1/* 2** 2001-09-15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef SQLITE3_H 34#define SQLITE3_H 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "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] ([dateof:3.6.18]), 112** SQLite source code has been stored in the 113** <a href="http://www.fossil-scm.org/">Fossil configuration management 114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115** a string which identifies a particular check-in of SQLite 116** within its configuration management system. ^The SQLITE_SOURCE_ID 117** string contains the date and time of the check-in (UTC) and a SHA1 118** or SHA3-256 hash of the entire source tree. If the source code has 119** been edited in any way since it was last checked in, then the last 120** four hexadecimal digits of the hash may be modified. 121** 122** See also: [sqlite3_libversion()], 123** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124** [sqlite_version()] and [sqlite_source_id()]. 125*/ 126#define SQLITE_VERSION "--VERS--" 127#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 128#define SQLITE_SOURCE_ID "--SOURCE-ID--" 129 130/* 131** CAPI3REF: Run-Time Library Version Numbers 132** KEYWORDS: sqlite3_version sqlite3_sourceid 133** 134** These interfaces provide the same information as the [SQLITE_VERSION], 135** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136** but are associated with the library instead of the header file. ^(Cautious 137** programmers might include assert() statements in their application to 138** verify that values returned by these interfaces match the macros in 139** the header, and thus ensure that the application is 140** compiled with matching library and header files. 141** 142** <blockquote><pre> 143** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146** </pre></blockquote>)^ 147** 148** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149** macro. ^The sqlite3_libversion() function returns a pointer to the 150** to the sqlite3_version[] string constant. The sqlite3_libversion() 151** function is provided for use in DLLs since DLL users usually do not have 152** direct access to string constants within the DLL. ^The 153** sqlite3_libversion_number() function returns an integer equal to 154** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155** a pointer to a string constant whose value is the same as the 156** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157** using an edited copy of [the amalgamation], then the last four characters 158** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159** 160** See also: [sqlite_version()] and [sqlite_source_id()]. 161*/ 162SQLITE_EXTERN const char sqlite3_version[]; 163const char *sqlite3_libversion(void); 164const char *sqlite3_sourceid(void); 165int sqlite3_libversion_number(void); 166 167/* 168** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169** 170** ^The sqlite3_compileoption_used() function returns 0 or 1 171** indicating whether the specified option was defined at 172** compile time. ^The SQLITE_ prefix may be omitted from the 173** option name passed to sqlite3_compileoption_used(). 174** 175** ^The sqlite3_compileoption_get() function allows iterating 176** over the list of options that were defined at compile time by 177** returning the N-th compile time option string. ^If N is out of range, 178** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179** prefix is omitted from any strings returned by 180** sqlite3_compileoption_get(). 181** 182** ^Support for the diagnostic functions sqlite3_compileoption_used() 183** and sqlite3_compileoption_get() may be omitted by specifying the 184** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185** 186** See also: SQL functions [sqlite_compileoption_used()] and 187** [sqlite_compileoption_get()] and the [compile_options pragma]. 188*/ 189#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190int sqlite3_compileoption_used(const char *zOptName); 191const char *sqlite3_compileoption_get(int N); 192#endif 193 194/* 195** CAPI3REF: Test To See If The Library Is Threadsafe 196** 197** ^The sqlite3_threadsafe() function returns zero if and only if 198** SQLite was compiled with mutexing code omitted due to the 199** [SQLITE_THREADSAFE] compile-time option being set to 0. 200** 201** SQLite can be compiled with or without mutexes. When 202** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 203** are enabled and SQLite is threadsafe. When the 204** [SQLITE_THREADSAFE] macro is 0, 205** the mutexes are omitted. Without the mutexes, it is not safe 206** to use SQLite concurrently from more than one thread. 207** 208** Enabling mutexes incurs a measurable performance penalty. 209** So if speed is of utmost importance, it makes sense to disable 210** the mutexes. But for maximum safety, mutexes should be enabled. 211** ^The default behavior is for mutexes to be enabled. 212** 213** This interface can be used by an application to make sure that the 214** version of SQLite that it is linking against was compiled with 215** the desired setting of the [SQLITE_THREADSAFE] macro. 216** 217** This interface only reports on the compile-time mutex setting 218** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 219** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 220** can be fully or partially disabled using a call to [sqlite3_config()] 221** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 222** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 223** sqlite3_threadsafe() function shows only the compile-time setting of 224** thread safety, not any run-time changes to that setting made by 225** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 226** is unchanged by calls to sqlite3_config().)^ 227** 228** See the [threading mode] documentation for additional information. 229*/ 230int sqlite3_threadsafe(void); 231 232/* 233** CAPI3REF: Database Connection Handle 234** KEYWORDS: {database connection} {database connections} 235** 236** Each open SQLite database is represented by a pointer to an instance of 237** the opaque structure named "sqlite3". It is useful to think of an sqlite3 238** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 239** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 240** and [sqlite3_close_v2()] are its destructors. There are many other 241** interfaces (such as 242** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 243** [sqlite3_busy_timeout()] to name but three) that are methods on an 244** sqlite3 object. 245*/ 246typedef struct sqlite3 sqlite3; 247 248/* 249** CAPI3REF: 64-Bit Integer Types 250** KEYWORDS: sqlite_int64 sqlite_uint64 251** 252** Because there is no cross-platform way to specify 64-bit integer types 253** SQLite includes typedefs for 64-bit signed and unsigned integers. 254** 255** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 256** The sqlite_int64 and sqlite_uint64 types are supported for backwards 257** compatibility only. 258** 259** ^The sqlite3_int64 and sqlite_int64 types can store integer values 260** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 261** sqlite3_uint64 and sqlite_uint64 types can store integer values 262** between 0 and +18446744073709551615 inclusive. 263*/ 264#ifdef SQLITE_INT64_TYPE 265 typedef SQLITE_INT64_TYPE sqlite_int64; 266# ifdef SQLITE_UINT64_TYPE 267 typedef SQLITE_UINT64_TYPE sqlite_uint64; 268# else 269 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 270# endif 271#elif defined(_MSC_VER) || defined(__BORLANDC__) 272 typedef __int64 sqlite_int64; 273 typedef unsigned __int64 sqlite_uint64; 274#else 275 typedef long long int sqlite_int64; 276 typedef unsigned long long int sqlite_uint64; 277#endif 278typedef sqlite_int64 sqlite3_int64; 279typedef sqlite_uint64 sqlite3_uint64; 280 281/* 282** If compiling for a processor that lacks floating point support, 283** substitute integer for floating-point. 284*/ 285#ifdef SQLITE_OMIT_FLOATING_POINT 286# define double sqlite3_int64 287#endif 288 289/* 290** CAPI3REF: Closing A Database Connection 291** DESTRUCTOR: sqlite3 292** 293** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 294** for the [sqlite3] object. 295** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 296** the [sqlite3] object is successfully destroyed and all associated 297** resources are deallocated. 298** 299** ^If the database connection is associated with unfinalized prepared 300** statements or unfinished sqlite3_backup objects then sqlite3_close() 301** will leave the database connection open and return [SQLITE_BUSY]. 302** ^If sqlite3_close_v2() is called with unfinalized prepared statements 303** and/or unfinished sqlite3_backups, then the database connection becomes 304** an unusable "zombie" which will automatically be deallocated when the 305** last prepared statement is finalized or the last sqlite3_backup is 306** finished. The sqlite3_close_v2() interface is intended for use with 307** host languages that are garbage collected, and where the order in which 308** destructors are called is arbitrary. 309** 310** Applications should [sqlite3_finalize | finalize] all [prepared statements], 311** [sqlite3_blob_close | close] all [BLOB handles], and 312** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 313** with the [sqlite3] object prior to attempting to close the object. ^If 314** sqlite3_close_v2() is called on a [database connection] that still has 315** outstanding [prepared statements], [BLOB handles], and/or 316** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 317** of resources is deferred until all [prepared statements], [BLOB handles], 318** and [sqlite3_backup] objects are also destroyed. 319** 320** ^If an [sqlite3] object is destroyed while a transaction is open, 321** the transaction is automatically rolled back. 322** 323** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 324** must be either a NULL 325** pointer or an [sqlite3] object pointer obtained 326** from [sqlite3_open()], [sqlite3_open16()], or 327** [sqlite3_open_v2()], and not previously closed. 328** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 329** argument is a harmless no-op. 330*/ 331int sqlite3_close(sqlite3*); 332int sqlite3_close_v2(sqlite3*); 333 334/* 335** The type for a callback function. 336** This is legacy and deprecated. It is included for historical 337** compatibility and is not documented. 338*/ 339typedef int (*sqlite3_callback)(void*,int,char**, char**); 340 341/* 342** CAPI3REF: One-Step Query Execution Interface 343** METHOD: sqlite3 344** 345** The sqlite3_exec() interface is a convenience wrapper around 346** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 347** that allows an application to run multiple statements of SQL 348** without having to use a lot of C code. 349** 350** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 351** semicolon-separate SQL statements passed into its 2nd argument, 352** in the context of the [database connection] passed in as its 1st 353** argument. ^If the callback function of the 3rd argument to 354** sqlite3_exec() is not NULL, then it is invoked for each result row 355** coming out of the evaluated SQL statements. ^The 4th argument to 356** sqlite3_exec() is relayed through to the 1st argument of each 357** callback invocation. ^If the callback pointer to sqlite3_exec() 358** is NULL, then no callback is ever invoked and result rows are 359** ignored. 360** 361** ^If an error occurs while evaluating the SQL statements passed into 362** sqlite3_exec(), then execution of the current statement stops and 363** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 364** is not NULL then any error message is written into memory obtained 365** from [sqlite3_malloc()] and passed back through the 5th parameter. 366** To avoid memory leaks, the application should invoke [sqlite3_free()] 367** on error message strings returned through the 5th parameter of 368** sqlite3_exec() after the error message string is no longer needed. 369** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 370** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 371** NULL before returning. 372** 373** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 374** routine returns SQLITE_ABORT without invoking the callback again and 375** without running any subsequent SQL statements. 376** 377** ^The 2nd argument to the sqlite3_exec() callback function is the 378** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 379** callback is an array of pointers to strings obtained as if from 380** [sqlite3_column_text()], one for each column. ^If an element of a 381** result row is NULL then the corresponding string pointer for the 382** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 383** sqlite3_exec() callback is an array of pointers to strings where each 384** entry represents the name of corresponding result column as obtained 385** from [sqlite3_column_name()]. 386** 387** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 388** to an empty string, or a pointer that contains only whitespace and/or 389** SQL comments, then no SQL statements are evaluated and the database 390** is not changed. 391** 392** Restrictions: 393** 394** <ul> 395** <li> The application must ensure that the 1st parameter to sqlite3_exec() 396** is a valid and open [database connection]. 397** <li> The application must not close the [database connection] specified by 398** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 399** <li> The application must not modify the SQL statement text passed into 400** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 401** </ul> 402*/ 403int sqlite3_exec( 404 sqlite3*, /* An open database */ 405 const char *sql, /* SQL to be evaluated */ 406 int (*callback)(void*,int,char**,char**), /* Callback function */ 407 void *, /* 1st argument to callback */ 408 char **errmsg /* Error msg written here */ 409); 410 411/* 412** CAPI3REF: Result Codes 413** KEYWORDS: {result code definitions} 414** 415** Many SQLite functions return an integer result code from the set shown 416** here in order to indicate success or failure. 417** 418** New error codes may be added in future versions of SQLite. 419** 420** See also: [extended result code definitions] 421*/ 422#define SQLITE_OK 0 /* Successful result */ 423/* beginning-of-error-codes */ 424#define SQLITE_ERROR 1 /* Generic error */ 425#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 426#define SQLITE_PERM 3 /* Access permission denied */ 427#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 428#define SQLITE_BUSY 5 /* The database file is locked */ 429#define SQLITE_LOCKED 6 /* A table in the database is locked */ 430#define SQLITE_NOMEM 7 /* A malloc() failed */ 431#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 432#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 433#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 434#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 435#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 436#define SQLITE_FULL 13 /* Insertion failed because database is full */ 437#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 438#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 439#define SQLITE_EMPTY 16 /* Internal use only */ 440#define SQLITE_SCHEMA 17 /* The database schema changed */ 441#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 442#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 443#define SQLITE_MISMATCH 20 /* Data type mismatch */ 444#define SQLITE_MISUSE 21 /* Library used incorrectly */ 445#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 446#define SQLITE_AUTH 23 /* Authorization denied */ 447#define SQLITE_FORMAT 24 /* Not used */ 448#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 449#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 450#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 451#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 452#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 453#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 454/* end-of-error-codes */ 455 456/* 457** CAPI3REF: Extended Result Codes 458** KEYWORDS: {extended result code definitions} 459** 460** In its default configuration, SQLite API routines return one of 30 integer 461** [result codes]. However, experience has shown that many of 462** these result codes are too coarse-grained. They do not provide as 463** much information about problems as programmers might like. In an effort to 464** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 465** and later) include 466** support for additional result codes that provide more detailed information 467** about errors. These [extended result codes] are enabled or disabled 468** on a per database connection basis using the 469** [sqlite3_extended_result_codes()] API. Or, the extended code for 470** the most recent error can be obtained using 471** [sqlite3_extended_errcode()]. 472*/ 473#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 474#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 475#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 476#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 477#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 478#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 479#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 480#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 481#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 482#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 483#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 484#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 485#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 486#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 487#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 488#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 489#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 490#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 491#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 492#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 493#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 494#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 495#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 496#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 497#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 498#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 499#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 500#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 501#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 502#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 503#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 504#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 505#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 506#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 507#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 508#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 509#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 510#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 511#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 512#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 513#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 514#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 515#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 516#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 517#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 518#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 519#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 520#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 521#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 522#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 523#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 524#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 525#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 526#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 527#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 528#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 529#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 530#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 531#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 532#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 533#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 534#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 535#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 536#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 537#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 538#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 539 540/* 541** CAPI3REF: Flags For File Open Operations 542** 543** These bit values are intended for use in the 544** 3rd parameter to the [sqlite3_open_v2()] interface and 545** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 546*/ 547#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 548#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 549#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 550#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 551#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 552#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 553#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 554#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 555#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 556#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 557#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 558#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 559#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 560#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 561#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 562#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 563#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 564#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 565#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 566#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 567 568/* Reserved: 0x00F00000 */ 569 570/* 571** CAPI3REF: Device Characteristics 572** 573** The xDeviceCharacteristics method of the [sqlite3_io_methods] 574** object returns an integer which is a vector of these 575** bit values expressing I/O characteristics of the mass storage 576** device that holds the file that the [sqlite3_io_methods] 577** refers to. 578** 579** The SQLITE_IOCAP_ATOMIC property means that all writes of 580** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 581** mean that writes of blocks that are nnn bytes in size and 582** are aligned to an address which is an integer multiple of 583** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 584** that when data is appended to a file, the data is appended 585** first then the size of the file is extended, never the other 586** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 587** information is written to disk in the same order as calls 588** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 589** after reboot following a crash or power loss, the only bytes in a 590** file that were written at the application level might have changed 591** and that adjacent bytes, even bytes within the same sector are 592** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 593** flag indicates that a file cannot be deleted when open. The 594** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 595** read-only media and cannot be changed even by processes with 596** elevated privileges. 597** 598** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 599** filesystem supports doing multiple write operations atomically when those 600** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 601** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 602*/ 603#define SQLITE_IOCAP_ATOMIC 0x00000001 604#define SQLITE_IOCAP_ATOMIC512 0x00000002 605#define SQLITE_IOCAP_ATOMIC1K 0x00000004 606#define SQLITE_IOCAP_ATOMIC2K 0x00000008 607#define SQLITE_IOCAP_ATOMIC4K 0x00000010 608#define SQLITE_IOCAP_ATOMIC8K 0x00000020 609#define SQLITE_IOCAP_ATOMIC16K 0x00000040 610#define SQLITE_IOCAP_ATOMIC32K 0x00000080 611#define SQLITE_IOCAP_ATOMIC64K 0x00000100 612#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 613#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 614#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 615#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 616#define SQLITE_IOCAP_IMMUTABLE 0x00002000 617#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 618 619/* 620** CAPI3REF: File Locking Levels 621** 622** SQLite uses one of these integer values as the second 623** argument to calls it makes to the xLock() and xUnlock() methods 624** of an [sqlite3_io_methods] object. 625*/ 626#define SQLITE_LOCK_NONE 0 627#define SQLITE_LOCK_SHARED 1 628#define SQLITE_LOCK_RESERVED 2 629#define SQLITE_LOCK_PENDING 3 630#define SQLITE_LOCK_EXCLUSIVE 4 631 632/* 633** CAPI3REF: Synchronization Type Flags 634** 635** When SQLite invokes the xSync() method of an 636** [sqlite3_io_methods] object it uses a combination of 637** these integer values as the second argument. 638** 639** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 640** sync operation only needs to flush data to mass storage. Inode 641** information need not be flushed. If the lower four bits of the flag 642** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 643** If the lower four bits equal SQLITE_SYNC_FULL, that means 644** to use Mac OS X style fullsync instead of fsync(). 645** 646** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 647** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 648** settings. The [synchronous pragma] determines when calls to the 649** xSync VFS method occur and applies uniformly across all platforms. 650** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 651** energetic or rigorous or forceful the sync operations are and 652** only make a difference on Mac OSX for the default SQLite code. 653** (Third-party VFS implementations might also make the distinction 654** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 655** operating systems natively supported by SQLite, only Mac OSX 656** cares about the difference.) 657*/ 658#define SQLITE_SYNC_NORMAL 0x00002 659#define SQLITE_SYNC_FULL 0x00003 660#define SQLITE_SYNC_DATAONLY 0x00010 661 662/* 663** CAPI3REF: OS Interface Open File Handle 664** 665** An [sqlite3_file] object represents an open file in the 666** [sqlite3_vfs | OS interface layer]. Individual OS interface 667** implementations will 668** want to subclass this object by appending additional fields 669** for their own use. The pMethods entry is a pointer to an 670** [sqlite3_io_methods] object that defines methods for performing 671** I/O operations on the open file. 672*/ 673typedef struct sqlite3_file sqlite3_file; 674struct sqlite3_file { 675 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 676}; 677 678/* 679** CAPI3REF: OS Interface File Virtual Methods Object 680** 681** Every file opened by the [sqlite3_vfs.xOpen] method populates an 682** [sqlite3_file] object (or, more commonly, a subclass of the 683** [sqlite3_file] object) with a pointer to an instance of this object. 684** This object defines the methods used to perform various operations 685** against the open file represented by the [sqlite3_file] object. 686** 687** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 688** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 689** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 690** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 691** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 692** to NULL. 693** 694** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 695** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 696** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 697** flag may be ORed in to indicate that only the data of the file 698** and not its inode needs to be synced. 699** 700** The integer values to xLock() and xUnlock() are one of 701** <ul> 702** <li> [SQLITE_LOCK_NONE], 703** <li> [SQLITE_LOCK_SHARED], 704** <li> [SQLITE_LOCK_RESERVED], 705** <li> [SQLITE_LOCK_PENDING], or 706** <li> [SQLITE_LOCK_EXCLUSIVE]. 707** </ul> 708** xLock() increases the lock. xUnlock() decreases the lock. 709** The xCheckReservedLock() method checks whether any database connection, 710** either in this process or in some other process, is holding a RESERVED, 711** PENDING, or EXCLUSIVE lock on the file. It returns true 712** if such a lock exists and false otherwise. 713** 714** The xFileControl() method is a generic interface that allows custom 715** VFS implementations to directly control an open file using the 716** [sqlite3_file_control()] interface. The second "op" argument is an 717** integer opcode. The third argument is a generic pointer intended to 718** point to a structure that may contain arguments or space in which to 719** write return values. Potential uses for xFileControl() might be 720** functions to enable blocking locks with timeouts, to change the 721** locking strategy (for example to use dot-file locks), to inquire 722** about the status of a lock, or to break stale locks. The SQLite 723** core reserves all opcodes less than 100 for its own use. 724** A [file control opcodes | list of opcodes] less than 100 is available. 725** Applications that define a custom xFileControl method should use opcodes 726** greater than 100 to avoid conflicts. VFS implementations should 727** return [SQLITE_NOTFOUND] for file control opcodes that they do not 728** recognize. 729** 730** The xSectorSize() method returns the sector size of the 731** device that underlies the file. The sector size is the 732** minimum write that can be performed without disturbing 733** other bytes in the file. The xDeviceCharacteristics() 734** method returns a bit vector describing behaviors of the 735** underlying device: 736** 737** <ul> 738** <li> [SQLITE_IOCAP_ATOMIC] 739** <li> [SQLITE_IOCAP_ATOMIC512] 740** <li> [SQLITE_IOCAP_ATOMIC1K] 741** <li> [SQLITE_IOCAP_ATOMIC2K] 742** <li> [SQLITE_IOCAP_ATOMIC4K] 743** <li> [SQLITE_IOCAP_ATOMIC8K] 744** <li> [SQLITE_IOCAP_ATOMIC16K] 745** <li> [SQLITE_IOCAP_ATOMIC32K] 746** <li> [SQLITE_IOCAP_ATOMIC64K] 747** <li> [SQLITE_IOCAP_SAFE_APPEND] 748** <li> [SQLITE_IOCAP_SEQUENTIAL] 749** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 750** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 751** <li> [SQLITE_IOCAP_IMMUTABLE] 752** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 753** </ul> 754** 755** The SQLITE_IOCAP_ATOMIC property means that all writes of 756** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 757** mean that writes of blocks that are nnn bytes in size and 758** are aligned to an address which is an integer multiple of 759** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 760** that when data is appended to a file, the data is appended 761** first then the size of the file is extended, never the other 762** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 763** information is written to disk in the same order as calls 764** to xWrite(). 765** 766** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 767** in the unread portions of the buffer with zeros. A VFS that 768** fails to zero-fill short reads might seem to work. However, 769** failure to zero-fill short reads will eventually lead to 770** database corruption. 771*/ 772typedef struct sqlite3_io_methods sqlite3_io_methods; 773struct sqlite3_io_methods { 774 int iVersion; 775 int (*xClose)(sqlite3_file*); 776 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 777 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 778 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 779 int (*xSync)(sqlite3_file*, int flags); 780 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 781 int (*xLock)(sqlite3_file*, int); 782 int (*xUnlock)(sqlite3_file*, int); 783 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 784 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 785 int (*xSectorSize)(sqlite3_file*); 786 int (*xDeviceCharacteristics)(sqlite3_file*); 787 /* Methods above are valid for version 1 */ 788 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 789 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 790 void (*xShmBarrier)(sqlite3_file*); 791 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 792 /* Methods above are valid for version 2 */ 793 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 794 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 795 /* Methods above are valid for version 3 */ 796 /* Additional methods may be added in future releases */ 797}; 798 799/* 800** CAPI3REF: Standard File Control Opcodes 801** KEYWORDS: {file control opcodes} {file control opcode} 802** 803** These integer constants are opcodes for the xFileControl method 804** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 805** interface. 806** 807** <ul> 808** <li>[[SQLITE_FCNTL_LOCKSTATE]] 809** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 810** opcode causes the xFileControl method to write the current state of 811** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 812** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 813** into an integer that the pArg argument points to. This capability 814** is used during testing and is only available when the SQLITE_TEST 815** compile-time option is used. 816** 817** <li>[[SQLITE_FCNTL_SIZE_HINT]] 818** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 819** layer a hint of how large the database file will grow to be during the 820** current transaction. This hint is not guaranteed to be accurate but it 821** is often close. The underlying VFS might choose to preallocate database 822** file space based on this hint in order to help writes to the database 823** file run faster. 824** 825** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 826** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 827** extends and truncates the database file in chunks of a size specified 828** by the user. The fourth argument to [sqlite3_file_control()] should 829** point to an integer (type int) containing the new chunk-size to use 830** for the nominated database. Allocating database file space in large 831** chunks (say 1MB at a time), may reduce file-system fragmentation and 832** improve performance on some systems. 833** 834** <li>[[SQLITE_FCNTL_FILE_POINTER]] 835** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 836** to the [sqlite3_file] object associated with a particular database 837** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 838** 839** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 840** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 841** to the [sqlite3_file] object associated with the journal file (either 842** the [rollback journal] or the [write-ahead log]) for a particular database 843** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 844** 845** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 846** No longer in use. 847** 848** <li>[[SQLITE_FCNTL_SYNC]] 849** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 850** sent to the VFS immediately before the xSync method is invoked on a 851** database file descriptor. Or, if the xSync method is not invoked 852** because the user has configured SQLite with 853** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 854** of the xSync method. In most cases, the pointer argument passed with 855** this file-control is NULL. However, if the database file is being synced 856** as part of a multi-database commit, the argument points to a nul-terminated 857** string containing the transactions master-journal file name. VFSes that 858** do not need this signal should silently ignore this opcode. Applications 859** should not call [sqlite3_file_control()] with this opcode as doing so may 860** disrupt the operation of the specialized VFSes that do require it. 861** 862** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 863** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 864** and sent to the VFS after a transaction has been committed immediately 865** but before the database is unlocked. VFSes that do not need this signal 866** should silently ignore this opcode. Applications should not call 867** [sqlite3_file_control()] with this opcode as doing so may disrupt the 868** operation of the specialized VFSes that do require it. 869** 870** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 871** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 872** retry counts and intervals for certain disk I/O operations for the 873** windows [VFS] in order to provide robustness in the presence of 874** anti-virus programs. By default, the windows VFS will retry file read, 875** file write, and file delete operations up to 10 times, with a delay 876** of 25 milliseconds before the first retry and with the delay increasing 877** by an additional 25 milliseconds with each subsequent retry. This 878** opcode allows these two values (10 retries and 25 milliseconds of delay) 879** to be adjusted. The values are changed for all database connections 880** within the same process. The argument is a pointer to an array of two 881** integers where the first integer is the new retry count and the second 882** integer is the delay. If either integer is negative, then the setting 883** is not changed but instead the prior value of that setting is written 884** into the array entry, allowing the current retry settings to be 885** interrogated. The zDbName parameter is ignored. 886** 887** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 888** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 889** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 890** write ahead log and shared memory files used for transaction control 891** are automatically deleted when the latest connection to the database 892** closes. Setting persistent WAL mode causes those files to persist after 893** close. Persisting the files is useful when other processes that do not 894** have write permission on the directory containing the database file want 895** to read the database file, as the WAL and shared memory files must exist 896** in order for the database to be readable. The fourth parameter to 897** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 898** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 899** WAL mode. If the integer is -1, then it is overwritten with the current 900** WAL persistence setting. 901** 902** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 903** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 904** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 905** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 906** xDeviceCharacteristics methods. The fourth parameter to 907** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 908** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 909** mode. If the integer is -1, then it is overwritten with the current 910** zero-damage mode setting. 911** 912** <li>[[SQLITE_FCNTL_OVERWRITE]] 913** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 914** a write transaction to indicate that, unless it is rolled back for some 915** reason, the entire database file will be overwritten by the current 916** transaction. This is used by VACUUM operations. 917** 918** <li>[[SQLITE_FCNTL_VFSNAME]] 919** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 920** all [VFSes] in the VFS stack. The names are of all VFS shims and the 921** final bottom-level VFS are written into memory obtained from 922** [sqlite3_malloc()] and the result is stored in the char* variable 923** that the fourth parameter of [sqlite3_file_control()] points to. 924** The caller is responsible for freeing the memory when done. As with 925** all file-control actions, there is no guarantee that this will actually 926** do anything. Callers should initialize the char* variable to a NULL 927** pointer in case this file-control is not implemented. This file-control 928** is intended for diagnostic use only. 929** 930** <li>[[SQLITE_FCNTL_VFS_POINTER]] 931** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 932** [VFSes] currently in use. ^(The argument X in 933** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 934** of type "[sqlite3_vfs] **". This opcodes will set *X 935** to a pointer to the top-level VFS.)^ 936** ^When there are multiple VFS shims in the stack, this opcode finds the 937** upper-most shim only. 938** 939** <li>[[SQLITE_FCNTL_PRAGMA]] 940** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 941** file control is sent to the open [sqlite3_file] object corresponding 942** to the database file to which the pragma statement refers. ^The argument 943** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 944** pointers to strings (char**) in which the second element of the array 945** is the name of the pragma and the third element is the argument to the 946** pragma or NULL if the pragma has no argument. ^The handler for an 947** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 948** of the char** argument point to a string obtained from [sqlite3_mprintf()] 949** or the equivalent and that string will become the result of the pragma or 950** the error message if the pragma fails. ^If the 951** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 952** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 953** file control returns [SQLITE_OK], then the parser assumes that the 954** VFS has handled the PRAGMA itself and the parser generates a no-op 955** prepared statement if result string is NULL, or that returns a copy 956** of the result string if the string is non-NULL. 957** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 958** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 959** that the VFS encountered an error while handling the [PRAGMA] and the 960** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 961** file control occurs at the beginning of pragma statement analysis and so 962** it is able to override built-in [PRAGMA] statements. 963** 964** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 965** ^The [SQLITE_FCNTL_BUSYHANDLER] 966** file-control may be invoked by SQLite on the database file handle 967** shortly after it is opened in order to provide a custom VFS with access 968** to the connections busy-handler callback. The argument is of type (void **) 969** - an array of two (void *) values. The first (void *) actually points 970** to a function of type (int (*)(void *)). In order to invoke the connections 971** busy-handler, this function should be invoked with the second (void *) in 972** the array as the only argument. If it returns non-zero, then the operation 973** should be retried. If it returns zero, the custom VFS should abandon the 974** current operation. 975** 976** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 977** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 978** to have SQLite generate a 979** temporary filename using the same algorithm that is followed to generate 980** temporary filenames for TEMP tables and other internal uses. The 981** argument should be a char** which will be filled with the filename 982** written into memory obtained from [sqlite3_malloc()]. The caller should 983** invoke [sqlite3_free()] on the result to avoid a memory leak. 984** 985** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 986** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 987** maximum number of bytes that will be used for memory-mapped I/O. 988** The argument is a pointer to a value of type sqlite3_int64 that 989** is an advisory maximum number of bytes in the file to memory map. The 990** pointer is overwritten with the old value. The limit is not changed if 991** the value originally pointed to is negative, and so the current limit 992** can be queried by passing in a pointer to a negative number. This 993** file-control is used internally to implement [PRAGMA mmap_size]. 994** 995** <li>[[SQLITE_FCNTL_TRACE]] 996** The [SQLITE_FCNTL_TRACE] file control provides advisory information 997** to the VFS about what the higher layers of the SQLite stack are doing. 998** This file control is used by some VFS activity tracing [shims]. 