking sqlite3_backup_step() it is 7473 ** possible that they return invalid values. 7474 */ 7475 SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init( 7476 sqlite3 *pDest, /* Destination database handle */ 7477 const char *zDestName, /* Destination database name */ 7478 sqlite3 *pSource, /* Source database handle */ 7479 const char *zSourceName /* Source database name */ 7480 ); 7481 SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage); 7482 SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p); 7483 SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p); 7484 SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p); 7485 7486 /* 7487 ** CAPI3REF: Unlock Notification 7488 ** METHOD: sqlite3 7489 ** 7490 ** ^When running in shared-cache mode, a database operation may fail with 7491 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7492 ** individual tables within the shared-cache cannot be obtained. See 7493 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7494 ** ^This API may be used to register a callback that SQLite will invoke 7495 ** when the connection currently holding the required lock relinquishes it. 7496 ** ^This API is only available if the library was compiled with the 7497 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7498 ** 7499 ** See Also: [Using the SQLite Unlock Notification Feature]. 7500 ** 7501 ** ^Shared-cache locks are released when a database connection concludes 7502 ** its current transaction, either by committing it or rolling it back. 7503 ** 7504 ** ^When a connection (known as the blocked connection) fails to obtain a 7505 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7506 ** identity of the database connection (the blocking connection) that 7507 ** has locked the required resource is stored internally. ^After an 7508 ** application receives an SQLITE_LOCKED error, it may call the 7509 ** sqlite3_unlock_notify() method with the blocked connection handle as 7510 ** the first argument to register for a callback that will be invoked 7511 ** when the blocking connections current transaction is concluded. ^The 7512 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7513 ** call that concludes the blocking connections transaction. 7514 ** 7515 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7516 ** there is a chance that the blocking connection will have already 7517 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7518 ** If this happens, then the specified callback is invoked immediately, 7519 ** from within the call to sqlite3_unlock_notify().)^ 7520 ** 7521 ** ^If the blocked connection is attempting to obtain a write-lock on a 7522 ** shared-cache table, and more than one other connection currently holds 7523 ** a read-lock on the same table, then SQLite arbitrarily selects one of 7524 ** the other connections to use as the blocking connection. 7525 ** 7526 ** ^(There may be at most one unlock-notify callback registered by a 7527 ** blocked connection. If sqlite3_unlock_notify() is called when the 7528 ** blocked connection already has a registered unlock-notify callback, 7529 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7530 ** called with a NULL pointer as its second argument, then any existing 7531 ** unlock-notify callback is canceled. ^The blocked connections 7532 ** unlock-notify callback may also be canceled by closing the blocked 7533 ** connection using [sqlite3_close()]. 7534 ** 7535 ** The unlock-notify callback is not reentrant. If an application invokes 7536 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 7537 ** crash or deadlock may be the result. 7538 ** 7539 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7540 ** returns SQLITE_OK. 7541 ** 7542 ** <b>Callback Invocation Details</b> 7543 ** 7544 ** When an unlock-notify callback is registered, the application provides a 7545 ** single void* pointer that is passed to the callback when it is invoked. 7546 ** However, the signature of the callback function allows SQLite to pass 7547 ** it an array of void* context pointers. The first argument passed to 7548 ** an unlock-notify callback is a pointer to an array of void* pointers, 7549 ** and the second is the number of entries in the array. 7550 ** 7551 ** When a blocking connections transaction is concluded, there may be 7552 ** more than one blocked connection that has registered for an unlock-notify 7553 ** callback. ^If two or more such blocked connections have specified the 7554 ** same callback function, then instead of invoking the callback function 7555 ** multiple times, it is invoked once with the set of void* context pointers 7556 ** specified by the blocked connections bundled together into an array. 7557 ** This gives the application an opportunity to prioritize any actions 7558 ** related to the set of unblocked database connections. 7559 ** 7560 ** <b>Deadlock Detection</b> 7561 ** 7562 ** Assuming that after registering for an unlock-notify callback a 7563 ** database waits for the callback to be issued before taking any further 7564 ** action (a reasonable assumption), then using this API may cause the 7565 ** application to deadlock. For example, if connection X is waiting for 7566 ** connection Y's transaction to be concluded, and similarly connection 7567 ** Y is waiting on connection X's transaction, then neither connection 7568 ** will proceed and the system may remain deadlocked indefinitely. 7569 ** 7570 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7571 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 7572 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7573 ** unlock-notify callback is registered. The system is said to be in 7574 ** a deadlocked state if connection A has registered for an unlock-notify 7575 ** callback on the conclusion of connection B's transaction, and connection 7576 ** B has itself registered for an unlock-notify callback when connection 7577 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 7578 ** the system is also considered to be deadlocked if connection B has 7579 ** registered for an unlock-notify callback on the conclusion of connection 7580 ** C's transaction, where connection C is waiting on connection A. ^Any 7581 ** number of levels of indirection are allowed. 7582 ** 7583 ** <b>The "DROP TABLE" Exception</b> 7584 ** 7585 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7586 ** always appropriate to call sqlite3_unlock_notify(). There is however, 7587 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7588 ** SQLite checks if there are any currently executing SELECT statements 7589 ** that belong to the same connection. If there are, SQLITE_LOCKED is 7590 ** returned. In this case there is no "blocking connection", so invoking 7591 ** sqlite3_unlock_notify() results in the unlock-notify callback being 7592 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 7593 ** or "DROP INDEX" query, an infinite loop might be the result. 7594 ** 7595 ** One way around this problem is to check the extended error code returned 7596 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7597 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7598 ** the special "DROP TABLE/INDEX" case, the extended error code is just 7599 ** SQLITE_LOCKED.)^ 7600 */ 7601 SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify( 7602 sqlite3 *pBlocked, /* Waiting connection */ 7603 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7604 void *pNotifyArg /* Argument to pass to xNotify */ 7605 ); 7606 7607 7608 /* 7609 ** CAPI3REF: String Comparison 7610 ** 7611 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7612 ** and extensions to compare the contents of two buffers containing UTF-8 7613 ** strings in a case-independent fashion, using the same definition of "case 7614 ** independence" that SQLite uses internally when comparing identifiers. 7615 */ 7616 SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *); 7617 SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int); 7618 7619 /* 7620 ** CAPI3REF: String Globbing 7621 * 7622 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7623 ** string X matches the [GLOB] pattern P. 7624 ** ^The definition of [GLOB] pattern matching used in 7625 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7626 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7627 ** is case sensitive. 7628 ** 7629 ** Note that this routine returns zero on a match and non-zero if the strings 7630 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7631 ** 7632 ** See also: [sqlite3_strlike()]. 7633 */ 7634 SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr); 7635 7636 /* 7637 ** CAPI3REF: String LIKE Matching 7638 * 7639 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7640 ** string X matches the [LIKE] pattern P with escape character E. 7641 ** ^The definition of [LIKE] pattern matching used in 7642 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7643 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7644 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7645 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7646 ** insensitive - equivalent upper and lower case ASCII characters match 7647 ** one another. 7648 ** 7649 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7650 ** only ASCII characters are case folded. 7651 ** 7652 ** Note that this routine returns zero on a match and non-zero if the strings 7653 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7654 ** 7655 ** See also: [sqlite3_strglob()]. 7656 */ 7657 SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7658 7659 /* 7660 ** CAPI3REF: Error Logging Interface 7661 ** 7662 ** ^The [sqlite3_log()] interface writes a message into the [error log] 7663 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7664 ** ^If logging is enabled, the zFormat string and subsequent arguments are 7665 ** used with [sqlite3_snprintf()] to generate the final output string. 7666 ** 7667 ** The sqlite3_log() interface is intended for use by extensions such as 7668 ** virtual tables, collating functions, and SQL functions. While there is 7669 ** nothing to prevent an application from calling sqlite3_log(), doing so 7670 ** is considered bad form. 7671 ** 7672 ** The zFormat string must not be NULL. 7673 ** 7674 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7675 ** will not use dynamically allocated memory. The log message is stored in 7676 ** a fixed-length buffer on the stack. If the log message is longer than 7677 ** a few hundred characters, it will be truncated to the length of the 7678 ** buffer. 7679 */ 7680 SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...); 7681 7682 /* 7683 ** CAPI3REF: Write-Ahead Log Commit Hook 7684 ** METHOD: sqlite3 7685 ** 7686 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 7687 ** is invoked each time data is committed to a database in wal mode. 7688 ** 7689 ** ^(The callback is invoked by SQLite after the commit has taken place and 7690 ** the associated write-lock on the database released)^, so the implementation 7691 ** may read, write or [checkpoint] the database as required. 7692 ** 7693 ** ^The first parameter passed to the callback function when it is invoked 7694 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 7695 ** registering the callback. ^The second is a copy of the database handle. 7696 ** ^The third parameter is the name of the database that was written to - 7697 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7698 ** is the number of pages currently in the write-ahead log file, 7699 ** including those that were just committed. 7700 ** 7701 ** The callback function should normally return [SQLITE_OK]. ^If an error 7702 ** code is returned, that error will propagate back up through the 7703 ** SQLite code base to cause the statement that provoked the callback 7704 ** to report an error, though the commit will have still occurred. If the 7705 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7706 ** that does not correspond to any valid SQLite error code, the results 7707 ** are undefined. 7708 ** 7709 ** A single database handle may have at most a single write-ahead log callback 7710 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7711 ** previously registered write-ahead log callback. ^Note that the 7712 ** [sqlite3_wal_autocheckpoint()] interface and the 7713 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7714 ** overwrite any prior [sqlite3_wal_hook()] settings. 7715 */ 7716 SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook( 7717 sqlite3*, 7718 int(*)(void *,sqlite3*,const char*,int), 7719 void* 7720 ); 7721 7722 /* 7723 ** CAPI3REF: Configure an auto-checkpoint 7724 ** METHOD: sqlite3 7725 ** 7726 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7727 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 7728 ** to automatically [checkpoint] 7729 ** after committing a transaction if there are N or 7730 ** more frames in the [write-ahead log] file. ^Passing zero or 7731 ** a negative value as the nFrame parameter disables automatic 7732 ** checkpoints entirely. 7733 ** 7734 ** ^The callback registered by this function replaces any existing callback 7735 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7736 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7737 ** configured by this function. 7738 ** 7739 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7740 ** from SQL. 7741 ** 7742 ** ^Checkpoints initiated by this mechanism are 7743 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7744 ** 7745 ** ^Every new [database connection] defaults to having the auto-checkpoint 7746 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7747 ** pages. The use of this interface 7748 ** is only necessary if the default setting is found to be suboptimal 7749 ** for a particular application. 7750 */ 7751 SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7752 7753 /* 7754 ** CAPI3REF: Checkpoint a database 7755 ** METHOD: sqlite3 7756 ** 7757 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7758 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7759 ** 7760 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7761 ** [write-ahead log] for database X on [database connection] D to be 7762 ** transferred into the database file and for the write-ahead log to 7763 ** be reset. See the [checkpointing] documentation for addition 7764 ** information. 7765 ** 7766 ** This interface used to be the only way to cause a checkpoint to 7767 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7768 ** interface was added. This interface is retained for backwards 7769 ** compatibility and as a convenience for applications that need to manually 7770 ** start a callback but which do not need the full power (and corresponding 7771 ** complication) of [sqlite3_wal_checkpoint_v2()]. 7772 */ 7773 SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7774 7775 /* 7776 ** CAPI3REF: Checkpoint a database 7777 ** METHOD: sqlite3 7778 ** 7779 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7780 ** operation on database X of [database connection] D in mode M. Status 7781 ** information is written back into integers pointed to by L and C.)^ 7782 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 7783 ** 7784 ** <dl> 7785 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7786 ** ^Checkpoint as many frames as possible without waiting for any database 7787 ** readers or writers to finish, then sync the database file if all frames 7788 ** in the log were checkpointed. ^The [busy-handler callback] 7789 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7790 ** ^On the other hand, passive mode might leave the checkpoint unfinished 7791 ** if there are concurrent readers or writers. 7792 ** 7793 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 7794 ** ^This mode blocks (it invokes the 7795 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 7796 ** database writer and all readers are reading from the most recent database 7797 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 7798 ** database file. ^This mode blocks new database writers while it is pending, 7799 ** but new database readers are allowed to continue unimpeded. 7800 ** 7801 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7802 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7803 ** that after checkpointing the log file it blocks (calls the 7804 ** [busy-handler callback]) 7805 ** until all readers are reading from the database file only. ^This ensures 7806 ** that the next writer will restart the log file from the beginning. 7807 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7808 ** database writer attempts while it is pending, but does not impede readers. 