999** The argument is a zero-terminated string. Higher layers in the 1000** SQLite stack may generate instances of this file control if 1001** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1002** 1003** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1004** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1005** pointer to an integer and it writes a boolean into that integer depending 1006** on whether or not the file has been renamed, moved, or deleted since it 1007** was first opened. 1008** 1009** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1010** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1011** underlying native file handle associated with a file handle. This file 1012** control interprets its argument as a pointer to a native file handle and 1013** writes the resulting value there. 1014** 1015** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1016** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1017** opcode causes the xFileControl method to swap the file handle with the one 1018** pointed to by the pArg argument. This capability is used during testing 1019** and only needs to be supported when SQLITE_TEST is defined. 1020** 1021** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1022** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1023** be advantageous to block on the next WAL lock if the lock is not immediately 1024** available. The WAL subsystem issues this signal during rare 1025** circumstances in order to fix a problem with priority inversion. 1026** Applications should <em>not</em> use this file-control. 1027** 1028** <li>[[SQLITE_FCNTL_ZIPVFS]] 1029** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1030** VFS should return SQLITE_NOTFOUND for this opcode. 1031** 1032** <li>[[SQLITE_FCNTL_RBU]] 1033** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1034** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1035** this opcode. 1036** 1037** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1038** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1039** the file descriptor is placed in "batch write mode", which 1040** means all subsequent write operations will be deferred and done 1041** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1042** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1043** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1044** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1045** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1046** no VFS interface calls on the same [sqlite3_file] file descriptor 1047** except for calls to the xWrite method and the xFileControl method 1048** with [SQLITE_FCNTL_SIZE_HINT]. 1049** 1050** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1051** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1052** operations since the previous successful call to 1053** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1054** This file control returns [SQLITE_OK] if and only if the writes were 1055** all performed successfully and have been committed to persistent storage. 1056** ^Regardless of whether or not it is successful, this file control takes 1057** the file descriptor out of batch write mode so that all subsequent 1058** write operations are independent. 1059** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1060** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1061** 1062** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1063** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1064** operations since the previous successful call to 1065** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1066** ^This file control takes the file descriptor out of batch write mode 1067** so that all subsequent write operations are independent. 1068** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1069** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1070** 1071** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1072** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1073** a file lock using the xLock or xShmLock methods of the VFS to wait 1074** for up to M milliseconds before failing, where M is the single 1075** unsigned integer parameter. 1076** </ul> 1077*/ 1078#define SQLITE_FCNTL_LOCKSTATE 1 1079#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1080#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1081#define SQLITE_FCNTL_LAST_ERRNO 4 1082#define SQLITE_FCNTL_SIZE_HINT 5 1083#define SQLITE_FCNTL_CHUNK_SIZE 6 1084#define SQLITE_FCNTL_FILE_POINTER 7 1085#define SQLITE_FCNTL_SYNC_OMITTED 8 1086#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1087#define SQLITE_FCNTL_PERSIST_WAL 10 1088#define SQLITE_FCNTL_OVERWRITE 11 1089#define SQLITE_FCNTL_VFSNAME 12 1090#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1091#define SQLITE_FCNTL_PRAGMA 14 1092#define SQLITE_FCNTL_BUSYHANDLER 15 1093#define SQLITE_FCNTL_TEMPFILENAME 16 1094#define SQLITE_FCNTL_MMAP_SIZE 18 1095#define SQLITE_FCNTL_TRACE 19 1096#define SQLITE_FCNTL_HAS_MOVED 20 1097#define SQLITE_FCNTL_SYNC 21 1098#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1099#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1100#define SQLITE_FCNTL_WAL_BLOCK 24 1101#define SQLITE_FCNTL_ZIPVFS 25 1102#define SQLITE_FCNTL_RBU 26 1103#define SQLITE_FCNTL_VFS_POINTER 27 1104#define SQLITE_FCNTL_JOURNAL_POINTER 28 1105#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1106#define SQLITE_FCNTL_PDB 30 1107#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1108#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1109#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1110#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1111 1112/* deprecated names */ 1113#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1114#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1115#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1116 1117 1118/* 1119** CAPI3REF: Mutex Handle 1120** 1121** The mutex module within SQLite defines [sqlite3_mutex] to be an 1122** abstract type for a mutex object. The SQLite core never looks 1123** at the internal representation of an [sqlite3_mutex]. It only 1124** deals with pointers to the [sqlite3_mutex] object. 1125** 1126** Mutexes are created using [sqlite3_mutex_alloc()]. 1127*/ 1128typedef struct sqlite3_mutex sqlite3_mutex; 1129 1130/* 1131** CAPI3REF: Loadable Extension Thunk 1132** 1133** A pointer to the opaque sqlite3_api_routines structure is passed as 1134** the third parameter to entry points of [loadable extensions]. This 1135** structure must be typedefed in order to work around compiler warnings 1136** on some platforms. 1137*/ 1138typedef struct sqlite3_api_routines sqlite3_api_routines; 1139 1140/* 1141** CAPI3REF: OS Interface Object 1142** 1143** An instance of the sqlite3_vfs object defines the interface between 1144** the SQLite core and the underlying operating system. The "vfs" 1145** in the name of the object stands for "virtual file system". See 1146** the [VFS | VFS documentation] for further information. 1147** 1148** The VFS interface is sometimes extended by adding new methods onto 1149** the end. Each time such an extension occurs, the iVersion field 1150** is incremented. The iVersion value started out as 1 in 1151** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1152** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1153** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1154** may be appended to the sqlite3_vfs object and the iVersion value 1155** may increase again in future versions of SQLite. 1156** Note that the structure 1157** of the sqlite3_vfs object changes in the transition from 1158** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1159** and yet the iVersion field was not modified. 1160** 1161** The szOsFile field is the size of the subclassed [sqlite3_file] 1162** structure used by this VFS. mxPathname is the maximum length of 1163** a pathname in this VFS. 1164** 1165** Registered sqlite3_vfs objects are kept on a linked list formed by 1166** the pNext pointer. The [sqlite3_vfs_register()] 1167** and [sqlite3_vfs_unregister()] interfaces manage this list 1168** in a thread-safe way. The [sqlite3_vfs_find()] interface 1169** searches the list. Neither the application code nor the VFS 1170** implementation should use the pNext pointer. 1171** 1172** The pNext field is the only field in the sqlite3_vfs 1173** structure that SQLite will ever modify. SQLite will only access 1174** or modify this field while holding a particular static mutex. 1175** The application should never modify anything within the sqlite3_vfs 1176** object once the object has been registered. 1177** 1178** The zName field holds the name of the VFS module. The name must 1179** be unique across all VFS modules. 1180** 1181** [[sqlite3_vfs.xOpen]] 1182** ^SQLite guarantees that the zFilename parameter to xOpen 1183** is either a NULL pointer or string obtained 1184** from xFullPathname() with an optional suffix added. 1185** ^If a suffix is added to the zFilename parameter, it will 1186** consist of a single "-" character followed by no more than 1187** 11 alphanumeric and/or "-" characters. 1188** ^SQLite further guarantees that 1189** the string will be valid and unchanged until xClose() is 1190** called. Because of the previous sentence, 1191** the [sqlite3_file] can safely store a pointer to the 1192** filename if it needs to remember the filename for some reason. 1193** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1194** must invent its own temporary name for the file. ^Whenever the 1195** xFilename parameter is NULL it will also be the case that the 1196** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1197** 1198** The flags argument to xOpen() includes all bits set in 1199** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1200** or [sqlite3_open16()] is used, then flags includes at least 1201** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1202** If xOpen() opens a file read-only then it sets *pOutFlags to 1203** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1204** 1205** ^(SQLite will also add one of the following flags to the xOpen() 1206** call, depending on the object being opened: 1207** 1208** <ul> 1209** <li> [SQLITE_OPEN_MAIN_DB] 1210** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1211** <li> [SQLITE_OPEN_TEMP_DB] 1212** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1213** <li> [SQLITE_OPEN_TRANSIENT_DB] 1214** <li> [SQLITE_OPEN_SUBJOURNAL] 1215** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1216** <li> [SQLITE_OPEN_WAL] 1217** </ul>)^ 1218** 1219** The file I/O implementation can use the object type flags to 1220** change the way it deals with files. For example, an application 1221** that does not care about crash recovery or rollback might make 1222** the open of a journal file a no-op. Writes to this journal would 1223** also be no-ops, and any attempt to read the journal would return 1224** SQLITE_IOERR. Or the implementation might recognize that a database 1225** file will be doing page-aligned sector reads and writes in a random 1226** order and set up its I/O subsystem accordingly. 1227** 1228** SQLite might also add one of the following flags to the xOpen method: 1229** 1230** <ul> 1231** <li> [SQLITE_OPEN_DELETEONCLOSE] 1232** <li> [SQLITE_OPEN_EXCLUSIVE] 1233** </ul> 1234** 1235** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1236** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1237** will be set for TEMP databases and their journals, transient 1238** databases, and subjournals. 1239** 1240** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1241** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1242** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1243** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1244** SQLITE_OPEN_CREATE, is used to indicate that file should always 1245** be created, and that it is an error if it already exists. 1246** It is <i>not</i> used to indicate the file should be opened 1247** for exclusive access. 1248** 1249** ^At least szOsFile bytes of memory are allocated by SQLite 1250** to hold the [sqlite3_file] structure passed as the third 1251** argument to xOpen. The xOpen method does not have to 1252** allocate the structure; it should just fill it in. Note that 1253** the xOpen method must set the sqlite3_file.pMethods to either 1254** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1255** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1256** element will be valid after xOpen returns regardless of the success 1257** or failure of the xOpen call. 1258** 1259** [[sqlite3_vfs.xAccess]] 1260** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1261** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1262** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1263** to test whether a file is at least readable. The file can be a 1264** directory. 1265** 1266** ^SQLite will always allocate at least mxPathname+1 bytes for the 1267** output buffer xFullPathname. The exact size of the output buffer 1268** is also passed as a parameter to both methods. If the output buffer 1269** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1270** handled as a fatal error by SQLite, vfs implementations should endeavor 1271** to prevent this by setting mxPathname to a sufficiently large value. 1272** 1273** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1274** interfaces are not strictly a part of the filesystem, but they are 1275** included in the VFS structure for completeness. 1276** The xRandomness() function attempts to return nBytes bytes 1277** of good-quality randomness into zOut. The return value is 1278** the actual number of bytes of randomness obtained. 1279** The xSleep() method causes the calling thread to sleep for at 1280** least the number of microseconds given. ^The xCurrentTime() 1281** method returns a Julian Day Number for the current date and time as 1282** a floating point value. 1283** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1284** Day Number multiplied by 86400000 (the number of milliseconds in 1285** a 24-hour day). 1286** ^SQLite will use the xCurrentTimeInt64() method to get the current 1287** date and time if that method is available (if iVersion is 2 or 1288** greater and the function pointer is not NULL) and will fall back 1289** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1290** 1291** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1292** are not used by the SQLite core. These optional interfaces are provided 1293** by some VFSes to facilitate testing of the VFS code. By overriding 1294** system calls with functions under its control, a test program can 1295** simulate faults and error conditions that would otherwise be difficult 1296** or impossible to induce. The set of system calls that can be overridden 1297** varies from one VFS to another, and from one version of the same VFS to the 1298** next. Applications that use these interfaces must be prepared for any 1299** or all of these interfaces to be NULL or for their behavior to change 1300** from one release to the next. Applications must not attempt to access 1301** any of these methods if the iVersion of the VFS is less than 3. 1302*/ 1303typedef struct sqlite3_vfs sqlite3_vfs; 1304typedef void (*sqlite3_syscall_ptr)(void); 1305struct sqlite3_vfs { 1306 int iVersion; /* Structure version number (currently 3) */ 1307 int szOsFile; /* Size of subclassed sqlite3_file */ 1308 int mxPathname; /* Maximum file pathname length */ 1309 sqlite3_vfs *pNext; /* Next registered VFS */ 1310 const char *zName; /* Name of this virtual file system */ 1311 void *pAppData; /* Pointer to application-specific data */ 1312 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1313 int flags, int *pOutFlags); 1314 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1315 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1316 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1317 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1318 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1319 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1320 void (*xDlClose)(sqlite3_vfs*, void*); 1321 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1322 int (*xSleep)(sqlite3_vfs*, int microseconds); 1323 int (*xCurrentTime)(sqlite3_vfs*, double*); 1324 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1325 /* 1326 ** The methods above are in version 1 of the sqlite_vfs object 1327 ** definition. Those that follow are added in version 2 or later 1328 */ 1329 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1330 /* 1331 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1332 ** Those below are for version 3 and greater. 1333 */ 1334 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1335 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1336 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1337 /* 1338 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1339 ** New fields may be appended in future versions. The iVersion 1340 ** value will increment whenever this happens. 1341 */ 1342}; 1343 1344/* 1345** CAPI3REF: Flags for the xAccess VFS method 1346** 1347** These integer constants can be used as the third parameter to 1348** the xAccess method of an [sqlite3_vfs] object. They determine 1349** what kind of permissions the xAccess method is looking for. 1350** With SQLITE_ACCESS_EXISTS, the xAccess method 1351** simply checks whether the file exists. 1352** With SQLITE_ACCESS_READWRITE, the xAccess method 1353** checks whether the named directory is both readable and writable 1354** (in other words, if files can be added, removed, and renamed within 1355** the directory). 1356** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1357** [temp_store_directory pragma], though this could change in a future 1358** release of SQLite. 1359** With SQLITE_ACCESS_READ, the xAccess method 1360** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1361** currently unused, though it might be used in a future release of 1362** SQLite. 1363*/ 1364#define SQLITE_ACCESS_EXISTS 0 1365#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1366#define SQLITE_ACCESS_READ 2 /* Unused */ 1367 1368/* 1369** CAPI3REF: Flags for the xShmLock VFS method 1370** 1371** These integer constants define the various locking operations 1372** allowed by the xShmLock method of [sqlite3_io_methods]. The 1373** following are the only legal combinations of flags to the 1374** xShmLock method: 1375** 1376** <ul> 1377** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1378** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1379** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1380** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1381** </ul> 1382** 1383** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1384** was given on the corresponding lock. 1385** 1386** The xShmLock method can transition between unlocked and SHARED or 1387** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1388** and EXCLUSIVE. 1389*/ 1390#define SQLITE_SHM_UNLOCK 1 1391#define SQLITE_SHM_LOCK 2 1392#define SQLITE_SHM_SHARED 4 1393#define SQLITE_SHM_EXCLUSIVE 8 1394 1395/* 1396** CAPI3REF: Maximum xShmLock index 1397** 1398** The xShmLock method on [sqlite3_io_methods] may use values 1399** between 0 and this upper bound as its "offset" argument. 1400** The SQLite core will never attempt to acquire or release a 1401** lock outside of this range 1402*/ 1403#define SQLITE_SHM_NLOCK 8 1404 1405 1406/* 1407** CAPI3REF: Initialize The SQLite Library 1408** 1409** ^The sqlite3_initialize() routine initializes the 1410** SQLite library. ^The sqlite3_shutdown() routine 1411** deallocates any resources that were allocated by sqlite3_initialize(). 1412** These routines are designed to aid in process initialization and 1413** shutdown on embedded systems. Workstation applications using 1414** SQLite normally do not need to invoke either of these routines. 1415** 1416** A call to sqlite3_initialize() is an "effective" call if it is 1417** the first time sqlite3_initialize() is invoked during the lifetime of 1418** the process, or if it is the first time sqlite3_initialize() is invoked 1419** following a call to sqlite3_shutdown(). ^(Only an effective call 1420** of sqlite3_initialize() does any initialization. All other calls 1421** are harmless no-ops.)^ 1422** 1423** A call to sqlite3_shutdown() is an "effective" call if it is the first 1424** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1425** an effective call to sqlite3_shutdown() does any deinitialization. 1426** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1427** 1428** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1429** is not. The sqlite3_shutdown() interface must only be called from a 1430** single thread. All open [database connections] must be closed and all 1431** other SQLite resources must be deallocated prior to invoking 1432** sqlite3_shutdown(). 1433** 1434** Among other things, ^sqlite3_initialize() will invoke 1435** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1436** will invoke sqlite3_os_end(). 1437** 1438** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1439** ^If for some reason, sqlite3_initialize() is unable to initialize 1440** the library (perhaps it is unable to allocate a needed resource such 1441** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1442** 1443** ^The sqlite3_initialize() routine is called internally by many other 1444** SQLite interfaces so that an application usually does not need to 1445** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1446** calls sqlite3_initialize() so the SQLite library will be automatically 1447** initialized when [sqlite3_open()] is called if it has not be initialized 1448** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1449** compile-time option, then the automatic calls to sqlite3_initialize() 1450** are omitted and the application must call sqlite3_initialize() directly 1451** prior to using any other SQLite interface. For maximum portability, 1452** it is recommended that applications always invoke sqlite3_initialize() 1453** directly prior to using any other SQLite interface. Future releases 1454** of SQLite may require this. In other words, the behavior exhibited 1455** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1456** default behavior in some future release of SQLite. 1457** 1458** The sqlite3_os_init() routine does operating-system specific 1459** initialization of the SQLite library. The sqlite3_os_end() 1460** routine undoes the effect of sqlite3_os_init(). Typical tasks 1461** performed by these routines include allocation or deallocation 1462** of static resources, initialization of global variables, 1463** setting up a default [sqlite3_vfs] module, or setting up 1464** a default configuration using [sqlite3_config()]. 1465** 1466** The application should never invoke either sqlite3_os_init() 1467** or sqlite3_os_end() directly. The application should only invoke 1468** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1469** interface is called automatically by sqlite3_initialize() and 1470** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1471** implementations for sqlite3_os_init() and sqlite3_os_end() 1472** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1473** When [custom builds | built for other platforms] 1474** (using the [SQLITE_OS_OTHER=1] compile-time 1475** option) the application must supply a suitable implementation for 1476** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1477** implementation of sqlite3_os_init() or sqlite3_os_end() 1478** must return [SQLITE_OK] on success and some other [error code] upon 1479** failure. 1480*/ 1481int sqlite3_initialize(void); 1482int sqlite3_shutdown(void); 1483int sqlite3_os_init(void); 1484int sqlite3_os_end(void); 1485 1486/* 1487** CAPI3REF: Configuring The SQLite Library 1488** 1489** The sqlite3_config() interface is used to make global configuration 1490** changes to SQLite in order to tune SQLite to the specific needs of 1491** the application. The default configuration is recommended for most 1492** applications and so this routine is usually not necessary. It is 1493** provided to support rare applications with unusual needs. 1494** 1495** <b>The sqlite3_config() interface is not threadsafe. The application 1496** must ensure that no other SQLite interfaces are invoked by other 1497** threads while sqlite3_config() is running.</b> 1498** 1499** The sqlite3_config() interface 1500** may only be invoked prior to library initialization using 1501** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1502** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1503** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1504** Note, however, that ^sqlite3_config() can be called as part of the 1505** implementation of an application-defined [sqlite3_os_init()]. 1506** 1507** The first argument to sqlite3_config() is an integer 1508** [configuration option] that determines 1509** what property of SQLite is to be configured. Subsequent arguments 1510** vary depending on the [configuration option] 1511** in the first argument. 1512** 1513** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1514** ^If the option is unknown or SQLite is unable to set the option 1515** then this routine returns a non-zero [error code]. 1516*/ 1517int sqlite3_config(int, ...); 1518 1519/* 1520** CAPI3REF: Configure database connections 1521** METHOD: sqlite3 1522** 1523** The sqlite3_db_config() interface is used to make configuration 1524** changes to a [database connection]. The interface is similar to 1525** [sqlite3_config()] except that the changes apply to a single 1526** [database connection] (specified in the first argument). 1527** 1528** The second argument to sqlite3_db_config(D,V,...) is the 1529** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1530** that indicates what aspect of the [database connection] is being configured. 1531** Subsequent arguments vary depending on the configuration verb. 1532** 1533** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1534** the call is considered successful. 1535*/ 1536int sqlite3_db_config(sqlite3*, int op, ...); 1537 1538/* 1539** CAPI3REF: Memory Allocation Routines 1540** 1541** An instance of this object defines the interface between SQLite 1542** and low-level memory allocation routines. 1543** 1544** This object is used in only one place in the SQLite interface. 1545** A pointer to an instance of this object is the argument to 1546** [sqlite3_config()] when the configuration option is 1547** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1548** By creating an instance of this object 1549** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1550** during configuration, an application can specify an alternative 1551** memory allocation subsystem for SQLite to use for all of its 1552** dynamic memory needs. 1553** 1554** Note that SQLite comes with several [built-in memory allocators] 1555** that are perfectly adequate for the overwhelming majority of applications 1556** and that this object is only useful to a tiny minority of applications 1557** with specialized memory allocation requirements. This object is 1558** also used during testing of SQLite in order to specify an alternative 1559** memory allocator that simulates memory out-of-memory conditions in 1560** order to verify that SQLite recovers gracefully from such 1561** conditions. 1562** 1563** The xMalloc, xRealloc, and xFree methods must work like the 1564** malloc(), realloc() and free() functions from the standard C library. 1565** ^SQLite guarantees that the second argument to 1566** xRealloc is always a value returned by a prior call to xRoundup. 1567** 1568** xSize should return the allocated size of a memory allocation 1569** previously obtained from xMalloc or xRealloc. The allocated size 1570** is always at least as big as the requested size but may be larger. 1571** 1572** The xRoundup method returns what would be the allocated size of 1573** a memory allocation given a particular requested size. Most memory 1574** allocators round up memory allocations at least to the next multiple 1575** of 8. Some allocators round up to a larger multiple or to a power of 2. 1576** Every memory allocation request coming in through [sqlite3_malloc()] 1577** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1578** that causes the corresponding memory allocation to fail. 1579** 1580** The xInit method initializes the memory allocator. For example, 1581** it might allocate any require mutexes or initialize internal data 1582** structures. The xShutdown method is invoked (indirectly) by 1583** [sqlite3_shutdown()] and should deallocate any resources acquired 1584** by xInit. The pAppData pointer is used as the only parameter to 1585** xInit and xShutdown. 1586** 1587** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1588** the xInit method, so the xInit method need not be threadsafe. The 1589** xShutdown method is only called from [sqlite3_shutdown()] so it does 1590** not need to be threadsafe either. For all other methods, SQLite 1591** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1592** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1593** it is by default) and so the methods are automatically serialized. 1594** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1595** methods must be threadsafe or else make their own arrangements for 1596** serialization. 1597** 1598** SQLite will never invoke xInit() more than once without an intervening 1599** call to xShutdown(). 1600*/ 1601typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1602struct sqlite3_mem_methods { 1603 void *(*xMalloc)(int); /* Memory allocation function */ 1604 void (*xFree)(void*); /* Free a prior allocation */ 1605 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1606 int (*xSize)(void*); /* Return the size of an allocation */ 1607 int (*xRoundup)(int); /* Round up request size to allocation size */ 1608 int (*xInit)(void*); /* Initialize the memory allocator */ 1609 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1610 void *pAppData; /* Argument to xInit() and xShutdown() */ 1611}; 1612 1613/* 1614** CAPI3REF: Configuration Options 1615** KEYWORDS: {configuration option} 1616** 1617** These constants are the available integer configuration options that 1618** can be passed as the first argument to the [sqlite3_config()] interface. 1619** 1620** New configuration options may be added in future releases of SQLite. 1621** Existing configuration options might be discontinued. Applications 1622** should check the return code from [sqlite3_config()] to make sure that 1623** the call worked. The [sqlite3_config()] interface will return a 1624** non-zero [error code] if a discontinued or unsupported configuration option 1625** is invoked. 1626** 1627** <dl> 1628** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1629** <dd>There are no arguments to this option. ^This option sets the 1630** [threading mode] to Single-thread. In other words, it disables 1631** all mutexing and puts SQLite into a mode where it can only be used 1632** by a single thread. ^If SQLite is compiled with 1633** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1634** it is not possible to change the [threading mode] from its default 1635** value of Single-thread and so [sqlite3_config()] will return 1636** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1637** configuration option.</dd> 1638** 1639** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1640** <dd>There are no arguments to this option. ^This option sets the 1641** [threading mode] to Multi-thread. In other words, it disables 1642** mutexing on [database connection] and [prepared statement] objects. 1643** The application is responsible for serializing access to 1644** [database connections] and [prepared statements]. But other mutexes 1645** are enabled so that SQLite will be safe to use in a multi-threaded 1646** environment as long as no two threads attempt to use the same 1647** [database connection] at the same time. ^If SQLite is compiled with 1648** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1649** it is not possible to set the Multi-thread [threading mode] and 1650** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1651** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1652** 1653** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1654** <dd>There are no arguments to this option. ^This option sets the 1655** [threading mode] to Serialized. In other words, this option enables 1656** all mutexes including the recursive 1657** mutexes on [database connection] and [prepared statement] objects. 1658** In this mode (which is the default when SQLite is compiled with 1659** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1660** to [database connections] and [prepared statements] so that the 1661** application is free to use the same [database connection] or the 1662** same [prepared statement] in different threads at the same time. 1663** ^If SQLite is compiled with 1664** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1665** it is not possible to set the Serialized [threading mode] and 1666** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1667** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1668** 1669** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1670** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1671** a pointer to an instance of the [sqlite3_mem_methods] structure. 1672** The argument specifies 1673** alternative low-level memory allocation routines to be used in place of 1674** the memory allocation routines built into SQLite.)^ ^SQLite makes 1675** its own private copy of the content of the [sqlite3_mem_methods] structure 1676** before the [sqlite3_config()] call returns.</dd> 1677** 1678** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1679** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1680** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1681** The [sqlite3_mem_methods] 1682** structure is filled with the currently defined memory allocation routines.)^ 1683** This option can be used to overload the default memory allocation 1684** routines with a wrapper that simulations memory allocation failure or 1685** tracks memory usage, for example. </dd> 1686** 1687** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1688** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1689** type int, interpreted as a boolean, which if true provides a hint to 1690** SQLite that it should avoid large memory allocations if possible. 1691** SQLite will run faster if it is free to make large memory allocations, 1692** but some application might prefer to run slower in exchange for 1693** guarantees about memory fragmentation that are possible if large 1694** allocations are avoided. This hint is normally off. 1695** </dd> 1696** 1697** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1698** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1699** interpreted as a boolean, which enables or disables the collection of 1700** memory allocation statistics. ^(When memory allocation statistics are 1701** disabled, the following SQLite interfaces become non-operational: 1702** <ul> 1703** <li> [sqlite3_memory_used()] 1704** <li> [sqlite3_memory_highwater()] 1705** <li> [sqlite3_soft_heap_limit64()] 1706** <li> [sqlite3_status64()] 1707** </ul>)^ 1708** ^Memory allocation statistics are enabled by default unless SQLite is 1709** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1710** allocation statistics are disabled by default. 1711** </dd> 1712** 1713** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1714** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1715** </dd> 1716** 1717** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1718** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1719** that SQLite can use for the database page cache with the default page 1720** cache implementation. 1721** This configuration option is a no-op if an application-define page 1722** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1723** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1724** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1725** and the number of cache lines (N). 1726** The sz argument should be the size of the largest database page 1727** (a power of two between 512 and 65536) plus some extra bytes for each 1728** page header. ^The number of extra bytes needed by the page header 1729** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1730** ^It is harmless, apart from the wasted memory, 1731** for the sz parameter to be larger than necessary. The pMem 1732** argument must be either a NULL pointer or a pointer to an 8-byte 1733** aligned block of memory of at least sz*N bytes, otherwise 1734** subsequent behavior is undefined. 1735** ^When pMem is not NULL, SQLite will strive to use the memory provided 1736** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1737** a page cache line is larger than sz bytes or if all of the pMem buffer 1738** is exhausted. 1739** ^If pMem is NULL and N is non-zero, then each database connection 1740** does an initial bulk allocation for page cache memory 1741** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1742** of -1024*N bytes if N is negative, . ^If additional 1743** page cache memory is needed beyond what is provided by the initial 1744** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1745** additional cache line. </dd> 1746** 1747** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1748** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1749** that SQLite will use for all of its dynamic memory allocation needs 1750** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1751** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1752** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1753** [SQLITE_ERROR] if invoked otherwise. 1754** ^There are three arguments to SQLITE_CONFIG_HEAP: 1755** An 8-byte aligned pointer to the memory, 1756** the number of bytes in the memory buffer, and the minimum allocation size. 1757** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1758** to using its default memory allocator (the system malloc() implementation), 1759** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1760** memory pointer is not NULL then the alternative memory 1761** allocator is engaged to handle all of SQLites memory allocation needs. 1762** The first pointer (the memory pointer) must be aligned to an 8-byte 1763** boundary or subsequent behavior of SQLite will be undefined. 1764** The minimum allocation size is capped at 2**12. Reasonable values 1765** for the minimum allocation size are 2**5 through 2**8.</dd> 1766** 1767** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1768** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1769** pointer to an instance of the [sqlite3_mutex_methods] structure. 1770** The argument specifies alternative low-level mutex routines to be used 1771** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1772** the content of the [sqlite3_mutex_methods] structure before the call to 1773** [sqlite3_config()] returns. ^If SQLite is compiled with 1774** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1775** the entire mutexing subsystem is omitted from the build and hence calls to 1776** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1777** return [SQLITE_ERROR].</dd> 1778** 1779** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1780** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1781** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1782** [sqlite3_mutex_methods] 1783** structure is filled with the currently defined mutex routines.)^ 1784** This option can be used to overload the default mutex allocation 1785** routines with a wrapper used to track mutex usage for performance 1786** profiling or testing, for example. ^If SQLite is compiled with 1787** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1788** the entire mutexing subsystem is omitted from the build and hence calls to 1789** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1790** return [SQLITE_ERROR].</dd> 1791** 1792** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1793** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1794** the default size of lookaside memory on each [database connection]. 1795** The first argument is the 1796** size of each lookaside buffer slot and the second is the number of 1797** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1798** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1799** option to [sqlite3_db_config()] can be used to change the lookaside 1800** configuration on individual connections.)^ </dd> 1801** 1802** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1803** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1804** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1805** the interface to a custom page cache implementation.)^ 1806** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1807** 1808** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1809** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1810** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1811** the current page cache implementation into that object.)^ </dd> 1812** 1813** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1814** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1815** global [error log]. 1816** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1817** function with a call signature of void(*)(void*,int,const char*), 1818** and a pointer to void. ^If the function pointer is not NULL, it is 1819** invoked by [sqlite3_log()] to process each logging event. ^If the 1820** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1821** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1822** passed through as the first parameter to the application-defined logger 1823** function whenever that function is invoked. ^The second parameter to 1824** the logger function is a copy of the first parameter to the corresponding 1825** [sqlite3_log()] call and is intended to be a [result code] or an 1826** [extended result code]. ^The third parameter passed to the logger is 1827** log message after formatting via [sqlite3_snprintf()]. 1828** The SQLite logging interface is not reentrant; the logger function 1829** supplied by the application must not invoke any SQLite interface. 1830** In a multi-threaded application, the application-defined logger 1831** function must be threadsafe. </dd> 1832** 1833** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1834** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1835** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1836** then URI handling is globally disabled.)^ ^If URI handling is globally 1837** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1838** [sqlite3_open16()] or 1839** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1840** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1841** connection is opened. ^If it is globally disabled, filenames are 1842** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1843** database connection is opened. ^(By default, URI handling is globally 1844** disabled. The default value may be changed by compiling with the 1845** [SQLITE_USE_URI] symbol defined.)^ 1846** 1847** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1848** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1849** argument which is interpreted as a boolean in order to enable or disable 1850** the use of covering indices for full table scans in the query optimizer. 1851** ^The default setting is determined 1852** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1853** if that compile-time option is omitted. 1854** The ability to disable the use of covering indices for full table scans 1855** is because some incorrectly coded legacy applications might malfunction 1856** when the optimization is enabled. Providing the ability to 1857** disable the optimization allows the older, buggy application code to work 1858** without change even with newer versions of SQLite. 1859** 1860** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1861** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1862** <dd> These options are obsolete and should not be used by new code. 1863** They are retained for backwards compatibility but are now no-ops. 1864** </dd> 1865** 1866** [[SQLITE_CONFIG_SQLLOG]] 1867** <dt>SQLITE_CONFIG_SQLLOG 1868** <dd>This option is only available if sqlite is compiled with the 1869** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1870** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1871** The second should be of type (void*). The callback is invoked by the library 1872** in three separate circumstances, identified by the value passed as the 1873** fourth parameter. If the fourth parameter is 0, then the database connection 1874** passed as the second argument has just been opened. The third argument 1875** points to a buffer containing the name of the main database file. If the 1876** fourth parameter is 1, then the SQL statement that the third parameter 1877** points to has just been executed. Or, if the fourth parameter is 2, then 1878** the connection being passed as the second parameter is being closed. The 1879** third parameter is passed NULL In this case. An example of using this 1880** configuration option can be seen in the "test_sqllog.c" source file in 1881** the canonical SQLite source tree.</dd> 1882** 1883** [[SQLITE_CONFIG_MMAP_SIZE]] 1884** <dt>SQLITE_CONFIG_MMAP_SIZE 1885** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1886** that are the default mmap size limit (the default setting for 1887** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1888** ^The default setting can be overridden by each database connection using 1889** either the [PRAGMA mmap_size] command, or by using the 1890** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1891** will be silently truncated if necessary so that it does not exceed the 1892** compile-time maximum mmap size set by the 1893** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1894** ^If either argument to this option is negative, then that argument is 1895** changed to its compile-time default. 1896** 1897** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1898** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1899** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1900** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1901** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1902** that specifies the maximum size of the created heap. 1903** 1904** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1905** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1906** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1907** is a pointer to an integer and writes into that integer the number of extra 1908** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1909** The amount of extra space required can change depending on the compiler, 1910** target platform, and SQLite version. 1911** 1912** [[SQLITE_CONFIG_PMASZ]] 1913** <dt>SQLITE_CONFIG_PMASZ 1914** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1915** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1916** sorter to that integer. The default minimum PMA Size is set by the 1917** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1918** to help with sort operations when multithreaded sorting 1919** is enabled (using the [PRAGMA threads] command) and the amount of content 1920** to be sorted exceeds the page size times the minimum of the 1921** [PRAGMA cache_size] setting and this value. 1922** 1923** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1924** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1925** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1926** becomes the [statement journal] spill-to-disk threshold. 1927** [Statement journals] are held in memory until their size (in bytes) 1928** exceeds this threshold, at which point they are written to disk. 1929** Or if the threshold is -1, statement journals are always held 1930** exclusively in memory. 1931** Since many statement journals never become large, setting the spill 1932** threshold to a value such as 64KiB can greatly reduce the amount of 1933** I/O required to support statement rollback. 1934** The default value for this setting is controlled by the 1935** [SQLITE_STMTJRNL_SPILL] compile-time option. 1936** 1937** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1938** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1939** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1940** of type (int) - the new value of the sorter-reference size threshold. 1941** Usually, when SQLite uses an external sort to order records according 1942** to an ORDER BY clause, all fields required by the caller are present in the 1943** sorted records. However, if SQLite determines based on the declared type 1944** of a table column that its values are likely to be very large - larger 1945** than the configured sorter-reference size threshold - then a reference 1946** is stored in each sorted record and the required column values loaded 1947** from the database as records are returned in sorted order. The default 1948** value for this option is to never use this optimization. Specifying a 1949** negative value for this option restores the default behaviour. 1950** This option is only available if SQLite is compiled with the 1951** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1952** </dl> 1953*/ 1954#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1955#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1956#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1957#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1958#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1959#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 1960#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1961#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1962#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1963#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1964#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1965/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1966#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1967#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1968#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1969#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1970#define SQLITE_CONFIG_URI 17 /* int */ 1971#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1972#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1973#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1974#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1975#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1976#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1977#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1978#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1979#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1980#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 1981#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 1982 1983/* 1984** CAPI3REF: Database Connection Configuration Options 1985** 1986** These constants are the available integer configuration options that 1987** can be passed as the second argument to the [sqlite3_db_config()] interface. 1988** 1989** New configuration options may be added in future releases of SQLite. 1990** Existing configuration options might be discontinued. Applications 1991** should check the return code from [sqlite3_db_config()] to make sure that 1992** the call worked. ^The [sqlite3_db_config()] interface will return a 1993** non-zero [error code] if a discontinued or unsupported configuration option 1994** is invoked. 1995** 1996** <dl> 1997** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1998** <dd> ^This option takes three additional arguments that determine the 1999** [lookaside memory allocator] configuration for the [database connection]. 2000** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2001** pointer to a memory buffer to use for lookaside memory. 2002** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2003** may be NULL in which case SQLite will allocate the 2004** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2005** size of each lookaside buffer slot. ^The third argument is the number of 2006** slots. The size of the buffer in the first argument must be greater than 2007** or equal to the product of the second and third arguments. The buffer 2008** must be aligned to an 8-byte boundary. ^If the second argument to 2009** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2010** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2011** configuration for a database connection can only be changed when that 2012** connection is not currently using lookaside memory, or in other words 2013** when the "current value" returned by 2014** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2015** Any attempt to change the lookaside memory configuration when lookaside 2016** memory is in use leaves the configuration unchanged and returns 2017** [SQLITE_BUSY].)^</dd> 2018** 2019** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2020** <dd> ^This option is used to enable or disable the enforcement of 2021** [foreign key constraints]. There should be two additional arguments. 2022** The first argument is an integer which is 0 to disable FK enforcement, 2023** positive to enable FK enforcement or negative to leave FK enforcement 2024** unchanged. The second parameter is a pointer to an integer into which 2025** is written 0 or 1 to indicate whether FK enforcement is off or on 2026** following this call. The second parameter may be a NULL pointer, in 2027** which case the FK enforcement setting is not reported back. </dd> 2028** 2029** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2030** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2031** There should be two additional arguments. 2032** The first argument is an integer which is 0 to disable triggers, 2033** positive to enable triggers or negative to leave the setting unchanged. 2034** The second parameter is a pointer to an integer into which 2035** is written 0 or 1 to indicate whether triggers are disabled or enabled 2036** following this call. The second parameter may be a NULL pointer, in 2037** which case the trigger setting is not reported back. </dd> 2038** 2039** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2040** <dd> ^This option is used to enable or disable the two-argument 2041** version of the [fts3_tokenizer()] function which is part of the 2042** [FTS3] full-text search engine extension. 2043** There should be two additional arguments. 2044** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2045** positive to enable fts3_tokenizer() or negative to leave the setting 2046** unchanged. 2047** The second parameter is a pointer to an integer into which 2048** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2049** following this call. The second parameter may be a NULL pointer, in 2050** which case the new setting is not reported back. </dd> 2051** 2052** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2053** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2054** interface independently of the [load_extension()] SQL function. 2055** The [sqlite3_enable_load_extension()] API enables or disables both the 2056** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2057** There should be two additional arguments. 2058** When the first argument to this interface is 1, then only the C-API is 2059** enabled and the SQL function remains disabled. If the first argument to 2060** this interface is 0, then both the C-API and the SQL function are disabled. 2061** If the first argument is -1, then no changes are made to state of either the 2062** C-API or the SQL function. 2063** The second parameter is a pointer to an integer into which 2064** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2065** is disabled or enabled following this call. The second parameter may 2066** be a NULL pointer, in which case the new setting is not reported back. 2067** </dd> 2068** 2069** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2070** <dd> ^This option is used to change the name of the "main" database 2071** schema. ^The sole argument is a pointer to a constant UTF8 string 2072** which will become the new schema name in place of "main". ^SQLite 2073** does not make a copy of the new main schema name string, so the application 2074** must ensure that the argument passed into this DBCONFIG option is unchanged 2075** until after the database connection closes. 2076** </dd> 2077** 2078** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2079** <dd> Usually, when a database in wal mode is closed or detached from a 2080** database handle, SQLite checks if this will mean that there are now no 2081** connections at all to the database. If so, it performs a checkpoint 2082** operation before closing the connection. This option may be used to 2083** override this behaviour. The first parameter passed to this operation 2084** is an integer - positive to disable checkpoints-on-close, or zero (the 2085** default) to enable them, and negative to leave the setting unchanged. 2086** The second parameter is a pointer to an integer 2087** into which is written 0 or 1 to indicate whether checkpoints-on-close 2088** have been disabled - 0 if they are not disabled, 1 if they are. 2089** </dd> 2090** 2091** <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2092** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2093** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2094** a single SQL query statement will always use the same algorithm regardless 2095** of values of [bound parameters].)^ The QPSG disables some query optimizations 2096** that look at the values of bound parameters, which can make some queries 2097** slower. But the QPSG has the advantage of more predictable behavior. With 2098** the QPSG active, SQLite will always use the same query plan in the field as 2099** was used during testing in the lab. 2100** The first argument to this setting is an integer which is 0 to disable 2101** the QPSG, positive to enable QPSG, or negative to leave the setting 2102** unchanged. The second parameter is a pointer to an integer into which 2103** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2104** following this call. 2105** </dd> 2106** 2107** <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2108** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2109** include output for any operations performed by trigger programs. This 2110** option is used to set or clear (the default) a flag that governs this 2111** behavior. The first parameter passed to this operation is an integer - 2112** positive to enable output for trigger programs, or zero to disable it, 2113** or negative to leave the setting unchanged. 2114** The second parameter is a pointer to an integer into which is written 2115** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2116** it is not disabled, 1 if it is. 2117** </dd> 2118** 2119** <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2120** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2121** [VACUUM] in order to reset a database back to an empty database 2122** with no schema and no content. The following process works even for 2123** a badly corrupted database file: 2124** <ol> 2125** <li> If the database connection is newly opened, make sure it has read the 2126** database schema by preparing then discarding some query against the 2127** database, or calling sqlite3_table_column_metadata(), ignoring any 2128** errors. This step is only necessary if the application desires to keep 2129** the database in WAL mode after the reset if it was in WAL mode before 2130** the reset. 2131** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2132** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2133** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2134** </ol> 2135** Because resetting a database is destructive and irreversible, the 2136** process requires the use of this obscure API and multiple steps to help 2137** ensure that it does not happen by accident. 2138** </dd> 2139** </dl> 2140*/ 2141#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2142#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2143#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2144#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2145#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2146#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2147#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2148#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2149#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2150#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2151#define SQLITE_DBCONFIG_MAX 1009 /* Largest DBCONFIG */ 2152 2153/* 2154** CAPI3REF: Enable Or Disable Extended Result Codes 2155** METHOD: sqlite3 2156** 2157** ^The sqlite3_extended_result_codes() routine enables or disables the 2158** [extended result codes] feature of SQLite. ^The extended result 2159** codes are disabled by default for historical compatibility. 2160*/ 2161int sqlite3_extended_result_codes(sqlite3*, int onoff); 2162 2163/* 2164** CAPI3REF: Last Insert Rowid 2165** METHOD: sqlite3 2166** 2167** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2168** has a unique 64-bit signed 2169** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2170** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2171** names are not also used by explicitly declared columns. ^If 2172** the table has a column of type [INTEGER PRIMARY KEY] then that column 2173** is another alias for the rowid. 2174** 2175** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2176** the most recent successful [INSERT] into a rowid table or [virtual table] 2177** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2178** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2179** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2180** zero. 2181** 2182** As well as being set automatically as rows are inserted into database 2183** tables, the value returned by this function may be set explicitly by 2184** [sqlite3_set_last_insert_rowid()] 2185** 2186** Some virtual table implementations may INSERT rows into rowid tables as 2187** part of committing a transaction (e.g. to flush data accumulated in memory 2188** to disk). In this case subsequent calls to this function return the rowid 2189** associated with these internal INSERT operations, which leads to 2190** unintuitive results. Virtual table implementations that do write to rowid 2191** tables in this way can avoid this problem by restoring the original 2192** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2193** control to the user. 2194** 2195** ^(If an [INSERT] occurs within a trigger then this routine will 2196** return the [rowid] of the inserted row as long as the trigger is 2197** running. Once the trigger program ends, the value returned 2198** by this routine reverts to what it was before the trigger was fired.)^ 2199** 2200** ^An [INSERT] that fails due to a constraint violation is not a 2201** successful [INSERT] and does not change the value returned by this 2202** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2203** and INSERT OR ABORT make no changes to the return value of this 2204** routine when their insertion fails. ^(When INSERT OR REPLACE 2205** encounters a constraint violation, it does not fail. The 2206** INSERT continues to completion after deleting rows that caused 2207** the constraint problem so INSERT OR REPLACE will always change 2208** the return value of this interface.)^ 2209** 2210** ^For the purposes of this routine, an [INSERT] is considered to 2211** be successful even if it is subsequently rolled back. 2212** 2213** This function is accessible to SQL statements via the 2214** [last_insert_rowid() SQL function]. 2215** 2216** If a separate thread performs a new [INSERT] on the same 2217** database connection while the [sqlite3_last_insert_rowid()] 2218** function is running and thus changes the last insert [rowid], 2219** then the value returned by [sqlite3_last_insert_rowid()] is 2220** unpredictable and might not equal either the old or the new 2221** last insert [rowid]. 2222*/ 2223sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2224 2225/* 2226** CAPI3REF: Set the Last Insert Rowid value. 2227** METHOD: sqlite3 2228** 2229** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2230** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2231** without inserting a row into the database. 2232*/ 2233void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2234 2235/* 2236** CAPI3REF: Count The Number Of Rows Modified 2237** METHOD: sqlite3 2238** 2239** ^This function returns the number of rows modified, inserted or 2240** deleted by the most recently completed INSERT, UPDATE or DELETE 2241** statement on the database connection specified by the only parameter. 2242** ^Executing any other type of SQL statement does not modify the value 2243** returned by this function. 2244** 2245** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2246** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2247** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2248** 2249** Changes to a view that are intercepted by 2250** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2251** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2252** DELETE statement run on a view is always zero. Only changes made to real 2253** tables are counted. 2254** 2255** Things are more complicated if the sqlite3_changes() function is 2256** executed while a trigger program is running. This may happen if the 2257** program uses the [changes() SQL function], or if some other callback 2258** function invokes sqlite3_changes() directly. Essentially: 2259** 2260** <ul> 2261** <li> ^(Before entering a trigger program the value returned by 2262** sqlite3_changes() function is saved. After the trigger program 2263** has finished, the original value is restored.)^ 2264** 2265** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2266** statement sets the value returned by sqlite3_changes() 2267** upon completion as normal. Of course, this value will not include 2268** any changes performed by sub-triggers, as the sqlite3_changes() 2269** value will be saved and restored after each sub-trigger has run.)^ 2270** </ul> 2271** 2272** ^This means that if the changes() SQL function (or similar) is used 2273** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2274** returns the value as set when the calling statement began executing. 2275** ^If it is used by the second or subsequent such statement within a trigger 2276** program, the value returned reflects the number of rows modified by the 2277** previous INSERT, UPDATE or DELETE statement within the same trigger. 2278** 2279** See also the [sqlite3_total_changes()] interface, the 2280** [count_changes pragma], and the [changes() SQL function]. 2281** 2282** If a separate thread makes changes on the same database connection 2283** while [sqlite3_changes()] is running then the value returned 2284** is unpredictable and not meaningful. 2285*/ 2286int sqlite3_changes(sqlite3*); 2287 2288/* 2289** CAPI3REF: Total Number Of Rows Modified 2290** METHOD: sqlite3 2291** 2292** ^This function returns the total number of rows inserted, modified or 2293** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2294** since the database connection was opened, including those executed as 2295** part of trigger programs. ^Executing any other type of SQL statement 2296** does not affect the value returned by sqlite3_total_changes(). 2297** 2298** ^Changes made as part of [foreign key actions] are included in the 2299** count, but those made as part of REPLACE constraint resolution are 2300** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2301** are not counted. 2302** 2303** See also the [sqlite3_changes()] interface, the 2304** [count_changes pragma], and the [total_changes() SQL function]. 2305** 2306** If a separate thread makes changes on the same database connection 2307** while [sqlite3_total_changes()] is running then the value 2308** returned is unpredictable and not meaningful. 2309*/ 2310int sqlite3_total_changes(sqlite3*); 2311 2312/* 2313** CAPI3REF: Interrupt A Long-Running Query 2314** METHOD: sqlite3 2315** 2316** ^This function causes any pending database operation to abort and 2317** return at its earliest opportunity. This routine is typically 2318** called in response to a user action such as pressing "Cancel" 2319** or Ctrl-C where the user wants a long query operation to halt 2320** immediately. 2321** 2322** ^It is safe to call this routine from a thread different from the 2323** thread that is currently running the database operation. But it 2324** is not safe to call this routine with a [database connection] that 2325** is closed or might close before sqlite3_interrupt() returns. 2326** 2327** ^If an SQL operation is very nearly finished at the time when 2328** sqlite3_interrupt() is called, then it might not have an opportunity 2329** to be interrupted and might continue to completion. 2330** 2331** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2332** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2333** that is inside an explicit transaction, then the entire transaction 2334** will be rolled back automatically. 2335** 2336** ^The sqlite3_interrupt(D) call is in effect until all currently running 2337** SQL statements on [database connection] D complete. ^Any new SQL statements 2338** that are started after the sqlite3_interrupt() call and before the 2339** running statements reaches zero are interrupted as if they had been 2340** running prior to the sqlite3_interrupt() call. ^New SQL statements 2341** that are started after the running statement count reaches zero are 2342** not effected by the sqlite3_interrupt(). 2343** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2344** SQL statements is a no-op and has no effect on SQL statements 2345** that are started after the sqlite3_interrupt() call returns. 2346*/ 2347void sqlite3_interrupt(sqlite3*); 2348 2349/* 2350** CAPI3REF: Determine If An SQL Statement Is Complete 2351** 2352** These routines are useful during command-line input to determine if the 2353** currently entered text seems to form a complete SQL statement or 2354** if additional input is needed before sending the text into 2355** SQLite for parsing. ^These routines return 1 if the input string 2356** appears to be a complete SQL statement. ^A statement is judged to be 2357** complete if it ends with a semicolon token and is not a prefix of a 2358** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2359** string literals or quoted identifier names or comments are not 2360** independent tokens (they are part of the token in which they are 2361** embedded) and thus do not count as a statement terminator. ^Whitespace 2362** and comments that follow the final semicolon are ignored. 2363** 2364** ^These routines return 0 if the statement is incomplete. ^If a 2365** memory allocation fails, then SQLITE_NOMEM is returned. 2366** 2367** ^These routines do not parse the SQL statements thus 2368** will not detect syntactically incorrect SQL. 2369** 2370** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2371** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2372** automatically by sqlite3_complete16(). If that initialization fails, 2373** then the return value from sqlite3_complete16() will be non-zero 2374** regardless of whether or not the input SQL is complete.)^ 2375** 2376** The input to [sqlite3_complete()] must be a zero-terminated 2377** UTF-8 string. 2378** 2379** The input to [sqlite3_complete16()] must be a zero-terminated 2380** UTF-16 string in native byte order. 2381*/ 2382int sqlite3_complete(const char *sql); 2383int sqlite3_complete16(const void *sql); 2384 2385/* 2386** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2387** KEYWORDS: {busy-handler callback} {busy handler} 2388** METHOD: sqlite3 2389** 2390** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2391** that might be invoked with argument P whenever 2392** an attempt is made to access a database table associated with 2393** [database connection] D when another thread 2394** or process has the table locked. 2395** The sqlite3_busy_handler() interface is used to implement 2396** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2397** 2398** ^If the busy callback is NULL, then [SQLITE_BUSY] 2399** is returned immediately upon encountering the lock. ^If the busy callback 2400** is not NULL, then the callback might be invoked with two arguments. 2401** 2402** ^The first argument to the busy handler is a copy of the void* pointer which 2403** is the third argument to sqlite3_busy_handler(). ^The second argument to 2404** the busy handler callback is the number of times that the busy handler has 2405** been invoked previously for the same locking event. ^If the 2406** busy callback returns 0, then no additional attempts are made to 2407** access the database and [SQLITE_BUSY] is returned 2408** to the application. 2409** ^If the callback returns non-zero, then another attempt 2410** is made to access the database and the cycle repeats. 2411** 2412** The presence of a busy handler does not guarantee that it will be invoked 2413** when there is lock contention. ^If SQLite determines that invoking the busy 2414** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2415** to the application instead of invoking the 2416** busy handler. 2417** Consider a scenario where one process is holding a read lock that 2418** it is trying to promote to a reserved lock and 2419** a second process is holding a reserved lock that it is trying 2420** to promote to an exclusive lock. The first process cannot proceed 2421** because it is blocked by the second and the second process cannot 2422** proceed because it is blocked by the first. If both processes 2423** invoke the busy handlers, neither will make any progress. Therefore, 2424** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2425** will induce the first process to release its read lock and allow 2426** the second process to proceed. 2427** 2428** ^The default busy callback is NULL. 2429** 2430** ^(There can only be a single busy handler defined for each 2431** [database connection]. Setting a new busy handler clears any 2432** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2433** or evaluating [PRAGMA busy_timeout=N] will change the 2434** busy handler and thus clear any previously set busy handler. 2435** 2436** The busy callback should not take any actions which modify the 2437** database connection that invoked the busy handler. In other words, 2438** the busy handler is not reentrant. Any such actions 2439** result in undefined behavior. 2440** 2441** A busy handler must not close the database connection 2442** or [prepared statement] that invoked the busy handler. 2443*/ 2444int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2445 2446/* 2447** CAPI3REF: Set A Busy Timeout 2448** METHOD: sqlite3 2449** 2450** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2451** for a specified amount of time when a table is locked. ^The handler 2452** will sleep multiple times until at least "ms" milliseconds of sleeping 2453** have accumulated. ^After at least "ms" milliseconds of sleeping, 2454** the handler returns 0 which causes [sqlite3_step()] to return 2455** [SQLITE_BUSY]. 2456** 2457** ^Calling this routine with an argument less than or equal to zero 2458** turns off all busy handlers. 2459** 2460** ^(There can only be a single busy handler for a particular 2461** [database connection] at any given moment. If another busy handler 2462** was defined (using [sqlite3_busy_handler()]) prior to calling 2463** this routine, that other busy handler is cleared.)^ 2464** 2465** See also: [PRAGMA busy_timeout] 2466*/ 2467int sqlite3_busy_timeout(sqlite3*, int ms); 2468 2469/* 2470** CAPI3REF: Convenience Routines For Running Queries 2471** METHOD: sqlite3 2472** 2473** This is a legacy interface that is preserved for backwards compatibility. 2474** Use of this interface is not recommended. 2475** 2476** Definition: A <b>result table</b> is memory data structure created by the 2477** [sqlite3_get_table()] interface. A result table records the 2478** complete query results from one or more queries. 2479** 2480** The table conceptually has a number of rows and columns. But 2481** these numbers are not part of the result table itself. These 2482** numbers are obtained separately. Let N be the number of rows 2483** and M be the number of columns. 2484** 2485** A result table is an array of pointers to zero-terminated UTF-8 strings. 2486** There are (N+1)*M elements in the array. The first M pointers point 2487** to zero-terminated strings that contain the names of the columns. 2488** The remaining entries all point to query results. NULL values result 2489** in NULL pointers. All other values are in their UTF-8 zero-terminated 2490** string representation as returned by [sqlite3_column_text()]. 2491** 2492** A result table might consist of one or more memory allocations. 2493** It is not safe to pass a result table directly to [sqlite3_free()]. 2494** A result table should be deallocated using [sqlite3_free_table()]. 2495** 2496** ^(As an example of the result table format, suppose a query result 2497** is as follows: 2498** 2499** <blockquote><pre> 2500** Name | Age 2501** ----------------------- 2502** Alice | 43 2503** Bob | 28 2504** Cindy | 21 2505** </pre></blockquote> 2506** 2507** There are two column (M==2) and three rows (N==3). Thus the 2508** result table has 8 entries. Suppose the result table is stored 2509** in an array names azResult. Then azResult holds this content: 2510** 2511** <blockquote><pre> 2512** azResult[0] = "Name"; 2513** azResult[1] = "Age"; 2514** azResult[2] = "Alice"; 2515** azResult[3] = "43"; 2516** azResult[4] = "Bob"; 2517** azResult[5] = "28"; 2518** azResult[6] = "Cindy"; 2519** azResult[7] = "21"; 2520** </pre></blockquote>)^ 2521** 2522** ^The sqlite3_get_table() function evaluates one or more 2523** semicolon-separated SQL statements in the zero-terminated UTF-8 2524** string of its 2nd parameter and returns a result table to the 2525** pointer given in its 3rd parameter. 2526** 2527** After the application has finished with the result from sqlite3_get_table(), 2528** it must pass the result table pointer to sqlite3_free_table() in order to 2529** release the memory that was malloced. Because of the way the 2530** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2531** function must not try to call [sqlite3_free()] directly. Only 2532** [sqlite3_free_table()] is able to release the memory properly and safely. 2533** 2534** The sqlite3_get_table() interface is implemented as a wrapper around 2535** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2536** to any internal data structures of SQLite. It uses only the public 2537** interface defined here. As a consequence, errors that occur in the 2538** wrapper layer outside of the internal [sqlite3_exec()] call are not 2539** reflected in subsequent calls to [sqlite3_errcode()] or 2540** [sqlite3_errmsg()]. 2541*/ 2542int sqlite3_get_table( 2543 sqlite3 *db, /* An open database */ 2544 const char *zSql, /* SQL to be evaluated */ 2545 char ***pazResult, /* Results of the query */ 2546 int *pnRow, /* Number of result rows written here */ 2547 int *pnColumn, /* Number of result columns written here */ 2548 char **pzErrmsg /* Error msg written here */ 2549); 2550void sqlite3_free_table(char **result); 2551 2552/* 2553** CAPI3REF: Formatted String Printing Functions 2554** 2555** These routines are work-alikes of the "printf()" family of functions 2556** from the standard C library. 2557** These routines understand most of the common formatting options from 2558** the standard library printf() 2559** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2560** See the [built-in printf()] documentation for details. 2561** 2562** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2563** results into memory obtained from [sqlite3_malloc64()]. 2564** The strings returned by these two routines should be 2565** released by [sqlite3_free()]. ^Both routines return a 2566** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2567** memory to hold the resulting string. 2568** 2569** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2570** the standard C library. The result is written into the 2571** buffer supplied as the second parameter whose size is given by 2572** the first parameter. Note that the order of the 2573** first two parameters is reversed from snprintf().)^ This is an 2574** historical accident that cannot be fixed without breaking 2575** backwards compatibility. ^(Note also that sqlite3_snprintf() 2576** returns a pointer to its buffer instead of the number of 2577** characters actually written into the buffer.)^ We admit that 2578** the number of characters written would be a more useful return 2579** value but we cannot change the implementation of sqlite3_snprintf() 2580** now without breaking compatibility. 2581** 2582** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2583** guarantees that the buffer is always zero-terminated. ^The first 2584** parameter "n" is the total size of the buffer, including space for 2585** the zero terminator. So the longest string that can be completely 2586** written will be n-1 characters. 2587** 2588** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2589** 2590** See also: [built-in printf()], [printf() SQL function] 2591*/ 2592char *sqlite3_mprintf(const char*,...); 2593char *sqlite3_vmprintf(const char*, va_list); 2594char *sqlite3_snprintf(int,char*,const char*, ...); 2595char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2596 2597/* 2598** CAPI3REF: Memory Allocation Subsystem 2599** 2600** The SQLite core uses these three routines for all of its own 2601** internal memory allocation needs. "Core" in the previous sentence 2602** does not include operating-system specific VFS implementation. The 2603** Windows VFS uses native malloc() and free() for some operations. 2604** 2605** ^The sqlite3_malloc() routine returns a pointer to a block 2606** of memory at least N bytes in length, where N is the parameter. 2607** ^If sqlite3_malloc() is unable to obtain sufficient free 2608** memory, it returns a NULL pointer. ^If the parameter N to 2609** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2610** a NULL pointer. 2611** 2612** ^The sqlite3_malloc64(N) routine works just like 2613** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2614** of a signed 32-bit integer. 2615** 2616** ^Calling sqlite3_free() with a pointer previously returned 2617** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2618** that it might be reused. ^The sqlite3_free() routine is 2619** a no-op if is called with a NULL pointer. Passing a NULL pointer 2620** to sqlite3_free() is harmless. After being freed, memory 2621** should neither be read nor written. Even reading previously freed 2622** memory might result in a segmentation fault or other severe error. 2623** Memory corruption, a segmentation fault, or other severe error 2624** might result if sqlite3_free() is called with a non-NULL pointer that 2625** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2626** 2627** ^The sqlite3_realloc(X,N) interface attempts to resize a 2628** prior memory allocation X to be at least N bytes. 2629** ^If the X parameter to sqlite3_realloc(X,N) 2630** is a NULL pointer then its behavior is identical to calling 2631** sqlite3_malloc(N). 2632** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2633** negative then the behavior is exactly the same as calling 2634** sqlite3_free(X). 2635** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2636** of at least N bytes in size or NULL if insufficient memory is available. 2637** ^If M is the size of the prior allocation, then min(N,M) bytes 2638** of the prior allocation are copied into the beginning of buffer returned 2639** by sqlite3_realloc(X,N) and the prior allocation is freed. 2640** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2641** prior allocation is not freed. 2642** 2643** ^The sqlite3_realloc64(X,N) interfaces works the same as 2644** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2645** of a 32-bit signed integer. 2646** 2647** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2648** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2649** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2650** ^The value returned by sqlite3_msize(X) might be larger than the number 2651** of bytes requested when X was allocated. ^If X is a NULL pointer then 2652** sqlite3_msize(X) returns zero. If X points to something that is not 2653** the beginning of memory allocation, or if it points to a formerly 2654** valid memory allocation that has now been freed, then the behavior 2655** of sqlite3_msize(X) is undefined and possibly harmful. 2656** 2657** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2658** sqlite3_malloc64(), and sqlite3_realloc64() 2659** is always aligned to at least an 8 byte boundary, or to a 2660** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2661** option is used. 2662** 2663** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2664** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2665** implementation of these routines to be omitted. That capability 2666** is no longer provided. Only built-in memory allocators can be used. 2667** 2668** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2669** the system malloc() and free() directly when converting 2670** filenames between the UTF-8 encoding used by SQLite 2671** and whatever filename encoding is used by the particular Windows 2672** installation. Memory allocation errors were detected, but 2673** they were reported back as [SQLITE_CANTOPEN] or 2674** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2675** 2676** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2677** must be either NULL or else pointers obtained from a prior 2678** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2679** not yet been released. 2680** 2681** The application must not read or write any part of 2682** a block of memory after it has been released using 2683** [sqlite3_free()] or [sqlite3_realloc()]. 2684*/ 2685void *sqlite3_malloc(int); 2686void *sqlite3_malloc64(sqlite3_uint64); 2687void *sqlite3_realloc(void*, int); 2688void *sqlite3_realloc64(void*, sqlite3_uint64); 2689void sqlite3_free(void*); 2690sqlite3_uint64 sqlite3_msize(void*); 2691 2692/* 2693** CAPI3REF: Memory Allocator Statistics 2694** 2695** SQLite provides these two interfaces for reporting on the status 2696** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2697** routines, which form the built-in memory allocation subsystem. 2698** 2699** ^The [sqlite3_memory_used()] routine returns the number of bytes 2700** of memory currently outstanding (malloced but not freed). 2701** ^The [sqlite3_memory_highwater()] routine returns the maximum 2702** value of [sqlite3_memory_used()] since the high-water mark 2703** was last reset. ^The values returned by [sqlite3_memory_used()] and 2704** [sqlite3_memory_highwater()] include any overhead 2705** added by SQLite in its implementation of [sqlite3_malloc()], 2706** but not overhead added by the any underlying system library 2707** routines that [sqlite3_malloc()] may call. 2708** 2709** ^The memory high-water mark is reset to the current value of 2710** [sqlite3_memory_used()] if and only if the parameter to 2711** [sqlite3_memory_highwater()] is true. ^The value returned 2712** by [sqlite3_memory_highwater(1)] is the high-water mark 2713** prior to the reset. 2714*/ 2715sqlite3_int64 sqlite3_memory_used(void); 2716sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2717 2718/* 2719** CAPI3REF: Pseudo-Random Number Generator 2720** 2721** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2722** select random [ROWID | ROWIDs] when inserting new records into a table that 2723** already uses the largest possible [ROWID]. The PRNG is also used for 2724** the build-in random() and randomblob() SQL functions. This interface allows 2725** applications to access the same PRNG for other purposes. 