7809 ** 7810 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7811 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7812 ** addition that it also truncates the log file to zero bytes just prior 7813 ** to a successful return. 7814 ** </dl> 7815 ** 7816 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7817 ** the log file or to -1 if the checkpoint could not run because 7818 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7819 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7820 ** log file (including any that were already checkpointed before the function 7821 ** was called) or to -1 if the checkpoint could not run due to an error or 7822 ** because the database is not in WAL mode. ^Note that upon successful 7823 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7824 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7825 ** 7826 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7827 ** any other process is running a checkpoint operation at the same time, the 7828 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7829 ** busy-handler configured, it will not be invoked in this case. 7830 ** 7831 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7832 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7833 ** obtained immediately, and a busy-handler is configured, it is invoked and 7834 ** the writer lock retried until either the busy-handler returns 0 or the lock 7835 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 7836 ** database readers as described above. ^If the busy-handler returns 0 before 7837 ** the writer lock is obtained or while waiting for database readers, the 7838 ** checkpoint operation proceeds from that point in the same way as 7839 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7840 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 7841 ** 7842 ** ^If parameter zDb is NULL or points to a zero length string, then the 7843 ** specified operation is attempted on all WAL databases [attached] to 7844 ** [database connection] db. In this case the 7845 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7846 ** an SQLITE_BUSY error is encountered when processing one or more of the 7847 ** attached WAL databases, the operation is still attempted on any remaining 7848 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7849 ** error occurs while processing an attached database, processing is abandoned 7850 ** and the error code is returned to the caller immediately. ^If no error 7851 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7852 ** databases, SQLITE_OK is returned. 7853 ** 7854 ** ^If database zDb is the name of an attached database that is not in WAL 7855 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7856 ** zDb is not NULL (or a zero length string) and is not the name of any 7857 ** attached database, SQLITE_ERROR is returned to the caller. 7858 ** 7859 ** ^Unless it returns SQLITE_MISUSE, 7860 ** the sqlite3_wal_checkpoint_v2() interface 7861 ** sets the error information that is queried by 7862 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7863 ** 7864 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7865 ** from SQL. 7866 */ 7867 SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2( 7868 sqlite3 *db, /* Database handle */ 7869 const char *zDb, /* Name of attached database (or NULL) */ 7870 int eMode, /* SQLITE_CHECKPOINT_* value */ 7871 int *pnLog, /* OUT: Size of WAL log in frames */ 7872 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7873 ); 7874 7875 /* 7876 ** CAPI3REF: Checkpoint Mode Values 7877 ** KEYWORDS: {checkpoint mode} 7878 ** 7879 ** These constants define all valid values for the "checkpoint mode" passed 7880 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7881 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7882 ** meaning of each of these checkpoint modes. 7883 */ 7884 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7885 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7886 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7887 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7888 7889 /* 7890 ** CAPI3REF: Virtual Table Interface Configuration 7891 ** 7892 ** This function may be called by either the [xConnect] or [xCreate] method 7893 ** of a [virtual table] implementation to configure 7894 ** various facets of the virtual table interface. 7895 ** 7896 ** If this interface is invoked outside the context of an xConnect or 7897 ** xCreate virtual table method then the behavior is undefined. 7898 ** 7899 ** At present, there is only one option that may be configured using 7900 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7901 ** may be added in the future. 7902 */ 7903 SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...); 7904 7905 /* 7906 ** CAPI3REF: Virtual Table Configuration Options 7907 ** 7908 ** These macros define the various options to the 7909 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 7910 ** can use to customize and optimize their behavior. 7911 ** 7912 ** <dl> 7913 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7914 ** <dd>Calls of the form 7915 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7916 ** where X is an integer. If X is zero, then the [virtual table] whose 7917 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7918 ** support constraints. In this configuration (which is the default) if 7919 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7920 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7921 ** specified as part of the users SQL statement, regardless of the actual 7922 ** ON CONFLICT mode specified. 7923 ** 7924 ** If X is non-zero, then the virtual table implementation guarantees 7925 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7926 ** any modifications to internal or persistent data structures have been made. 7927 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7928 ** is able to roll back a statement or database transaction, and abandon 7929 ** or continue processing the current SQL statement as appropriate. 7930 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7931 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7932 ** had been ABORT. 7933 ** 7934 ** Virtual table implementations that are required to handle OR REPLACE 7935 ** must do so within the [xUpdate] method. If a call to the 7936 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7937 ** CONFLICT policy is REPLACE, the virtual table implementation should 7938 ** silently replace the appropriate rows within the xUpdate callback and 7939 ** return SQLITE_OK. Or, if this is not possible, it may return 7940 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7941 ** constraint handling. 7942 ** </dl> 7943 */ 7944 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7945 7946 /* 7947 ** CAPI3REF: Determine The Virtual Table Conflict Policy 7948 ** 7949 ** This function may only be called from within a call to the [xUpdate] method 7950 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7951 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7952 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7953 ** of the SQL statement that triggered the call to the [xUpdate] method of the 7954 ** [virtual table]. 7955 */ 7956 SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *); 7957 7958 /* 7959 ** CAPI3REF: Conflict resolution modes 7960 ** KEYWORDS: {conflict resolution mode} 7961 ** 7962 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 7963 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 7964 ** is for the SQL statement being evaluated. 7965 ** 7966 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 7967 ** return value from the [sqlite3_set_authorizer()] callback and that 7968 ** [SQLITE_ABORT] is also a [result code]. 7969 */ 7970 #define SQLITE_ROLLBACK 1 7971 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7972 #define SQLITE_FAIL 3 7973 /* #define SQLITE_ABORT 4 // Also an error code */ 7974 #define SQLITE_REPLACE 5 7975 7976 /* 7977 ** CAPI3REF: Prepared Statement Scan Status Opcodes 7978 ** KEYWORDS: {scanstatus options} 7979 ** 7980 ** The following constants can be used for the T parameter to the 7981 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7982 ** different metric for sqlite3_stmt_scanstatus() to return. 7983 ** 7984 ** When the value returned to V is a string, space to hold that string is 7985 ** managed by the prepared statement S and will be automatically freed when 7986 ** S is finalized. 7987 ** 7988 ** <dl> 7989 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7990 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7991 ** set to the total number of times that the X-th loop has run.</dd> 7992 ** 7993 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7994 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7995 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 7996 ** 7997 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7998 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 7999 ** query planner's estimate for the average number of rows output from each 8000 ** iteration of the X-th loop. If the query planner's estimates was accurate, 8001 ** then this value will approximate the quotient NVISIT/NLOOP and the 8002 ** product of this value for all prior loops with the same SELECTID will 8003 ** be the NLOOP value for the current loop. 8004 ** 8005 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8006 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8007 ** to a zero-terminated UTF-8 string containing the name of the index or table 8008 ** used for the X-th loop. 8009 ** 8010 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8011 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8012 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8013 ** description for the X-th loop. 8014 ** 8015 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8016 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 8017 ** "select-id" for the X-th loop. The select-id identifies which query or 8018 ** subquery the loop is part of. The main query has a select-id of zero. 8019 ** The select-id is the same value as is output in the first column 8020 ** of an [EXPLAIN QUERY PLAN] query. 8021 ** </dl> 8022 */ 8023 #define SQLITE_SCANSTAT_NLOOP 0 8024 #define SQLITE_SCANSTAT_NVISIT 1 8025 #define SQLITE_SCANSTAT_EST 2 8026 #define SQLITE_SCANSTAT_NAME 3 8027 #define SQLITE_SCANSTAT_EXPLAIN 4 8028 #define SQLITE_SCANSTAT_SELECTID 5 8029 8030 /* 8031 ** CAPI3REF: Prepared Statement Scan Status 8032 ** METHOD: sqlite3_stmt 8033 ** 8034 ** This interface returns information about the predicted and measured 8035 ** performance for pStmt. Advanced applications can use this 8036 ** interface to compare the predicted and the measured performance and 8037 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8038 ** 8039 ** Since this interface is expected to be rarely used, it is only 8040 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8041 ** compile-time option. 8042 ** 8043 ** The "iScanStatusOp" parameter determines which status information to return. 8044 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8045 ** of this interface is undefined. 8046 ** ^The requested measurement is written into a variable pointed to by 8047 ** the "pOut" parameter. 8048 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 8049 ** Loops are numbered starting from zero. ^If idx is out of range - less than 8050 ** zero or greater than or equal to the total number of loops used to implement 8051 ** the statement - a non-zero value is returned and the variable that pOut 8052 ** points to is unchanged. 8053 ** 8054 ** ^Statistics might not be available for all loops in all statements. ^In cases 8055 ** where there exist loops with no available statistics, this function behaves 8056 ** as if the loop did not exist - it returns non-zero and leave the variable 8057 ** that pOut points to unchanged. 8058 ** 8059 ** See also: [sqlite3_stmt_scanstatus_reset()] 8060 */ 8061 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus( 8062 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8063 int idx, /* Index of loop to report on */ 8064 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8065 void *pOut /* Result written here */ 8066 ); 8067 8068 /* 8069 ** CAPI3REF: Zero Scan-Status Counters 8070 ** METHOD: sqlite3_stmt 8071 ** 8072 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8073 ** 8074 ** This API is only available if the library is built with pre-processor 8075 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8076 */ 8077 SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8078 8079 /* 8080 ** CAPI3REF: Flush caches to disk mid-transaction 8081 ** 8082 ** ^If a write-transaction is open on [database connection] D when the 8083 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8084 ** pages in the pager-cache that are not currently in use are written out 8085 ** to disk. A dirty page may be in use if a database cursor created by an 8086 ** active SQL statement is reading from it, or if it is page 1 of a database 8087 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8088 ** interface flushes caches for all schemas - "main", "temp", and 8089 ** any [attached] databases. 8090 ** 8091 ** ^If this function needs to obtain extra database locks before dirty pages 8092 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 8093 ** immediately and there is a busy-handler callback configured, it is invoked 8094 ** in the usual manner. ^If the required lock still cannot be obtained, then 8095 ** the database is skipped and an attempt made to flush any dirty pages 8096 ** belonging to the next (if any) database. ^If any databases are skipped 8097 ** because locks cannot be obtained, but no other error occurs, this 8098 ** function returns SQLITE_BUSY. 8099 ** 8100 ** ^If any other error occurs while flushing dirty pages to disk (for 8101 ** example an IO error or out-of-memory condition), then processing is 8102 ** abandoned and an SQLite [error code] is returned to the caller immediately. 8103 ** 8104 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8105 ** 8106 ** ^This function does not set the database handle error code or message 8107 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8108 */ 8109 SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3*); 8110 8111 /* 8112 ** CAPI3REF: The pre-update hook. 8113 ** 8114 ** ^These interfaces are only available if SQLite is compiled using the 8115 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8116 ** 8117 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8118 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8119 ** on a [rowid table]. 8120 ** ^At most one preupdate hook may be registered at a time on a single 8121 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8122 ** the previous setting. 8123 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8124 ** with a NULL pointer as the second parameter. 8125 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8126 ** the first parameter to callbacks. 8127 ** 8128 ** ^The preupdate hook only fires for changes to [rowid tables]; the preupdate 8129 ** hook is not invoked for changes to [virtual tables] or [WITHOUT ROWID] 8130 ** tables. 8131 ** 8132 ** ^The second parameter to the preupdate callback is a pointer to 8133 ** the [database connection] that registered the preupdate hook. 8134 ** ^The third parameter to the preupdate callback is one of the constants 8135 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8136 ** kind of update operation that is about to occur. 8137 ** ^(The fourth parameter to the preupdate callback is the name of the 8138 ** database within the database connection that is being modified. This 8139 ** will be "main" for the main database or "temp" for TEMP tables or 8140 ** the name given after the AS keyword in the [ATTACH] statement for attached 8141 ** databases.)^ 8142 ** ^The fifth parameter to the preupdate callback is the name of the 8143 ** table that is being modified. 8144 ** ^The sixth parameter to the preupdate callback is the initial [rowid] of the 8145 ** row being changes for SQLITE_UPDATE and SQLITE_DELETE changes and is 8146 ** undefined for SQLITE_INSERT changes. 8147 ** ^The seventh parameter to the preupdate callback is the final [rowid] of 8148 ** the row being changed for SQLITE_UPDATE and SQLITE_INSERT changes and is 8149 ** undefined for SQLITE_DELETE changes. 