2726** 2727** ^A call to this routine stores N bytes of randomness into buffer P. 2728** ^The P parameter can be a NULL pointer. 2729** 2730** ^If this routine has not been previously called or if the previous 2731** call had N less than one or a NULL pointer for P, then the PRNG is 2732** seeded using randomness obtained from the xRandomness method of 2733** the default [sqlite3_vfs] object. 2734** ^If the previous call to this routine had an N of 1 or more and a 2735** non-NULL P then the pseudo-randomness is generated 2736** internally and without recourse to the [sqlite3_vfs] xRandomness 2737** method. 2738*/ 2739void sqlite3_randomness(int N, void *P); 2740 2741/* 2742** CAPI3REF: Compile-Time Authorization Callbacks 2743** METHOD: sqlite3 2744** KEYWORDS: {authorizer callback} 2745** 2746** ^This routine registers an authorizer callback with a particular 2747** [database connection], supplied in the first argument. 2748** ^The authorizer callback is invoked as SQL statements are being compiled 2749** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2750** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2751** and [sqlite3_prepare16_v3()]. ^At various 2752** points during the compilation process, as logic is being created 2753** to perform various actions, the authorizer callback is invoked to 2754** see if those actions are allowed. ^The authorizer callback should 2755** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2756** specific action but allow the SQL statement to continue to be 2757** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2758** rejected with an error. ^If the authorizer callback returns 2759** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2760** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2761** the authorizer will fail with an error message. 2762** 2763** When the callback returns [SQLITE_OK], that means the operation 2764** requested is ok. ^When the callback returns [SQLITE_DENY], the 2765** [sqlite3_prepare_v2()] or equivalent call that triggered the 2766** authorizer will fail with an error message explaining that 2767** access is denied. 2768** 2769** ^The first parameter to the authorizer callback is a copy of the third 2770** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2771** to the callback is an integer [SQLITE_COPY | action code] that specifies 2772** the particular action to be authorized. ^The third through sixth parameters 2773** to the callback are either NULL pointers or zero-terminated strings 2774** that contain additional details about the action to be authorized. 2775** Applications must always be prepared to encounter a NULL pointer in any 2776** of the third through the sixth parameters of the authorization callback. 2777** 2778** ^If the action code is [SQLITE_READ] 2779** and the callback returns [SQLITE_IGNORE] then the 2780** [prepared statement] statement is constructed to substitute 2781** a NULL value in place of the table column that would have 2782** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2783** return can be used to deny an untrusted user access to individual 2784** columns of a table. 2785** ^When a table is referenced by a [SELECT] but no column values are 2786** extracted from that table (for example in a query like 2787** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2788** is invoked once for that table with a column name that is an empty string. 2789** ^If the action code is [SQLITE_DELETE] and the callback returns 2790** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2791** [truncate optimization] is disabled and all rows are deleted individually. 2792** 2793** An authorizer is used when [sqlite3_prepare | preparing] 2794** SQL statements from an untrusted source, to ensure that the SQL statements 2795** do not try to access data they are not allowed to see, or that they do not 2796** try to execute malicious statements that damage the database. For 2797** example, an application may allow a user to enter arbitrary 2798** SQL queries for evaluation by a database. But the application does 2799** not want the user to be able to make arbitrary changes to the 2800** database. An authorizer could then be put in place while the 2801** user-entered SQL is being [sqlite3_prepare | prepared] that 2802** disallows everything except [SELECT] statements. 2803** 2804** Applications that need to process SQL from untrusted sources 2805** might also consider lowering resource limits using [sqlite3_limit()] 2806** and limiting database size using the [max_page_count] [PRAGMA] 2807** in addition to using an authorizer. 2808** 2809** ^(Only a single authorizer can be in place on a database connection 2810** at a time. Each call to sqlite3_set_authorizer overrides the 2811** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2812** The authorizer is disabled by default. 2813** 2814** The authorizer callback must not do anything that will modify 2815** the database connection that invoked the authorizer callback. 2816** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2817** database connections for the meaning of "modify" in this paragraph. 2818** 2819** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2820** statement might be re-prepared during [sqlite3_step()] due to a 2821** schema change. Hence, the application should ensure that the 2822** correct authorizer callback remains in place during the [sqlite3_step()]. 2823** 2824** ^Note that the authorizer callback is invoked only during 2825** [sqlite3_prepare()] or its variants. Authorization is not 2826** performed during statement evaluation in [sqlite3_step()], unless 2827** as stated in the previous paragraph, sqlite3_step() invokes 2828** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2829*/ 2830int sqlite3_set_authorizer( 2831 sqlite3*, 2832 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2833 void *pUserData 2834); 2835 2836/* 2837** CAPI3REF: Authorizer Return Codes 2838** 2839** The [sqlite3_set_authorizer | authorizer callback function] must 2840** return either [SQLITE_OK] or one of these two constants in order 2841** to signal SQLite whether or not the action is permitted. See the 2842** [sqlite3_set_authorizer | authorizer documentation] for additional 2843** information. 2844** 2845** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2846** returned from the [sqlite3_vtab_on_conflict()] interface. 2847*/ 2848#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2849#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2850 2851/* 2852** CAPI3REF: Authorizer Action Codes 2853** 2854** The [sqlite3_set_authorizer()] interface registers a callback function 2855** that is invoked to authorize certain SQL statement actions. The 2856** second parameter to the callback is an integer code that specifies 2857** what action is being authorized. These are the integer action codes that 2858** the authorizer callback may be passed. 2859** 2860** These action code values signify what kind of operation is to be 2861** authorized. The 3rd and 4th parameters to the authorization 2862** callback function will be parameters or NULL depending on which of these 2863** codes is used as the second parameter. ^(The 5th parameter to the 2864** authorizer callback is the name of the database ("main", "temp", 2865** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2866** is the name of the inner-most trigger or view that is responsible for 2867** the access attempt or NULL if this access attempt is directly from 2868** top-level SQL code. 2869*/ 2870/******************************************* 3rd ************ 4th ***********/ 2871#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2872#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2873#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2874#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2875#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2876#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2877#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2878#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2879#define SQLITE_DELETE 9 /* Table Name NULL */ 2880#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2881#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2882#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2883#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2884#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2885#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2886#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2887#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2888#define SQLITE_INSERT 18 /* Table Name NULL */ 2889#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2890#define SQLITE_READ 20 /* Table Name Column Name */ 2891#define SQLITE_SELECT 21 /* NULL NULL */ 2892#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2893#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2894#define SQLITE_ATTACH 24 /* Filename NULL */ 2895#define SQLITE_DETACH 25 /* Database Name NULL */ 2896#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2897#define SQLITE_REINDEX 27 /* Index Name NULL */ 2898#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2899#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2900#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2901#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2902#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2903#define SQLITE_COPY 0 /* No longer used */ 2904#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2905 2906/* 2907** CAPI3REF: Tracing And Profiling Functions 2908** METHOD: sqlite3 2909** 2910** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2911** instead of the routines described here. 2912** 2913** These routines register callback functions that can be used for 2914** tracing and profiling the execution of SQL statements. 2915** 2916** ^The callback function registered by sqlite3_trace() is invoked at 2917** various times when an SQL statement is being run by [sqlite3_step()]. 2918** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2919** SQL statement text as the statement first begins executing. 2920** ^(Additional sqlite3_trace() callbacks might occur 2921** as each triggered subprogram is entered. The callbacks for triggers 2922** contain a UTF-8 SQL comment that identifies the trigger.)^ 2923** 2924** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2925** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2926** 2927** ^The callback function registered by sqlite3_profile() is invoked 2928** as each SQL statement finishes. ^The profile callback contains 2929** the original statement text and an estimate of wall-clock time 2930** of how long that statement took to run. ^The profile callback 2931** time is in units of nanoseconds, however the current implementation 2932** is only capable of millisecond resolution so the six least significant 2933** digits in the time are meaningless. Future versions of SQLite 2934** might provide greater resolution on the profiler callback. The 2935** sqlite3_profile() function is considered experimental and is 2936** subject to change in future versions of SQLite. 2937*/ 2938SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2939 void(*xTrace)(void*,const char*), void*); 2940SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2941 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2942 2943/* 2944** CAPI3REF: SQL Trace Event Codes 2945** KEYWORDS: SQLITE_TRACE 2946** 2947** These constants identify classes of events that can be monitored 2948** using the [sqlite3_trace_v2()] tracing logic. The M argument 2949** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 2950** the following constants. ^The first argument to the trace callback 2951** is one of the following constants. 2952** 2953** New tracing constants may be added in future releases. 2954** 2955** ^A trace callback has four arguments: xCallback(T,C,P,X). 2956** ^The T argument is one of the integer type codes above. 2957** ^The C argument is a copy of the context pointer passed in as the 2958** fourth argument to [sqlite3_trace_v2()]. 2959** The P and X arguments are pointers whose meanings depend on T. 2960** 2961** <dl> 2962** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2963** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2964** first begins running and possibly at other times during the 2965** execution of the prepared statement, such as at the start of each 2966** trigger subprogram. ^The P argument is a pointer to the 2967** [prepared statement]. ^The X argument is a pointer to a string which 2968** is the unexpanded SQL text of the prepared statement or an SQL comment 2969** that indicates the invocation of a trigger. ^The callback can compute 2970** the same text that would have been returned by the legacy [sqlite3_trace()] 2971** interface by using the X argument when X begins with "--" and invoking 2972** [sqlite3_expanded_sql(P)] otherwise. 2973** 2974** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2975** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2976** information as is provided by the [sqlite3_profile()] callback. 2977** ^The P argument is a pointer to the [prepared statement] and the 2978** X argument points to a 64-bit integer which is the estimated of 2979** the number of nanosecond that the prepared statement took to run. 2980** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2981** 2982** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2983** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2984** statement generates a single row of result. 2985** ^The P argument is a pointer to the [prepared statement] and the 2986** X argument is unused. 2987** 2988** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2989** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2990** connection closes. 2991** ^The P argument is a pointer to the [database connection] object 2992** and the X argument is unused. 2993** </dl> 2994*/ 2995#define SQLITE_TRACE_STMT 0x01 2996#define SQLITE_TRACE_PROFILE 0x02 2997#define SQLITE_TRACE_ROW 0x04 2998#define SQLITE_TRACE_CLOSE 0x08 2999 3000/* 3001** CAPI3REF: SQL Trace Hook 3002** METHOD: sqlite3 3003** 3004** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3005** function X against [database connection] D, using property mask M 3006** and context pointer P. ^If the X callback is 3007** NULL or if the M mask is zero, then tracing is disabled. The 3008** M argument should be the bitwise OR-ed combination of 3009** zero or more [SQLITE_TRACE] constants. 3010** 3011** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3012** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3013** 3014** ^The X callback is invoked whenever any of the events identified by 3015** mask M occur. ^The integer return value from the callback is currently 3016** ignored, though this may change in future releases. Callback 3017** implementations should return zero to ensure future compatibility. 3018** 3019** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3020** ^The T argument is one of the [SQLITE_TRACE] 3021** constants to indicate why the callback was invoked. 3022** ^The C argument is a copy of the context pointer. 3023** The P and X arguments are pointers whose meanings depend on T. 3024** 3025** The sqlite3_trace_v2() interface is intended to replace the legacy 3026** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3027** are deprecated. 3028*/ 3029int sqlite3_trace_v2( 3030 sqlite3*, 3031 unsigned uMask, 3032 int(*xCallback)(unsigned,void*,void*,void*), 3033 void *pCtx 3034); 3035 3036/* 3037** CAPI3REF: Query Progress Callbacks 3038** METHOD: sqlite3 3039** 3040** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3041** function X to be invoked periodically during long running calls to 3042** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3043** database connection D. An example use for this 3044** interface is to keep a GUI updated during a large query. 3045** 3046** ^The parameter P is passed through as the only parameter to the 3047** callback function X. ^The parameter N is the approximate number of 3048** [virtual machine instructions] that are evaluated between successive 3049** invocations of the callback X. ^If N is less than one then the progress 3050** handler is disabled. 3051** 3052** ^Only a single progress handler may be defined at one time per 3053** [database connection]; setting a new progress handler cancels the 3054** old one. ^Setting parameter X to NULL disables the progress handler. 3055** ^The progress handler is also disabled by setting N to a value less 3056** than 1. 3057** 3058** ^If the progress callback returns non-zero, the operation is 3059** interrupted. This feature can be used to implement a 3060** "Cancel" button on a GUI progress dialog box. 3061** 3062** The progress handler callback must not do anything that will modify 3063** the database connection that invoked the progress handler. 3064** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3065** database connections for the meaning of "modify" in this paragraph. 3066** 3067*/ 3068void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3069 3070/* 3071** CAPI3REF: Opening A New Database Connection 3072** CONSTRUCTOR: sqlite3 3073** 3074** ^These routines open an SQLite database file as specified by the 3075** filename argument. ^The filename argument is interpreted as UTF-8 for 3076** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3077** order for sqlite3_open16(). ^(A [database connection] handle is usually 3078** returned in *ppDb, even if an error occurs. The only exception is that 3079** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3080** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3081** object.)^ ^(If the database is opened (and/or created) successfully, then 3082** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3083** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3084** an English language description of the error following a failure of any 3085** of the sqlite3_open() routines. 3086** 3087** ^The default encoding will be UTF-8 for databases created using 3088** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3089** created using sqlite3_open16() will be UTF-16 in the native byte order. 3090** 3091** Whether or not an error occurs when it is opened, resources 3092** associated with the [database connection] handle should be released by 3093** passing it to [sqlite3_close()] when it is no longer required. 3094** 3095** The sqlite3_open_v2() interface works like sqlite3_open() 3096** except that it accepts two additional parameters for additional control 3097** over the new database connection. ^(The flags parameter to 3098** sqlite3_open_v2() can take one of 3099** the following three values, optionally combined with the 3100** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3101** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3102** 3103** <dl> 3104** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3105** <dd>The database is opened in read-only mode. If the database does not 3106** already exist, an error is returned.</dd>)^ 3107** 3108** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3109** <dd>The database is opened for reading and writing if possible, or reading 3110** only if the file is write protected by the operating system. In either 3111** case the database must already exist, otherwise an error is returned.</dd>)^ 3112** 3113** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3114** <dd>The database is opened for reading and writing, and is created if 3115** it does not already exist. This is the behavior that is always used for 3116** sqlite3_open() and sqlite3_open16().</dd>)^ 3117** </dl> 3118** 3119** If the 3rd parameter to sqlite3_open_v2() is not one of the 3120** combinations shown above optionally combined with other 3121** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3122** then the behavior is undefined. 3123** 3124** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3125** opens in the multi-thread [threading mode] as long as the single-thread 3126** mode has not been set at compile-time or start-time. ^If the 3127** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3128** in the serialized [threading mode] unless single-thread was 3129** previously selected at compile-time or start-time. 3130** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3131** eligible to use [shared cache mode], regardless of whether or not shared 3132** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3133** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3134** participate in [shared cache mode] even if it is enabled. 3135** 3136** ^The fourth parameter to sqlite3_open_v2() is the name of the 3137** [sqlite3_vfs] object that defines the operating system interface that 3138** the new database connection should use. ^If the fourth parameter is 3139** a NULL pointer then the default [sqlite3_vfs] object is used. 3140** 3141** ^If the filename is ":memory:", then a private, temporary in-memory database 3142** is created for the connection. ^This in-memory database will vanish when 3143** the database connection is closed. Future versions of SQLite might 3144** make use of additional special filenames that begin with the ":" character. 3145** It is recommended that when a database filename actually does begin with 3146** a ":" character you should prefix the filename with a pathname such as 3147** "./" to avoid ambiguity. 3148** 3149** ^If the filename is an empty string, then a private, temporary 3150** on-disk database will be created. ^This private database will be 3151** automatically deleted as soon as the database connection is closed. 3152** 3153** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3154** 3155** ^If [URI filename] interpretation is enabled, and the filename argument 3156** begins with "file:", then the filename is interpreted as a URI. ^URI 3157** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3158** set in the third argument to sqlite3_open_v2(), or if it has 3159** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3160** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3161** URI filename interpretation is turned off 3162** by default, but future releases of SQLite might enable URI filename 3163** interpretation by default. See "[URI filenames]" for additional 3164** information. 3165** 3166** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3167** authority, then it must be either an empty string or the string 3168** "localhost". ^If the authority is not an empty string or "localhost", an 3169** error is returned to the caller. ^The fragment component of a URI, if 3170** present, is ignored. 3171** 3172** ^SQLite uses the path component of the URI as the name of the disk file 3173** which contains the database. ^If the path begins with a '/' character, 3174** then it is interpreted as an absolute path. ^If the path does not begin 3175** with a '/' (meaning that the authority section is omitted from the URI) 3176** then the path is interpreted as a relative path. 3177** ^(On windows, the first component of an absolute path 3178** is a drive specification (e.g. "C:").)^ 3179** 3180** [[core URI query parameters]] 3181** The query component of a URI may contain parameters that are interpreted 3182** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3183** SQLite and its built-in [VFSes] interpret the 3184** following query parameters: 3185** 3186** <ul> 3187** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3188** a VFS object that provides the operating system interface that should 3189** be used to access the database file on disk. ^If this option is set to 3190** an empty string the default VFS object is used. ^Specifying an unknown 3191** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3192** present, then the VFS specified by the option takes precedence over 3193** the value passed as the fourth parameter to sqlite3_open_v2(). 3194** 3195** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3196** "rwc", or "memory". Attempting to set it to any other value is 3197** an error)^. 3198** ^If "ro" is specified, then the database is opened for read-only 3199** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3200** third argument to sqlite3_open_v2(). ^If the mode option is set to 3201** "rw", then the database is opened for read-write (but not create) 3202** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3203** been set. ^Value "rwc" is equivalent to setting both 3204** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3205** set to "memory" then a pure [in-memory database] that never reads 3206** or writes from disk is used. ^It is an error to specify a value for 3207** the mode parameter that is less restrictive than that specified by 3208** the flags passed in the third parameter to sqlite3_open_v2(). 3209** 3210** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3211** "private". ^Setting it to "shared" is equivalent to setting the 3212** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3213** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3214** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3215** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3216** a URI filename, its value overrides any behavior requested by setting 3217** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3218** 3219** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3220** [powersafe overwrite] property does or does not apply to the 3221** storage media on which the database file resides. 3222** 3223** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3224** which if set disables file locking in rollback journal modes. This 3225** is useful for accessing a database on a filesystem that does not 3226** support locking. Caution: Database corruption might result if two 3227** or more processes write to the same database and any one of those 3228** processes uses nolock=1. 3229** 3230** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3231** parameter that indicates that the database file is stored on 3232** read-only media. ^When immutable is set, SQLite assumes that the 3233** database file cannot be changed, even by a process with higher 3234** privilege, and so the database is opened read-only and all locking 3235** and change detection is disabled. Caution: Setting the immutable 3236** property on a database file that does in fact change can result 3237** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3238** See also: [SQLITE_IOCAP_IMMUTABLE]. 3239** 3240** </ul> 3241** 3242** ^Specifying an unknown parameter in the query component of a URI is not an 3243** error. Future versions of SQLite might understand additional query 3244** parameters. See "[query parameters with special meaning to SQLite]" for 3245** additional information. 3246** 3247** [[URI filename examples]] <h3>URI filename examples</h3> 3248** 3249** <table border="1" align=center cellpadding=5> 3250** <tr><th> URI filenames <th> Results 3251** <tr><td> file:data.db <td> 3252** Open the file "data.db" in the current directory. 3253** <tr><td> file:/home/fred/data.db<br> 3254** file:///home/fred/data.db <br> 3255** file://localhost/home/fred/data.db <br> <td> 3256** Open the database file "/home/fred/data.db". 3257** <tr><td> file://darkstar/home/fred/data.db <td> 3258** An error. "darkstar" is not a recognized authority. 3259** <tr><td style="white-space:nowrap"> 3260** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3261** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3262** C:. Note that the %20 escaping in this example is not strictly 3263** necessary - space characters can be used literally 3264** in URI filenames. 3265** <tr><td> file:data.db?mode=ro&cache=private <td> 3266** Open file "data.db" in the current directory for read-only access. 3267** Regardless of whether or not shared-cache mode is enabled by 3268** default, use a private cache. 3269** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3270** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3271** that uses dot-files in place of posix advisory locking. 3272** <tr><td> file:data.db?mode=readonly <td> 3273** An error. "readonly" is not a valid option for the "mode" parameter. 3274** </table> 3275** 3276** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3277** query components of a URI. A hexadecimal escape sequence consists of a 3278** percent sign - "%" - followed by exactly two hexadecimal digits 3279** specifying an octet value. ^Before the path or query components of a 3280** URI filename are interpreted, they are encoded using UTF-8 and all 3281** hexadecimal escape sequences replaced by a single byte containing the 3282** corresponding octet. If this process generates an invalid UTF-8 encoding, 3283** the results are undefined. 3284** 3285** <b>Note to Windows users:</b> The encoding used for the filename argument 3286** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3287** codepage is currently defined. Filenames containing international 3288** characters must be converted to UTF-8 prior to passing them into 3289** sqlite3_open() or sqlite3_open_v2(). 3290** 3291** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3292** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3293** features that require the use of temporary files may fail. 3294** 3295** See also: [sqlite3_temp_directory] 3296*/ 3297int sqlite3_open( 3298 const char *filename, /* Database filename (UTF-8) */ 3299 sqlite3 **ppDb /* OUT: SQLite db handle */ 3300); 3301int sqlite3_open16( 3302 const void *filename, /* Database filename (UTF-16) */ 3303 sqlite3 **ppDb /* OUT: SQLite db handle */ 3304); 3305int sqlite3_open_v2( 3306 const char *filename, /* Database filename (UTF-8) */ 3307 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3308 int flags, /* Flags */ 3309 const char *zVfs /* Name of VFS module to use */ 3310); 3311 3312/* 3313** CAPI3REF: Obtain Values For URI Parameters 3314** 3315** These are utility routines, useful to VFS implementations, that check 3316** to see if a database file was a URI that contained a specific query 3317** parameter, and if so obtains the value of that query parameter. 3318** 3319** If F is the database filename pointer passed into the xOpen() method of 3320** a VFS implementation when the flags parameter to xOpen() has one or 3321** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3322** P is the name of the query parameter, then 3323** sqlite3_uri_parameter(F,P) returns the value of the P 3324** parameter if it exists or a NULL pointer if P does not appear as a 3325** query parameter on F. If P is a query parameter of F 3326** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3327** a pointer to an empty string. 3328** 3329** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3330** parameter and returns true (1) or false (0) according to the value 3331** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3332** value of query parameter P is one of "yes", "true", or "on" in any 3333** case or if the value begins with a non-zero number. The 3334** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3335** query parameter P is one of "no", "false", or "off" in any case or 3336** if the value begins with a numeric zero. If P is not a query 3337** parameter on F or if the value of P is does not match any of the 3338** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3339** 3340** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3341** 64-bit signed integer and returns that integer, or D if P does not 3342** exist. If the value of P is something other than an integer, then 3343** zero is returned. 3344** 3345** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3346** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3347** is not a database file pathname pointer that SQLite passed into the xOpen 3348** VFS method, then the behavior of this routine is undefined and probably 3349** undesirable. 3350*/ 3351const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3352int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3353sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3354 3355 3356/* 3357** CAPI3REF: Error Codes And Messages 3358** METHOD: sqlite3 3359** 3360** ^If the most recent sqlite3_* API call associated with 3361** [database connection] D failed, then the sqlite3_errcode(D) interface 3362** returns the numeric [result code] or [extended result code] for that 3363** API call. 3364** ^The sqlite3_extended_errcode() 3365** interface is the same except that it always returns the 3366** [extended result code] even when extended result codes are 3367** disabled. 3368** 3369** The values returned by sqlite3_errcode() and/or 3370** sqlite3_extended_errcode() might change with each API call. 3371** Except, there are some interfaces that are guaranteed to never 3372** change the value of the error code. The error-code preserving 3373** interfaces are: 3374** 3375** <ul> 3376** <li> sqlite3_errcode() 3377** <li> sqlite3_extended_errcode() 3378** <li> sqlite3_errmsg() 3379** <li> sqlite3_errmsg16() 3380** </ul> 3381** 3382** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3383** text that describes the error, as either UTF-8 or UTF-16 respectively. 3384** ^(Memory to hold the error message string is managed internally. 3385** The application does not need to worry about freeing the result. 3386** However, the error string might be overwritten or deallocated by 3387** subsequent calls to other SQLite interface functions.)^ 3388** 3389** ^The sqlite3_errstr() interface returns the English-language text 3390** that describes the [result code], as UTF-8. 3391** ^(Memory to hold the error message string is managed internally 3392** and must not be freed by the application)^. 3393** 3394** When the serialized [threading mode] is in use, it might be the 3395** case that a second error occurs on a separate thread in between 3396** the time of the first error and the call to these interfaces. 3397** When that happens, the second error will be reported since these 3398** interfaces always report the most recent result. To avoid 3399** this, each thread can obtain exclusive use of the [database connection] D 3400** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3401** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3402** all calls to the interfaces listed here are completed. 3403** 3404** If an interface fails with SQLITE_MISUSE, that means the interface 3405** was invoked incorrectly by the application. In that case, the 3406** error code and message may or may not be set. 3407*/ 3408int sqlite3_errcode(sqlite3 *db); 3409int sqlite3_extended_errcode(sqlite3 *db); 3410const char *sqlite3_errmsg(sqlite3*); 3411const void *sqlite3_errmsg16(sqlite3*); 3412const char *sqlite3_errstr(int); 3413 3414/* 3415** CAPI3REF: Prepared Statement Object 3416** KEYWORDS: {prepared statement} {prepared statements} 3417** 3418** An instance of this object represents a single SQL statement that 3419** has been compiled into binary form and is ready to be evaluated. 3420** 3421** Think of each SQL statement as a separate computer program. The 3422** original SQL text is source code. A prepared statement object 3423** is the compiled object code. All SQL must be converted into a 3424** prepared statement before it can be run. 3425** 3426** The life-cycle of a prepared statement object usually goes like this: 3427** 3428** <ol> 3429** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3430** <li> Bind values to [parameters] using the sqlite3_bind_*() 3431** interfaces. 3432** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3433** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3434** to step 2. Do this zero or more times. 3435** <li> Destroy the object using [sqlite3_finalize()]. 3436** </ol> 3437*/ 3438typedef struct sqlite3_stmt sqlite3_stmt; 3439 3440/* 3441** CAPI3REF: Run-time Limits 3442** METHOD: sqlite3 3443** 3444** ^(This interface allows the size of various constructs to be limited 3445** on a connection by connection basis. The first parameter is the 3446** [database connection] whose limit is to be set or queried. The 3447** second parameter is one of the [limit categories] that define a 3448** class of constructs to be size limited. The third parameter is the 3449** new limit for that construct.)^ 3450** 3451** ^If the new limit is a negative number, the limit is unchanged. 3452** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3453** [limits | hard upper bound] 3454** set at compile-time by a C preprocessor macro called 3455** [limits | SQLITE_MAX_<i>NAME</i>]. 3456** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3457** ^Attempts to increase a limit above its hard upper bound are 3458** silently truncated to the hard upper bound. 3459** 3460** ^Regardless of whether or not the limit was changed, the 3461** [sqlite3_limit()] interface returns the prior value of the limit. 3462** ^Hence, to find the current value of a limit without changing it, 3463** simply invoke this interface with the third parameter set to -1. 3464** 3465** Run-time limits are intended for use in applications that manage 3466** both their own internal database and also databases that are controlled 3467** by untrusted external sources. An example application might be a 3468** web browser that has its own databases for storing history and 3469** separate databases controlled by JavaScript applications downloaded 3470** off the Internet. The internal databases can be given the 3471** large, default limits. Databases managed by external sources can 3472** be given much smaller limits designed to prevent a denial of service 3473** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3474** interface to further control untrusted SQL. The size of the database 3475** created by an untrusted script can be contained using the 3476** [max_page_count] [PRAGMA]. 3477** 3478** New run-time limit categories may be added in future releases. 3479*/ 3480int sqlite3_limit(sqlite3*, int id, int newVal); 3481 3482/* 3483** CAPI3REF: Run-Time Limit Categories 3484** KEYWORDS: {limit category} {*limit categories} 3485** 3486** These constants define various performance limits 3487** that can be lowered at run-time using [sqlite3_limit()]. 3488** The synopsis of the meanings of the various limits is shown below. 3489** Additional information is available at [limits | Limits in SQLite]. 3490** 3491** <dl> 3492** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3493** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3494** 3495** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3496** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3497** 3498** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3499** <dd>The maximum number of columns in a table definition or in the 3500** result set of a [SELECT] or the maximum number of columns in an index 3501** or in an ORDER BY or GROUP BY clause.</dd>)^ 3502** 3503** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3504** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3505** 3506** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3507** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3508** 3509** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3510** <dd>The maximum number of instructions in a virtual machine program 3511** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3512** the equivalent tries to allocate space for more than this many opcodes 3513** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3514** 3515** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3516** <dd>The maximum number of arguments on a function.</dd>)^ 3517** 3518** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3519** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3520** 3521** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3522** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3523** <dd>The maximum length of the pattern argument to the [LIKE] or 3524** [GLOB] operators.</dd>)^ 3525** 3526** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3527** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3528** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3529** 3530** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3531** <dd>The maximum depth of recursion for triggers.</dd>)^ 3532** 3533** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3534** <dd>The maximum number of auxiliary worker threads that a single 3535** [prepared statement] may start.</dd>)^ 3536** </dl> 3537*/ 3538#define SQLITE_LIMIT_LENGTH 0 3539#define SQLITE_LIMIT_SQL_LENGTH 1 3540#define SQLITE_LIMIT_COLUMN 2 3541#define SQLITE_LIMIT_EXPR_DEPTH 3 3542#define SQLITE_LIMIT_COMPOUND_SELECT 4 3543#define SQLITE_LIMIT_VDBE_OP 5 3544#define SQLITE_LIMIT_FUNCTION_ARG 6 3545#define SQLITE_LIMIT_ATTACHED 7 3546#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3547#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3548#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3549#define SQLITE_LIMIT_WORKER_THREADS 11 3550 3551/* 3552** CAPI3REF: Prepare Flags 3553** 3554** These constants define various flags that can be passed into 3555** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3556** [sqlite3_prepare16_v3()] interfaces. 3557** 3558** New flags may be added in future releases of SQLite. 3559** 3560** <dl> 3561** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3562** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3563** that the prepared statement will be retained for a long time and 3564** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3565** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3566** be used just once or at most a few times and then destroyed using 3567** [sqlite3_finalize()] relatively soon. The current implementation acts 3568** on this hint by avoiding the use of [lookaside memory] so as not to 3569** deplete the limited store of lookaside memory. Future versions of 3570** SQLite may act on this hint differently. 3571** </dl> 3572*/ 3573#define SQLITE_PREPARE_PERSISTENT 0x01 3574 3575/* 3576** CAPI3REF: Compiling An SQL Statement 3577** KEYWORDS: {SQL statement compiler} 3578** METHOD: sqlite3 3579** CONSTRUCTOR: sqlite3_stmt 3580** 3581** To execute an SQL statement, it must first be compiled into a byte-code 3582** program using one of these routines. Or, in other words, these routines 3583** are constructors for the [prepared statement] object. 3584** 3585** The preferred routine to use is [sqlite3_prepare_v2()]. The 3586** [sqlite3_prepare()] interface is legacy and should be avoided. 3587** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3588** for special purposes. 3589** 3590** The use of the UTF-8 interfaces is preferred, as SQLite currently 3591** does all parsing using UTF-8. The UTF-16 interfaces are provided 3592** as a convenience. The UTF-16 interfaces work by converting the 3593** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3594** 3595** The first argument, "db", is a [database connection] obtained from a 3596** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3597** [sqlite3_open16()]. The database connection must not have been closed. 3598** 3599** The second argument, "zSql", is the statement to be compiled, encoded 3600** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3601** and sqlite3_prepare_v3() 3602** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3603** and sqlite3_prepare16_v3() use UTF-16. 3604** 3605** ^If the nByte argument is negative, then zSql is read up to the 3606** first zero terminator. ^If nByte is positive, then it is the 3607** number of bytes read from zSql. ^If nByte is zero, then no prepared 3608** statement is generated. 3609** If the caller knows that the supplied string is nul-terminated, then 3610** there is a small performance advantage to passing an nByte parameter that 3611** is the number of bytes in the input string <i>including</i> 3612** the nul-terminator. 3613** 3614** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3615** past the end of the first SQL statement in zSql. These routines only 3616** compile the first statement in zSql, so *pzTail is left pointing to 3617** what remains uncompiled. 