8150 ** 8151 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8152 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8153 ** provide additional information about a preupdate event. These routines 8154 ** may only be called from within a preupdate callback. Invoking any of 8155 ** these routines from outside of a preupdate callback or with a 8156 ** [database connection] pointer that is different from the one supplied 8157 ** to the preupdate callback results in undefined and probably undesirable 8158 ** behavior. 8159 ** 8160 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8161 ** in the row that is being inserted, updated, or deleted. 8162 ** 8163 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8164 ** a [protected sqlite3_value] that contains the value of the Nth column of 8165 ** the table row before it is updated. The N parameter must be between 0 8166 ** and one less than the number of columns or the behavior will be 8167 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8168 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8169 ** behavior is undefined. The [sqlite3_value] that P points to 8170 ** will be destroyed when the preupdate callback returns. 8171 ** 8172 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8173 ** a [protected sqlite3_value] that contains the value of the Nth column of 8174 ** the table row after it is updated. The N parameter must be between 0 8175 ** and one less than the number of columns or the behavior will be 8176 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8177 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8178 ** behavior is undefined. The [sqlite3_value] that P points to 8179 ** will be destroyed when the preupdate callback returns. 8180 ** 8181 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8182 ** callback was invoked as a result of a direct insert, update, or delete 8183 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 8184 ** triggers; or 2 for changes resulting from triggers called by top-level 8185 ** triggers; and so forth. 8186 ** 8187 ** See also: [sqlite3_update_hook()] 8188 */ 8189 SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_preupdate_hook( 8190 sqlite3 *db, 8191 void(*xPreUpdate)( 8192 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8193 sqlite3 *db, /* Database handle */ 8194 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8195 char const *zDb, /* Database name */ 8196 char const *zName, /* Table name */ 8197 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8198 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8199 ), 8200 void* 8201 ); 8202 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8203 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_count(sqlite3 *); 8204 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_depth(sqlite3 *); 8205 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8206 8207 /* 8208 ** CAPI3REF: Low-level system error code 8209 ** 8210 ** ^Attempt to return the underlying operating system error code or error 8211 ** number that caused the most recent I/O error or failure to open a file. 8212 ** The return value is OS-dependent. For example, on unix systems, after 8213 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8214 ** called to get back the underlying "errno" that caused the problem, such 8215 ** as ENOSPC, EAUTH, EISDIR, and so forth. 8216 */ 8217 SQLITE_API int SQLITE_STDCALL sqlite3_system_errno(sqlite3*); 8218 8219 /* 8220 ** CAPI3REF: Database Snapshot 8221 ** KEYWORDS: {snapshot} 8222 ** EXPERIMENTAL 8223 ** 8224 ** An instance of the snapshot object records the state of a [WAL mode] 8225 ** database for some specific point in history. 8226 ** 8227 ** In [WAL mode], multiple [database connections] that are open on the 8228 ** same database file can each be reading a different historical version 8229 ** of the database file. When a [database connection] begins a read 8230 ** transaction, that connection sees an unchanging copy of the database 8231 ** as it existed for the point in time when the transaction first started. 8232 ** Subsequent changes to the database from other connections are not seen 8233 ** by the reader until a new read transaction is started. 8234 ** 8235 ** The sqlite3_snapshot object records state information about an historical 8236 ** version of the database file so that it is possible to later open a new read 8237 ** transaction that sees that historical version of the database rather than 8238 ** the most recent version. 8239 ** 8240 ** The constructor for this object is [sqlite3_snapshot_get()]. The 8241 ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8242 ** to an historical snapshot (if possible). The destructor for 8243 ** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8244 */ 8245 typedef struct sqlite3_snapshot sqlite3_snapshot; 8246 8247 /* 8248 ** CAPI3REF: Record A Database Snapshot 8249 ** EXPERIMENTAL 8250 ** 8251 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8252 ** new [sqlite3_snapshot] object that records the current state of 8253 ** schema S in database connection D. ^On success, the 8254 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8255 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8256 ** ^If schema S of [database connection] D is not a [WAL mode] database 8257 ** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)] 8258 ** leaves the *P value unchanged and returns an appropriate [error code]. 8259 ** 8260 ** The [sqlite3_snapshot] object returned from a successful call to 8261 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8262 ** to avoid a memory leak. 8263 ** 8264 ** The [sqlite3_snapshot_get()] interface is only available when the 8265 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8266 */ 8267 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_get( 8268 sqlite3 *db, 8269 const char *zSchema, 8270 sqlite3_snapshot **ppSnapshot 8271 ); 8272 8273 /* 8274 ** CAPI3REF: Start a read transaction on an historical snapshot 8275 ** EXPERIMENTAL 8276 ** 8277 ** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8278 ** read transaction for schema S of 8279 ** [database connection] D such that the read transaction 8280 ** refers to historical [snapshot] P, rather than the most 8281 ** recent change to the database. 8282 ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8283 ** or an appropriate [error code] if it fails. 8284 ** 8285 ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8286 ** the first operation following the [BEGIN] that takes the schema S 8287 ** out of [autocommit mode]. 8288 ** ^In other words, schema S must not currently be in 8289 ** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8290 ** database connection D must be out of [autocommit mode]. 8291 ** ^A [snapshot] will fail to open if it has been overwritten by a 8292 ** [checkpoint]. 8293 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8294 ** database connection D does not know that the database file for 8295 ** schema S is in [WAL mode]. A database connection might not know 8296 ** that the database file is in [WAL mode] if there has been no prior 8297 ** I/O on that database connection, or if the database entered [WAL mode] 8298 ** after the most recent I/O on the database connection.)^ 8299 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 8300 ** database connection in order to make it ready to use snapshots.) 8301 ** 8302 ** The [sqlite3_snapshot_open()] interface is only available when the 8303 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8304 */ 8305 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_open( 8306 sqlite3 *db, 8307 const char *zSchema, 8308 sqlite3_snapshot *pSnapshot 8309 ); 8310 8311 /* 8312 ** CAPI3REF: Destroy a snapshot 8313 ** EXPERIMENTAL 8314 ** 8315 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8316 ** The application must eventually free every [sqlite3_snapshot] object 8317 ** using this routine to avoid a memory leak. 8318 ** 8319 ** The [sqlite3_snapshot_free()] interface is only available when the 8320 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8321 */ 8322 SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot*); 8323 8324 /* 8325 ** CAPI3REF: Compare the ages of two snapshot handles. 8326 ** EXPERIMENTAL 8327 ** 8328 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8329 ** of two valid snapshot handles. 8330 ** 8331 ** If the two snapshot handles are not associated with the same database 8332 ** file, the result of the comparison is undefined. 8333 ** 8334 ** Additionally, the result of the comparison is only valid if both of the 8335 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8336 ** last time the wal file was deleted. The wal file is deleted when the 8337 ** database is changed back to rollback mode or when the number of database 8338 ** clients drops to zero. If either snapshot handle was obtained before the 8339 ** wal file was last deleted, the value returned by this function 8340 ** is undefined. 8341 ** 8342 ** Otherwise, this API returns a negative value if P1 refers to an older 8343 ** snapshot than P2, zero if the two handles refer to the same database 8344 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 8345 */ 8346 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_cmp( 8347 sqlite3_snapshot *p1, 8348 sqlite3_snapshot *p2 8349 ); 8350 8351 /* 8352 ** Undo the hack that converts floating point types to integer for 8353 ** builds on processors without floating point support. 8354 */ 8355 #ifdef SQLITE_OMIT_FLOATING_POINT 8356 # undef double 8357 #endif 8358 8359 #ifdef __cplusplus 8360 } /* End of the 'extern "C"' block */ 8361 #endif 8362 #endif /* SQLITE3_H */ 8363 8364 /******** Begin file sqlite3rtree.h *********/ 8365 /* 8366 ** 2010 August 30 8367 ** 8368 ** The author disclaims copyright to this source code. In place of 8369 ** a legal notice, here is a blessing: 8370 ** 8371 ** May you do good and not evil. 8372 ** May you find forgiveness for yourself and forgive others. 8373 ** May you share freely, never taking more than you give. 8374 ** 8375 ************************************************************************* 8376 */ 8377 8378 #ifndef _SQLITE3RTREE_H_ 8379 #define _SQLITE3RTREE_H_ 8380 8381 8382 #ifdef __cplusplus 8383 extern "C" { 8384 #endif 8385 8386 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8387 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8388 8389 /* The double-precision datatype used by RTree depends on the 8390 ** SQLITE_RTREE_INT_ONLY compile-time option. 8391 */ 8392 #ifdef SQLITE_RTREE_INT_ONLY 8393 typedef sqlite3_int64 sqlite3_rtree_dbl; 8394 #else 8395 typedef double sqlite3_rtree_dbl; 8396 #endif 8397 8398 /* 8399 ** Register a geometry callback named zGeom that can be used as part of an 8400 ** R-Tree geometry query as follows: 8401 ** 8402 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8403 */ 8404 SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback( 8405 sqlite3 *db, 8406 const char *zGeom, 8407 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8408 void *pContext 8409 ); 8410 8411 8412 /* 8413 ** A pointer to a structure of the following type is passed as the first 8414 ** argument to callbacks registered using rtree_geometry_callback(). 8415 */ 8416 struct sqlite3_rtree_geometry { 8417 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8418 int nParam; /* Size of array aParam[] */ 8419 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8420 void *pUser; /* Callback implementation user data */ 8421 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8422 }; 8423 8424 /* 8425 ** Register a 2nd-generation geometry callback named zScore that can be 8426 ** used as part of an R-Tree geometry query as follows: 8427 ** 8428 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8429 */ 8430 SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback( 8431 sqlite3 *db, 8432 const char *zQueryFunc, 8433 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8434 void *pContext, 8435 void (*xDestructor)(void*) 8436 ); 8437 8438 8439 /* 8440 ** A pointer to a structure of the following type is passed as the 8441 ** argument to scored geometry callback registered using 8442 ** sqlite3_rtree_query_callback(). 8443 ** 8444 ** Note that the first 5 fields of this structure are identical to 8445 ** sqlite3_rtree_geometry. This structure is a subclass of 8446 ** sqlite3_rtree_geometry. 8447 */ 8448 struct sqlite3_rtree_query_info { 8449 void *pContext; /* pContext from when function registered */ 8450 int nParam; /* Number of function parameters */ 8451 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8452 void *pUser; /* callback can use this, if desired */ 8453 void (*xDelUser)(void*); /* function to free pUser */ 8454 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8455 unsigned int *anQueue; /* Number of pending entries in the queue */ 8456 int nCoord; /* Number of coordinates */ 8457 int iLevel; /* Level of current node or entry */ 8458 int mxLevel; /* The largest iLevel value in the tree */ 8459 sqlite3_int64 iRowid; /* Rowid for current entry */ 8460 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8461 int eParentWithin; /* Visibility of parent node */ 8462 int eWithin; /* OUT: Visiblity */ 8463 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8464 /* The following fields are only available in 3.8.11 and later */ 8465 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8466 }; 8467 8468 /* 8469 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8470 */ 8471 #define NOT_WITHIN 0 /* Object completely outside of query region */ 8472 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8473 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 8474 8475 8476 #ifdef __cplusplus 8477 } /* end of the 'extern "C"' block */ 8478 #endif 8479 8480 #endif /* ifndef _SQLITE3RTREE_H_ */ 8481 8482 /******** End of sqlite3rtree.h *********/ 8483 /******** Begin file sqlite3session.h *********/ 8484 8485 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 8486 #define __SQLITESESSION_H_ 1 8487 8488 /* 8489 ** Make sure we can call this stuff from C++. 8490 */ 8491 #ifdef __cplusplus 8492 extern "C" { 8493 #endif 8494 8495 8496 /* 8497 ** CAPI3REF: Session Object Handle 8498 */ 8499 typedef struct sqlite3_session sqlite3_session; 8500 8501 /* 8502 ** CAPI3REF: Changeset Iterator Handle 8503 */ 8504 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 8505 8506 /* 8507 ** CAPI3REF: Create A New Session Object 8508 ** 8509 ** Create a new session object attached to database handle db. If successful, 8510 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 8511 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 8512 ** error code (e.g. SQLITE_NOMEM) is returned. 8513 ** 8514 ** It is possible to create multiple session objects attached to a single 8515 ** database handle. 8516 ** 8517 ** Session objects created using this function should be deleted using the 8518 ** [sqlite3session_delete()] function before the database handle that they 8519 ** are attached to is itself closed. If the database handle is closed before 8520 ** the session object is deleted, then the results of calling any session 8521 ** module function, including [sqlite3session_delete()] on the session object 8522 ** are undefined. 8523 ** 8524 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 8525 ** is not possible for an application to register a pre-update hook on a 8526 ** database handle that has one or more session objects attached. Nor is 8527 ** it possible to create a session object attached to a database handle for 8528 ** which a pre-update hook is already defined. The results of attempting 8529 ** either of these things are undefined. 8530 ** 8531 ** The session object will be used to create changesets for tables in 8532 ** database zDb, where zDb is either "main", or "temp", or the name of an 8533 ** attached database. It is not an error if database zDb is not attached 8534 ** to the database when the session object is created. 8535 */ 8536 int sqlite3session_create( 8537 sqlite3 *db, /* Database handle */ 8538 const char *zDb, /* Name of db (e.g. "main") */ 8539 sqlite3_session **ppSession /* OUT: New session object */ 8540 ); 8541 8542 /* 8543 ** CAPI3REF: Delete A Session Object 8544 ** 8545 ** Delete a session object previously allocated using 8546 ** [sqlite3session_create()]. Once a session object has been deleted, the 8547 ** results of attempting to use pSession with any other session module 8548 ** function are undefined. 8549 ** 8550 ** Session objects must be deleted before the database handle to which they 8551 ** are attached is closed. Refer to the documentation for 8552 ** [sqlite3session_create()] for details. 8553 */ 8554 void sqlite3session_delete(sqlite3_session *pSession); 8555 8556 8557 /* 8558 ** CAPI3REF: Enable Or Disable A Session Object 8559 ** 8560 ** Enable or disable the recording of changes by a session object. When 8561 ** enabled, a session object records changes made to the database. When 8562 ** disabled - it does not. A newly created session object is enabled. 8563 ** Refer to the documentation for [sqlite3session_changeset()] for further 8564 ** details regarding how enabling and disabling a session object affects 8565 ** the eventual changesets. 8566 ** 8567 ** Passing zero to this function disables the session. Passing a value 8568 ** greater than zero enables it. Passing a value less than zero is a 8569 ** no-op, and may be used to query the current state of the session. 8570 ** 8571 ** The return value indicates the final state of the session object: 0 if 8572 ** the session is disabled, or 1 if it is enabled. 8573 */ 8574 int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 8575 8576 /* 8577 ** CAPI3REF: Set Or Clear the Indirect Change Flag 8578 ** 8579 ** Each change recorded by a session object is marked as either direct or 8580 ** indirect. A change is marked as indirect if either: 8581 ** 8582 ** <ul> 8583 ** <li> The session object "indirect" flag is set when the change is 8584 ** made, or 8585 ** <li> The change is made by an SQL trigger or foreign key action 8586 ** instead of directly as a result of a users SQL statement. 8587 ** </ul> 8588 ** 8589 ** If a single row is affected by more than one operation within a session, 8590 ** then the change is considered indirect if all operations meet the criteria 8591 ** for an indirect change above, or direct otherwise. 8592 ** 8593 ** This function is used to set, clear or query the session object indirect 8594 ** flag. If the second argument passed to this function is zero, then the 8595 ** indirect flag is cleared. If it is greater than zero, the indirect flag 8596 ** is set. Passing a value less than zero does not modify the current value 8597 ** of the indirect flag, and may be used to query the current state of the 8598 ** indirect flag for the specified session object. 8599 ** 8600 ** The return value indicates the final state of the indirect flag: 0 if 8601 ** it is clear, or 1 if it is set. 8602 */ 8603 int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 8604 8605 /* 8606 ** CAPI3REF: Attach A Table To A Session Object 8607 ** 8608 ** If argument zTab is not NULL, then it is the name of a table to attach 8609 ** to the session object passed as the first argument. All subsequent changes 8610 ** made to the table while the session object is enabled will be recorded. See 8611 ** documentation for [sqlite3session_changeset()] for further details. 8612 ** 8613 ** Or, if argument zTab is NULL, then changes are recorded for all tables 8614 ** in the database. If additional tables are added to the database (by 8615 ** executing "CREATE TABLE" statements) after this call is made, changes for 8616 ** the new tables are also recorded. 8617 ** 8618 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 8619 ** defined as part of their CREATE TABLE statement. It does not matter if the 8620 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 8621 ** KEY may consist of a single column, or may be a composite key. 8622 ** 8623 ** It is not an error if the named table does not exist in the database. Nor 8624 ** is it an error if the named table does not have a PRIMARY KEY. However, 8625 ** no changes will be recorded in either of these scenarios. 8626 ** 8627 ** Changes are not recorded for individual rows that have NULL values stored 8628 ** in one or more of their PRIMARY KEY columns. 8629 ** 8630 ** SQLITE_OK is returned if the call completes without error. Or, if an error 8631 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 8632 */ 8633 int sqlite3session_attach( 8634 sqlite3_session *pSession, /* Session object */ 8635 const char *zTab /* Table name */ 8636 ); 8637 8638 /* 8639 ** CAPI3REF: Set a table filter on a Session Object. 8640 ** 8641 ** The second argument (xFilter) is the "filter callback". For changes to rows 8642 ** in tables that are not attached to the Session oject, the filter is called 8643 ** to determine whether changes to the table's rows should be tracked or not. 8644 ** If xFilter returns 0, changes is not tracked. Note that once a table is 8645 ** attached, xFilter will not be called again. 8646 */ 8647 void sqlite3session_table_filter( 8648 sqlite3_session *pSession, /* Session object */ 8649 int(*xFilter)( 8650 void *pCtx, /* Copy of third arg to _filter_table() */ 8651 const char *zTab /* Table name */ 8652 ), 8653 void *pCtx /* First argument passed to xFilter */ 8654 ); 8655 8656 /* 8657 ** CAPI3REF: Generate A Changeset From A Session Object 8658 ** 8659 ** Obtain a changeset containing changes to the tables attached to the 8660 ** session object passed as the first argument. If successful, 8661 ** set *ppChangeset to point to a buffer containing the changeset 8662 ** and *pnChangeset to the size of the changeset in bytes before returning 8663 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 8664 ** zero and return an SQLite error code. 8665 ** 8666 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 8667 ** each representing a change to a single row of an attached table. An INSERT 8668 ** change contains the values of each field of a new database row. A DELETE 8669 ** contains the original values of each field of a deleted database row. An 8670 ** UPDATE change contains the original values of each field of an updated 8671 ** database row along with the updated values for each updated non-primary-key 8672 ** column. It is not possible for an UPDATE change to represent a change that 8673 ** modifies the values of primary key columns. If such a change is made, it 8674 ** is represented in a changeset as a DELETE followed by an INSERT. 8675 ** 8676 ** Changes are not recorded for rows that have NULL values stored in one or 8677 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 8678 ** no corresponding change is present in the changesets returned by this 8679 ** function. If an existing row with one or more NULL values stored in 8680 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 8681 ** only an INSERT is appears in the changeset. Similarly, if an existing row 8682 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 8683 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 8684 ** DELETE change only. 8685 ** 8686 ** The contents of a changeset may be traversed using an iterator created 8687 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 8688 ** a database with a compatible schema using the [sqlite3changeset_apply()] 8689 ** API. 8690 ** 8691 ** Within a changeset generated by this function, all changes related to a 8692 ** single table are grouped together. In other words, when iterating through 8693 ** a changeset or when applying a changeset to a database, all changes related 8694 ** to a single table are processed before moving on to the next table. Tables 8695 ** are sorted in the same order in which they were attached (or auto-attached) 8696 ** to the sqlite3_session object. The order in which the changes related to 8697 ** a single table are stored is undefined. 8698 ** 8699 ** Following a successful call to this function, it is the responsibility of 8700 ** the caller to eventually free the buffer that *ppChangeset points to using 8701 ** [sqlite3_free()]. 8702 ** 8703 ** <h3>Changeset Generation</h3> 8704 ** 8705 ** Once a table has been attached to a session object, the session object 8706 ** records the primary key values of all new rows inserted into the table. 8707 ** It also records the original primary key and other column values of any 8708 ** deleted or updated rows. For each unique primary key value, data is only 8709 ** recorded once - the first time a row with said primary key is inserted, 8710 ** updated or deleted in the lifetime of the session. 8711 ** 8712 ** There is one exception to the previous paragraph: when a row is inserted, 8713 ** updated or deleted, if one or more of its primary key columns contain a 8714 ** NULL value, no record of the change is made. 8715 ** 8716 ** The session object therefore accumulates two types of records - those 8717 ** that consist of primary key values only (created when the user inserts 8718 ** a new record) and those that consist of the primary key values and the 8719 ** original values of other table columns (created when the users deletes 8720 ** or updates a record). 8721 ** 8722 ** When this function is called, the requested changeset is created using 8723 ** both the accumulated records and the current contents of the database 8724 ** file. Specifically: 8725 ** 8726 ** <ul> 8727 ** <li> For each record generated by an insert, the database is queried 8728 ** for a row with a matching primary key. If one is found, an INSERT 8729 ** change is added to the changeset. If no such row is found, no change 8730 ** is added to the changeset. 8731 ** 8732 ** <li> For each record generated by an update or delete, the database is 8733 ** queried for a row with a matching primary key. If such a row is 8734 ** found and one or more of the non-primary key fields have been 8735 ** modified from their original values, an UPDATE change is added to 8736 ** the changeset. Or, if no such row is found in the table, a DELETE 8737 ** change is added to the changeset. If there is a row with a matching 8738 ** primary key in the database, but all fields contain their original 8739 ** values, no change is added to the changeset. 8740 ** </ul> 8741 ** 8742 ** This means, amongst other things, that if a row is inserted and then later 8743 ** deleted while a session object is active, neither the insert nor the delete 8744 ** will be present in the changeset. Or if a row is deleted and then later a 8745 ** row with the same primary key values inserted while a session object is 8746 ** active, the resulting changeset will contain an UPDATE change instead of 8747 ** a DELETE and an INSERT. 8748 ** 8749 ** When a session object is disabled (see the [sqlite3session_enable()] API), 8750 ** it does not accumulate records when rows are inserted, updated or deleted. 8751 ** This may appear to have some counter-intuitive effects if a single row 8752 ** is written to more than once during a session. For example, if a row 8753 ** is inserted while a session object is enabled, then later deleted while 8754 ** the same session object is disabled, no INSERT record will appear in the 8755 ** changeset, even though the delete took place while the session was disabled. 8756 ** Or, if one field of a row is updated while a session is disabled, and 8757 ** another field of the same row is updated while the session is enabled, the 8758 ** resulting changeset will contain an UPDATE change that updates both fields. 8759 */ 8760 int sqlite3session_changeset( 8761 sqlite3_session *pSession, /* Session object */ 8762 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 8763 void **ppChangeset /* OUT: Buffer containing changeset */ 8764 ); 8765 8766 /* 8767 ** CAPI3REF: Load The Difference Between Tables Into A Session 8768 ** 8769 ** If it is not already attached to the session object passed as the first 8770 ** argument, this function attaches table zTbl in the same manner as the 8771 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 8772 ** does not have a primary key, this function is a no-op (but does not return 8773 ** an error). 8774 ** 8775 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 8776 ** attached to the same database handle as the session object that contains 8777 ** a table compatible with the table attached to the session by this function. 8778 ** A table is considered compatible if it: 8779 ** 8780 ** <ul> 8781 ** <li> Has the same name, 8782 ** <li> Has the same set of columns declared in the same order, and 8783 ** <li> Has the same PRIMARY KEY definition. 8784 ** </ul> 8785 ** 8786 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 8787 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 8788 ** but no changes are added to the session object. As with other session 8789 ** APIs, tables without PRIMARY KEYs are simply ignored. 8790 ** 8791 ** This function adds a set of changes to the session object that could be 8792 ** used to update the table in database zFrom (call this the "from-table") 8793 ** so that its content is the same as the table attached to the session 8794 ** object (call this the "to-table"). Specifically: 8795 ** 8796 ** <ul> 8797 ** <li> For each row (primary key) that exists in the to-table but not in 8798 ** the from-table, an INSERT record is added to the session object. 8799 ** 8800 ** <li> For each row (primary key) that exists in the to-table but not in 8801 ** the from-table, a DELETE record is added to the session object. 8802 ** 8803 ** <li> For each row (primary key) that exists in both tables, but features 8804 ** different in each, an UPDATE record is added to the session. 8805 ** </ul> 8806 ** 8807 ** To clarify, if this function is called and then a changeset constructed 8808 ** using [sqlite3session_changeset()], then after applying that changeset to 8809 ** database zFrom the contents of the two compatible tables would be 8810 ** identical. 8811 ** 8812 ** It an error if database zFrom does not exist or does not contain the 8813 ** required compatible table. 8814 ** 8815 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 8816 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 8817 ** may be set to point to a buffer containing an English language error 8818 ** message. It is the responsibility of the caller to free this buffer using 8819 ** sqlite3_free(). 8820 */ 8821 int sqlite3session_diff( 8822 sqlite3_session *pSession, 8823 const char *zFromDb, 8824 const char *zTbl, 8825 char **pzErrMsg 8826 ); 8827 8828 8829 /* 8830 ** CAPI3REF: Generate A Patchset From A Session Object 8831 ** 8832 ** The differences between a patchset and a changeset are that: 8833 ** 8834 ** <ul> 8835 ** <li> DELETE records consist of the primary key fields only. The 8836 ** original values of other fields are omitted. 8837 ** <li> The original values of any modified fields are omitted from 8838 ** UPDATE records. 8839 ** </ul> 8840 ** 8841 ** A patchset blob may be used with up to date versions of all 8842 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 8843 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 8844 ** attempting to use a patchset blob with old versions of the 8845 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 8846 ** 8847 ** Because the non-primary key "old.*" fields are omitted, no 8848 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 8849 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 8850 ** in the same way as for changesets. 8851 ** 8852 ** Changes within a patchset are ordered in the same way as for changesets 8853 ** generated by the sqlite3session_changeset() function (i.e. all changes for 8854 ** a single table are grouped together, tables appear in the order in which 8855 ** they were attached to the session object). 8856 */ 8857 int sqlite3session_patchset( 8858 sqlite3_session *pSession, /* Session object */ 8859 int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */ 8860 void **ppPatchset /* OUT: Buffer containing changeset */ 8861 ); 8862 8863 /* 8864 ** CAPI3REF: Test if a changeset has recorded any changes. 8865 ** 8866 ** Return non-zero if no changes to attached tables have been recorded by 8867 ** the session object passed as the first argument. Otherwise, if one or 8868 ** more changes have been recorded, return zero. 8869 ** 8870 ** Even if this function returns zero, it is possible that calling 8871 ** [sqlite3session_changeset()] on the session handle may still return a 8872 ** changeset that contains no changes. This can happen when a row in 8873 ** an attached table is modified and then later on the original values 8874 ** are restored. However, if this function returns non-zero, then it is 8875 ** guaranteed that a call to sqlite3session_changeset() will return a 8876 ** changeset containing zero changes. 8877 */ 8878 int sqlite3session_isempty(sqlite3_session *pSession); 8879 8880 /* 8881 ** CAPI3REF: Create An Iterator To Traverse A Changeset 8882 ** 8883 ** Create an iterator used to iterate through the contents of a changeset. 8884 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 8885 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 8886 ** SQLite error code is returned. 