3618** 3619** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3620** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3621** to NULL. ^If the input text contains no SQL (if the input is an empty 3622** string or a comment) then *ppStmt is set to NULL. 3623** The calling procedure is responsible for deleting the compiled 3624** SQL statement using [sqlite3_finalize()] after it has finished with it. 3625** ppStmt may not be NULL. 3626** 3627** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3628** otherwise an [error code] is returned. 3629** 3630** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3631** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3632** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3633** are retained for backwards compatibility, but their use is discouraged. 3634** ^In the "vX" interfaces, the prepared statement 3635** that is returned (the [sqlite3_stmt] object) contains a copy of the 3636** original SQL text. This causes the [sqlite3_step()] interface to 3637** behave differently in three ways: 3638** 3639** <ol> 3640** <li> 3641** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3642** always used to do, [sqlite3_step()] will automatically recompile the SQL 3643** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3644** retries will occur before sqlite3_step() gives up and returns an error. 3645** </li> 3646** 3647** <li> 3648** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3649** [error codes] or [extended error codes]. ^The legacy behavior was that 3650** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3651** and the application would have to make a second call to [sqlite3_reset()] 3652** in order to find the underlying cause of the problem. With the "v2" prepare 3653** interfaces, the underlying reason for the error is returned immediately. 3654** </li> 3655** 3656** <li> 3657** ^If the specific value bound to [parameter | host parameter] in the 3658** WHERE clause might influence the choice of query plan for a statement, 3659** then the statement will be automatically recompiled, as if there had been 3660** a schema change, on the first [sqlite3_step()] call following any change 3661** to the [sqlite3_bind_text | bindings] of that [parameter]. 3662** ^The specific value of WHERE-clause [parameter] might influence the 3663** choice of query plan if the parameter is the left-hand side of a [LIKE] 3664** or [GLOB] operator or if the parameter is compared to an indexed column 3665** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3666** </li> 3667** </ol> 3668** 3669** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3670** the extra prepFlags parameter, which is a bit array consisting of zero or 3671** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3672** sqlite3_prepare_v2() interface works exactly the same as 3673** sqlite3_prepare_v3() with a zero prepFlags parameter. 3674*/ 3675int sqlite3_prepare( 3676 sqlite3 *db, /* Database handle */ 3677 const char *zSql, /* SQL statement, UTF-8 encoded */ 3678 int nByte, /* Maximum length of zSql in bytes. */ 3679 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3680 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3681); 3682int sqlite3_prepare_v2( 3683 sqlite3 *db, /* Database handle */ 3684 const char *zSql, /* SQL statement, UTF-8 encoded */ 3685 int nByte, /* Maximum length of zSql in bytes. */ 3686 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3687 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3688); 3689int sqlite3_prepare_v3( 3690 sqlite3 *db, /* Database handle */ 3691 const char *zSql, /* SQL statement, UTF-8 encoded */ 3692 int nByte, /* Maximum length of zSql in bytes. */ 3693 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3694 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3695 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3696); 3697int sqlite3_prepare16( 3698 sqlite3 *db, /* Database handle */ 3699 const void *zSql, /* SQL statement, UTF-16 encoded */ 3700 int nByte, /* Maximum length of zSql in bytes. */ 3701 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3702 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3703); 3704int sqlite3_prepare16_v2( 3705 sqlite3 *db, /* Database handle */ 3706 const void *zSql, /* SQL statement, UTF-16 encoded */ 3707 int nByte, /* Maximum length of zSql in bytes. */ 3708 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3709 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3710); 3711int sqlite3_prepare16_v3( 3712 sqlite3 *db, /* Database handle */ 3713 const void *zSql, /* SQL statement, UTF-16 encoded */ 3714 int nByte, /* Maximum length of zSql in bytes. */ 3715 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3716 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3717 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3718); 3719 3720/* 3721** CAPI3REF: Retrieving Statement SQL 3722** METHOD: sqlite3_stmt 3723** 3724** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3725** SQL text used to create [prepared statement] P if P was 3726** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3727** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3728** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3729** string containing the SQL text of prepared statement P with 3730** [bound parameters] expanded. 3731** 3732** ^(For example, if a prepared statement is created using the SQL 3733** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3734** and parameter :xyz is unbound, then sqlite3_sql() will return 3735** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3736** will return "SELECT 2345,NULL".)^ 3737** 3738** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3739** is available to hold the result, or if the result would exceed the 3740** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3741** 3742** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3743** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3744** option causes sqlite3_expanded_sql() to always return NULL. 3745** 3746** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3747** automatically freed when the prepared statement is finalized. 3748** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3749** is obtained from [sqlite3_malloc()] and must be free by the application 3750** by passing it to [sqlite3_free()]. 3751*/ 3752const char *sqlite3_sql(sqlite3_stmt *pStmt); 3753char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3754 3755/* 3756** CAPI3REF: Determine If An SQL Statement Writes The Database 3757** METHOD: sqlite3_stmt 3758** 3759** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3760** and only if the [prepared statement] X makes no direct changes to 3761** the content of the database file. 3762** 3763** Note that [application-defined SQL functions] or 3764** [virtual tables] might change the database indirectly as a side effect. 3765** ^(For example, if an application defines a function "eval()" that 3766** calls [sqlite3_exec()], then the following SQL statement would 3767** change the database file through side-effects: 3768** 3769** <blockquote><pre> 3770** SELECT eval('DELETE FROM t1') FROM t2; 3771** </pre></blockquote> 3772** 3773** But because the [SELECT] statement does not change the database file 3774** directly, sqlite3_stmt_readonly() would still return true.)^ 3775** 3776** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3777** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3778** since the statements themselves do not actually modify the database but 3779** rather they control the timing of when other statements modify the 3780** database. ^The [ATTACH] and [DETACH] statements also cause 3781** sqlite3_stmt_readonly() to return true since, while those statements 3782** change the configuration of a database connection, they do not make 3783** changes to the content of the database files on disk. 3784** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3785** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3786** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3787** sqlite3_stmt_readonly() returns false for those commands. 3788*/ 3789int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3790 3791/* 3792** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3793** METHOD: sqlite3_stmt 3794** 3795** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3796** [prepared statement] S has been stepped at least once using 3797** [sqlite3_step(S)] but has neither run to completion (returned 3798** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3799** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3800** interface returns false if S is a NULL pointer. If S is not a 3801** NULL pointer and is not a pointer to a valid [prepared statement] 3802** object, then the behavior is undefined and probably undesirable. 3803** 3804** This interface can be used in combination [sqlite3_next_stmt()] 3805** to locate all prepared statements associated with a database 3806** connection that are in need of being reset. This can be used, 3807** for example, in diagnostic routines to search for prepared 3808** statements that are holding a transaction open. 3809*/ 3810int sqlite3_stmt_busy(sqlite3_stmt*); 3811 3812/* 3813** CAPI3REF: Dynamically Typed Value Object 3814** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3815** 3816** SQLite uses the sqlite3_value object to represent all values 3817** that can be stored in a database table. SQLite uses dynamic typing 3818** for the values it stores. ^Values stored in sqlite3_value objects 3819** can be integers, floating point values, strings, BLOBs, or NULL. 3820** 3821** An sqlite3_value object may be either "protected" or "unprotected". 3822** Some interfaces require a protected sqlite3_value. Other interfaces 3823** will accept either a protected or an unprotected sqlite3_value. 3824** Every interface that accepts sqlite3_value arguments specifies 3825** whether or not it requires a protected sqlite3_value. The 3826** [sqlite3_value_dup()] interface can be used to construct a new 3827** protected sqlite3_value from an unprotected sqlite3_value. 3828** 3829** The terms "protected" and "unprotected" refer to whether or not 3830** a mutex is held. An internal mutex is held for a protected 3831** sqlite3_value object but no mutex is held for an unprotected 3832** sqlite3_value object. If SQLite is compiled to be single-threaded 3833** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3834** or if SQLite is run in one of reduced mutex modes 3835** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3836** then there is no distinction between protected and unprotected 3837** sqlite3_value objects and they can be used interchangeably. However, 3838** for maximum code portability it is recommended that applications 3839** still make the distinction between protected and unprotected 3840** sqlite3_value objects even when not strictly required. 3841** 3842** ^The sqlite3_value objects that are passed as parameters into the 3843** implementation of [application-defined SQL functions] are protected. 3844** ^The sqlite3_value object returned by 3845** [sqlite3_column_value()] is unprotected. 3846** Unprotected sqlite3_value objects may only be used as arguments 3847** to [sqlite3_result_value()], [sqlite3_bind_value()], and 3848** [sqlite3_value_dup()]. 3849** The [sqlite3_value_blob | sqlite3_value_type()] family of 3850** interfaces require protected sqlite3_value objects. 3851*/ 3852typedef struct sqlite3_value sqlite3_value; 3853 3854/* 3855** CAPI3REF: SQL Function Context Object 3856** 3857** The context in which an SQL function executes is stored in an 3858** sqlite3_context object. ^A pointer to an sqlite3_context object 3859** is always first parameter to [application-defined SQL functions]. 3860** The application-defined SQL function implementation will pass this 3861** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3862** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3863** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3864** and/or [sqlite3_set_auxdata()]. 3865*/ 3866typedef struct sqlite3_context sqlite3_context; 3867 3868/* 3869** CAPI3REF: Binding Values To Prepared Statements 3870** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3871** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3872** METHOD: sqlite3_stmt 3873** 3874** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3875** literals may be replaced by a [parameter] that matches one of following 3876** templates: 3877** 3878** <ul> 3879** <li> ? 3880** <li> ?NNN 3881** <li> :VVV 3882** <li> @VVV 3883** <li> $VVV 3884** </ul> 3885** 3886** In the templates above, NNN represents an integer literal, 3887** and VVV represents an alphanumeric identifier.)^ ^The values of these 3888** parameters (also called "host parameter names" or "SQL parameters") 3889** can be set using the sqlite3_bind_*() routines defined here. 3890** 3891** ^The first argument to the sqlite3_bind_*() routines is always 3892** a pointer to the [sqlite3_stmt] object returned from 3893** [sqlite3_prepare_v2()] or its variants. 3894** 3895** ^The second argument is the index of the SQL parameter to be set. 3896** ^The leftmost SQL parameter has an index of 1. ^When the same named 3897** SQL parameter is used more than once, second and subsequent 3898** occurrences have the same index as the first occurrence. 3899** ^The index for named parameters can be looked up using the 3900** [sqlite3_bind_parameter_index()] API if desired. ^The index 3901** for "?NNN" parameters is the value of NNN. 3902** ^The NNN value must be between 1 and the [sqlite3_limit()] 3903** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3904** 3905** ^The third argument is the value to bind to the parameter. 3906** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3907** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3908** is ignored and the end result is the same as sqlite3_bind_null(). 3909** 3910** ^(In those routines that have a fourth argument, its value is the 3911** number of bytes in the parameter. To be clear: the value is the 3912** number of <u>bytes</u> in the value, not the number of characters.)^ 3913** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3914** is negative, then the length of the string is 3915** the number of bytes up to the first zero terminator. 3916** If the fourth parameter to sqlite3_bind_blob() is negative, then 3917** the behavior is undefined. 3918** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3919** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3920** that parameter must be the byte offset 3921** where the NUL terminator would occur assuming the string were NUL 3922** terminated. If any NUL characters occur at byte offsets less than 3923** the value of the fourth parameter then the resulting string value will 3924** contain embedded NULs. The result of expressions involving strings 3925** with embedded NULs is undefined. 3926** 3927** ^The fifth argument to the BLOB and string binding interfaces 3928** is a destructor used to dispose of the BLOB or 3929** string after SQLite has finished with it. ^The destructor is called 3930** to dispose of the BLOB or string even if the call to bind API fails. 3931** ^If the fifth argument is 3932** the special value [SQLITE_STATIC], then SQLite assumes that the 3933** information is in static, unmanaged space and does not need to be freed. 3934** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3935** SQLite makes its own private copy of the data immediately, before 3936** the sqlite3_bind_*() routine returns. 3937** 3938** ^The sixth argument to sqlite3_bind_text64() must be one of 3939** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3940** to specify the encoding of the text in the third parameter. If 3941** the sixth argument to sqlite3_bind_text64() is not one of the 3942** allowed values shown above, or if the text encoding is different 3943** from the encoding specified by the sixth parameter, then the behavior 3944** is undefined. 3945** 3946** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3947** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3948** (just an integer to hold its size) while it is being processed. 3949** Zeroblobs are intended to serve as placeholders for BLOBs whose 3950** content is later written using 3951** [sqlite3_blob_open | incremental BLOB I/O] routines. 3952** ^A negative value for the zeroblob results in a zero-length BLOB. 3953** 3954** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 3955** [prepared statement] S to have an SQL value of NULL, but to also be 3956** associated with the pointer P of type T. ^D is either a NULL pointer or 3957** a pointer to a destructor function for P. ^SQLite will invoke the 3958** destructor D with a single argument of P when it is finished using 3959** P. The T parameter should be a static string, preferably a string 3960** literal. The sqlite3_bind_pointer() routine is part of the 3961** [pointer passing interface] added for SQLite 3.20.0. 3962** 3963** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3964** for the [prepared statement] or with a prepared statement for which 3965** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3966** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3967** routine is passed a [prepared statement] that has been finalized, the 3968** result is undefined and probably harmful. 3969** 3970** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3971** ^Unbound parameters are interpreted as NULL. 3972** 3973** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3974** [error code] if anything goes wrong. 3975** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3976** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3977** [SQLITE_MAX_LENGTH]. 3978** ^[SQLITE_RANGE] is returned if the parameter 3979** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3980** 3981** See also: [sqlite3_bind_parameter_count()], 3982** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3983*/ 3984int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3985int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3986 void(*)(void*)); 3987int sqlite3_bind_double(sqlite3_stmt*, int, double); 3988int sqlite3_bind_int(sqlite3_stmt*, int, int); 3989int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3990int sqlite3_bind_null(sqlite3_stmt*, int); 3991int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3992int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3993int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3994 void(*)(void*), unsigned char encoding); 3995int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3996int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 3997int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3998int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3999 4000/* 4001** CAPI3REF: Number Of SQL Parameters 4002** METHOD: sqlite3_stmt 4003** 4004** ^This routine can be used to find the number of [SQL parameters] 4005** in a [prepared statement]. SQL parameters are tokens of the 4006** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4007** placeholders for values that are [sqlite3_bind_blob | bound] 4008** to the parameters at a later time. 4009** 4010** ^(This routine actually returns the index of the largest (rightmost) 4011** parameter. For all forms except ?NNN, this will correspond to the 4012** number of unique parameters. If parameters of the ?NNN form are used, 4013** there may be gaps in the list.)^ 4014** 4015** See also: [sqlite3_bind_blob|sqlite3_bind()], 4016** [sqlite3_bind_parameter_name()], and 4017** [sqlite3_bind_parameter_index()]. 4018*/ 4019int sqlite3_bind_parameter_count(sqlite3_stmt*); 4020 4021/* 4022** CAPI3REF: Name Of A Host Parameter 4023** METHOD: sqlite3_stmt 4024** 4025** ^The sqlite3_bind_parameter_name(P,N) interface returns 4026** the name of the N-th [SQL parameter] in the [prepared statement] P. 4027** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4028** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4029** respectively. 4030** In other words, the initial ":" or "$" or "@" or "?" 4031** is included as part of the name.)^ 4032** ^Parameters of the form "?" without a following integer have no name 4033** and are referred to as "nameless" or "anonymous parameters". 4034** 4035** ^The first host parameter has an index of 1, not 0. 4036** 4037** ^If the value N is out of range or if the N-th parameter is 4038** nameless, then NULL is returned. ^The returned string is 4039** always in UTF-8 encoding even if the named parameter was 4040** originally specified as UTF-16 in [sqlite3_prepare16()], 4041** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4042** 4043** See also: [sqlite3_bind_blob|sqlite3_bind()], 4044** [sqlite3_bind_parameter_count()], and 4045** [sqlite3_bind_parameter_index()]. 4046*/ 4047const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4048 4049/* 4050** CAPI3REF: Index Of A Parameter With A Given Name 4051** METHOD: sqlite3_stmt 4052** 4053** ^Return the index of an SQL parameter given its name. ^The 4054** index value returned is suitable for use as the second 4055** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4056** is returned if no matching parameter is found. ^The parameter 4057** name must be given in UTF-8 even if the original statement 4058** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4059** [sqlite3_prepare16_v3()]. 4060** 4061** See also: [sqlite3_bind_blob|sqlite3_bind()], 4062** [sqlite3_bind_parameter_count()], and 4063** [sqlite3_bind_parameter_name()]. 4064*/ 4065int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4066 4067/* 4068** CAPI3REF: Reset All Bindings On A Prepared Statement 4069** METHOD: sqlite3_stmt 4070** 4071** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4072** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4073** ^Use this routine to reset all host parameters to NULL. 4074*/ 4075int sqlite3_clear_bindings(sqlite3_stmt*); 4076 4077/* 4078** CAPI3REF: Number Of Columns In A Result Set 4079** METHOD: sqlite3_stmt 4080** 4081** ^Return the number of columns in the result set returned by the 4082** [prepared statement]. ^If this routine returns 0, that means the 4083** [prepared statement] returns no data (for example an [UPDATE]). 4084** ^However, just because this routine returns a positive number does not 4085** mean that one or more rows of data will be returned. ^A SELECT statement 4086** will always have a positive sqlite3_column_count() but depending on the 4087** WHERE clause constraints and the table content, it might return no rows. 4088** 4089** See also: [sqlite3_data_count()] 4090*/ 4091int sqlite3_column_count(sqlite3_stmt *pStmt); 4092 4093/* 4094** CAPI3REF: Column Names In A Result Set 4095** METHOD: sqlite3_stmt 4096** 4097** ^These routines return the name assigned to a particular column 4098** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4099** interface returns a pointer to a zero-terminated UTF-8 string 4100** and sqlite3_column_name16() returns a pointer to a zero-terminated 4101** UTF-16 string. ^The first parameter is the [prepared statement] 4102** that implements the [SELECT] statement. ^The second parameter is the 4103** column number. ^The leftmost column is number 0. 4104** 4105** ^The returned string pointer is valid until either the [prepared statement] 4106** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4107** reprepared by the first call to [sqlite3_step()] for a particular run 4108** or until the next call to 4109** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4110** 4111** ^If sqlite3_malloc() fails during the processing of either routine 4112** (for example during a conversion from UTF-8 to UTF-16) then a 4113** NULL pointer is returned. 4114** 4115** ^The name of a result column is the value of the "AS" clause for 4116** that column, if there is an AS clause. If there is no AS clause 4117** then the name of the column is unspecified and may change from 4118** one release of SQLite to the next. 4119*/ 4120const char *sqlite3_column_name(sqlite3_stmt*, int N); 4121const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4122 4123/* 4124** CAPI3REF: Source Of Data In A Query Result 4125** METHOD: sqlite3_stmt 4126** 4127** ^These routines provide a means to determine the database, table, and 4128** table column that is the origin of a particular result column in 4129** [SELECT] statement. 4130** ^The name of the database or table or column can be returned as 4131** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4132** the database name, the _table_ routines return the table name, and 4133** the origin_ routines return the column name. 4134** ^The returned string is valid until the [prepared statement] is destroyed 4135** using [sqlite3_finalize()] or until the statement is automatically 4136** reprepared by the first call to [sqlite3_step()] for a particular run 4137** or until the same information is requested 4138** again in a different encoding. 4139** 4140** ^The names returned are the original un-aliased names of the 4141** database, table, and column. 4142** 4143** ^The first argument to these interfaces is a [prepared statement]. 4144** ^These functions return information about the Nth result column returned by 4145** the statement, where N is the second function argument. 4146** ^The left-most column is column 0 for these routines. 4147** 4148** ^If the Nth column returned by the statement is an expression or 4149** subquery and is not a column value, then all of these functions return 4150** NULL. ^These routine might also return NULL if a memory allocation error 4151** occurs. ^Otherwise, they return the name of the attached database, table, 4152** or column that query result column was extracted from. 4153** 4154** ^As with all other SQLite APIs, those whose names end with "16" return 4155** UTF-16 encoded strings and the other functions return UTF-8. 4156** 4157** ^These APIs are only available if the library was compiled with the 4158** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4159** 4160** If two or more threads call one or more of these routines against the same 4161** prepared statement and column at the same time then the results are 4162** undefined. 4163** 4164** If two or more threads call one or more 4165** [sqlite3_column_database_name | column metadata interfaces] 4166** for the same [prepared statement] and result column 4167** at the same time then the results are undefined. 4168*/ 4169const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4170const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4171const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4172const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4173const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4174const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4175 4176/* 4177** CAPI3REF: Declared Datatype Of A Query Result 4178** METHOD: sqlite3_stmt 4179** 4180** ^(The first parameter is a [prepared statement]. 4181** If this statement is a [SELECT] statement and the Nth column of the 4182** returned result set of that [SELECT] is a table column (not an 4183** expression or subquery) then the declared type of the table 4184** column is returned.)^ ^If the Nth column of the result set is an 4185** expression or subquery, then a NULL pointer is returned. 4186** ^The returned string is always UTF-8 encoded. 4187** 4188** ^(For example, given the database schema: 4189** 4190** CREATE TABLE t1(c1 VARIANT); 4191** 4192** and the following statement to be compiled: 4193** 4194** SELECT c1 + 1, c1 FROM t1; 4195** 4196** this routine would return the string "VARIANT" for the second result 4197** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4198** 4199** ^SQLite uses dynamic run-time typing. ^So just because a column 4200** is declared to contain a particular type does not mean that the 4201** data stored in that column is of the declared type. SQLite is 4202** strongly typed, but the typing is dynamic not static. ^Type 4203** is associated with individual values, not with the containers 4204** used to hold those values. 4205*/ 4206const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4207const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4208 4209/* 4210** CAPI3REF: Evaluate An SQL Statement 4211** METHOD: sqlite3_stmt 4212** 4213** After a [prepared statement] has been prepared using any of 4214** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4215** or [sqlite3_prepare16_v3()] or one of the legacy 4216** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4217** must be called one or more times to evaluate the statement. 4218** 4219** The details of the behavior of the sqlite3_step() interface depend 4220** on whether the statement was prepared using the newer "vX" interfaces 4221** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4222** [sqlite3_prepare16_v2()] or the older legacy 4223** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4224** new "vX" interface is recommended for new applications but the legacy 4225** interface will continue to be supported. 4226** 4227** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4228** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4229** ^With the "v2" interface, any of the other [result codes] or 4230** [extended result codes] might be returned as well. 4231** 4232** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4233** database locks it needs to do its job. ^If the statement is a [COMMIT] 4234** or occurs outside of an explicit transaction, then you can retry the 4235** statement. If the statement is not a [COMMIT] and occurs within an 4236** explicit transaction then you should rollback the transaction before 4237** continuing. 4238** 4239** ^[SQLITE_DONE] means that the statement has finished executing 4240** successfully. sqlite3_step() should not be called again on this virtual 4241** machine without first calling [sqlite3_reset()] to reset the virtual 4242** machine back to its initial state. 4243** 4244** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4245** is returned each time a new row of data is ready for processing by the 4246** caller. The values may be accessed using the [column access functions]. 4247** sqlite3_step() is called again to retrieve the next row of data. 4248** 4249** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4250** violation) has occurred. sqlite3_step() should not be called again on 4251** the VM. More information may be found by calling [sqlite3_errmsg()]. 4252** ^With the legacy interface, a more specific error code (for example, 4253** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4254** can be obtained by calling [sqlite3_reset()] on the 4255** [prepared statement]. ^In the "v2" interface, 4256** the more specific error code is returned directly by sqlite3_step(). 4257** 4258** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4259** Perhaps it was called on a [prepared statement] that has 4260** already been [sqlite3_finalize | finalized] or on one that had 4261** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4262** be the case that the same database connection is being used by two or 4263** more threads at the same moment in time. 4264** 4265** For all versions of SQLite up to and including 3.6.23.1, a call to 4266** [sqlite3_reset()] was required after sqlite3_step() returned anything 4267** other than [SQLITE_ROW] before any subsequent invocation of 4268** sqlite3_step(). Failure to reset the prepared statement using 4269** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4270** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4271** sqlite3_step() began 4272** calling [sqlite3_reset()] automatically in this circumstance rather 4273** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4274** break because any application that ever receives an SQLITE_MISUSE error 4275** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4276** can be used to restore the legacy behavior. 4277** 4278** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4279** API always returns a generic error code, [SQLITE_ERROR], following any 4280** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4281** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4282** specific [error codes] that better describes the error. 4283** We admit that this is a goofy design. The problem has been fixed 4284** with the "v2" interface. If you prepare all of your SQL statements 4285** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4286** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4287** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4288** then the more specific [error codes] are returned directly 4289** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4290*/ 4291int sqlite3_step(sqlite3_stmt*); 4292 4293/* 4294** CAPI3REF: Number of columns in a result set 4295** METHOD: sqlite3_stmt 4296** 4297** ^The sqlite3_data_count(P) interface returns the number of columns in the 4298** current row of the result set of [prepared statement] P. 4299** ^If prepared statement P does not have results ready to return 4300** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4301** interfaces) then sqlite3_data_count(P) returns 0. 4302** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4303** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4304** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4305** will return non-zero if previous call to [sqlite3_step](P) returned 4306** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4307** where it always returns zero since each step of that multi-step 4308** pragma returns 0 columns of data. 4309** 4310** See also: [sqlite3_column_count()] 4311*/ 4312int sqlite3_data_count(sqlite3_stmt *pStmt); 4313 4314/* 4315** CAPI3REF: Fundamental Datatypes 4316** KEYWORDS: SQLITE_TEXT 4317** 4318** ^(Every value in SQLite has one of five fundamental datatypes: 4319** 4320** <ul> 4321** <li> 64-bit signed integer 4322** <li> 64-bit IEEE floating point number 4323** <li> string 4324** <li> BLOB 4325** <li> NULL 4326** </ul>)^ 4327** 4328** These constants are codes for each of those types. 4329** 4330** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4331** for a completely different meaning. Software that links against both 4332** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4333** SQLITE_TEXT. 4334*/ 4335#define SQLITE_INTEGER 1 4336#define SQLITE_FLOAT 2 4337#define SQLITE_BLOB 4 4338#define SQLITE_NULL 5 4339#ifdef SQLITE_TEXT 4340# undef SQLITE_TEXT 4341#else 4342# define SQLITE_TEXT 3 4343#endif 4344#define SQLITE3_TEXT 3 4345 4346/* 4347** CAPI3REF: Result Values From A Query 4348** KEYWORDS: {column access functions} 4349** METHOD: sqlite3_stmt 4350** 4351** <b>Summary:</b> 4352** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4353** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4354** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4355** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4356** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4357** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4358** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4359** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4360** [sqlite3_value|unprotected sqlite3_value] object. 4361** <tr><td> <td> <td> 4362** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4363** or a UTF-8 TEXT result in bytes 4364** <tr><td><b>sqlite3_column_bytes16 </b> 4365** <td>→ <td>Size of UTF-16 4366** TEXT in bytes 4367** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4368** datatype of the result 4369** </table></blockquote> 4370** 4371** <b>Details:</b> 4372** 4373** ^These routines return information about a single column of the current 4374** result row of a query. ^In every case the first argument is a pointer 4375** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4376** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4377** and the second argument is the index of the column for which information 4378** should be returned. ^The leftmost column of the result set has the index 0. 4379** ^The number of columns in the result can be determined using 4380** [sqlite3_column_count()]. 4381** 4382** If the SQL statement does not currently point to a valid row, or if the 4383** column index is out of range, the result is undefined. 4384** These routines may only be called when the most recent call to 4385** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4386** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4387** If any of these routines are called after [sqlite3_reset()] or 4388** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4389** something other than [SQLITE_ROW], the results are undefined. 4390** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4391** are called from a different thread while any of these routines 4392** are pending, then the results are undefined. 4393** 4394** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4395** each return the value of a result column in a specific data format. If 4396** the result column is not initially in the requested format (for example, 4397** if the query returns an integer but the sqlite3_column_text() interface 4398** is used to extract the value) then an automatic type conversion is performed. 4399** 4400** ^The sqlite3_column_type() routine returns the 4401** [SQLITE_INTEGER | datatype code] for the initial data type 4402** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4403** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4404** The return value of sqlite3_column_type() can be used to decide which 4405** of the first six interface should be used to extract the column value. 4406** The value returned by sqlite3_column_type() is only meaningful if no 4407** automatic type conversions have occurred for the value in question. 4408** After a type conversion, the result of calling sqlite3_column_type() 4409** is undefined, though harmless. Future 4410** versions of SQLite may change the behavior of sqlite3_column_type() 4411** following a type conversion. 4412** 4413** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4414** or sqlite3_column_bytes16() interfaces can be used to determine the size 4415** of that BLOB or string. 4416** 4417** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4418** routine returns the number of bytes in that BLOB or string. 4419** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4420** the string to UTF-8 and then returns the number of bytes. 4421** ^If the result is a numeric value then sqlite3_column_bytes() uses 4422** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4423** the number of bytes in that string. 4424** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4425** 4426** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4427** routine returns the number of bytes in that BLOB or string. 4428** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4429** the string to UTF-16 and then returns the number of bytes. 4430** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4431** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4432** the number of bytes in that string. 4433** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4434** 4435** ^The values returned by [sqlite3_column_bytes()] and 4436** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4437** of the string. ^For clarity: the values returned by 4438** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4439** bytes in the string, not the number of characters. 4440** 4441** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4442** even empty strings, are always zero-terminated. ^The return 4443** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4444** 4445** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4446** [unprotected sqlite3_value] object. In a multithreaded environment, 4447** an unprotected sqlite3_value object may only be used safely with 4448** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4449** If the [unprotected sqlite3_value] object returned by 4450** [sqlite3_column_value()] is used in any other way, including calls 4451** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4452** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4453** Hence, the sqlite3_column_value() interface 4454** is normally only useful within the implementation of 4455** [application-defined SQL functions] or [virtual tables], not within 4456** top-level application code. 4457** 4458** The these routines may attempt to convert the datatype of the result. 4459** ^For example, if the internal representation is FLOAT and a text result 4460** is requested, [sqlite3_snprintf()] is used internally to perform the 4461** conversion automatically. ^(The following table details the conversions 4462** that are applied: 4463** 4464** <blockquote> 4465** <table border="1"> 4466** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4467** 4468** <tr><td> NULL <td> INTEGER <td> Result is 0 4469** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4470** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4471** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4472** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4473** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4474** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4475** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4476** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4477** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4478** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4479** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4480** <tr><td> TEXT <td> BLOB <td> No change 4481** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4482** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4483** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4484** </table> 4485** </blockquote>)^ 4486** 4487** Note that when type conversions occur, pointers returned by prior 4488** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4489** sqlite3_column_text16() may be invalidated. 4490** Type conversions and pointer invalidations might occur 4491** in the following cases: 4492** 4493** <ul> 4494** <li> The initial content is a BLOB and sqlite3_column_text() or 4495** sqlite3_column_text16() is called. A zero-terminator might 4496** need to be added to the string.</li> 4497** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4498** sqlite3_column_text16() is called. The content must be converted 4499** to UTF-16.</li> 4500** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4501** sqlite3_column_text() is called. The content must be converted 4502** to UTF-8.</li> 4503** </ul> 4504** 4505** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4506** not invalidate a prior pointer, though of course the content of the buffer 4507** that the prior pointer references will have been modified. Other kinds 4508** of conversion are done in place when it is possible, but sometimes they 4509** are not possible and in those cases prior pointers are invalidated. 4510** 4511** The safest policy is to invoke these routines 4512** in one of the following ways: 4513** 4514** <ul> 4515** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4516** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4517** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4518** </ul> 4519** 4520** In other words, you should call sqlite3_column_text(), 4521** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4522** into the desired format, then invoke sqlite3_column_bytes() or 4523** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4524** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4525** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4526** with calls to sqlite3_column_bytes(). 4527** 4528** ^The pointers returned are valid until a type conversion occurs as 4529** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4530** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4531** and BLOBs is freed automatically. Do not pass the pointers returned 4532** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4533** [sqlite3_free()]. 4534** 4535** As long as the input parameters are correct, these routines will only 4536** fail if an out-of-memory error occurs during a format conversion. 4537** Only the following subset of interfaces are subject to out-of-memory 4538** errors: 4539** 4540** <ul> 4541** <li> sqlite3_column_blob() 4542** <li> sqlite3_column_text() 4543** <li> sqlite3_column_text16() 4544** <li> sqlite3_column_bytes() 4545** <li> sqlite3_column_bytes16() 4546** </ul> 4547** 4548** If an out-of-memory error occurs, then the return value from these 4549** routines is the same as if the column had contained an SQL NULL value. 4550** Valid SQL NULL returns can be distinguished from out-of-memory errors 4551** by invoking the [sqlite3_errcode()] immediately after the suspect 4552** return value is obtained and before any 4553** other SQLite interface is called on the same [database connection]. 4554*/ 4555const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4556double sqlite3_column_double(sqlite3_stmt*, int iCol); 4557int sqlite3_column_int(sqlite3_stmt*, int iCol); 4558sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4559const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4560const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4561sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4562int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4563int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4564int sqlite3_column_type(sqlite3_stmt*, int iCol); 4565 4566/* 4567** CAPI3REF: Destroy A Prepared Statement Object 4568** DESTRUCTOR: sqlite3_stmt 4569** 4570** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4571** ^If the most recent evaluation of the statement encountered no errors 4572** or if the statement is never been evaluated, then sqlite3_finalize() returns 4573** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4574** sqlite3_finalize(S) returns the appropriate [error code] or 4575** [extended error code]. 4576** 4577** ^The sqlite3_finalize(S) routine can be called at any point during 4578** the life cycle of [prepared statement] S: 4579** before statement S is ever evaluated, after 4580** one or more calls to [sqlite3_reset()], or after any call 4581** to [sqlite3_step()] regardless of whether or not the statement has 4582** completed execution. 4583** 4584** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4585** 4586** The application must finalize every [prepared statement] in order to avoid 4587** resource leaks. It is a grievous error for the application to try to use 4588** a prepared statement after it has been finalized. Any use of a prepared 4589** statement after it has been finalized can result in undefined and 4590** undesirable behavior such as segfaults and heap corruption. 4591*/ 4592int sqlite3_finalize(sqlite3_stmt *pStmt); 4593 4594/* 4595** CAPI3REF: Reset A Prepared Statement Object 4596** METHOD: sqlite3_stmt 4597** 4598** The sqlite3_reset() function is called to reset a [prepared statement] 4599** object back to its initial state, ready to be re-executed. 4600** ^Any SQL statement variables that had values bound to them using 4601** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4602** Use [sqlite3_clear_bindings()] to reset the bindings. 4603** 4604** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4605** back to the beginning of its program. 4606** 4607** ^If the most recent call to [sqlite3_step(S)] for the 4608** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4609** or if [sqlite3_step(S)] has never before been called on S, 4610** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4611** 4612** ^If the most recent call to [sqlite3_step(S)] for the 4613** [prepared statement] S indicated an error, then 4614** [sqlite3_reset(S)] returns an appropriate [error code]. 4615** 4616** ^The [sqlite3_reset(S)] interface does not change the values 4617** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4618*/ 4619int sqlite3_reset(sqlite3_stmt *pStmt); 4620 4621/* 4622** CAPI3REF: Create Or Redefine SQL Functions 4623** KEYWORDS: {function creation routines} 4624** KEYWORDS: {application-defined SQL function} 4625** KEYWORDS: {application-defined SQL functions} 4626** METHOD: sqlite3 4627** 4628** ^These functions (collectively known as "function creation routines") 4629** are used to add SQL functions or aggregates or to redefine the behavior 4630** of existing SQL functions or aggregates. The only differences between 4631** the three "sqlite3_create_function*" routines are the text encoding 4632** expected for the second parameter (the name of the function being 4633** created) and the presence or absence of a destructor callback for 4634** the application data pointer. Function sqlite3_create_window_function() 4635** is similar, but allows the user to supply the extra callback functions 4636** needed by [aggregate window functions]. 4637** 4638** ^The first parameter is the [database connection] to which the SQL 4639** function is to be added. ^If an application uses more than one database 4640** connection then application-defined SQL functions must be added 4641** to each database connection separately. 4642** 4643** ^The second parameter is the name of the SQL function to be created or 4644** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4645** representation, exclusive of the zero-terminator. ^Note that the name 4646** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4647** ^Any attempt to create a function with a longer name 4648** will result in [SQLITE_MISUSE] being returned. 4649** 4650** ^The third parameter (nArg) 4651** is the number of arguments that the SQL function or 4652** aggregate takes. ^If this parameter is -1, then the SQL function or 4653** aggregate may take any number of arguments between 0 and the limit 4654** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4655** parameter is less than -1 or greater than 127 then the behavior is 4656** undefined. 4657** 4658** ^The fourth parameter, eTextRep, specifies what 4659** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4660** its parameters. The application should set this parameter to 4661** [SQLITE_UTF16LE] if the function implementation invokes 4662** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4663** implementation invokes [sqlite3_value_text16be()] on an input, or 4664** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4665** otherwise. ^The same SQL function may be registered multiple times using 4666** different preferred text encodings, with different implementations for 4667** each encoding. 4668** ^When multiple implementations of the same function are available, SQLite 4669** will pick the one that involves the least amount of data conversion. 4670** 4671** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4672** to signal that the function will always return the same result given 4673** the same inputs within a single SQL statement. Most SQL functions are 4674** deterministic. The built-in [random()] SQL function is an example of a 4675** function that is not deterministic. The SQLite query planner is able to 4676** perform additional optimizations on deterministic functions, so use 4677** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4678** 4679** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4680** function can gain access to this pointer using [sqlite3_user_data()].)^ 4681** 4682** ^The sixth, seventh and eighth parameters passed to the three 4683** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4684** pointers to C-language functions that implement the SQL function or 4685** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4686** callback only; NULL pointers must be passed as the xStep and xFinal 4687** parameters. ^An aggregate SQL function requires an implementation of xStep 4688** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4689** SQL function or aggregate, pass NULL pointers for all three function 4690** callbacks. 4691** 4692** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4693** and xInverse) passed to sqlite3_create_window_function are pointers to 4694** C-lanugage callbacks that implement the new function. xStep and xFinal 4695** must both be non-NULL. xValue and xInverse may either both be NULL, in 4696** which case a regular aggregate function is created, or must both be 4697** non-NULL, in which case the new function may be used as either an aggregate 4698** or aggregate window function. More details regarding the implementation 4699** of aggregate window functions are 4700** [user-defined window functions|available here]. 4701** 4702** ^(If the final parameter to sqlite3_create_function_v2() or 4703** sqlite3_create_window_function() is not NULL, then it is destructor for 4704** the application data pointer. The destructor is invoked when the function 4705** is deleted, either by being overloaded or when the database connection 4706** closes.)^ ^The destructor is also invoked if the call to 4707** sqlite3_create_function_v2() fails. ^When the destructor callback is 4708** invoked, it is passed a single argument which is a copy of the application 4709** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4710** 4711** ^It is permitted to register multiple implementations of the same 4712** functions with the same name but with either differing numbers of 4713** arguments or differing preferred text encodings. ^SQLite will use 4714** the implementation that most closely matches the way in which the 4715** SQL function is used. ^A function implementation with a non-negative 4716** nArg parameter is a better match than a function implementation with 4717** a negative nArg. ^A function where the preferred text encoding 4718** matches the database encoding is a better 4719** match than a function where the encoding is different. 4720** ^A function where the encoding difference is between UTF16le and UTF16be 4721** is a closer match than a function where the encoding difference is 4722** between UTF8 and UTF16. 4723** 4724** ^Built-in functions may be overloaded by new application-defined functions. 4725** 4726** ^An application-defined function is permitted to call other 4727** SQLite interfaces. However, such calls must not 4728** close the database connection nor finalize or reset the prepared 4729** statement in which the function is running. 4730*/ 4731int sqlite3_create_function( 4732 sqlite3 *db, 4733 const char *zFunctionName, 4734 int nArg, 4735 int eTextRep, 4736 void *pApp, 4737 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4738 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4739 void (*xFinal)(sqlite3_context*) 4740); 4741int sqlite3_create_function16( 4742 sqlite3 *db, 4743 const void *zFunctionName, 4744 int nArg, 4745 int eTextRep, 4746 void *pApp, 4747 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4748 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4749 void (*xFinal)(sqlite3_context*) 4750); 4751int sqlite3_create_function_v2( 4752 sqlite3 *db, 4753 const char *zFunctionName, 4754 int nArg, 4755 int eTextRep, 4756 void *pApp, 4757 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4758 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4759 void (*xFinal)(sqlite3_context*), 4760 void(*xDestroy)(void*) 4761); 4762int sqlite3_create_window_function( 4763 sqlite3 *db, 4764 const char *zFunctionName, 4765 int nArg, 4766 int eTextRep, 4767 void *pApp, 4768 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4769 void (*xFinal)(sqlite3_context*), 4770 void (*xValue)(sqlite3_context*), 4771 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 4772 void(*xDestroy)(void*) 4773); 4774 4775/* 4776** CAPI3REF: Text Encodings 4777** 4778** These constant define integer codes that represent the various 4779** text encodings supported by SQLite. 4780*/ 4781#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4782#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4783#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4784#define SQLITE_UTF16 4 /* Use native byte order */ 4785#define SQLITE_ANY 5 /* Deprecated */ 4786#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4787 4788/* 4789** CAPI3REF: Function Flags 4790** 4791** These constants may be ORed together with the 4792** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4793** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4794** [sqlite3_create_function_v2()]. 4795*/ 4796#define SQLITE_DETERMINISTIC 0x800 4797 4798/* 4799** CAPI3REF: Deprecated Functions 4800** DEPRECATED 4801** 4802** These functions are [deprecated]. In order to maintain 4803** backwards compatibility with older code, these functions continue 4804** to be supported. However, new applications should avoid 4805** the use of these functions. To encourage programmers to avoid 4806** these functions, we will not explain what they do. 4807*/ 4808#ifndef SQLITE_OMIT_DEPRECATED 4809SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4810SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4811SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4812SQLITE_DEPRECATED int sqlite3_global_recover(void); 4813SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4814SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4815 void*,sqlite3_int64); 4816#endif 4817 4818/* 4819** CAPI3REF: Obtaining SQL Values 4820** METHOD: sqlite3_value 4821** 4822** <b>Summary:</b> 4823** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4824** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 4825** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 4826** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 4827** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 4828** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 4829** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 4830** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 4831** the native byteorder 4832** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 4833** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 4834** <tr><td> <td> <td> 4835** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 4836** or a UTF-8 TEXT in bytes 4837** <tr><td><b>sqlite3_value_bytes16 </b> 4838** <td>→ <td>Size of UTF-16 4839** TEXT in bytes 4840** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 4841** datatype of the value 4842** <tr><td><b>sqlite3_value_numeric_type </b> 4843** <td>→ <td>Best numeric datatype of the value 4844** <tr><td><b>sqlite3_value_nochange </b> 4845** <td>→ <td>True if the column is unchanged in an UPDATE 4846** against a virtual table. 4847** </table></blockquote> 4848** 4849** <b>Details:</b> 4850** 4851** These routines extract type, size, and content information from 4852** [protected sqlite3_value] objects. Protected sqlite3_value objects 4853** are used to pass parameter information into implementation of 4854** [application-defined SQL functions] and [virtual tables]. 4855** 4856** These routines work only with [protected sqlite3_value] objects. 4857** Any attempt to use these routines on an [unprotected sqlite3_value] 4858** is not threadsafe. 4859** 4860** ^These routines work just like the corresponding [column access functions] 4861** except that these routines take a single [protected sqlite3_value] object 4862** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4863** 4864** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4865** in the native byte-order of the host machine. ^The 4866** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4867** extract UTF-16 strings as big-endian and little-endian respectively. 4868** 4869** ^If [sqlite3_value] object V was initialized 4870** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 4871** and if X and Y are strings that compare equal according to strcmp(X,Y), 4872** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 4873** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 4874** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 4875** 4876** ^(The sqlite3_value_type(V) interface returns the 4877** [SQLITE_INTEGER | datatype code] for the initial datatype of the 4878** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 4879** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 4880** Other interfaces might change the datatype for an sqlite3_value object. 4881** For example, if the datatype is initially SQLITE_INTEGER and 4882** sqlite3_value_text(V) is called to extract a text value for that 4883** integer, then subsequent calls to sqlite3_value_type(V) might return 4884** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 4885** occurs is undefined and may change from one release of SQLite to the next. 4886** 4887** ^(The sqlite3_value_numeric_type() interface attempts to apply 4888** numeric affinity to the value. This means that an attempt is 4889** made to convert the value to an integer or floating point. If 4890** such a conversion is possible without loss of information (in other 4891** words, if the value is a string that looks like a number) 4892** then the conversion is performed. Otherwise no conversion occurs. 4893** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4894** 4895** ^Within the [xUpdate] method of a [virtual table], the 4896** sqlite3_value_nochange(X) interface returns true if and only if 4897** the column corresponding to X is unchanged by the UPDATE operation 4898** that the xUpdate method call was invoked to implement and if 4899** and the prior [xColumn] method call that was invoked to extracted 4900** the value for that column returned without setting a result (probably 4901** because it queried [sqlite3_vtab_nochange()] and found that the column 4902** was unchanging). ^Within an [xUpdate] method, any value for which 4903** sqlite3_value_nochange(X) is true will in all other respects appear 4904** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 4905** than within an [xUpdate] method call for an UPDATE statement, then 4906** the return value is arbitrary and meaningless. 4907** 4908** Please pay particular attention to the fact that the pointer returned 4909** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4910** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4911** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4912** or [sqlite3_value_text16()]. 4913** 4914** These routines must be called from the same thread as 4915** the SQL function that supplied the [sqlite3_value*] parameters. 4916** 4917** As long as the input parameter is correct, these routines can only 4918** fail if an out-of-memory error occurs during a format conversion. 4919** Only the following subset of interfaces are subject to out-of-memory 4920** errors: 4921** 4922** <ul> 4923** <li> sqlite3_value_blob() 4924** <li> sqlite3_value_text() 4925** <li> sqlite3_value_text16() 4926** <li> sqlite3_value_text16le() 4927** <li> sqlite3_value_text16be() 4928** <li> sqlite3_value_bytes() 4929** <li> sqlite3_value_bytes16() 4930** </ul> 4931** 4932** If an out-of-memory error occurs, then the return value from these 4933** routines is the same as if the column had contained an SQL NULL value. 4934** Valid SQL NULL returns can be distinguished from out-of-memory errors 4935** by invoking the [sqlite3_errcode()] immediately after the suspect 4936** return value is obtained and before any 4937** other SQLite interface is called on the same [database connection]. 4938*/ 4939const void *sqlite3_value_blob(sqlite3_value*); 4940double sqlite3_value_double(sqlite3_value*); 4941int sqlite3_value_int(sqlite3_value*); 4942sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4943void *sqlite3_value_pointer(sqlite3_value*, const char*); 4944const unsigned char *sqlite3_value_text(sqlite3_value*); 4945const void *sqlite3_value_text16(sqlite3_value*); 4946const void *sqlite3_value_text16le(sqlite3_value*); 4947const void *sqlite3_value_text16be(sqlite3_value*); 4948int sqlite3_value_bytes(sqlite3_value*); 4949int sqlite3_value_bytes16(sqlite3_value*); 4950int sqlite3_value_type(sqlite3_value*); 4951int sqlite3_value_numeric_type(sqlite3_value*); 4952int sqlite3_value_nochange(sqlite3_value*); 4953 4954/* 4955** CAPI3REF: Finding The Subtype Of SQL Values 4956** METHOD: sqlite3_value 4957** 4958** The sqlite3_value_subtype(V) function returns the subtype for 4959** an [application-defined SQL function] argument V. The subtype 4960** information can be used to pass a limited amount of context from 4961** one SQL function to another. Use the [sqlite3_result_subtype()] 4962** routine to set the subtype for the return value of an SQL function. 4963*/ 4964unsigned int sqlite3_value_subtype(sqlite3_value*); 4965 4966/* 4967** CAPI3REF: Copy And Free SQL Values 4968** METHOD: sqlite3_value 4969** 4970** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4971** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4972** is a [protected sqlite3_value] object even if the input is not. 4973** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4974** memory allocation fails. 4975** 4976** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4977** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4978** then sqlite3_value_free(V) is a harmless no-op. 4979*/ 4980sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4981void sqlite3_value_free(sqlite3_value*); 4982 4983/* 4984** CAPI3REF: Obtain Aggregate Function Context 4985** METHOD: sqlite3_context 4986** 4987** Implementations of aggregate SQL functions use this 4988** routine to allocate memory for storing their state. 4989** 4990** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4991** for a particular aggregate function, SQLite 4992** allocates N of memory, zeroes out that memory, and returns a pointer 4993** to the new memory. ^On second and subsequent calls to 4994** sqlite3_aggregate_context() for the same aggregate function instance, 4995** the same buffer is returned. Sqlite3_aggregate_context() is normally 4996** called once for each invocation of the xStep callback and then one 4997** last time when the xFinal callback is invoked. ^(When no rows match 4998** an aggregate query, the xStep() callback of the aggregate function 4999** implementation is never called and xFinal() is called exactly once. 5000** In those cases, sqlite3_aggregate_context() might be called for the 5001** first time from within xFinal().)^ 5002** 5003** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5004** when first called if N is less than or equal to zero or if a memory 5005** allocate error occurs. 5006** 5007** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5008** determined by the N parameter on first successful call. Changing the 5009** value of N in subsequent call to sqlite3_aggregate_context() within 5010** the same aggregate function instance will not resize the memory 5011** allocation.)^ Within the xFinal callback, it is customary to set 5012** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5013** pointless memory allocations occur. 5014** 5015** ^SQLite automatically frees the memory allocated by 5016** sqlite3_aggregate_context() when the aggregate query concludes. 5017** 5018** The first parameter must be a copy of the 5019** [sqlite3_context | SQL function context] that is the first parameter 5020** to the xStep or xFinal callback routine that implements the aggregate 5021** function. 5022** 5023** This routine must be called from the same thread in which 5024** the aggregate SQL function is running. 5025*/ 5026void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5027 5028/* 5029** CAPI3REF: User Data For Functions 5030** METHOD: sqlite3_context 5031** 5032** ^The sqlite3_user_data() interface returns a copy of 5033** the pointer that was the pUserData parameter (the 5th parameter) 5034** of the [sqlite3_create_function()] 5035** and [sqlite3_create_function16()] routines that originally 5036** registered the application defined function. 5037** 5038** This routine must be called from the same thread in which 5039** the application-defined function is running. 5040*/ 5041void *sqlite3_user_data(sqlite3_context*); 5042 5043/* 5044** CAPI3REF: Database Connection For Functions 5045** METHOD: sqlite3_context 5046** 5047** ^The sqlite3_context_db_handle() interface returns a copy of 5048** the pointer to the [database connection] (the 1st parameter) 5049** of the [sqlite3_create_function()] 5050** and [sqlite3_create_function16()] routines that originally 5051** registered the application defined function. 5052*/ 5053sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5054 5055/* 5056** CAPI3REF: Function Auxiliary Data 5057** METHOD: sqlite3_context 5058** 5059** These functions may be used by (non-aggregate) SQL functions to 5060** associate metadata with argument values. If the same value is passed to 5061** multiple invocations of the same SQL function during query execution, under 5062** some circumstances the associated metadata may be preserved. An example 5063** of where this might be useful is in a regular-expression matching 5064** function. The compiled version of the regular expression can be stored as 5065** metadata associated with the pattern string. 5066** Then as long as the pattern string remains the same, 5067** the compiled regular expression can be reused on multiple 5068** invocations of the same function. 5069** 5070** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5071** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5072** value to the application-defined function. ^N is zero for the left-most 5073** function argument. ^If there is no metadata 5074** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5075** returns a NULL pointer. 5076** 5077** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5078** argument of the application-defined function. ^Subsequent 5079** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5080** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5081** NULL if the metadata has been discarded. 5082** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5083** SQLite will invoke the destructor function X with parameter P exactly 5084** once, when the metadata is discarded. 5085** SQLite is free to discard the metadata at any time, including: <ul> 5086** <li> ^(when the corresponding function parameter changes)^, or 5087** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5088** SQL statement)^, or 5089** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5090** parameter)^, or 5091** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5092** allocation error occurs.)^ </ul> 5093** 5094** Note the last bullet in particular. The destructor X in 5095** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5096** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5097** should be called near the end of the function implementation and the 5098** function implementation should not make any use of P after 5099** sqlite3_set_auxdata() has been called. 5100** 5101** ^(In practice, metadata is preserved between function calls for 5102** function parameters that are compile-time constants, including literal 5103** values and [parameters] and expressions composed from the same.)^ 5104** 5105** The value of the N parameter to these interfaces should be non-negative. 5106** Future enhancements may make use of negative N values to define new 5107** kinds of function caching behavior. 5108** 5109** These routines must be called from the same thread in which 5110** the SQL function is running. 5111*/ 5112void *sqlite3_get_auxdata(sqlite3_context*, int N); 5113void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5114 5115 5116/* 5117** CAPI3REF: Constants Defining Special Destructor Behavior 5118** 5119** These are special values for the destructor that is passed in as the 5120** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5121** argument is SQLITE_STATIC, it means that the content pointer is constant 5122** and will never change. It does not need to be destroyed. ^The 5123** SQLITE_TRANSIENT value means that the content will likely change in 5124** the near future and that SQLite should make its own private copy of 5125** the content before returning. 5126** 5127** The typedef is necessary to work around problems in certain 5128** C++ compilers. 5129*/ 5130typedef void (*sqlite3_destructor_type)(void*); 5131#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5132#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5133 5134/* 5135** CAPI3REF: Setting The Result Of An SQL Function 5136** METHOD: sqlite3_context 5137** 5138** These routines are used by the xFunc or xFinal callbacks that 5139** implement SQL functions and aggregates. See 5140** [sqlite3_create_function()] and [sqlite3_create_function16()] 5141** for additional information. 5142** 5143** These functions work very much like the [parameter binding] family of 5144** functions used to bind values to host parameters in prepared statements. 5145** Refer to the [SQL parameter] documentation for additional information. 5146** 5147** ^The sqlite3_result_blob() interface sets the result from 5148** an application-defined function to be the BLOB whose content is pointed 5149** to by the second parameter and which is N bytes long where N is the 5150** third parameter. 5151** 5152** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5153** interfaces set the result of the application-defined function to be 5154** a BLOB containing all zero bytes and N bytes in size. 5155** 5156** ^The sqlite3_result_double() interface sets the result from 5157** an application-defined function to be a floating point value specified 5158** by its 2nd argument. 5159** 5160** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5161** cause the implemented SQL function to throw an exception. 5162** ^SQLite uses the string pointed to by the 5163** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5164** as the text of an error message. ^SQLite interprets the error 5165** message string from sqlite3_result_error() as UTF-8. ^SQLite 5166** interprets the string from sqlite3_result_error16() as UTF-16 in native 5167** byte order. ^If the third parameter to sqlite3_result_error() 5168** or sqlite3_result_error16() is negative then SQLite takes as the error 5169** message all text up through the first zero character. 5170** ^If the third parameter to sqlite3_result_error() or 5171** sqlite3_result_error16() is non-negative then SQLite takes that many 5172** bytes (not characters) from the 2nd parameter as the error message. 5173** ^The sqlite3_result_error() and sqlite3_result_error16() 5174** routines make a private copy of the error message text before 5175** they return. Hence, the calling function can deallocate or 5176** modify the text after they return without harm. 5177** ^The sqlite3_result_error_code() function changes the error code 5178** returned by SQLite as a result of an error in a function. ^By default, 5179** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5180** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5181** 5182** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5183** error indicating that a string or BLOB is too long to represent. 5184** 5185** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5186** error indicating that a memory allocation failed. 5187** 5188** ^The sqlite3_result_int() interface sets the return value 5189** of the application-defined function to be the 32-bit signed integer 5190** value given in the 2nd argument. 5191** ^The sqlite3_result_int64() interface sets the return value 5192** of the application-defined function to be the 64-bit signed integer 5193** value given in the 2nd argument. 5194** 5195** ^The sqlite3_result_null() interface sets the return value 5196** of the application-defined function to be NULL. 5197** 5198** ^The sqlite3_result_text(), sqlite3_result_text16(), 5199** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5200** set the return value of the application-defined function to be 5201** a text string which is represented as UTF-8, UTF-16 native byte order, 5202** UTF-16 little endian, or UTF-16 big endian, respectively. 5203** ^The sqlite3_result_text64() interface sets the return value of an 5204** application-defined function to be a text string in an encoding 5205** specified by the fifth (and last) parameter, which must be one 5206** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5207** ^SQLite takes the text result from the application from 5208** the 2nd parameter of the sqlite3_result_text* interfaces. 5209** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5210** is negative, then SQLite takes result text from the 2nd parameter 5211** through the first zero character. 5212** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5213** is non-negative, then as many bytes (not characters) of the text 5214** pointed to by the 2nd parameter are taken as the application-defined 5215** function result. If the 3rd parameter is non-negative, then it 5216** must be the byte offset into the string where the NUL terminator would 5217** appear if the string where NUL terminated. If any NUL characters occur 5218** in the string at a byte offset that is less than the value of the 3rd 5219** parameter, then the resulting string will contain embedded NULs and the 5220** result of expressions operating on strings with embedded NULs is undefined. 5221** ^If the 4th parameter to the sqlite3_result_text* interfaces 5222** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5223** function as the destructor on the text or BLOB result when it has 5224** finished using that result. 5225** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5226** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5227** assumes that the text or BLOB result is in constant space and does not 5228** copy the content of the parameter nor call a destructor on the content 5229** when it has finished using that result. 5230** ^If the 4th parameter to the sqlite3_result_text* interfaces 5231** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5232** then SQLite makes a copy of the result into space obtained 5233** from [sqlite3_malloc()] before it returns. 5234** 5235** ^The sqlite3_result_value() interface sets the result of 5236** the application-defined function to be a copy of the 5237** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5238** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5239** so that the [sqlite3_value] specified in the parameter may change or 5240** be deallocated after sqlite3_result_value() returns without harm. 5241** ^A [protected sqlite3_value] object may always be used where an 5242** [unprotected sqlite3_value] object is required, so either 5243** kind of [sqlite3_value] object can be used with this interface. 5244** 5245** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5246** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5247** also associates the host-language pointer P or type T with that 5248** NULL value such that the pointer can be retrieved within an 5249** [application-defined SQL function] using [sqlite3_value_pointer()]. 5250** ^If the D parameter is not NULL, then it is a pointer to a destructor 5251** for the P parameter. ^SQLite invokes D with P as its only argument 5252** when SQLite is finished with P. The T parameter should be a static 5253** string and preferably a string literal. The sqlite3_result_pointer() 5254** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5255** 5256** If these routines are called from within the different thread 5257** than the one containing the application-defined function that received 5258** the [sqlite3_context] pointer, the results are undefined. 5259*/ 5260void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5261void sqlite3_result_blob64(sqlite3_context*,const void*, 5262 sqlite3_uint64,void(*)(void*)); 5263void sqlite3_result_double(sqlite3_context*, double); 5264void sqlite3_result_error(sqlite3_context*, const char*, int); 5265void sqlite3_result_error16(sqlite3_context*, const void*, int); 5266void sqlite3_result_error_toobig(sqlite3_context*); 5267void sqlite3_result_error_nomem(sqlite3_context*); 5268void sqlite3_result_error_code(sqlite3_context*, int); 5269void sqlite3_result_int(sqlite3_context*, int); 5270void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5271void sqlite3_result_null(sqlite3_context*); 5272void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5273void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5274 void(*)(void*), unsigned char encoding); 5275void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5276void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5277void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5278void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5279void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5280void sqlite3_result_zeroblob(sqlite3_context*, int n); 5281int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5282 5283 5284/* 5285** CAPI3REF: Setting The Subtype Of An SQL Function 5286** METHOD: sqlite3_context 5287** 5288** The sqlite3_result_subtype(C,T) function causes the subtype of 5289** the result from the [application-defined SQL function] with 5290** [sqlite3_context] C to be the value T. Only the lower 8 bits 5291** of the subtype T are preserved in current versions of SQLite; 5292** higher order bits are discarded. 5293** The number of subtype bytes preserved by SQLite might increase 5294** in future releases of SQLite. 5295*/ 5296void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5297 5298/* 5299** CAPI3REF: Define New Collating Sequences 5300** METHOD: sqlite3 5301** 5302** ^These functions add, remove, or modify a [collation] associated 5303** with the [database connection] specified as the first argument. 5304** 5305** ^The name of the collation is a UTF-8 string 5306** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5307** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5308** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5309** considered to be the same name. 5310** 5311** ^(The third argument (eTextRep) must be one of the constants: 5312** <ul> 5313** <li> [SQLITE_UTF8], 5314** <li> [SQLITE_UTF16LE], 5315** <li> [SQLITE_UTF16BE], 5316** <li> [SQLITE_UTF16], or 5317** <li> [SQLITE_UTF16_ALIGNED]. 5318** </ul>)^ 5319** ^The eTextRep argument determines the encoding of strings passed 5320** to the collating function callback, xCallback. 5321** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5322** force strings to be UTF16 with native byte order. 5323** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5324** on an even byte address. 5325** 5326** ^The fourth argument, pArg, is an application data pointer that is passed 5327** through as the first argument to the collating function callback. 5328** 5329** ^The fifth argument, xCallback, is a pointer to the collating function. 5330** ^Multiple collating functions can be registered using the same name but 5331** with different eTextRep parameters and SQLite will use whichever 5332** function requires the least amount of data transformation. 5333** ^If the xCallback argument is NULL then the collating function is 5334** deleted. ^When all collating functions having the same name are deleted, 5335** that collation is no longer usable. 5336** 5337** ^The collating function callback is invoked with a copy of the pArg 5338** application data pointer and with two strings in the encoding specified 5339** by the eTextRep argument. The collating function must return an 5340** integer that is negative, zero, or positive 5341** if the first string is less than, equal to, or greater than the second, 5342** respectively. A collating function must always return the same answer 5343** given the same inputs. If two or more collating functions are registered 5344** to the same collation name (using different eTextRep values) then all 5345** must give an equivalent answer when invoked with equivalent strings. 5346** The collating function must obey the following properties for all 5347** strings A, B, and C: 5348** 5349** <ol> 5350** <li> If A==B then B==A. 5351** <li> If A==B and B==C then A==C. 5352** <li> If A<B THEN B>A. 5353** <li> If A<B and B<C then A<C. 5354** </ol> 5355** 5356** If a collating function fails any of the above constraints and that 5357** collating function is registered and used, then the behavior of SQLite 5358** is undefined. 5359** 5360** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5361** with the addition that the xDestroy callback is invoked on pArg when 5362** the collating function is deleted. 5363** ^Collating functions are deleted when they are overridden by later 5364** calls to the collation creation functions or when the 5365** [database connection] is closed using [sqlite3_close()]. 5366** 5367** ^The xDestroy callback is <u>not</u> called if the 5368** sqlite3_create_collation_v2() function fails. Applications that invoke 5369** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5370** check the return code and dispose of the application data pointer 5371** themselves rather than expecting SQLite to deal with it for them. 5372** This is different from every other SQLite interface. The inconsistency 5373** is unfortunate but cannot be changed without breaking backwards 5374** compatibility. 5375** 5376** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5377*/ 5378int sqlite3_create_collation( 5379 sqlite3*, 5380 const char *zName, 5381 int eTextRep, 5382 void *pArg, 5383 int(*xCompare)(void*,int,const void*,int,const void*) 5384); 5385int sqlite3_create_collation_v2( 5386 sqlite3*, 5387 const char *zName, 5388 int eTextRep, 5389 void *pArg, 5390 int(*xCompare)(void*,int,const void*,int,const void*), 5391 void(*xDestroy)(void*) 5392); 5393int sqlite3_create_collation16( 5394 sqlite3*, 5395 const void *zName, 5396 int eTextRep, 5397 void *pArg, 5398 int(*xCompare)(void*,int,const void*,int,const void*) 5399); 5400 5401/* 5402** CAPI3REF: Collation Needed Callbacks 5403** METHOD: sqlite3 5404** 5405** ^To avoid having to register all collation sequences before a database 5406** can be used, a single callback function may be registered with the 5407** [database connection] to be invoked whenever an undefined collation 5408** sequence is required. 5409** 5410** ^If the function is registered using the sqlite3_collation_needed() API, 5411** then it is passed the names of undefined collation sequences as strings 5412** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5413** the names are passed as UTF-16 in machine native byte order. 5414** ^A call to either function replaces the existing collation-needed callback. 5415** 5416** ^(When the callback is invoked, the first argument passed is a copy 5417** of the second argument to sqlite3_collation_needed() or 5418** sqlite3_collation_needed16(). The second argument is the database 5419** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5420** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5421** sequence function required. The fourth parameter is the name of the 5422** required collation sequence.)^ 5423** 5424** The callback function should register the desired collation using 5425** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5426** [sqlite3_create_collation_v2()]. 5427*/ 5428int sqlite3_collation_needed( 5429 sqlite3*, 5430 void*, 5431 void(*)(void*,sqlite3*,int eTextRep,const char*) 5432); 5433int sqlite3_collation_needed16( 5434 sqlite3*, 5435 void*, 5436 void(*)(void*,sqlite3*,int eTextRep,const void*) 5437); 5438 5439#ifdef SQLITE_HAS_CODEC 5440/* 5441** Specify the key for an encrypted database. This routine should be 5442** called right after sqlite3_open(). 5443** 5444** The code to implement this API is not available in the public release 5445** of SQLite. 5446*/ 5447int sqlite3_key( 5448 sqlite3 *db, /* Database to be rekeyed */ 5449 const void *pKey, int nKey /* The key */ 5450); 5451int sqlite3_key_v2( 5452 sqlite3 *db, /* Database to be rekeyed */ 5453 const char *zDbName, /* Name of the database */ 5454 const void *pKey, int nKey /* The key */ 5455); 5456 5457/* 5458** Change the key on an open database. If the current database is not 5459** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5460** database is decrypted. 5461** 5462** The code to implement this API is not available in the public release 5463** of SQLite. 