8887 ** 8888 ** The following functions can be used to advance and query a changeset 8889 ** iterator created by this function: 8890 ** 8891 ** <ul> 8892 ** <li> [sqlite3changeset_next()] 8893 ** <li> [sqlite3changeset_op()] 8894 ** <li> [sqlite3changeset_new()] 8895 ** <li> [sqlite3changeset_old()] 8896 ** </ul> 8897 ** 8898 ** It is the responsibility of the caller to eventually destroy the iterator 8899 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 8900 ** changeset (pChangeset) must remain valid until after the iterator is 8901 ** destroyed. 8902 ** 8903 ** Assuming the changeset blob was created by one of the 8904 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 8905 ** [sqlite3changeset_invert()] functions, all changes within the changeset 8906 ** that apply to a single table are grouped together. This means that when 8907 ** an application iterates through a changeset using an iterator created by 8908 ** this function, all changes that relate to a single table are visted 8909 ** consecutively. There is no chance that the iterator will visit a change 8910 ** the applies to table X, then one for table Y, and then later on visit 8911 ** another change for table X. 8912 */ 8913 int sqlite3changeset_start( 8914 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 8915 int nChangeset, /* Size of changeset blob in bytes */ 8916 void *pChangeset /* Pointer to blob containing changeset */ 8917 ); 8918 8919 8920 /* 8921 ** CAPI3REF: Advance A Changeset Iterator 8922 ** 8923 ** This function may only be used with iterators created by function 8924 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 8925 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 8926 ** is returned and the call has no effect. 8927 ** 8928 ** Immediately after an iterator is created by sqlite3changeset_start(), it 8929 ** does not point to any change in the changeset. Assuming the changeset 8930 ** is not empty, the first call to this function advances the iterator to 8931 ** point to the first change in the changeset. Each subsequent call advances 8932 ** the iterator to point to the next change in the changeset (if any). If 8933 ** no error occurs and the iterator points to a valid change after a call 8934 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 8935 ** Otherwise, if all changes in the changeset have already been visited, 8936 ** SQLITE_DONE is returned. 8937 ** 8938 ** If an error occurs, an SQLite error code is returned. Possible error 8939 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 8940 ** SQLITE_NOMEM. 8941 */ 8942 int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 8943 8944 /* 8945 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 8946 ** 8947 ** The pIter argument passed to this function may either be an iterator 8948 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 8949 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 8950 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 8951 ** is not the case, this function returns [SQLITE_MISUSE]. 8952 ** 8953 ** If argument pzTab is not NULL, then *pzTab is set to point to a 8954 ** nul-terminated utf-8 encoded string containing the name of the table 8955 ** affected by the current change. The buffer remains valid until either 8956 ** sqlite3changeset_next() is called on the iterator or until the 8957 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 8958 ** set to the number of columns in the table affected by the change. If 8959 ** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 8960 ** is an indirect change, or false (0) otherwise. See the documentation for 8961 ** [sqlite3session_indirect()] for a description of direct and indirect 8962 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 8963 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 8964 ** type of change that the iterator currently points to. 8965 ** 8966 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 8967 ** SQLite error code is returned. The values of the output variables may not 8968 ** be trusted in this case. 8969 */ 8970 int sqlite3changeset_op( 8971 sqlite3_changeset_iter *pIter, /* Iterator object */ 8972 const char **pzTab, /* OUT: Pointer to table name */ 8973 int *pnCol, /* OUT: Number of columns in table */ 8974 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 8975 int *pbIndirect /* OUT: True for an 'indirect' change */ 8976 ); 8977 8978 /* 8979 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 8980 ** 8981 ** For each modified table, a changeset includes the following: 8982 ** 8983 ** <ul> 8984 ** <li> The number of columns in the table, and 8985 ** <li> Which of those columns make up the tables PRIMARY KEY. 8986 ** </ul> 8987 ** 8988 ** This function is used to find which columns comprise the PRIMARY KEY of 8989 ** the table modified by the change that iterator pIter currently points to. 8990 ** If successful, *pabPK is set to point to an array of nCol entries, where 8991 ** nCol is the number of columns in the table. Elements of *pabPK are set to 8992 ** 0x01 if the corresponding column is part of the tables primary key, or 8993 ** 0x00 if it is not. 8994 ** 8995 ** If argumet pnCol is not NULL, then *pnCol is set to the number of columns 8996 ** in the table. 8997 ** 8998 ** If this function is called when the iterator does not point to a valid 8999 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 9000 ** SQLITE_OK is returned and the output variables populated as described 9001 ** above. 9002 */ 9003 int sqlite3changeset_pk( 9004 sqlite3_changeset_iter *pIter, /* Iterator object */ 9005 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 9006 int *pnCol /* OUT: Number of entries in output array */ 9007 ); 9008 9009 /* 9010 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 9011 ** 9012 ** The pIter argument passed to this function may either be an iterator 9013 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9014 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9015 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9016 ** Furthermore, it may only be called if the type of change that the iterator 9017 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 9018 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9019 ** 9020 ** Argument iVal must be greater than or equal to 0, and less than the number 9021 ** of columns in the table affected by the current change. Otherwise, 9022 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9023 ** 9024 ** If successful, this function sets *ppValue to point to a protected 9025 ** sqlite3_value object containing the iVal'th value from the vector of 9026 ** original row values stored as part of the UPDATE or DELETE change and 9027 ** returns SQLITE_OK. The name of the function comes from the fact that this 9028 ** is similar to the "old.*" columns available to update or delete triggers. 9029 ** 9030 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9031 ** is returned and *ppValue is set to NULL. 9032 */ 9033 int sqlite3changeset_old( 9034 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9035 int iVal, /* Column number */ 9036 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 9037 ); 9038 9039 /* 9040 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 9041 ** 9042 ** The pIter argument passed to this function may either be an iterator 9043 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9044 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9045 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9046 ** Furthermore, it may only be called if the type of change that the iterator 9047 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 9048 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9049 ** 9050 ** Argument iVal must be greater than or equal to 0, and less than the number 9051 ** of columns in the table affected by the current change. Otherwise, 9052 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9053 ** 9054 ** If successful, this function sets *ppValue to point to a protected 9055 ** sqlite3_value object containing the iVal'th value from the vector of 9056 ** new row values stored as part of the UPDATE or INSERT change and 9057 ** returns SQLITE_OK. If the change is an UPDATE and does not include 9058 ** a new value for the requested column, *ppValue is set to NULL and 9059 ** SQLITE_OK returned. The name of the function comes from the fact that 9060 ** this is similar to the "new.*" columns available to update or delete 9061 ** triggers. 9062 ** 9063 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9064 ** is returned and *ppValue is set to NULL. 9065 */ 9066 int sqlite3changeset_new( 9067 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9068 int iVal, /* Column number */ 9069 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 9070 ); 9071 9072 /* 9073 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 9074 ** 9075 ** This function should only be used with iterator objects passed to a 9076 ** conflict-handler callback by [sqlite3changeset_apply()] with either 9077 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 9078 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 9079 ** is set to NULL. 9080 ** 9081 ** Argument iVal must be greater than or equal to 0, and less than the number 9082 ** of columns in the table affected by the current change. Otherwise, 9083 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9084 ** 9085 ** If successful, this function sets *ppValue to point to a protected 9086 ** sqlite3_value object containing the iVal'th value from the 9087 ** "conflicting row" associated with the current conflict-handler callback 9088 ** and returns SQLITE_OK. 9089 ** 9090 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9091 ** is returned and *ppValue is set to NULL. 9092 */ 9093 int sqlite3changeset_conflict( 9094 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9095 int iVal, /* Column number */ 9096 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 9097 ); 9098 9099 /* 9100 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 9101 ** 9102 ** This function may only be called with an iterator passed to an 9103 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 9104 ** it sets the output variable to the total number of known foreign key 9105 ** violations in the destination database and returns SQLITE_OK. 9106 ** 9107 ** In all other cases this function returns SQLITE_MISUSE. 9108 */ 9109 int sqlite3changeset_fk_conflicts( 9110 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9111 int *pnOut /* OUT: Number of FK violations */ 9112 ); 9113 9114 9115 /* 9116 ** CAPI3REF: Finalize A Changeset Iterator 9117 ** 9118 ** This function is used to finalize an iterator allocated with 9119 ** [sqlite3changeset_start()]. 9120 ** 9121 ** This function should only be called on iterators created using the 9122 ** [sqlite3changeset_start()] function. If an application calls this 9123 ** function with an iterator passed to a conflict-handler by 9124 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 9125 ** call has no effect. 9126 ** 9127 ** If an error was encountered within a call to an sqlite3changeset_xxx() 9128 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 9129 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 9130 ** to that error is returned by this function. Otherwise, SQLITE_OK is 9131 ** returned. This is to allow the following pattern (pseudo-code): 9132 ** 9133 ** sqlite3changeset_start(); 9134 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 9135 ** // Do something with change. 9136 ** } 9137 ** rc = sqlite3changeset_finalize(); 9138 ** if( rc!=SQLITE_OK ){ 9139 ** // An error has occurred 9140 ** } 9141 */ 9142 int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 9143 9144 /* 9145 ** CAPI3REF: Invert A Changeset 9146 ** 9147 ** This function is used to "invert" a changeset object. Applying an inverted 9148 ** changeset to a database reverses the effects of applying the uninverted 9149 ** changeset. Specifically: 9150 ** 9151 ** <ul> 9152 ** <li> Each DELETE change is changed to an INSERT, and 9153 ** <li> Each INSERT change is changed to a DELETE, and 9154 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 9155 ** </ul> 9156 ** 9157 ** This function does not change the order in which changes appear within 9158 ** the changeset. It merely reverses the sense of each individual change. 9159 ** 9160 ** If successful, a pointer to a buffer containing the inverted changeset 9161 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 9162 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 9163 ** zeroed and an SQLite error code returned. 9164 ** 9165 ** It is the responsibility of the caller to eventually call sqlite3_free() 9166 ** on the *ppOut pointer to free the buffer allocation following a successful 9167 ** call to this function. 9168 ** 9169 ** WARNING/TODO: This function currently assumes that the input is a valid 9170 ** changeset. If it is not, the results are undefined. 9171 */ 9172 int sqlite3changeset_invert( 9173 int nIn, const void *pIn, /* Input changeset */ 9174 int *pnOut, void **ppOut /* OUT: Inverse of input */ 9175 ); 9176 9177 /* 9178 ** CAPI3REF: Concatenate Two Changeset Objects 9179 ** 9180 ** This function is used to concatenate two changesets, A and B, into a 9181 ** single changeset. The result is a changeset equivalent to applying 9182 ** changeset A followed by changeset B. 9183 ** 9184 ** This function combines the two input changesets using an 9185 ** sqlite3_changegroup object. Calling it produces similar results as the 9186 ** following code fragment: 9187 ** 9188 ** sqlite3_changegroup *pGrp; 9189 ** rc = sqlite3_changegroup_new(&pGrp); 9190 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 9191 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 9192 ** if( rc==SQLITE_OK ){ 9193 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 9194 ** }else{ 9195 ** *ppOut = 0; 9196 ** *pnOut = 0; 9197 ** } 9198 ** 9199 ** Refer to the sqlite3_changegroup documentation below for details. 9200 */ 9201 int sqlite3changeset_concat( 9202 int nA, /* Number of bytes in buffer pA */ 9203 void *pA, /* Pointer to buffer containing changeset A */ 9204 int nB, /* Number of bytes in buffer pB */ 9205 void *pB, /* Pointer to buffer containing changeset B */ 9206 int *pnOut, /* OUT: Number of bytes in output changeset */ 9207 void **ppOut /* OUT: Buffer containing output changeset */ 9208 ); 9209 9210 9211 /* 9212 ** Changegroup handle. 9213 */ 9214 typedef struct sqlite3_changegroup sqlite3_changegroup; 9215 9216 /* 9217 ** CAPI3REF: Combine two or more changesets into a single changeset. 9218 ** 9219 ** An sqlite3_changegroup object is used to combine two or more changesets 9220 ** (or patchsets) into a single changeset (or patchset). A single changegroup 9221 ** object may combine changesets or patchsets, but not both. The output is 9222 ** always in the same format as the input. 9223 ** 9224 ** If successful, this function returns SQLITE_OK and populates (*pp) with 9225 ** a pointer to a new sqlite3_changegroup object before returning. The caller 9226 ** should eventually free the returned object using a call to 9227 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 9228 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 9229 ** 9230 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 9231 ** 9232 ** <ul> 9233 ** <li> It is created using a call to sqlite3changegroup_new(). 9234 ** 9235 ** <li> Zero or more changesets (or patchsets) are added to the object 9236 ** by calling sqlite3changegroup_add(). 9237 ** 9238 ** <li> The result of combining all input changesets together is obtained 9239 ** by the application via a call to sqlite3changegroup_output(). 9240 ** 9241 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 9242 ** </ul> 9243 ** 9244 ** Any number of calls to add() and output() may be made between the calls to 9245 ** new() and delete(), and in any order. 9246 ** 9247 ** As well as the regular sqlite3changegroup_add() and 9248 ** sqlite3changegroup_output() functions, also available are the streaming 9249 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 9250 */ 9251 int sqlite3changegroup_new(sqlite3_changegroup **pp); 9252 9253 /* 9254 ** Add all changes within the changeset (or patchset) in buffer pData (size 9255 ** nData bytes) to the changegroup. 9256 ** 9257 ** If the buffer contains a patchset, then all prior calls to this function 9258 ** on the same changegroup object must also have specified patchsets. Or, if 9259 ** the buffer contains a changeset, so must have the earlier calls to this 9260 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 9261 ** to the changegroup. 9262 ** 9263 ** Rows within the changeset and changegroup are identified by the values in 9264 ** their PRIMARY KEY columns. A change in the changeset is considered to 9265 ** apply to the same row as a change already present in the changegroup if 9266 ** the two rows have the same primary key. 9267 ** 9268 ** Changes to rows that that do not already appear in the changegroup are 9269 ** simply copied into it. Or, if both the new changeset and the changegroup 9270 ** contain changes that apply to a single row, the final contents of the 9271 ** changegroup depends on the type of each change, as follows: 9272 ** 9273 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9274 ** <tr><th style="white-space:pre">Existing Change </th> 9275 ** <th style="white-space:pre">New Change </th> 9276 ** <th>Output Change 9277 ** <tr><td>INSERT <td>INSERT <td> 9278 ** The new change is ignored. This case does not occur if the new 9279 ** changeset was recorded immediately after the changesets already 9280 ** added to the changegroup. 9281 ** <tr><td>INSERT <td>UPDATE <td> 9282 ** The INSERT change remains in the changegroup. The values in the 9283 ** INSERT change are modified as if the row was inserted by the 9284 ** existing change and then updated according to the new change. 9285 ** <tr><td>INSERT <td>DELETE <td> 9286 ** The existing INSERT is removed from the changegroup. The DELETE is 9287 ** not added. 9288 ** <tr><td>UPDATE <td>INSERT <td> 9289 ** The new change is ignored. This case does not occur if the new 9290 ** changeset was recorded immediately after the changesets already 9291 ** added to the changegroup. 9292 ** <tr><td>UPDATE <td>UPDATE <td> 9293 ** The existing UPDATE remains within the changegroup. It is amended 9294 ** so that the accompanying values are as if the row was updated once 9295 ** by the existing change and then again by the new change. 9296 ** <tr><td>UPDATE <td>DELETE <td> 9297 ** The existing UPDATE is replaced by the new DELETE within the 9298 ** changegroup. 9299 ** <tr><td>DELETE <td>INSERT <td> 9300 ** If one or more of the column values in the row inserted by the 9301 ** new change differ from those in the row deleted by the existing 9302 ** change, the existing DELETE is replaced by an UPDATE within the 9303 ** changegroup. Otherwise, if the inserted row is exactly the same 9304 ** as the deleted row, the existing DELETE is simply discarded. 9305 ** <tr><td>DELETE <td>UPDATE <td> 9306 ** The new change is ignored. This case does not occur if the new 9307 ** changeset was recorded immediately after the changesets already 9308 ** added to the changegroup. 9309 ** <tr><td>DELETE <td>DELETE <td> 9310 ** The new change is ignored. This case does not occur if the new 9311 ** changeset was recorded immediately after the changesets already 9312 ** added to the changegroup. 9313 ** </table> 9314 ** 9315 ** If the new changeset contains changes to a table that is already present 9316 ** in the changegroup, then the number of columns and the position of the 9317 ** primary key columns for the table must be consistent. If this is not the 9318 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 9319 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 9320 ** returned. Or, if an out-of-memory condition occurs during processing, this 9321 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the 9322 ** final contents of the changegroup is undefined. 9323 ** 9324 ** If no error occurs, SQLITE_OK is returned. 9325 */ 9326 int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 9327 9328 /* 9329 ** Obtain a buffer containing a changeset (or patchset) representing the 9330 ** current contents of the changegroup. If the inputs to the changegroup 9331 ** were themselves changesets, the output is a changeset. Or, if the 9332 ** inputs were patchsets, the output is also a patchset. 9333 ** 9334 ** As with the output of the sqlite3session_changeset() and 9335 ** sqlite3session_patchset() functions, all changes related to a single 9336 ** table are grouped together in the output of this function. Tables appear 9337 ** in the same order as for the very first changeset added to the changegroup. 9338 ** If the second or subsequent changesets added to the changegroup contain 9339 ** changes for tables that do not appear in the first changeset, they are 9340 ** appended onto the end of the output changeset, again in the order in 9341 ** which they are first encountered. 9342 ** 9343 ** If an error occurs, an SQLite error code is returned and the output 9344 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 9345 ** is returned and the output variables are set to the size of and a 9346 ** pointer to the output buffer, respectively. In this case it is the 9347 ** responsibility of the caller to eventually free the buffer using a 9348 ** call to sqlite3_free(). 9349 */ 9350 int sqlite3changegroup_output( 9351 sqlite3_changegroup*, 9352 int *pnData, /* OUT: Size of output buffer in bytes */ 9353 void **ppData /* OUT: Pointer to output buffer */ 9354 ); 9355 9356 /* 9357 ** Delete a changegroup object. 9358 */ 9359 void sqlite3changegroup_delete(sqlite3_changegroup*); 9360 9361 /* 9362 ** CAPI3REF: Apply A Changeset To A Database 9363 ** 9364 ** Apply a changeset to a database. This function attempts to update the 9365 ** "main" database attached to handle db with the changes found in the 9366 ** changeset passed via the second and third arguments. 9367 ** 9368 ** The fourth argument (xFilter) passed to this function is the "filter 9369 ** callback". If it is not NULL, then for each table affected by at least one 9370 ** change in the changeset, the filter callback is invoked with 9371 ** the table name as the second argument, and a copy of the context pointer 9372 ** passed as the sixth argument to this function as the first. If the "filter 9373 ** callback" returns zero, then no attempt is made to apply any changes to 9374 ** the table. Otherwise, if the return value is non-zero or the xFilter 9375 ** argument to this function is NULL, all changes related to the table are 9376 ** attempted. 9377 ** 9378 ** For each table that is not excluded by the filter callback, this function 9379 ** tests that the target database contains a compatible table. A table is 9380 ** considered compatible if all of the following are true: 9381 ** 9382 ** <ul> 9383 ** <li> The table has the same name as the name recorded in the 9384 ** changeset, and 9385 ** <li> The table has the same number of columns as recorded in the 9386 ** changeset, and 9387 ** <li> The table has primary key columns in the same position as 9388 ** recorded in the changeset. 9389 ** </ul> 9390 ** 9391 ** If there is no compatible table, it is not an error, but none of the 9392 ** changes associated with the table are applied. A warning message is issued 9393 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 9394 ** one such warning is issued for each table in the changeset. 9395 ** 9396 ** For each change for which there is a compatible table, an attempt is made 9397 ** to modify the table contents according to the UPDATE, INSERT or DELETE 9398 ** change. If a change cannot be applied cleanly, the conflict handler 9399 ** function passed as the fifth argument to sqlite3changeset_apply() may be 9400 ** invoked. A description of exactly when the conflict handler is invoked for 9401 ** each type of change is below. 9402 ** 9403 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 9404 ** of passing anything other than a valid function pointer as the xConflict 9405 ** argument are undefined. 9406 ** 9407 ** Each time the conflict handler function is invoked, it must return one 9408 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 9409 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 9410 ** if the second argument passed to the conflict handler is either 9411 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 9412 ** returns an illegal value, any changes already made are rolled back and 9413 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 9414 ** actions are taken by sqlite3changeset_apply() depending on the value 9415 ** returned by each invocation of the conflict-handler function. Refer to 9416 ** the documentation for the three 9417 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 9418 ** 9419 ** <dl> 9420 ** <dt>DELETE Changes<dd> 9421 ** For each DELETE change, this function checks if the target database 9422 ** contains a row with the same primary key value (or values) as the 9423 ** original row values stored in the changeset. If it does, and the values 9424 ** stored in all non-primary key columns also match the values stored in 9425 ** the changeset the row is deleted from the target database. 9426 ** 9427 ** If a row with matching primary key values is found, but one or more of 9428 ** the non-primary key fields contains a value different from the original 9429 ** row value stored in the changeset, the conflict-handler function is 9430 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. 9431 ** 9432 ** If no row with matching primary key values is found in the database, 9433 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9434 ** passed as the second argument. 9435 ** 9436 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 9437 ** (which can only happen if a foreign key constraint is violated), the 9438 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 9439 ** passed as the second argument. This includes the case where the DELETE 9440 ** operation is attempted because an earlier call to the conflict handler 9441 ** function returned [SQLITE_CHANGESET_REPLACE]. 9442 ** 9443 ** <dt>INSERT Changes<dd> 9444 ** For each INSERT change, an attempt is made to insert the new row into 9445 ** the database. 9446 ** 9447 ** If the attempt to insert the row fails because the database already 9448 ** contains a row with the same primary key values, the conflict handler 9449 ** function is invoked with the second argument set to 9450 ** [SQLITE_CHANGESET_CONFLICT]. 9451 ** 9452 ** If the attempt to insert the row fails because of some other constraint 9453 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 9454 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 9455 ** This includes the case where the INSERT operation is re-attempted because 9456 ** an earlier call to the conflict handler function returned 9457 ** [SQLITE_CHANGESET_REPLACE]. 9458 ** 9459 ** <dt>UPDATE Changes<dd> 9460 ** For each UPDATE change, this function checks if the target database 9461 ** contains a row with the same primary key value (or values) as the 9462 ** original row values stored in the changeset. If it does, and the values 9463 ** stored in all non-primary key columns also match the values stored in 9464 ** the changeset the row is updated within the target database. 9465 ** 9466 ** If a row with matching primary key values is found, but one or more of 9467 ** the non-primary key fields contains a value different from an original 9468 ** row value stored in the changeset, the conflict-handler function is 9469 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 9470 ** UPDATE changes only contain values for non-primary key fields that are 9471 ** to be modified, only those fields need to match the original values to 9472 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 9473 ** 9474 ** If no row with matching primary key values is found in the database, 9475 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9476 ** passed as the second argument. 9477 ** 9478 ** If the UPDATE operation is attempted, but SQLite returns 9479 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 9480 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 9481 ** This includes the case where the UPDATE operation is attempted after 9482 ** an earlier call to the conflict handler function returned 9483 ** [SQLITE_CHANGESET_REPLACE]. 9484 ** </dl> 9485 ** 9486 ** It is safe to execute SQL statements, including those that write to the 9487 ** table that the callback related to, from within the xConflict callback. 9488 ** This can be used to further customize the applications conflict 9489 ** resolution strategy. 9490 ** 9491 ** All changes made by this function are enclosed in a savepoint transaction. 9492 ** If any other error (aside from a constraint failure when attempting to 9493 ** write to the target database) occurs, then the savepoint transaction is 9494 ** rolled back, restoring the target database to its original state, and an 9495 ** SQLite error code returned. 9496 */ 9497 int sqlite3changeset_apply( 9498 sqlite3 *db, /* Apply change to "main" db of this handle */ 9499 int nChangeset, /* Size of changeset in bytes */ 9500 void *pChangeset, /* Changeset blob */ 9501 int(*xFilter)( 9502 void *pCtx, /* Copy of sixth arg to _apply() */ 9503 const char *zTab /* Table name */ 9504 ), 9505 int(*xConflict)( 9506 void *pCtx, /* Copy of sixth arg to _apply() */ 9507 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9508 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9509 ), 9510 void *pCtx /* First argument passed to xConflict */ 9511 ); 9512 9513 /* 9514 ** CAPI3REF: Constants Passed To The Conflict Handler 9515 ** 9516 ** Values that may be passed as the second argument to a conflict-handler. 9517 ** 9518 ** <dl> 9519 ** <dt>SQLITE_CHANGESET_DATA<dd> 9520 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 9521 ** when processing a DELETE or UPDATE change if a row with the required 9522 ** PRIMARY KEY fields is present in the database, but one or more other 9523 ** (non primary-key) fields modified by the update do not contain the 9524 ** expected "before" values. 9525 ** 9526 ** The conflicting row, in this case, is the database row with the matching 9527 ** primary key. 9528 ** 9529 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 9530 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 9531 ** argument when processing a DELETE or UPDATE change if a row with the 9532 ** required PRIMARY KEY fields is not present in the database. 9533 ** 9534 ** There is no conflicting row in this case. The results of invoking the 9535 ** sqlite3changeset_conflict() API are undefined. 9536 ** 9537 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 9538 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 9539 ** handler while processing an INSERT change if the operation would result 9540 ** in duplicate primary key values. 9541 ** 9542 ** The conflicting row in this case is the database row with the matching 9543 ** primary key. 9544 ** 9545 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 9546 ** If foreign key handling is enabled, and applying a changeset leaves the 9547 ** database in a state containing foreign key violations, the conflict 9548 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 9549 ** exactly once before the changeset is committed. If the conflict handler 9550 ** returns CHANGESET_OMIT, the changes, including those that caused the 9551 ** foreign key constraint violation, are committed. Or, if it returns 9552 ** CHANGESET_ABORT, the changeset is rolled back. 9553 ** 9554 ** No current or conflicting row information is provided. The only function 9555 ** it is possible to call on the supplied sqlite3_changeset_iter handle 9556 ** is sqlite3changeset_fk_conflicts(). 9557 ** 9558 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 9559 ** If any other constraint violation occurs while applying a change (i.e. 9560 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 9561 ** invoked with CHANGESET_CONSTRAINT as the second argument. 9562 ** 9563 ** There is no conflicting row in this case. The results of invoking the 9564 ** sqlite3changeset_conflict() API are undefined. 9565 ** 9566 ** </dl> 9567 */ 9568 #define SQLITE_CHANGESET_DATA 1 9569 #define SQLITE_CHANGESET_NOTFOUND 2 9570 #define SQLITE_CHANGESET_CONFLICT 3 9571 #define SQLITE_CHANGESET_CONSTRAINT 4 9572 #define SQLITE_CHANGESET_FOREIGN_KEY 5 9573 9574 /* 9575 ** CAPI3REF: Constants Returned By The Conflict Handler 9576 ** 9577 ** A conflict handler callback must return one of the following three values. 9578 ** 9579 ** <dl> 9580 ** <dt>SQLITE_CHANGESET_OMIT<dd> 9581 ** If a conflict handler returns this value no special action is taken. The 9582 ** change that caused the conflict is not applied. The session module 9583 ** continues to the next change in the changeset. 