5464*/ 5465int sqlite3_rekey( 5466 sqlite3 *db, /* Database to be rekeyed */ 5467 const void *pKey, int nKey /* The new key */ 5468); 5469int sqlite3_rekey_v2( 5470 sqlite3 *db, /* Database to be rekeyed */ 5471 const char *zDbName, /* Name of the database */ 5472 const void *pKey, int nKey /* The new key */ 5473); 5474 5475/* 5476** Specify the activation key for a SEE database. Unless 5477** activated, none of the SEE routines will work. 5478*/ 5479void sqlite3_activate_see( 5480 const char *zPassPhrase /* Activation phrase */ 5481); 5482#endif 5483 5484#ifdef SQLITE_ENABLE_CEROD 5485/* 5486** Specify the activation key for a CEROD database. Unless 5487** activated, none of the CEROD routines will work. 5488*/ 5489void sqlite3_activate_cerod( 5490 const char *zPassPhrase /* Activation phrase */ 5491); 5492#endif 5493 5494/* 5495** CAPI3REF: Suspend Execution For A Short Time 5496** 5497** The sqlite3_sleep() function causes the current thread to suspend execution 5498** for at least a number of milliseconds specified in its parameter. 5499** 5500** If the operating system does not support sleep requests with 5501** millisecond time resolution, then the time will be rounded up to 5502** the nearest second. The number of milliseconds of sleep actually 5503** requested from the operating system is returned. 5504** 5505** ^SQLite implements this interface by calling the xSleep() 5506** method of the default [sqlite3_vfs] object. If the xSleep() method 5507** of the default VFS is not implemented correctly, or not implemented at 5508** all, then the behavior of sqlite3_sleep() may deviate from the description 5509** in the previous paragraphs. 5510*/ 5511int sqlite3_sleep(int); 5512 5513/* 5514** CAPI3REF: Name Of The Folder Holding Temporary Files 5515** 5516** ^(If this global variable is made to point to a string which is 5517** the name of a folder (a.k.a. directory), then all temporary files 5518** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5519** will be placed in that directory.)^ ^If this variable 5520** is a NULL pointer, then SQLite performs a search for an appropriate 5521** temporary file directory. 5522** 5523** Applications are strongly discouraged from using this global variable. 5524** It is required to set a temporary folder on Windows Runtime (WinRT). 5525** But for all other platforms, it is highly recommended that applications 5526** neither read nor write this variable. This global variable is a relic 5527** that exists for backwards compatibility of legacy applications and should 5528** be avoided in new projects. 5529** 5530** It is not safe to read or modify this variable in more than one 5531** thread at a time. It is not safe to read or modify this variable 5532** if a [database connection] is being used at the same time in a separate 5533** thread. 5534** It is intended that this variable be set once 5535** as part of process initialization and before any SQLite interface 5536** routines have been called and that this variable remain unchanged 5537** thereafter. 5538** 5539** ^The [temp_store_directory pragma] may modify this variable and cause 5540** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5541** the [temp_store_directory pragma] always assumes that any string 5542** that this variable points to is held in memory obtained from 5543** [sqlite3_malloc] and the pragma may attempt to free that memory 5544** using [sqlite3_free]. 5545** Hence, if this variable is modified directly, either it should be 5546** made NULL or made to point to memory obtained from [sqlite3_malloc] 5547** or else the use of the [temp_store_directory pragma] should be avoided. 5548** Except when requested by the [temp_store_directory pragma], SQLite 5549** does not free the memory that sqlite3_temp_directory points to. If 5550** the application wants that memory to be freed, it must do 5551** so itself, taking care to only do so after all [database connection] 5552** objects have been destroyed. 5553** 5554** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5555** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5556** features that require the use of temporary files may fail. Here is an 5557** example of how to do this using C++ with the Windows Runtime: 5558** 5559** <blockquote><pre> 5560** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5561** TemporaryFolder->Path->Data(); 5562** char zPathBuf[MAX_PATH + 1]; 5563** memset(zPathBuf, 0, sizeof(zPathBuf)); 5564** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5565** NULL, NULL); 5566** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5567** </pre></blockquote> 5568*/ 5569SQLITE_EXTERN char *sqlite3_temp_directory; 5570 5571/* 5572** CAPI3REF: Name Of The Folder Holding Database Files 5573** 5574** ^(If this global variable is made to point to a string which is 5575** the name of a folder (a.k.a. directory), then all database files 5576** specified with a relative pathname and created or accessed by 5577** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5578** to be relative to that directory.)^ ^If this variable is a NULL 5579** pointer, then SQLite assumes that all database files specified 5580** with a relative pathname are relative to the current directory 5581** for the process. Only the windows VFS makes use of this global 5582** variable; it is ignored by the unix VFS. 5583** 5584** Changing the value of this variable while a database connection is 5585** open can result in a corrupt database. 5586** 5587** It is not safe to read or modify this variable in more than one 5588** thread at a time. It is not safe to read or modify this variable 5589** if a [database connection] is being used at the same time in a separate 5590** thread. 5591** It is intended that this variable be set once 5592** as part of process initialization and before any SQLite interface 5593** routines have been called and that this variable remain unchanged 5594** thereafter. 5595** 5596** ^The [data_store_directory pragma] may modify this variable and cause 5597** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5598** the [data_store_directory pragma] always assumes that any string 5599** that this variable points to is held in memory obtained from 5600** [sqlite3_malloc] and the pragma may attempt to free that memory 5601** using [sqlite3_free]. 5602** Hence, if this variable is modified directly, either it should be 5603** made NULL or made to point to memory obtained from [sqlite3_malloc] 5604** or else the use of the [data_store_directory pragma] should be avoided. 5605*/ 5606SQLITE_EXTERN char *sqlite3_data_directory; 5607 5608/* 5609** CAPI3REF: Win32 Specific Interface 5610** 5611** These interfaces are available only on Windows. The 5612** [sqlite3_win32_set_directory] interface is used to set the value associated 5613** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5614** zValue, depending on the value of the type parameter. The zValue parameter 5615** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5616** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5617** prior to being used. The [sqlite3_win32_set_directory] interface returns 5618** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5619** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5620** [sqlite3_data_directory] variable is intended to act as a replacement for 5621** the current directory on the sub-platforms of Win32 where that concept is 5622** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5623** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5624** sqlite3_win32_set_directory interface except the string parameter must be 5625** UTF-8 or UTF-16, respectively. 5626*/ 5627int sqlite3_win32_set_directory( 5628 unsigned long type, /* Identifier for directory being set or reset */ 5629 void *zValue /* New value for directory being set or reset */ 5630); 5631int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5632int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5633 5634/* 5635** CAPI3REF: Win32 Directory Types 5636** 5637** These macros are only available on Windows. They define the allowed values 5638** for the type argument to the [sqlite3_win32_set_directory] interface. 5639*/ 5640#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5641#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5642 5643/* 5644** CAPI3REF: Test For Auto-Commit Mode 5645** KEYWORDS: {autocommit mode} 5646** METHOD: sqlite3 5647** 5648** ^The sqlite3_get_autocommit() interface returns non-zero or 5649** zero if the given database connection is or is not in autocommit mode, 5650** respectively. ^Autocommit mode is on by default. 5651** ^Autocommit mode is disabled by a [BEGIN] statement. 5652** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5653** 5654** If certain kinds of errors occur on a statement within a multi-statement 5655** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5656** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5657** transaction might be rolled back automatically. The only way to 5658** find out whether SQLite automatically rolled back the transaction after 5659** an error is to use this function. 5660** 5661** If another thread changes the autocommit status of the database 5662** connection while this routine is running, then the return value 5663** is undefined. 5664*/ 5665int sqlite3_get_autocommit(sqlite3*); 5666 5667/* 5668** CAPI3REF: Find The Database Handle Of A Prepared Statement 5669** METHOD: sqlite3_stmt 5670** 5671** ^The sqlite3_db_handle interface returns the [database connection] handle 5672** to which a [prepared statement] belongs. ^The [database connection] 5673** returned by sqlite3_db_handle is the same [database connection] 5674** that was the first argument 5675** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5676** create the statement in the first place. 5677*/ 5678sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5679 5680/* 5681** CAPI3REF: Return The Filename For A Database Connection 5682** METHOD: sqlite3 5683** 5684** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5685** associated with database N of connection D. ^The main database file 5686** has the name "main". If there is no attached database N on the database 5687** connection D, or if database N is a temporary or in-memory database, then 5688** a NULL pointer is returned. 5689** 5690** ^The filename returned by this function is the output of the 5691** xFullPathname method of the [VFS]. ^In other words, the filename 5692** will be an absolute pathname, even if the filename used 5693** to open the database originally was a URI or relative pathname. 5694*/ 5695const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5696 5697/* 5698** CAPI3REF: Determine if a database is read-only 5699** METHOD: sqlite3 5700** 5701** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5702** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5703** the name of a database on connection D. 5704*/ 5705int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5706 5707/* 5708** CAPI3REF: Find the next prepared statement 5709** METHOD: sqlite3 5710** 5711** ^This interface returns a pointer to the next [prepared statement] after 5712** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5713** then this interface returns a pointer to the first prepared statement 5714** associated with the database connection pDb. ^If no prepared statement 5715** satisfies the conditions of this routine, it returns NULL. 5716** 5717** The [database connection] pointer D in a call to 5718** [sqlite3_next_stmt(D,S)] must refer to an open database 5719** connection and in particular must not be a NULL pointer. 5720*/ 5721sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5722 5723/* 5724** CAPI3REF: Commit And Rollback Notification Callbacks 5725** METHOD: sqlite3 5726** 5727** ^The sqlite3_commit_hook() interface registers a callback 5728** function to be invoked whenever a transaction is [COMMIT | committed]. 5729** ^Any callback set by a previous call to sqlite3_commit_hook() 5730** for the same database connection is overridden. 5731** ^The sqlite3_rollback_hook() interface registers a callback 5732** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5733** ^Any callback set by a previous call to sqlite3_rollback_hook() 5734** for the same database connection is overridden. 5735** ^The pArg argument is passed through to the callback. 5736** ^If the callback on a commit hook function returns non-zero, 5737** then the commit is converted into a rollback. 5738** 5739** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5740** return the P argument from the previous call of the same function 5741** on the same [database connection] D, or NULL for 5742** the first call for each function on D. 5743** 5744** The commit and rollback hook callbacks are not reentrant. 5745** The callback implementation must not do anything that will modify 5746** the database connection that invoked the callback. Any actions 5747** to modify the database connection must be deferred until after the 5748** completion of the [sqlite3_step()] call that triggered the commit 5749** or rollback hook in the first place. 5750** Note that running any other SQL statements, including SELECT statements, 5751** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5752** the database connections for the meaning of "modify" in this paragraph. 5753** 5754** ^Registering a NULL function disables the callback. 5755** 5756** ^When the commit hook callback routine returns zero, the [COMMIT] 5757** operation is allowed to continue normally. ^If the commit hook 5758** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5759** ^The rollback hook is invoked on a rollback that results from a commit 5760** hook returning non-zero, just as it would be with any other rollback. 5761** 5762** ^For the purposes of this API, a transaction is said to have been 5763** rolled back if an explicit "ROLLBACK" statement is executed, or 5764** an error or constraint causes an implicit rollback to occur. 5765** ^The rollback callback is not invoked if a transaction is 5766** automatically rolled back because the database connection is closed. 5767** 5768** See also the [sqlite3_update_hook()] interface. 5769*/ 5770void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5771void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5772 5773/* 5774** CAPI3REF: Data Change Notification Callbacks 5775** METHOD: sqlite3 5776** 5777** ^The sqlite3_update_hook() interface registers a callback function 5778** with the [database connection] identified by the first argument 5779** to be invoked whenever a row is updated, inserted or deleted in 5780** a [rowid table]. 5781** ^Any callback set by a previous call to this function 5782** for the same database connection is overridden. 5783** 5784** ^The second argument is a pointer to the function to invoke when a 5785** row is updated, inserted or deleted in a rowid table. 5786** ^The first argument to the callback is a copy of the third argument 5787** to sqlite3_update_hook(). 5788** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5789** or [SQLITE_UPDATE], depending on the operation that caused the callback 5790** to be invoked. 5791** ^The third and fourth arguments to the callback contain pointers to the 5792** database and table name containing the affected row. 5793** ^The final callback parameter is the [rowid] of the row. 5794** ^In the case of an update, this is the [rowid] after the update takes place. 5795** 5796** ^(The update hook is not invoked when internal system tables are 5797** modified (i.e. sqlite_master and sqlite_sequence).)^ 5798** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5799** 5800** ^In the current implementation, the update hook 5801** is not invoked when conflicting rows are deleted because of an 5802** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5803** invoked when rows are deleted using the [truncate optimization]. 5804** The exceptions defined in this paragraph might change in a future 5805** release of SQLite. 5806** 5807** The update hook implementation must not do anything that will modify 5808** the database connection that invoked the update hook. Any actions 5809** to modify the database connection must be deferred until after the 5810** completion of the [sqlite3_step()] call that triggered the update hook. 5811** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5812** database connections for the meaning of "modify" in this paragraph. 5813** 5814** ^The sqlite3_update_hook(D,C,P) function 5815** returns the P argument from the previous call 5816** on the same [database connection] D, or NULL for 5817** the first call on D. 5818** 5819** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5820** and [sqlite3_preupdate_hook()] interfaces. 5821*/ 5822void *sqlite3_update_hook( 5823 sqlite3*, 5824 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5825 void* 5826); 5827 5828/* 5829** CAPI3REF: Enable Or Disable Shared Pager Cache 5830** 5831** ^(This routine enables or disables the sharing of the database cache 5832** and schema data structures between [database connection | connections] 5833** to the same database. Sharing is enabled if the argument is true 5834** and disabled if the argument is false.)^ 5835** 5836** ^Cache sharing is enabled and disabled for an entire process. 5837** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5838** In prior versions of SQLite, 5839** sharing was enabled or disabled for each thread separately. 5840** 5841** ^(The cache sharing mode set by this interface effects all subsequent 5842** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5843** Existing database connections continue use the sharing mode 5844** that was in effect at the time they were opened.)^ 5845** 5846** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5847** successfully. An [error code] is returned otherwise.)^ 5848** 5849** ^Shared cache is disabled by default. But this might change in 5850** future releases of SQLite. Applications that care about shared 5851** cache setting should set it explicitly. 5852** 5853** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5854** and will always return SQLITE_MISUSE. On those systems, 5855** shared cache mode should be enabled per-database connection via 5856** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5857** 5858** This interface is threadsafe on processors where writing a 5859** 32-bit integer is atomic. 5860** 5861** See Also: [SQLite Shared-Cache Mode] 5862*/ 5863int sqlite3_enable_shared_cache(int); 5864 5865/* 5866** CAPI3REF: Attempt To Free Heap Memory 5867** 5868** ^The sqlite3_release_memory() interface attempts to free N bytes 5869** of heap memory by deallocating non-essential memory allocations 5870** held by the database library. Memory used to cache database 5871** pages to improve performance is an example of non-essential memory. 5872** ^sqlite3_release_memory() returns the number of bytes actually freed, 5873** which might be more or less than the amount requested. 5874** ^The sqlite3_release_memory() routine is a no-op returning zero 5875** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5876** 5877** See also: [sqlite3_db_release_memory()] 5878*/ 5879int sqlite3_release_memory(int); 5880 5881/* 5882** CAPI3REF: Free Memory Used By A Database Connection 5883** METHOD: sqlite3 5884** 5885** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5886** memory as possible from database connection D. Unlike the 5887** [sqlite3_release_memory()] interface, this interface is in effect even 5888** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5889** omitted. 5890** 5891** See also: [sqlite3_release_memory()] 5892*/ 5893int sqlite3_db_release_memory(sqlite3*); 5894 5895/* 5896** CAPI3REF: Impose A Limit On Heap Size 5897** 5898** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5899** soft limit on the amount of heap memory that may be allocated by SQLite. 5900** ^SQLite strives to keep heap memory utilization below the soft heap 5901** limit by reducing the number of pages held in the page cache 5902** as heap memory usages approaches the limit. 5903** ^The soft heap limit is "soft" because even though SQLite strives to stay 5904** below the limit, it will exceed the limit rather than generate 5905** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5906** is advisory only. 5907** 5908** ^The return value from sqlite3_soft_heap_limit64() is the size of 5909** the soft heap limit prior to the call, or negative in the case of an 5910** error. ^If the argument N is negative 5911** then no change is made to the soft heap limit. Hence, the current 5912** size of the soft heap limit can be determined by invoking 5913** sqlite3_soft_heap_limit64() with a negative argument. 5914** 5915** ^If the argument N is zero then the soft heap limit is disabled. 5916** 5917** ^(The soft heap limit is not enforced in the current implementation 5918** if one or more of following conditions are true: 5919** 5920** <ul> 5921** <li> The soft heap limit is set to zero. 5922** <li> Memory accounting is disabled using a combination of the 5923** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5924** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5925** <li> An alternative page cache implementation is specified using 5926** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5927** <li> The page cache allocates from its own memory pool supplied 5928** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5929** from the heap. 5930** </ul>)^ 5931** 5932** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5933** the soft heap limit is enforced 5934** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5935** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5936** the soft heap limit is enforced on every memory allocation. Without 5937** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5938** when memory is allocated by the page cache. Testing suggests that because 5939** the page cache is the predominate memory user in SQLite, most 5940** applications will achieve adequate soft heap limit enforcement without 5941** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5942** 5943** The circumstances under which SQLite will enforce the soft heap limit may 5944** changes in future releases of SQLite. 5945*/ 5946sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5947 5948/* 5949** CAPI3REF: Deprecated Soft Heap Limit Interface 5950** DEPRECATED 5951** 5952** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5953** interface. This routine is provided for historical compatibility 5954** only. All new applications should use the 5955** [sqlite3_soft_heap_limit64()] interface rather than this one. 5956*/ 5957SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5958 5959 5960/* 5961** CAPI3REF: Extract Metadata About A Column Of A Table 5962** METHOD: sqlite3 5963** 5964** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5965** information about column C of table T in database D 5966** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5967** interface returns SQLITE_OK and fills in the non-NULL pointers in 5968** the final five arguments with appropriate values if the specified 5969** column exists. ^The sqlite3_table_column_metadata() interface returns 5970** SQLITE_ERROR and if the specified column does not exist. 5971** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5972** NULL pointer, then this routine simply checks for the existence of the 5973** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5974** does not. If the table name parameter T in a call to 5975** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 5976** undefined behavior. 5977** 5978** ^The column is identified by the second, third and fourth parameters to 5979** this function. ^(The second parameter is either the name of the database 5980** (i.e. "main", "temp", or an attached database) containing the specified 5981** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5982** for the table using the same algorithm used by the database engine to 5983** resolve unqualified table references. 5984** 5985** ^The third and fourth parameters to this function are the table and column 5986** name of the desired column, respectively. 5987** 5988** ^Metadata is returned by writing to the memory locations passed as the 5th 5989** and subsequent parameters to this function. ^Any of these arguments may be 5990** NULL, in which case the corresponding element of metadata is omitted. 5991** 5992** ^(<blockquote> 5993** <table border="1"> 5994** <tr><th> Parameter <th> Output<br>Type <th> Description 5995** 5996** <tr><td> 5th <td> const char* <td> Data type 5997** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5998** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5999** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6000** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6001** </table> 6002** </blockquote>)^ 6003** 6004** ^The memory pointed to by the character pointers returned for the 6005** declaration type and collation sequence is valid until the next 6006** call to any SQLite API function. 6007** 6008** ^If the specified table is actually a view, an [error code] is returned. 6009** 6010** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6011** is not a [WITHOUT ROWID] table and an 6012** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6013** parameters are set for the explicitly declared column. ^(If there is no 6014** [INTEGER PRIMARY KEY] column, then the outputs 6015** for the [rowid] are set as follows: 6016** 6017** <pre> 6018** data type: "INTEGER" 6019** collation sequence: "BINARY" 6020** not null: 0 6021** primary key: 1 6022** auto increment: 0 6023** </pre>)^ 6024** 6025** ^This function causes all database schemas to be read from disk and 6026** parsed, if that has not already been done, and returns an error if 6027** any errors are encountered while loading the schema. 6028*/ 6029int sqlite3_table_column_metadata( 6030 sqlite3 *db, /* Connection handle */ 6031 const char *zDbName, /* Database name or NULL */ 6032 const char *zTableName, /* Table name */ 6033 const char *zColumnName, /* Column name */ 6034 char const **pzDataType, /* OUTPUT: Declared data type */ 6035 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6036 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6037 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6038 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6039); 6040 6041/* 6042** CAPI3REF: Load An Extension 6043** METHOD: sqlite3 6044** 6045** ^This interface loads an SQLite extension library from the named file. 6046** 6047** ^The sqlite3_load_extension() interface attempts to load an 6048** [SQLite extension] library contained in the file zFile. If 6049** the file cannot be loaded directly, attempts are made to load 6050** with various operating-system specific extensions added. 6051** So for example, if "samplelib" cannot be loaded, then names like 6052** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6053** be tried also. 6054** 6055** ^The entry point is zProc. 6056** ^(zProc may be 0, in which case SQLite will try to come up with an 6057** entry point name on its own. It first tries "sqlite3_extension_init". 6058** If that does not work, it constructs a name "sqlite3_X_init" where the 6059** X is consists of the lower-case equivalent of all ASCII alphabetic 6060** characters in the filename from the last "/" to the first following 6061** "." and omitting any initial "lib".)^ 6062** ^The sqlite3_load_extension() interface returns 6063** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6064** ^If an error occurs and pzErrMsg is not 0, then the 6065** [sqlite3_load_extension()] interface shall attempt to 6066** fill *pzErrMsg with error message text stored in memory 6067** obtained from [sqlite3_malloc()]. The calling function 6068** should free this memory by calling [sqlite3_free()]. 6069** 6070** ^Extension loading must be enabled using 6071** [sqlite3_enable_load_extension()] or 6072** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6073** prior to calling this API, 6074** otherwise an error will be returned. 6075** 6076** <b>Security warning:</b> It is recommended that the 6077** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6078** interface. The use of the [sqlite3_enable_load_extension()] interface 6079** should be avoided. This will keep the SQL function [load_extension()] 6080** disabled and prevent SQL injections from giving attackers 6081** access to extension loading capabilities. 6082** 6083** See also the [load_extension() SQL function]. 6084*/ 6085int sqlite3_load_extension( 6086 sqlite3 *db, /* Load the extension into this database connection */ 6087 const char *zFile, /* Name of the shared library containing extension */ 6088 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6089 char **pzErrMsg /* Put error message here if not 0 */ 6090); 6091 6092/* 6093** CAPI3REF: Enable Or Disable Extension Loading 6094** METHOD: sqlite3 6095** 6096** ^So as not to open security holes in older applications that are 6097** unprepared to deal with [extension loading], and as a means of disabling 6098** [extension loading] while evaluating user-entered SQL, the following API 6099** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6100** 6101** ^Extension loading is off by default. 6102** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6103** to turn extension loading on and call it with onoff==0 to turn 6104** it back off again. 6105** 6106** ^This interface enables or disables both the C-API 6107** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6108** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6109** to enable or disable only the C-API.)^ 6110** 6111** <b>Security warning:</b> It is recommended that extension loading 6112** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6113** rather than this interface, so the [load_extension()] SQL function 6114** remains disabled. This will prevent SQL injections from giving attackers 6115** access to extension loading capabilities. 6116*/ 6117int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6118 6119/* 6120** CAPI3REF: Automatically Load Statically Linked Extensions 6121** 6122** ^This interface causes the xEntryPoint() function to be invoked for 6123** each new [database connection] that is created. The idea here is that 6124** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6125** that is to be automatically loaded into all new database connections. 6126** 6127** ^(Even though the function prototype shows that xEntryPoint() takes 6128** no arguments and returns void, SQLite invokes xEntryPoint() with three 6129** arguments and expects an integer result as if the signature of the 6130** entry point where as follows: 6131** 6132** <blockquote><pre> 6133** int xEntryPoint( 6134** sqlite3 *db, 6135** const char **pzErrMsg, 6136** const struct sqlite3_api_routines *pThunk 6137** ); 6138** </pre></blockquote>)^ 6139** 6140** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6141** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6142** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6143** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6144** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6145** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6146** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6147** 6148** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6149** on the list of automatic extensions is a harmless no-op. ^No entry point 6150** will be called more than once for each database connection that is opened. 6151** 6152** See also: [sqlite3_reset_auto_extension()] 6153** and [sqlite3_cancel_auto_extension()] 6154*/ 6155int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6156 6157/* 6158** CAPI3REF: Cancel Automatic Extension Loading 6159** 6160** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6161** initialization routine X that was registered using a prior call to 6162** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6163** routine returns 1 if initialization routine X was successfully 6164** unregistered and it returns 0 if X was not on the list of initialization 6165** routines. 6166*/ 6167int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6168 6169/* 6170** CAPI3REF: Reset Automatic Extension Loading 6171** 6172** ^This interface disables all automatic extensions previously 6173** registered using [sqlite3_auto_extension()]. 6174*/ 6175void sqlite3_reset_auto_extension(void); 6176 6177/* 6178** The interface to the virtual-table mechanism is currently considered 6179** to be experimental. The interface might change in incompatible ways. 6180** If this is a problem for you, do not use the interface at this time. 6181** 6182** When the virtual-table mechanism stabilizes, we will declare the 6183** interface fixed, support it indefinitely, and remove this comment. 6184*/ 6185 6186/* 6187** Structures used by the virtual table interface 6188*/ 6189typedef struct sqlite3_vtab sqlite3_vtab; 6190typedef struct sqlite3_index_info sqlite3_index_info; 6191typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6192typedef struct sqlite3_module sqlite3_module; 6193 6194/* 6195** CAPI3REF: Virtual Table Object 6196** KEYWORDS: sqlite3_module {virtual table module} 6197** 6198** This structure, sometimes called a "virtual table module", 6199** defines the implementation of a [virtual tables]. 6200** This structure consists mostly of methods for the module. 6201** 6202** ^A virtual table module is created by filling in a persistent 6203** instance of this structure and passing a pointer to that instance 6204** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6205** ^The registration remains valid until it is replaced by a different 6206** module or until the [database connection] closes. The content 6207** of this structure must not change while it is registered with 6208** any database connection. 6209*/ 6210struct sqlite3_module { 6211 int iVersion; 6212 int (*xCreate)(sqlite3*, void *pAux, 6213 int argc, const char *const*argv, 6214 sqlite3_vtab **ppVTab, char**); 6215 int (*xConnect)(sqlite3*, void *pAux, 6216 int argc, const char *const*argv, 6217 sqlite3_vtab **ppVTab, char**); 6218 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6219 int (*xDisconnect)(sqlite3_vtab *pVTab); 6220 int (*xDestroy)(sqlite3_vtab *pVTab); 6221 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6222 int (*xClose)(sqlite3_vtab_cursor*); 6223 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6224 int argc, sqlite3_value **argv); 6225 int (*xNext)(sqlite3_vtab_cursor*); 6226 int (*xEof)(sqlite3_vtab_cursor*); 6227 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6228 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6229 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6230 int (*xBegin)(sqlite3_vtab *pVTab); 6231 int (*xSync)(sqlite3_vtab *pVTab); 6232 int (*xCommit)(sqlite3_vtab *pVTab); 6233 int (*xRollback)(sqlite3_vtab *pVTab); 6234 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6235 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6236 void **ppArg); 6237 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6238 /* The methods above are in version 1 of the sqlite_module object. Those 6239 ** below are for version 2 and greater. */ 6240 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6241 int (*xRelease)(sqlite3_vtab *pVTab, int); 6242 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6243}; 6244 6245/* 6246** CAPI3REF: Virtual Table Indexing Information 6247** KEYWORDS: sqlite3_index_info 6248** 6249** The sqlite3_index_info structure and its substructures is used as part 6250** of the [virtual table] interface to 6251** pass information into and receive the reply from the [xBestIndex] 6252** method of a [virtual table module]. The fields under **Inputs** are the 6253** inputs to xBestIndex and are read-only. xBestIndex inserts its 6254** results into the **Outputs** fields. 6255** 6256** ^(The aConstraint[] array records WHERE clause constraints of the form: 6257** 6258** <blockquote>column OP expr</blockquote> 6259** 6260** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6261** stored in aConstraint[].op using one of the 6262** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6263** ^(The index of the column is stored in 6264** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6265** expr on the right-hand side can be evaluated (and thus the constraint 6266** is usable) and false if it cannot.)^ 6267** 6268** ^The optimizer automatically inverts terms of the form "expr OP column" 6269** and makes other simplifications to the WHERE clause in an attempt to 6270** get as many WHERE clause terms into the form shown above as possible. 6271** ^The aConstraint[] array only reports WHERE clause terms that are 6272** relevant to the particular virtual table being queried. 6273** 6274** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6275** ^Each term of aOrderBy records a column of the ORDER BY clause. 6276** 6277** The colUsed field indicates which columns of the virtual table may be 6278** required by the current scan. Virtual table columns are numbered from 6279** zero in the order in which they appear within the CREATE TABLE statement 6280** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6281** the corresponding bit is set within the colUsed mask if the column may be 6282** required by SQLite. If the table has at least 64 columns and any column 6283** to the right of the first 63 is required, then bit 63 of colUsed is also 6284** set. In other words, column iCol may be required if the expression 6285** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6286** non-zero. 6287** 6288** The [xBestIndex] method must fill aConstraintUsage[] with information 6289** about what parameters to pass to xFilter. ^If argvIndex>0 then 6290** the right-hand side of the corresponding aConstraint[] is evaluated 6291** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6292** is true, then the constraint is assumed to be fully handled by the 6293** virtual table and is not checked again by SQLite.)^ 6294** 6295** ^The idxNum and idxPtr values are recorded and passed into the 6296** [xFilter] method. 6297** ^[sqlite3_free()] is used to free idxPtr if and only if 6298** needToFreeIdxPtr is true. 6299** 6300** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6301** the correct order to satisfy the ORDER BY clause so that no separate 6302** sorting step is required. 6303** 6304** ^The estimatedCost value is an estimate of the cost of a particular 6305** strategy. A cost of N indicates that the cost of the strategy is similar 6306** to a linear scan of an SQLite table with N rows. A cost of log(N) 6307** indicates that the expense of the operation is similar to that of a 6308** binary search on a unique indexed field of an SQLite table with N rows. 6309** 6310** ^The estimatedRows value is an estimate of the number of rows that 6311** will be returned by the strategy. 6312** 6313** The xBestIndex method may optionally populate the idxFlags field with a 6314** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6315** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6316** assumes that the strategy may visit at most one row. 6317** 6318** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6319** SQLite also assumes that if a call to the xUpdate() method is made as 6320** part of the same statement to delete or update a virtual table row and the 6321** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6322** any database changes. In other words, if the xUpdate() returns 6323** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6324** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6325** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6326** the xUpdate method are automatically rolled back by SQLite. 6327** 6328** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6329** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6330** If a virtual table extension is 6331** used with an SQLite version earlier than 3.8.2, the results of attempting 6332** to read or write the estimatedRows field are undefined (but are likely 6333** to included crashing the application). The estimatedRows field should 6334** therefore only be used if [sqlite3_libversion_number()] returns a 6335** value greater than or equal to 3008002. Similarly, the idxFlags field 6336** was added for [version 3.9.0] ([dateof:3.9.0]). 6337** It may therefore only be used if 6338** sqlite3_libversion_number() returns a value greater than or equal to 6339** 3009000. 6340*/ 6341struct sqlite3_index_info { 6342 /* Inputs */ 6343 int nConstraint; /* Number of entries in aConstraint */ 6344 struct sqlite3_index_constraint { 6345 int iColumn; /* Column constrained. -1 for ROWID */ 6346 unsigned char op; /* Constraint operator */ 6347 unsigned char usable; /* True if this constraint is usable */ 6348 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6349 } *aConstraint; /* Table of WHERE clause constraints */ 6350 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6351 struct sqlite3_index_orderby { 6352 int iColumn; /* Column number */ 6353 unsigned char desc; /* True for DESC. False for ASC. */ 6354 } *aOrderBy; /* The ORDER BY clause */ 6355 /* Outputs */ 6356 struct sqlite3_index_constraint_usage { 6357 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6358 unsigned char omit; /* Do not code a test for this constraint */ 6359 } *aConstraintUsage; 6360 int idxNum; /* Number used to identify the index */ 6361 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6362 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6363 int orderByConsumed; /* True if output is already ordered */ 6364 double estimatedCost; /* Estimated cost of using this index */ 6365 /* Fields below are only available in SQLite 3.8.2 and later */ 6366 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6367 /* Fields below are only available in SQLite 3.9.0 and later */ 6368 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6369 /* Fields below are only available in SQLite 3.10.0 and later */ 6370 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6371}; 6372 6373/* 6374** CAPI3REF: Virtual Table Scan Flags 6375** 6376** Virtual table implementations are allowed to set the 6377** [sqlite3_index_info].idxFlags field to some combination of 6378** these bits. 6379*/ 6380#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6381 6382/* 6383** CAPI3REF: Virtual Table Constraint Operator Codes 6384** 6385** These macros defined the allowed values for the 6386** [sqlite3_index_info].aConstraint[].op field. Each value represents 6387** an operator that is part of a constraint term in the wHERE clause of 6388** a query that uses a [virtual table]. 6389*/ 6390#define SQLITE_INDEX_CONSTRAINT_EQ 2 6391#define SQLITE_INDEX_CONSTRAINT_GT 4 6392#define SQLITE_INDEX_CONSTRAINT_LE 8 6393#define SQLITE_INDEX_CONSTRAINT_LT 16 6394#define SQLITE_INDEX_CONSTRAINT_GE 32 6395#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6396#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6397#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6398#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6399#define SQLITE_INDEX_CONSTRAINT_NE 68 6400#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6401#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6402#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6403#define SQLITE_INDEX_CONSTRAINT_IS 72 6404 6405/* 6406** CAPI3REF: Register A Virtual Table Implementation 6407** METHOD: sqlite3 6408** 6409** ^These routines are used to register a new [virtual table module] name. 6410** ^Module names must be registered before 6411** creating a new [virtual table] using the module and before using a 6412** preexisting [virtual table] for the module. 6413** 6414** ^The module name is registered on the [database connection] specified 6415** by the first parameter. ^The name of the module is given by the 6416** second parameter. ^The third parameter is a pointer to 6417** the implementation of the [virtual table module]. ^The fourth 6418** parameter is an arbitrary client data pointer that is passed through 6419** into the [xCreate] and [xConnect] methods of the virtual table module 6420** when a new virtual table is be being created or reinitialized. 6421** 6422** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6423** is a pointer to a destructor for the pClientData. ^SQLite will 6424** invoke the destructor function (if it is not NULL) when SQLite 6425** no longer needs the pClientData pointer. ^The destructor will also 6426** be invoked if the call to sqlite3_create_module_v2() fails. 