9584 ** 9585 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 9586 ** This value may only be returned if the second argument to the conflict 9587 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 9588 ** is not the case, any changes applied so far are rolled back and the 9589 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 9590 ** 9591 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 9592 ** handler, then the conflicting row is either updated or deleted, depending 9593 ** on the type of change. 9594 ** 9595 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 9596 ** handler, then the conflicting row is removed from the database and a 9597 ** second attempt to apply the change is made. If this second attempt fails, 9598 ** the original row is restored to the database before continuing. 9599 ** 9600 ** <dt>SQLITE_CHANGESET_ABORT<dd> 9601 ** If this value is returned, any changes applied so far are rolled back 9602 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 9603 ** </dl> 9604 */ 9605 #define SQLITE_CHANGESET_OMIT 0 9606 #define SQLITE_CHANGESET_REPLACE 1 9607 #define SQLITE_CHANGESET_ABORT 2 9608 9609 /* 9610 ** CAPI3REF: Streaming Versions of API functions. 9611 ** 9612 ** The six streaming API xxx_strm() functions serve similar purposes to the 9613 ** corresponding non-streaming API functions: 9614 ** 9615 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9616 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 9617 ** <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply] 9618 ** <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat] 9619 ** <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert] 9620 ** <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start] 9621 ** <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset] 9622 ** <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset] 9623 ** </table> 9624 ** 9625 ** Non-streaming functions that accept changesets (or patchsets) as input 9626 ** require that the entire changeset be stored in a single buffer in memory. 9627 ** Similarly, those that return a changeset or patchset do so by returning 9628 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 9629 ** Normally this is convenient. However, if an application running in a 9630 ** low-memory environment is required to handle very large changesets, the 9631 ** large contiguous memory allocations required can become onerous. 9632 ** 9633 ** In order to avoid this problem, instead of a single large buffer, input 9634 ** is passed to a streaming API functions by way of a callback function that 9635 ** the sessions module invokes to incrementally request input data as it is 9636 ** required. In all cases, a pair of API function parameters such as 9637 ** 9638 ** <pre> 9639 ** int nChangeset, 9640 ** void *pChangeset, 9641 ** </pre> 9642 ** 9643 ** Is replaced by: 9644 ** 9645 ** <pre> 9646 ** int (*xInput)(void *pIn, void *pData, int *pnData), 9647 ** void *pIn, 9648 ** </pre> 9649 ** 9650 ** Each time the xInput callback is invoked by the sessions module, the first 9651 ** argument passed is a copy of the supplied pIn context pointer. The second 9652 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 9653 ** error occurs the xInput method should copy up to (*pnData) bytes of data 9654 ** into the buffer and set (*pnData) to the actual number of bytes copied 9655 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 9656 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 9657 ** error code should be returned. In all cases, if an xInput callback returns 9658 ** an error, all processing is abandoned and the streaming API function 9659 ** returns a copy of the error code to the caller. 9660 ** 9661 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 9662 ** invoked by the sessions module at any point during the lifetime of the 9663 ** iterator. If such an xInput callback returns an error, the iterator enters 9664 ** an error state, whereby all subsequent calls to iterator functions 9665 ** immediately fail with the same error code as returned by xInput. 9666 ** 9667 ** Similarly, streaming API functions that return changesets (or patchsets) 9668 ** return them in chunks by way of a callback function instead of via a 9669 ** pointer to a single large buffer. In this case, a pair of parameters such 9670 ** as: 9671 ** 9672 ** <pre> 9673 ** int *pnChangeset, 9674 ** void **ppChangeset, 9675 ** </pre> 9676 ** 9677 ** Is replaced by: 9678 ** 9679 ** <pre> 9680 ** int (*xOutput)(void *pOut, const void *pData, int nData), 9681 ** void *pOut 9682 ** </pre> 9683 ** 9684 ** The xOutput callback is invoked zero or more times to return data to 9685 ** the application. The first parameter passed to each call is a copy of the 9686 ** pOut pointer supplied by the application. The second parameter, pData, 9687 ** points to a buffer nData bytes in size containing the chunk of output 9688 ** data being returned. If the xOutput callback successfully processes the 9689 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 9690 ** it should return some other SQLite error code. In this case processing 9691 ** is immediately abandoned and the streaming API function returns a copy 9692 ** of the xOutput error code to the application. 9693 ** 9694 ** The sessions module never invokes an xOutput callback with the third 9695 ** parameter set to a value less than or equal to zero. Other than this, 9696 ** no guarantees are made as to the size of the chunks of data returned. 9697 */ 9698 int sqlite3changeset_apply_strm( 9699 sqlite3 *db, /* Apply change to "main" db of this handle */ 9700 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 9701 void *pIn, /* First arg for xInput */ 9702 int(*xFilter)( 9703 void *pCtx, /* Copy of sixth arg to _apply() */ 9704 const char *zTab /* Table name */ 9705 ), 9706 int(*xConflict)( 9707 void *pCtx, /* Copy of sixth arg to _apply() */ 9708 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9709 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9710 ), 9711 void *pCtx /* First argument passed to xConflict */ 9712 ); 9713 int sqlite3changeset_concat_strm( 9714 int (*xInputA)(void *pIn, void *pData, int *pnData), 9715 void *pInA, 9716 int (*xInputB)(void *pIn, void *pData, int *pnData), 9717 void *pInB, 9718 int (*xOutput)(void *pOut, const void *pData, int nData), 9719 void *pOut 9720 ); 9721 int sqlite3changeset_invert_strm( 9722 int (*xInput)(void *pIn, void *pData, int *pnData), 9723 void *pIn, 9724 int (*xOutput)(void *pOut, const void *pData, int nData), 9725 void *pOut 9726 ); 9727 int sqlite3changeset_start_strm( 9728 sqlite3_changeset_iter **pp, 9729 int (*xInput)(void *pIn, void *pData, int *pnData), 9730 void *pIn 9731 ); 9732 int sqlite3session_changeset_strm( 9733 sqlite3_session *pSession, 9734 int (*xOutput)(void *pOut, const void *pData, int nData), 9735 void *pOut 9736 ); 9737 int sqlite3session_patchset_strm( 9738 sqlite3_session *pSession, 9739 int (*xOutput)(void *pOut, const void *pData, int nData), 9740 void *pOut 9741 ); 9742 int sqlite3changegroup_add_strm(sqlite3_changegroup*, 9743 int (*xInput)(void *pIn, void *pData, int *pnData), 9744 void *pIn 9745 ); 9746 int sqlite3changegroup_output_strm(sqlite3_changegroup*, 9747 int (*xOutput)(void *pOut, const void *pData, int nData), 9748 void *pOut 9749 ); 9750 9751 9752 /* 9753 ** Make sure we can call this stuff from C++. 9754 */ 9755 #ifdef __cplusplus 9756 } 9757 #endif 9758 9759 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 9760 9761 /******** End of sqlite3session.h *********/ 9762 /******** Begin file fts5.h *********/ 9763 /* 9764 ** 2014 May 31 9765 ** 9766 ** The author disclaims copyright to this source code. In place of 9767 ** a legal notice, here is a blessing: 9768 ** 9769 ** May you do good and not evil. 9770 ** May you find forgiveness for yourself and forgive others. 9771 ** May you share freely, never taking more than you give. 9772 ** 9773 ****************************************************************************** 9774 ** 9775 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 9776 ** FTS5 may be extended with: 9777 ** 9778 ** * custom tokenizers, and 9779 ** * custom auxiliary functions. 9780 */ 9781 9782 9783 #ifndef _FTS5_H 9784 #define _FTS5_H 9785 9786 9787 #ifdef __cplusplus 9788 extern "C" { 9789 #endif 9790 9791 /************************************************************************* 9792 ** CUSTOM AUXILIARY FUNCTIONS 9793 ** 9794 ** Virtual table implementations may overload SQL functions by implementing 9795 ** the sqlite3_module.xFindFunction() method. 9796 */ 9797 9798 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 9799 typedef struct Fts5Context Fts5Context; 9800 typedef struct Fts5PhraseIter Fts5PhraseIter; 9801 9802 typedef void (*fts5_extension_function)( 9803 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 9804 Fts5Context *pFts, /* First arg to pass to pApi functions */ 9805 sqlite3_context *pCtx, /* Context for returning result/error */ 9806 int nVal, /* Number of values in apVal[] array */ 9807 sqlite3_value **apVal /* Array of trailing arguments */ 9808 ); 9809 9810 struct Fts5PhraseIter { 9811 const unsigned char *a; 9812 const unsigned char *b; 9813 }; 9814 9815 /* 9816 ** EXTENSION API FUNCTIONS 9817 ** 9818 ** xUserData(pFts): 9819 ** Return a copy of the context pointer the extension function was 9820 ** registered with. 9821 ** 9822 ** xColumnTotalSize(pFts, iCol, pnToken): 9823 ** If parameter iCol is less than zero, set output variable *pnToken 9824 ** to the total number of tokens in the FTS5 table. Or, if iCol is 9825 ** non-negative but less than the number of columns in the table, return 9826 ** the total number of tokens in column iCol, considering all rows in 9827 ** the FTS5 table. 9828 ** 9829 ** If parameter iCol is greater than or equal to the number of columns 9830 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9831 ** an OOM condition or IO error), an appropriate SQLite error code is 9832 ** returned. 9833 ** 9834 ** xColumnCount(pFts): 9835 ** Return the number of columns in the table. 9836 ** 9837 ** xColumnSize(pFts, iCol, pnToken): 9838 ** If parameter iCol is less than zero, set output variable *pnToken 9839 ** to the total number of tokens in the current row. Or, if iCol is 9840 ** non-negative but less than the number of columns in the table, set 9841 ** *pnToken to the number of tokens in column iCol of the current row. 9842 ** 9843 ** If parameter iCol is greater than or equal to the number of columns 9844 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9845 ** an OOM condition or IO error), an appropriate SQLite error code is 9846 ** returned. 9847 ** 9848 ** This function may be quite inefficient if used with an FTS5 table 9849 ** created with the "columnsize=0" option. 9850 ** 9851 ** xColumnText: 9852 ** This function attempts to retrieve the text of column iCol of the 9853 ** current document. If successful, (*pz) is set to point to a buffer 9854 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 9855 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 9856 ** if an error occurs, an SQLite error code is returned and the final values 9857 ** of (*pz) and (*pn) are undefined. 9858 ** 9859 ** xPhraseCount: 9860 ** Returns the number of phrases in the current query expression. 9861 ** 9862 ** xPhraseSize: 9863 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 9864 ** are numbered starting from zero. 9865 ** 9866 ** xInstCount: 9867 ** Set *pnInst to the total number of occurrences of all phrases within 9868 ** the query within the current row. Return SQLITE_OK if successful, or 9869 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 9870 ** 9871 ** This API can be quite slow if used with an FTS5 table created with the 9872 ** "detail=none" or "detail=column" option. If the FTS5 table is created 9873 ** with either "detail=none" or "detail=column" and "content=" option 9874 ** (i.e. if it is a contentless table), then this API always returns 0. 9875 ** 9876 ** xInst: 9877 ** Query for the details of phrase match iIdx within the current row. 9878 ** Phrase matches are numbered starting from zero, so the iIdx argument 9879 ** should be greater than or equal to zero and smaller than the value 9880 ** output by xInstCount(). 9881 ** 9882 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 9883 ** to the column in which it occurs and *piOff the token offset of the 9884 ** first token of the phrase. The exception is if the table was created 9885 ** with the offsets=0 option specified. In this case *piOff is always 9886 ** set to -1. 9887 ** 9888 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 9889 ** if an error occurs. 9890 ** 9891 ** This API can be quite slow if used with an FTS5 table created with the 9892 ** "detail=none" or "detail=column" option. 9893 ** 9894 ** xRowid: 9895 ** Returns the rowid of the current row. 9896 ** 9897 ** xTokenize: 9898 ** Tokenize text using the tokenizer belonging to the FTS5 table. 9899 ** 9900 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 9901 ** This API function is used to query the FTS table for phrase iPhrase 9902 ** of the current query. Specifically, a query equivalent to: 9903 ** 9904 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 9905 ** 9906 ** with $p set to a phrase equivalent to the phrase iPhrase of the 9907 ** current query is executed. Any column filter that applies to 9908 ** phrase iPhrase of the current query is included in $p. For each 9909 ** row visited, the callback function passed as the fourth argument 9910 ** is invoked. The context and API objects passed to the callback 9911 ** function may be used to access the properties of each matched row. 9912 ** Invoking Api.xUserData() returns a copy of the pointer passed as 9913 ** the third argument to pUserData. 9914 ** 9915 ** If the callback function returns any value other than SQLITE_OK, the 9916 ** query is abandoned and the xQueryPhrase function returns immediately. 9917 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 9918 ** Otherwise, the error code is propagated upwards. 9919 ** 9920 ** If the query runs to completion without incident, SQLITE_OK is returned. 9921 ** Or, if some error occurs before the query completes or is aborted by 9922 ** the callback, an SQLite error code is returned. 9923 ** 9924 ** 9925 ** xSetAuxdata(pFts5, pAux, xDelete) 9926 ** 9927 ** Save the pointer passed as the second argument as the extension functions 9928 ** "auxiliary data". The pointer may then be retrieved by the current or any 9929 ** future invocation of the same fts5 extension function made as part of 9930 ** of the same MATCH query using the xGetAuxdata() API. 9931 ** 9932 ** Each extension function is allocated a single auxiliary data slot for 9933 ** each FTS query (MATCH expression). If the extension function is invoked 9934 ** more than once for a single FTS query, then all invocations share a 9935 ** single auxiliary data context. 9936 ** 9937 ** If there is already an auxiliary data pointer when this function is 9938 ** invoked, then it is replaced by the new pointer. If an xDelete callback 9939 ** was specified along with the original pointer, it is invoked at this 9940 ** point. 9941 ** 9942 ** The xDelete callback, if one is specified, is also invoked on the 9943 ** auxiliary data pointer after the FTS5 query has finished. 9944 ** 9945 ** If an error (e.g. an OOM condition) occurs within this function, an 9946 ** the auxiliary data is set to NULL and an error code returned. If the 9947 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 9948 ** pointer before returning. 9949 ** 9950 ** 9951 ** xGetAuxdata(pFts5, bClear) 9952 ** 9953 ** Returns the current auxiliary data pointer for the fts5 extension 9954 ** function. See the xSetAuxdata() method for details. 9955 ** 9956 ** If the bClear argument is non-zero, then the auxiliary data is cleared 9957 ** (set to NULL) before this function returns. In this case the xDelete, 9958 ** if any, is not invoked. 9959 ** 9960 ** 9961 ** xRowCount(pFts5, pnRow) 9962 ** 9963 ** This function is used to retrieve the total number of rows in the table. 9964 ** In other words, the same value that would be returned by: 9965 ** 9966 ** SELECT count(*) FROM ftstable; 9967 ** 9968 ** xPhraseFirst() 9969 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 9970 ** method, to iterate through all instances of a single query phrase within 9971 ** the current row. This is the same information as is accessible via the 9972 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 9973 ** to use, this API may be faster under some circumstances. To iterate 9974 ** through instances of phrase iPhrase, use the following code: 9975 ** 9976 ** Fts5PhraseIter iter; 9977 ** int iCol, iOff; 9978 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 9979 ** iCol>=0; 9980 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 9981 ** ){ 9982 ** // An instance of phrase iPhrase at offset iOff of column iCol 9983 ** } 9984 ** 9985 ** The Fts5PhraseIter structure is defined above. Applications should not 9986 ** modify this structure directly - it should only be used as shown above 9987 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 9988 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 9989 ** 9990 ** This API can be quite slow if used with an FTS5 table created with the 9991 ** "detail=none" or "detail=column" option. If the FTS5 table is created 9992 ** with either "detail=none" or "detail=column" and "content=" option 9993 ** (i.e. if it is a contentless table), then this API always iterates 9994 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 9995 ** 9996 ** xPhraseNext() 9997 ** See xPhraseFirst above. 9998 ** 9999 ** xPhraseFirstColumn() 10000 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 10001 ** and xPhraseNext() APIs described above. The difference is that instead 10002 ** of iterating through all instances of a phrase in the current row, these 10003 ** APIs are used to iterate through the set of columns in the current row 10004 ** that contain one or more instances of a specified phrase. For example: 10005 ** 10006 ** Fts5PhraseIter iter; 10007 ** int iCol; 10008 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 10009 ** iCol>=0; 10010 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 10011 ** ){ 10012 ** // Column iCol contains at least one instance of phrase iPhrase 10013 ** } 10014 ** 10015 ** This API can be quite slow if used with an FTS5 table created with the 10016 ** "detail=none" option. If the FTS5 table is created with either 10017 ** "detail=none" "content=" option (i.e. if it is a contentless table), 10018 ** then this API always iterates through an empty set (all calls to 10019 ** xPhraseFirstColumn() set iCol to -1). 10020 ** 10021 ** The information accessed using this API and its companion 10022 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 10023 ** (or xInst/xInstCount). The chief advantage of this API is that it is 10024 ** significantly more efficient than those alternatives when used with 10025 ** "detail=column" tables. 10026 ** 10027 ** xPhraseNextColumn() 10028 ** See xPhraseFirstColumn above. 10029 */ 10030 struct Fts5ExtensionApi { 10031 int iVersion; /* Currently always set to 3 */ 10032 10033 void *(*xUserData)(Fts5Context*); 10034 10035 int (*xColumnCount)(Fts5Context*); 10036 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 10037 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 10038 10039 int (*xTokenize)(Fts5Context*, 10040 const char *pText, int nText, /* Text to tokenize */ 10041 void *pCtx, /* Context passed to xToken() */ 10042 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 10043 ); 10044 10045 int (*xPhraseCount)(Fts5Context*); 10046 int (*xPhraseSize)(Fts5Context*, int iPhrase); 10047 10048 int (*xInstCount)(Fts5Context*, int *pnInst); 10049 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 10050 10051 sqlite3_int64 (*xRowid)(Fts5Context*); 10052 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 10053 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 10054 10055 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 10056 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 10057 ); 10058 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 10059 void *(*xGetAuxdata)(Fts5Context*, int bClear); 10060 10061 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 10062 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 10063 10064 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 10065 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 10066 }; 10067 10068 /* 10069 ** CUSTOM AUXILIARY FUNCTIONS 10070 *************************************************************************/ 10071 10072 /************************************************************************* 10073 ** CUSTOM TOKENIZERS 10074 ** 10075 ** Applications may also register custom tokenizer types. A tokenizer 10076 ** is registered by providing fts5 with a populated instance of the 10077 ** following structure. All structure methods must be defined, setting 10078 ** any member of the fts5_tokenizer struct to NULL leads to undefined 10079 ** behaviour. The structure methods are expected to function as follows: 10080 ** 10081 ** xCreate: 10082 ** This function is used to allocate and initialize a tokenizer instance. 10083 ** A tokenizer instance is required to actually tokenize text. 10084 ** 10085 ** The first argument passed to this function is a copy of the (void*) 10086 ** pointer provided by the application when the fts5_tokenizer object 10087 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 10088 ** The second and third arguments are an array of nul-terminated strings 10089 ** containing the tokenizer arguments, if any, specified following the 10090 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 10091 ** to create the FTS5 table. 10092 ** 10093 ** The final argument is an output variable. If successful, (*ppOut) 10094 ** should be set to point to the new tokenizer handle and SQLITE_OK 10095 ** returned. If an error occurs, some value other than SQLITE_OK should 10096 ** be returned. In this case, fts5 assumes that the final value of *ppOut 10097 ** is undefined. 10098 ** 10099 ** xDelete: 10100 ** This function is invoked to delete a tokenizer handle previously 10101 ** allocated using xCreate(). Fts5 guarantees that this function will 10102 ** be invoked exactly once for each successful call to xCreate(). 10103 ** 10104 ** xTokenize: 10105 ** This function is expected to tokenize the nText byte string indicated 10106 ** by argument pText. pText may or may not be nul-terminated. The first 10107 ** argument passed to this function is a pointer to an Fts5Tokenizer object 10108 ** returned by an earlier call to xCreate(). 10109 ** 10110 ** The second argument indicates the reason that FTS5 is requesting 10111 ** tokenization of the supplied text. This is always one of the following 10112 ** four values: 10113 ** 10114 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 10115 ** or removed from the FTS table. The tokenizer is being invoked to 10116 ** determine the set of tokens to add to (or delete from) the 10117 ** FTS index. 10118 ** 10119 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 10120 ** against the FTS index. The tokenizer is being called to tokenize 10121 ** a bareword or quoted string specified as part of the query. 10122 ** 10123 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 10124 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 10125 ** followed by a "*" character, indicating that the last token 10126 ** returned by the tokenizer will be treated as a token prefix. 10127 ** 10128 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 10129 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 10130 ** function. Or an fts5_api.xColumnSize() request made by the same 10131 ** on a columnsize=0 database. 10132 ** </ul> 10133 ** 10134 ** For each token in the input string, the supplied callback xToken() must 10135 ** be invoked. The first argument to it should be a copy of the pointer 10136 ** passed as the second argument to xTokenize(). The third and fourth 10137 ** arguments are a pointer to a buffer containing the token text, and the 10138 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 10139 ** of the first byte of and first byte immediately following the text from 10140 ** which the token is derived within the input. 10141 ** 10142 ** The second argument passed to the xToken() callback ("tflags") should 10143 ** normally be set to 0. The exception is if the tokenizer supports 10144 ** synonyms. In this case see the discussion below for details. 10145 ** 10146 ** FTS5 assumes the xToken() callback is invoked for each token in the 10147 ** order that they occur within the input text. 10148 ** 10149 ** If an xToken() callback returns any value other than SQLITE_OK, then 10150 ** the tokenization should be abandoned and the xTokenize() method should 10151 ** immediately return a copy of the xToken() return value. Or, if the 10152 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 10153 ** if an error occurs with the xTokenize() implementation itself, it 10154 ** may abandon the tokenization and return any error code other than 10155 ** SQLITE_OK or SQLITE_DONE. 10156 ** 10157 ** SYNONYM SUPPORT 10158 ** 10159 ** Custom tokenizers may also support synonyms. Consider a case in which a 10160 ** user wishes to query for a phrase such as "first place". Using the 10161 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 10162 ** of "first place" within the document set, but not alternative forms 10163 ** such as "1st place". In some applications, it would be better to match 10164 ** all instances of "first place" or "1st place" regardless of which form 10165 ** the user specified in the MATCH query text. 10166 ** 10167 ** There are several ways to approach this in FTS5: 10168 ** 10169 ** <ol><li> By mapping all synonyms to a single token. In this case, the 10170 ** In the above example, this means that the tokenizer returns the 10171 ** same token for inputs "first" and "1st". Say that token is in 10172 ** fact "first", so that when the user inserts the document "I won 10173 ** 1st place" entries are added to the index for tokens "i", "won", 10174 ** "first" and "place". If the user then queries for '1st + place', 10175 ** the tokenizer substitutes "first" for "1st" and the query works 10176 ** as expected. 10177 ** 10178 ** <li> By adding multiple synonyms for a single term to the FTS index. 10179 ** In this case, when tokenizing query text, the tokenizer may 10180 ** provide multiple synonyms for a single term within the document. 10181 ** FTS5 then queries the index for each synonym individually. For 10182 ** example, faced with the query: 10183 ** 10184 ** <codeblock> 10185 ** ... MATCH 'first place'</codeblock> 10186 ** 10187 ** the tokenizer offers both "1st" and "first" as synonyms for the 10188 ** first token in the MATCH query and FTS5 effectively runs a query 10189 ** similar to: 10190 ** 10191 ** <codeblock> 10192 ** ... MATCH '(first OR 1st) place'</codeblock> 10193 ** 10194 ** except that, for the purposes of auxiliary functions, the query 10195 ** still appears to contain just two phrases - "(first OR 1st)" 10196 ** being treated as a single phrase. 10197 ** 10198 ** <li> By adding multiple synonyms for a single term to the FTS index. 10199 ** Using this method, when tokenizing document text, the tokenizer 10200 ** provides multiple synonyms for each token. So that when a 10201 ** document such as "I won first place" is tokenized, entries are 10202 ** added to the FTS index for "i", "won", "first", "1st" and 10203 ** "place". 10204 ** 10205 ** This way, even if the tokenizer does not provide synonyms 10206 ** when tokenizing query text (it should not - to do would be 10207 ** inefficient), it doesn't matter if the user queries for 10208 ** 'first + place' or '1st + place', as there are entires in the 10209 ** FTS index corresponding to both forms of the first token. 10210 ** </ol> 10211 ** 10212 ** Whether it is parsing document or query text, any call to xToken that 10213 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 10214 ** is considered to supply a synonym for the previous token. For example, 10215 ** when parsing the document "I won first place", a tokenizer that supports 10216 ** synonyms would call xToken() 5 times, as follows: 10217 ** 10218 ** <codeblock> 10219 ** xToken(pCtx, 0, "i", 1, 0, 1); 10220 ** xToken(pCtx, 0, "won", 3, 2, 5); 10221 ** xToken(pCtx, 0, "first", 5, 6, 11); 10222 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 10223 ** xToken(pCtx, 0, "place", 5, 12, 17); 10224 **</codeblock> 10225 ** 10226 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 10227 ** xToken() is called. Multiple synonyms may be specified for a single token 10228 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 10229 ** There is no limit to the number of synonyms that may be provided for a 10230 ** single token. 10231 ** 10232 ** In many cases, method (1) above is the best approach. It does not add 10233 ** extra data to the FTS index or require FTS5 to query for multiple terms, 10234 ** so it is efficient in terms of disk space and query speed. However, it 10235 ** does not support prefix queries very well. If, as suggested above, the 10236 ** token "first" is subsituted for "1st" by the tokenizer, then the query: 10237 ** 10238 ** <codeblock> 10239 ** ... MATCH '1s*'</codeblock> 10240 ** 10241 ** will not match documents that contain the token "1st" (as the tokenizer 10242 ** will probably not map "1s" to any prefix of "first"). 10243 ** 10244 ** For full prefix support, method (3) may be preferred. In this case, 10245 ** because the index contains entries for both "first" and "1st", prefix 10246 ** queries such as 'fi*' or '1s*' will match correctly. However, because 10247 ** extra entries are added to the FTS index, this method uses more space 10248 ** within the database. 10249 ** 10250 ** Method (2) offers a midpoint between (1) and (3). Using this method, 10251 ** a query such as '1s*' will match documents that contain the literal 10252 ** token "1st", but not "first" (assuming the tokenizer is not able to 10253 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 10254 ** will match against "1st" and "first". This method does not require 10255 ** extra disk space, as no extra entries are added to the FTS index. 10256 ** On the other hand, it may require more CPU cycles to run MATCH queries, 10257 ** as separate queries of the FTS index are required for each synonym. 10258 ** 10259 ** When using methods (2) or (3), it is important that the tokenizer only 10260 ** provide synonyms when tokenizing document text (method (2)) or query 10261 ** text (method (3)), not both. Doing so will not cause any errors, but is 10262 ** inefficient. 10263 */ 10264 typedef struct Fts5Tokenizer Fts5Tokenizer; 10265 typedef struct fts5_tokenizer fts5_tokenizer; 10266 struct fts5_tokenizer { 10267 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 10268 void (*xDelete)(Fts5Tokenizer*); 10269 int (*xTokenize)(Fts5Tokenizer*, 10270 void *pCtx, 10271 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 10272 const char *pText, int nText, 10273 int (*xToken)( 10274 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 10275 int tflags, /* Mask of FTS5_TOKEN_* flags */ 10276 const char *pToken, /* Pointer to buffer containing token */ 10277 int nToken, /* Size of token in bytes */ 10278 int iStart, /* Byte offset of token within input text */ 10279 int iEnd /* Byte offset of end of token within input text */ 10280 ) 10281 ); 10282 }; 10283 10284 /* Flags that may be passed as the third argument to xTokenize() */ 10285 #define FTS5_TOKENIZE_QUERY 0x0001 10286 #define FTS5_TOKENIZE_PREFIX 0x0002 10287 #define FTS5_TOKENIZE_DOCUMENT 0x0004 10288 #define FTS5_TOKENIZE_AUX 0x0008 10289 10290 /* Flags that may be passed by the tokenizer implementation back to FTS5 10291 ** as the third argument to the supplied xToken callback. */ 10292 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 10293 10294 /* 10295 ** END OF CUSTOM TOKENIZERS 10296 *************************************************************************/ 10297 10298 /************************************************************************* 10299 ** FTS5 EXTENSION REGISTRATION API 10300 */ 10301 typedef struct fts5_api fts5_api; 10302 struct fts5_api { 10303 int iVersion; /* Currently always set to 2 */ 10304 10305 /* Create a new tokenizer */ 10306 int (*xCreateTokenizer)( 10307 fts5_api *pApi, 10308 const char *zName, 10309 void *pContext, 10310 fts5_tokenizer *pTokenizer, 10311 void (*xDestroy)(void*) 10312 ); 10313 10314 /* Find an existing tokenizer */ 10315 int (*xFindTokenizer)( 10316 fts5_api *pApi, 10317 const char *zName, 10318 void **ppContext, 10319 fts5_tokenizer *pTokenizer 10320 ); 10321 10322 /* Create a new auxiliary function */ 10323 int (*xCreateFunction)( 10324 fts5_api *pApi, 10325 const char *zName, 10326 void *pContext, 10327 fts5_extension_function xFunction, 10328 void (*xDestroy)(void*) 10329 ); 10330 }; 10331 10332 /* 10333 ** END OF REGISTRATION API 10334 *************************************************************************/ 10335 10336 #ifdef __cplusplus 10337 } /* end of the 'extern "C"' block */ 10338 #endif 10339 10340 #endif /* _FTS5_H */ 10341 10342 /******** End of fts5.h *********/ 10343