6427** ^The sqlite3_create_module() 6428** interface is equivalent to sqlite3_create_module_v2() with a NULL 6429** destructor. 6430*/ 6431int sqlite3_create_module( 6432 sqlite3 *db, /* SQLite connection to register module with */ 6433 const char *zName, /* Name of the module */ 6434 const sqlite3_module *p, /* Methods for the module */ 6435 void *pClientData /* Client data for xCreate/xConnect */ 6436); 6437int sqlite3_create_module_v2( 6438 sqlite3 *db, /* SQLite connection to register module with */ 6439 const char *zName, /* Name of the module */ 6440 const sqlite3_module *p, /* Methods for the module */ 6441 void *pClientData, /* Client data for xCreate/xConnect */ 6442 void(*xDestroy)(void*) /* Module destructor function */ 6443); 6444 6445/* 6446** CAPI3REF: Virtual Table Instance Object 6447** KEYWORDS: sqlite3_vtab 6448** 6449** Every [virtual table module] implementation uses a subclass 6450** of this object to describe a particular instance 6451** of the [virtual table]. Each subclass will 6452** be tailored to the specific needs of the module implementation. 6453** The purpose of this superclass is to define certain fields that are 6454** common to all module implementations. 6455** 6456** ^Virtual tables methods can set an error message by assigning a 6457** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6458** take care that any prior string is freed by a call to [sqlite3_free()] 6459** prior to assigning a new string to zErrMsg. ^After the error message 6460** is delivered up to the client application, the string will be automatically 6461** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6462*/ 6463struct sqlite3_vtab { 6464 const sqlite3_module *pModule; /* The module for this virtual table */ 6465 int nRef; /* Number of open cursors */ 6466 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6467 /* Virtual table implementations will typically add additional fields */ 6468}; 6469 6470/* 6471** CAPI3REF: Virtual Table Cursor Object 6472** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6473** 6474** Every [virtual table module] implementation uses a subclass of the 6475** following structure to describe cursors that point into the 6476** [virtual table] and are used 6477** to loop through the virtual table. Cursors are created using the 6478** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6479** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6480** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6481** of the module. Each module implementation will define 6482** the content of a cursor structure to suit its own needs. 6483** 6484** This superclass exists in order to define fields of the cursor that 6485** are common to all implementations. 6486*/ 6487struct sqlite3_vtab_cursor { 6488 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6489 /* Virtual table implementations will typically add additional fields */ 6490}; 6491 6492/* 6493** CAPI3REF: Declare The Schema Of A Virtual Table 6494** 6495** ^The [xCreate] and [xConnect] methods of a 6496** [virtual table module] call this interface 6497** to declare the format (the names and datatypes of the columns) of 6498** the virtual tables they implement. 6499*/ 6500int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6501 6502/* 6503** CAPI3REF: Overload A Function For A Virtual Table 6504** METHOD: sqlite3 6505** 6506** ^(Virtual tables can provide alternative implementations of functions 6507** using the [xFindFunction] method of the [virtual table module]. 6508** But global versions of those functions 6509** must exist in order to be overloaded.)^ 6510** 6511** ^(This API makes sure a global version of a function with a particular 6512** name and number of parameters exists. If no such function exists 6513** before this API is called, a new function is created.)^ ^The implementation 6514** of the new function always causes an exception to be thrown. So 6515** the new function is not good for anything by itself. Its only 6516** purpose is to be a placeholder function that can be overloaded 6517** by a [virtual table]. 6518*/ 6519int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6520 6521/* 6522** The interface to the virtual-table mechanism defined above (back up 6523** to a comment remarkably similar to this one) is currently considered 6524** to be experimental. The interface might change in incompatible ways. 6525** If this is a problem for you, do not use the interface at this time. 6526** 6527** When the virtual-table mechanism stabilizes, we will declare the 6528** interface fixed, support it indefinitely, and remove this comment. 6529*/ 6530 6531/* 6532** CAPI3REF: A Handle To An Open BLOB 6533** KEYWORDS: {BLOB handle} {BLOB handles} 6534** 6535** An instance of this object represents an open BLOB on which 6536** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6537** ^Objects of this type are created by [sqlite3_blob_open()] 6538** and destroyed by [sqlite3_blob_close()]. 6539** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6540** can be used to read or write small subsections of the BLOB. 6541** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6542*/ 6543typedef struct sqlite3_blob sqlite3_blob; 6544 6545/* 6546** CAPI3REF: Open A BLOB For Incremental I/O 6547** METHOD: sqlite3 6548** CONSTRUCTOR: sqlite3_blob 6549** 6550** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6551** in row iRow, column zColumn, table zTable in database zDb; 6552** in other words, the same BLOB that would be selected by: 6553** 6554** <pre> 6555** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6556** </pre>)^ 6557** 6558** ^(Parameter zDb is not the filename that contains the database, but 6559** rather the symbolic name of the database. For attached databases, this is 6560** the name that appears after the AS keyword in the [ATTACH] statement. 6561** For the main database file, the database name is "main". For TEMP 6562** tables, the database name is "temp".)^ 6563** 6564** ^If the flags parameter is non-zero, then the BLOB is opened for read 6565** and write access. ^If the flags parameter is zero, the BLOB is opened for 6566** read-only access. 6567** 6568** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6569** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6570** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6571** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6572** on *ppBlob after this function it returns. 6573** 6574** This function fails with SQLITE_ERROR if any of the following are true: 6575** <ul> 6576** <li> ^(Database zDb does not exist)^, 6577** <li> ^(Table zTable does not exist within database zDb)^, 6578** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6579** <li> ^(Column zColumn does not exist)^, 6580** <li> ^(Row iRow is not present in the table)^, 6581** <li> ^(The specified column of row iRow contains a value that is not 6582** a TEXT or BLOB value)^, 6583** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6584** constraint and the blob is being opened for read/write access)^, 6585** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6586** column zColumn is part of a [child key] definition and the blob is 6587** being opened for read/write access)^. 6588** </ul> 6589** 6590** ^Unless it returns SQLITE_MISUSE, this function sets the 6591** [database connection] error code and message accessible via 6592** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6593** 6594** A BLOB referenced by sqlite3_blob_open() may be read using the 6595** [sqlite3_blob_read()] interface and modified by using 6596** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6597** different row of the same table using the [sqlite3_blob_reopen()] 6598** interface. However, the column, table, or database of a [BLOB handle] 6599** cannot be changed after the [BLOB handle] is opened. 6600** 6601** ^(If the row that a BLOB handle points to is modified by an 6602** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6603** then the BLOB handle is marked as "expired". 6604** This is true if any column of the row is changed, even a column 6605** other than the one the BLOB handle is open on.)^ 6606** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6607** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6608** ^(Changes written into a BLOB prior to the BLOB expiring are not 6609** rolled back by the expiration of the BLOB. Such changes will eventually 6610** commit if the transaction continues to completion.)^ 6611** 6612** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6613** the opened blob. ^The size of a blob may not be changed by this 6614** interface. Use the [UPDATE] SQL command to change the size of a 6615** blob. 6616** 6617** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6618** and the built-in [zeroblob] SQL function may be used to create a 6619** zero-filled blob to read or write using the incremental-blob interface. 6620** 6621** To avoid a resource leak, every open [BLOB handle] should eventually 6622** be released by a call to [sqlite3_blob_close()]. 6623** 6624** See also: [sqlite3_blob_close()], 6625** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6626** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6627*/ 6628int sqlite3_blob_open( 6629 sqlite3*, 6630 const char *zDb, 6631 const char *zTable, 6632 const char *zColumn, 6633 sqlite3_int64 iRow, 6634 int flags, 6635 sqlite3_blob **ppBlob 6636); 6637 6638/* 6639** CAPI3REF: Move a BLOB Handle to a New Row 6640** METHOD: sqlite3_blob 6641** 6642** ^This function is used to move an existing [BLOB handle] so that it points 6643** to a different row of the same database table. ^The new row is identified 6644** by the rowid value passed as the second argument. Only the row can be 6645** changed. ^The database, table and column on which the blob handle is open 6646** remain the same. Moving an existing [BLOB handle] to a new row is 6647** faster than closing the existing handle and opening a new one. 6648** 6649** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6650** it must exist and there must be either a blob or text value stored in 6651** the nominated column.)^ ^If the new row is not present in the table, or if 6652** it does not contain a blob or text value, or if another error occurs, an 6653** SQLite error code is returned and the blob handle is considered aborted. 6654** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6655** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6656** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6657** always returns zero. 6658** 6659** ^This function sets the database handle error code and message. 6660*/ 6661int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6662 6663/* 6664** CAPI3REF: Close A BLOB Handle 6665** DESTRUCTOR: sqlite3_blob 6666** 6667** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6668** unconditionally. Even if this routine returns an error code, the 6669** handle is still closed.)^ 6670** 6671** ^If the blob handle being closed was opened for read-write access, and if 6672** the database is in auto-commit mode and there are no other open read-write 6673** blob handles or active write statements, the current transaction is 6674** committed. ^If an error occurs while committing the transaction, an error 6675** code is returned and the transaction rolled back. 6676** 6677** Calling this function with an argument that is not a NULL pointer or an 6678** open blob handle results in undefined behaviour. ^Calling this routine 6679** with a null pointer (such as would be returned by a failed call to 6680** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6681** is passed a valid open blob handle, the values returned by the 6682** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6683*/ 6684int sqlite3_blob_close(sqlite3_blob *); 6685 6686/* 6687** CAPI3REF: Return The Size Of An Open BLOB 6688** METHOD: sqlite3_blob 6689** 6690** ^Returns the size in bytes of the BLOB accessible via the 6691** successfully opened [BLOB handle] in its only argument. ^The 6692** incremental blob I/O routines can only read or overwriting existing 6693** blob content; they cannot change the size of a blob. 6694** 6695** This routine only works on a [BLOB handle] which has been created 6696** by a prior successful call to [sqlite3_blob_open()] and which has not 6697** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6698** to this routine results in undefined and probably undesirable behavior. 6699*/ 6700int sqlite3_blob_bytes(sqlite3_blob *); 6701 6702/* 6703** CAPI3REF: Read Data From A BLOB Incrementally 6704** METHOD: sqlite3_blob 6705** 6706** ^(This function is used to read data from an open [BLOB handle] into a 6707** caller-supplied buffer. N bytes of data are copied into buffer Z 6708** from the open BLOB, starting at offset iOffset.)^ 6709** 6710** ^If offset iOffset is less than N bytes from the end of the BLOB, 6711** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6712** less than zero, [SQLITE_ERROR] is returned and no data is read. 6713** ^The size of the blob (and hence the maximum value of N+iOffset) 6714** can be determined using the [sqlite3_blob_bytes()] interface. 6715** 6716** ^An attempt to read from an expired [BLOB handle] fails with an 6717** error code of [SQLITE_ABORT]. 6718** 6719** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6720** Otherwise, an [error code] or an [extended error code] is returned.)^ 6721** 6722** This routine only works on a [BLOB handle] which has been created 6723** by a prior successful call to [sqlite3_blob_open()] and which has not 6724** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6725** to this routine results in undefined and probably undesirable behavior. 6726** 6727** See also: [sqlite3_blob_write()]. 6728*/ 6729int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6730 6731/* 6732** CAPI3REF: Write Data Into A BLOB Incrementally 6733** METHOD: sqlite3_blob 6734** 6735** ^(This function is used to write data into an open [BLOB handle] from a 6736** caller-supplied buffer. N bytes of data are copied from the buffer Z 6737** into the open BLOB, starting at offset iOffset.)^ 6738** 6739** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6740** Otherwise, an [error code] or an [extended error code] is returned.)^ 6741** ^Unless SQLITE_MISUSE is returned, this function sets the 6742** [database connection] error code and message accessible via 6743** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6744** 6745** ^If the [BLOB handle] passed as the first argument was not opened for 6746** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6747** this function returns [SQLITE_READONLY]. 6748** 6749** This function may only modify the contents of the BLOB; it is 6750** not possible to increase the size of a BLOB using this API. 6751** ^If offset iOffset is less than N bytes from the end of the BLOB, 6752** [SQLITE_ERROR] is returned and no data is written. The size of the 6753** BLOB (and hence the maximum value of N+iOffset) can be determined 6754** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6755** than zero [SQLITE_ERROR] is returned and no data is written. 6756** 6757** ^An attempt to write to an expired [BLOB handle] fails with an 6758** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6759** before the [BLOB handle] expired are not rolled back by the 6760** expiration of the handle, though of course those changes might 6761** have been overwritten by the statement that expired the BLOB handle 6762** or by other independent statements. 6763** 6764** This routine only works on a [BLOB handle] which has been created 6765** by a prior successful call to [sqlite3_blob_open()] and which has not 6766** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6767** to this routine results in undefined and probably undesirable behavior. 6768** 6769** See also: [sqlite3_blob_read()]. 6770*/ 6771int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6772 6773/* 6774** CAPI3REF: Virtual File System Objects 6775** 6776** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6777** that SQLite uses to interact 6778** with the underlying operating system. Most SQLite builds come with a 6779** single default VFS that is appropriate for the host computer. 6780** New VFSes can be registered and existing VFSes can be unregistered. 6781** The following interfaces are provided. 6782** 6783** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6784** ^Names are case sensitive. 6785** ^Names are zero-terminated UTF-8 strings. 6786** ^If there is no match, a NULL pointer is returned. 6787** ^If zVfsName is NULL then the default VFS is returned. 6788** 6789** ^New VFSes are registered with sqlite3_vfs_register(). 6790** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6791** ^The same VFS can be registered multiple times without injury. 6792** ^To make an existing VFS into the default VFS, register it again 6793** with the makeDflt flag set. If two different VFSes with the 6794** same name are registered, the behavior is undefined. If a 6795** VFS is registered with a name that is NULL or an empty string, 6796** then the behavior is undefined. 6797** 6798** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6799** ^(If the default VFS is unregistered, another VFS is chosen as 6800** the default. The choice for the new VFS is arbitrary.)^ 6801*/ 6802sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6803int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6804int sqlite3_vfs_unregister(sqlite3_vfs*); 6805 6806/* 6807** CAPI3REF: Mutexes 6808** 6809** The SQLite core uses these routines for thread 6810** synchronization. Though they are intended for internal 6811** use by SQLite, code that links against SQLite is 6812** permitted to use any of these routines. 6813** 6814** The SQLite source code contains multiple implementations 6815** of these mutex routines. An appropriate implementation 6816** is selected automatically at compile-time. The following 6817** implementations are available in the SQLite core: 6818** 6819** <ul> 6820** <li> SQLITE_MUTEX_PTHREADS 6821** <li> SQLITE_MUTEX_W32 6822** <li> SQLITE_MUTEX_NOOP 6823** </ul> 6824** 6825** The SQLITE_MUTEX_NOOP implementation is a set of routines 6826** that does no real locking and is appropriate for use in 6827** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6828** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6829** and Windows. 6830** 6831** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6832** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6833** implementation is included with the library. In this case the 6834** application must supply a custom mutex implementation using the 6835** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6836** before calling sqlite3_initialize() or any other public sqlite3_ 6837** function that calls sqlite3_initialize(). 6838** 6839** ^The sqlite3_mutex_alloc() routine allocates a new 6840** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6841** routine returns NULL if it is unable to allocate the requested 6842** mutex. The argument to sqlite3_mutex_alloc() must one of these 6843** integer constants: 6844** 6845** <ul> 6846** <li> SQLITE_MUTEX_FAST 6847** <li> SQLITE_MUTEX_RECURSIVE 6848** <li> SQLITE_MUTEX_STATIC_MASTER 6849** <li> SQLITE_MUTEX_STATIC_MEM 6850** <li> SQLITE_MUTEX_STATIC_OPEN 6851** <li> SQLITE_MUTEX_STATIC_PRNG 6852** <li> SQLITE_MUTEX_STATIC_LRU 6853** <li> SQLITE_MUTEX_STATIC_PMEM 6854** <li> SQLITE_MUTEX_STATIC_APP1 6855** <li> SQLITE_MUTEX_STATIC_APP2 6856** <li> SQLITE_MUTEX_STATIC_APP3 6857** <li> SQLITE_MUTEX_STATIC_VFS1 6858** <li> SQLITE_MUTEX_STATIC_VFS2 6859** <li> SQLITE_MUTEX_STATIC_VFS3 6860** </ul> 6861** 6862** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6863** cause sqlite3_mutex_alloc() to create 6864** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6865** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6866** The mutex implementation does not need to make a distinction 6867** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6868** not want to. SQLite will only request a recursive mutex in 6869** cases where it really needs one. If a faster non-recursive mutex 6870** implementation is available on the host platform, the mutex subsystem 6871** might return such a mutex in response to SQLITE_MUTEX_FAST. 6872** 6873** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6874** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6875** a pointer to a static preexisting mutex. ^Nine static mutexes are 6876** used by the current version of SQLite. Future versions of SQLite 6877** may add additional static mutexes. Static mutexes are for internal 6878** use by SQLite only. Applications that use SQLite mutexes should 6879** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6880** SQLITE_MUTEX_RECURSIVE. 6881** 6882** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6883** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6884** returns a different mutex on every call. ^For the static 6885** mutex types, the same mutex is returned on every call that has 6886** the same type number. 6887** 6888** ^The sqlite3_mutex_free() routine deallocates a previously 6889** allocated dynamic mutex. Attempting to deallocate a static 6890** mutex results in undefined behavior. 6891** 6892** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6893** to enter a mutex. ^If another thread is already within the mutex, 6894** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6895** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6896** upon successful entry. ^(Mutexes created using 6897** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6898** In such cases, the 6899** mutex must be exited an equal number of times before another thread 6900** can enter.)^ If the same thread tries to enter any mutex other 6901** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6902** 6903** ^(Some systems (for example, Windows 95) do not support the operation 6904** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6905** will always return SQLITE_BUSY. The SQLite core only ever uses 6906** sqlite3_mutex_try() as an optimization so this is acceptable 6907** behavior.)^ 6908** 6909** ^The sqlite3_mutex_leave() routine exits a mutex that was 6910** previously entered by the same thread. The behavior 6911** is undefined if the mutex is not currently entered by the 6912** calling thread or is not currently allocated. 6913** 6914** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6915** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6916** behave as no-ops. 6917** 6918** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6919*/ 6920sqlite3_mutex *sqlite3_mutex_alloc(int); 6921void sqlite3_mutex_free(sqlite3_mutex*); 6922void sqlite3_mutex_enter(sqlite3_mutex*); 6923int sqlite3_mutex_try(sqlite3_mutex*); 6924void sqlite3_mutex_leave(sqlite3_mutex*); 6925 6926/* 6927** CAPI3REF: Mutex Methods Object 6928** 6929** An instance of this structure defines the low-level routines 6930** used to allocate and use mutexes. 6931** 6932** Usually, the default mutex implementations provided by SQLite are 6933** sufficient, however the application has the option of substituting a custom 6934** implementation for specialized deployments or systems for which SQLite 6935** does not provide a suitable implementation. In this case, the application 6936** creates and populates an instance of this structure to pass 6937** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6938** Additionally, an instance of this structure can be used as an 6939** output variable when querying the system for the current mutex 6940** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6941** 6942** ^The xMutexInit method defined by this structure is invoked as 6943** part of system initialization by the sqlite3_initialize() function. 6944** ^The xMutexInit routine is called by SQLite exactly once for each 6945** effective call to [sqlite3_initialize()]. 6946** 6947** ^The xMutexEnd method defined by this structure is invoked as 6948** part of system shutdown by the sqlite3_shutdown() function. The 6949** implementation of this method is expected to release all outstanding 6950** resources obtained by the mutex methods implementation, especially 6951** those obtained by the xMutexInit method. ^The xMutexEnd() 6952** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6953** 6954** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6955** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6956** xMutexNotheld) implement the following interfaces (respectively): 6957** 6958** <ul> 6959** <li> [sqlite3_mutex_alloc()] </li> 6960** <li> [sqlite3_mutex_free()] </li> 6961** <li> [sqlite3_mutex_enter()] </li> 6962** <li> [sqlite3_mutex_try()] </li> 6963** <li> [sqlite3_mutex_leave()] </li> 6964** <li> [sqlite3_mutex_held()] </li> 6965** <li> [sqlite3_mutex_notheld()] </li> 6966** </ul>)^ 6967** 6968** The only difference is that the public sqlite3_XXX functions enumerated 6969** above silently ignore any invocations that pass a NULL pointer instead 6970** of a valid mutex handle. The implementations of the methods defined 6971** by this structure are not required to handle this case, the results 6972** of passing a NULL pointer instead of a valid mutex handle are undefined 6973** (i.e. it is acceptable to provide an implementation that segfaults if 6974** it is passed a NULL pointer). 6975** 6976** The xMutexInit() method must be threadsafe. It must be harmless to 6977** invoke xMutexInit() multiple times within the same process and without 6978** intervening calls to xMutexEnd(). Second and subsequent calls to 6979** xMutexInit() must be no-ops. 6980** 6981** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6982** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6983** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6984** memory allocation for a fast or recursive mutex. 6985** 6986** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6987** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6988** If xMutexInit fails in any way, it is expected to clean up after itself 6989** prior to returning. 6990*/ 6991typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6992struct sqlite3_mutex_methods { 6993 int (*xMutexInit)(void); 6994 int (*xMutexEnd)(void); 6995 sqlite3_mutex *(*xMutexAlloc)(int); 6996 void (*xMutexFree)(sqlite3_mutex *); 6997 void (*xMutexEnter)(sqlite3_mutex *); 6998 int (*xMutexTry)(sqlite3_mutex *); 6999 void (*xMutexLeave)(sqlite3_mutex *); 7000 int (*xMutexHeld)(sqlite3_mutex *); 7001 int (*xMutexNotheld)(sqlite3_mutex *); 7002}; 7003 7004/* 7005** CAPI3REF: Mutex Verification Routines 7006** 7007** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7008** are intended for use inside assert() statements. The SQLite core 7009** never uses these routines except inside an assert() and applications 7010** are advised to follow the lead of the core. The SQLite core only 7011** provides implementations for these routines when it is compiled 7012** with the SQLITE_DEBUG flag. External mutex implementations 7013** are only required to provide these routines if SQLITE_DEBUG is 7014** defined and if NDEBUG is not defined. 7015** 7016** These routines should return true if the mutex in their argument 7017** is held or not held, respectively, by the calling thread. 7018** 7019** The implementation is not required to provide versions of these 7020** routines that actually work. If the implementation does not provide working 7021** versions of these routines, it should at least provide stubs that always 7022** return true so that one does not get spurious assertion failures. 7023** 7024** If the argument to sqlite3_mutex_held() is a NULL pointer then 7025** the routine should return 1. This seems counter-intuitive since 7026** clearly the mutex cannot be held if it does not exist. But 7027** the reason the mutex does not exist is because the build is not 7028** using mutexes. And we do not want the assert() containing the 7029** call to sqlite3_mutex_held() to fail, so a non-zero return is 7030** the appropriate thing to do. The sqlite3_mutex_notheld() 7031** interface should also return 1 when given a NULL pointer. 7032*/ 7033#ifndef NDEBUG 7034int sqlite3_mutex_held(sqlite3_mutex*); 7035int sqlite3_mutex_notheld(sqlite3_mutex*); 7036#endif 7037 7038/* 7039** CAPI3REF: Mutex Types 7040** 7041** The [sqlite3_mutex_alloc()] interface takes a single argument 7042** which is one of these integer constants. 7043** 7044** The set of static mutexes may change from one SQLite release to the 7045** next. Applications that override the built-in mutex logic must be 7046** prepared to accommodate additional static mutexes. 7047*/ 7048#define SQLITE_MUTEX_FAST 0 7049#define SQLITE_MUTEX_RECURSIVE 1 7050#define SQLITE_MUTEX_STATIC_MASTER 2 7051#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7052#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7053#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7054#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7055#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7056#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7057#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7058#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7059#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7060#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7061#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7062#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7063#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7064 7065/* 7066** CAPI3REF: Retrieve the mutex for a database connection 7067** METHOD: sqlite3 7068** 7069** ^This interface returns a pointer the [sqlite3_mutex] object that 7070** serializes access to the [database connection] given in the argument 7071** when the [threading mode] is Serialized. 7072** ^If the [threading mode] is Single-thread or Multi-thread then this 7073** routine returns a NULL pointer. 7074*/ 7075sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7076 7077/* 7078** CAPI3REF: Low-Level Control Of Database Files 7079** METHOD: sqlite3 7080** 7081** ^The [sqlite3_file_control()] interface makes a direct call to the 7082** xFileControl method for the [sqlite3_io_methods] object associated 7083** with a particular database identified by the second argument. ^The 7084** name of the database is "main" for the main database or "temp" for the 7085** TEMP database, or the name that appears after the AS keyword for 7086** databases that are added using the [ATTACH] SQL command. 7087** ^A NULL pointer can be used in place of "main" to refer to the 7088** main database file. 7089** ^The third and fourth parameters to this routine 7090** are passed directly through to the second and third parameters of 7091** the xFileControl method. ^The return value of the xFileControl 7092** method becomes the return value of this routine. 7093** 7094** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7095** a pointer to the underlying [sqlite3_file] object to be written into 7096** the space pointed to by the 4th parameter. ^The [SQLITE_FCNTL_FILE_POINTER] 7097** case is a short-circuit path which does not actually invoke the 7098** underlying sqlite3_io_methods.xFileControl method. 7099** 7100** ^If the second parameter (zDbName) does not match the name of any 7101** open database file, then SQLITE_ERROR is returned. ^This error 7102** code is not remembered and will not be recalled by [sqlite3_errcode()] 7103** or [sqlite3_errmsg()]. The underlying xFileControl method might 7104** also return SQLITE_ERROR. There is no way to distinguish between 7105** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7106** xFileControl method. 7107** 7108** See also: [file control opcodes] 7109*/ 7110int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7111 7112/* 7113** CAPI3REF: Testing Interface 7114** 7115** ^The sqlite3_test_control() interface is used to read out internal 7116** state of SQLite and to inject faults into SQLite for testing 7117** purposes. ^The first parameter is an operation code that determines 7118** the number, meaning, and operation of all subsequent parameters. 7119** 7120** This interface is not for use by applications. It exists solely 7121** for verifying the correct operation of the SQLite library. Depending 7122** on how the SQLite library is compiled, this interface might not exist. 7123** 7124** The details of the operation codes, their meanings, the parameters 7125** they take, and what they do are all subject to change without notice. 7126** Unlike most of the SQLite API, this function is not guaranteed to 7127** operate consistently from one release to the next. 7128*/ 7129int sqlite3_test_control(int op, ...); 7130 7131/* 7132** CAPI3REF: Testing Interface Operation Codes 7133** 7134** These constants are the valid operation code parameters used 7135** as the first argument to [sqlite3_test_control()]. 7136** 7137** These parameters and their meanings are subject to change 7138** without notice. These values are for testing purposes only. 7139** Applications should not use any of these parameters or the 7140** [sqlite3_test_control()] interface. 7141*/ 7142#define SQLITE_TESTCTRL_FIRST 5 7143#define SQLITE_TESTCTRL_PRNG_SAVE 5 7144#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7145#define SQLITE_TESTCTRL_PRNG_RESET 7 7146#define SQLITE_TESTCTRL_BITVEC_TEST 8 7147#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7148#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7149#define SQLITE_TESTCTRL_PENDING_BYTE 11 7150#define SQLITE_TESTCTRL_ASSERT 12 7151#define SQLITE_TESTCTRL_ALWAYS 13 7152#define SQLITE_TESTCTRL_RESERVE 14 7153#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7154#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7155#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7156#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7157#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7158#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7159#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7160#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7161#define SQLITE_TESTCTRL_BYTEORDER 22 7162#define SQLITE_TESTCTRL_ISINIT 23 7163#define SQLITE_TESTCTRL_SORTER_MMAP 24 7164#define SQLITE_TESTCTRL_IMPOSTER 25 7165#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7166#define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */ 7167 7168/* 7169** CAPI3REF: SQL Keyword Checking 7170** 7171** These routines provide access to the set of SQL language keywords 7172** recognized by SQLite. Applications can uses these routines to determine 7173** whether or not a specific identifier needs to be escaped (for example, 7174** by enclosing in double-quotes) so as not to confuse the parser. 7175** 7176** The sqlite3_keyword_count() interface returns the number of distinct 7177** keywords understood by SQLite. 7178** 7179** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7180** makes *Z point to that keyword expressed as UTF8 and writes the number 7181** of bytes in the keyword into *L. The string that *Z points to is not 7182** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7183** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7184** or L are NULL or invalid pointers then calls to 7185** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7186** 7187** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7188** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7189** if it is and zero if not. 7190** 7191** The parser used by SQLite is forgiving. It is often possible to use 7192** a keyword as an identifier as long as such use does not result in a 7193** parsing ambiguity. For example, the statement 7194** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7195** creates a new table named "BEGIN" with three columns named 7196** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7197** using keywords as identifiers. Common techniques used to avoid keyword 7198** name collisions include: 7199** <ul> 7200** <li> Put all identifier names inside double-quotes. This is the official 7201** SQL way to escape identifier names. 7202** <li> Put identifier names inside [...]. This is not standard SQL, 7203** but it is what SQL Server does and so lots of programmers use this 7204** technique. 7205** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7206** with "Z". 7207** <li> Include a digit somewhere in every identifier name. 7208** </ul> 7209** 7210** Note that the number of keywords understood by SQLite can depend on 7211** compile-time options. For example, "VACUUM" is not a keyword if 7212** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7213** new keywords may be added to future releases of SQLite. 7214*/ 7215int sqlite3_keyword_count(void); 7216int sqlite3_keyword_name(int,const char**,int*); 7217int sqlite3_keyword_check(const char*,int); 7218 7219/* 7220** CAPI3REF: Dynamic String Object 7221** KEYWORDS: {dynamic string} 7222** 7223** An instance of the sqlite3_str object contains a dynamically-sized 7224** string under construction. 7225** 7226** The lifecycle of an sqlite3_str object is as follows: 7227** <ol> 7228** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7229** <li> ^Text is appended to the sqlite3_str object using various 7230** methods, such as [sqlite3_str_appendf()]. 7231** <li> ^The sqlite3_str object is destroyed and the string it created 7232** is returned using the [sqlite3_str_finish()] interface. 7233** </ol> 7234*/ 7235typedef struct sqlite3_str sqlite3_str; 7236 7237/* 7238** CAPI3REF: Create A New Dynamic String Object 7239** CONSTRUCTOR: sqlite3_str 7240** 7241** ^The [sqlite3_str_new(D)] interface allocates and initializes 7242** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7243** [sqlite3_str_new()] must be freed by a subsequent call to 7244** [sqlite3_str_finish(X)]. 7245** 7246** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7247** valid [sqlite3_str] object, though in the event of an out-of-memory 7248** error the returned object might be a special singleton that will 7249** silently reject new text, always return SQLITE_NOMEM from 7250** [sqlite3_str_errcode()], always return 0 for 7251** [sqlite3_str_length()], and always return NULL from 7252** [sqlite3_str_finish(X)]. It is always safe to use the value 7253** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7254** to any of the other [sqlite3_str] methods. 7255** 7256** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7257** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7258** length of the string contained in the [sqlite3_str] object will be 7259** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7260** of [SQLITE_MAX_LENGTH]. 7261*/ 7262sqlite3_str *sqlite3_str_new(sqlite3*); 7263 7264/* 7265** CAPI3REF: Finalize A Dynamic String 7266** DESTRUCTOR: sqlite3_str 7267** 7268** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7269** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7270** that contains the constructed string. The calling application should 7271** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7272** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7273** errors were encountered during construction of the string. ^The 7274** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7275** string in [sqlite3_str] object X is zero bytes long. 7276*/ 7277char *sqlite3_str_finish(sqlite3_str*); 7278 7279/* 7280** CAPI3REF: Add Content To A Dynamic String 7281** METHOD: sqlite3_str 7282** 7283** These interfaces add content to an sqlite3_str object previously obtained 7284** from [sqlite3_str_new()]. 7285** 7286** ^The [sqlite3_str_appendf(X,F,...)] and 7287** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7288** functionality of SQLite to append formatted text onto the end of 7289** [sqlite3_str] object X. 7290** 7291** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7292** onto the end of the [sqlite3_str] object X. N must be non-negative. 7293** S must contain at least N non-zero bytes of content. To append a 7294** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7295** method instead. 7296** 7297** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7298** zero-terminated string S onto the end of [sqlite3_str] object X. 7299** 7300** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7301** single-byte character C onto the end of [sqlite3_str] object X. 7302** ^This method can be used, for example, to add whitespace indentation. 7303** 7304** ^The [sqlite3_str_reset(X)] method resets the string under construction 7305** inside [sqlite3_str] object X back to zero bytes in length. 7306** 7307** These methods do not return a result code. ^If an error occurs, that fact 7308** is recorded in the [sqlite3_str] object and can be recovered by a 7309** subsequent call to [sqlite3_str_errcode(X)]. 7310*/ 7311void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7312void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7313void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7314void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7315void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7316void sqlite3_str_reset(sqlite3_str*); 7317 7318/* 7319** CAPI3REF: Status Of A Dynamic String 7320** METHOD: sqlite3_str 7321** 7322** These interfaces return the current status of an [sqlite3_str] object. 7323** 7324** ^If any prior errors have occurred while constructing the dynamic string 7325** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7326** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7327** [SQLITE_NOMEM] following any out-of-memory error, or 7328** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7329** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7330** 7331** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7332** of the dynamic string under construction in [sqlite3_str] object X. 7333** ^The length returned by [sqlite3_str_length(X)] does not include the 7334** zero-termination byte. 7335** 7336** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7337** content of the dynamic string under construction in X. The value 7338** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7339** and might be freed or altered by any subsequent method on the same 7340** [sqlite3_str] object. Applications must not used the pointer returned 7341** [sqlite3_str_value(X)] after any subsequent method call on the same 7342** object. ^Applications may change the content of the string returned 7343** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7344** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7345** write any byte after any subsequent sqlite3_str method call. 7346*/ 7347int sqlite3_str_errcode(sqlite3_str*); 7348int sqlite3_str_length(sqlite3_str*); 7349char *sqlite3_str_value(sqlite3_str*); 7350 7351/* 7352** CAPI3REF: SQLite Runtime Status 7353** 7354** ^These interfaces are used to retrieve runtime status information 7355** about the performance of SQLite, and optionally to reset various 7356** highwater marks. ^The first argument is an integer code for 7357** the specific parameter to measure. ^(Recognized integer codes 7358** are of the form [status parameters | SQLITE_STATUS_...].)^ 7359** ^The current value of the parameter is returned into *pCurrent. 7360** ^The highest recorded value is returned in *pHighwater. ^If the 7361** resetFlag is true, then the highest record value is reset after 7362** *pHighwater is written. ^(Some parameters do not record the highest 7363** value. For those parameters 7364** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7365** ^(Other parameters record only the highwater mark and not the current 7366** value. For these latter parameters nothing is written into *pCurrent.)^ 7367** 7368** ^The sqlite3_status() and sqlite3_status64() routines return 7369** SQLITE_OK on success and a non-zero [error code] on failure. 7370** 7371** If either the current value or the highwater mark is too large to 7372** be represented by a 32-bit integer, then the values returned by 7373** sqlite3_status() are undefined. 7374** 7375** See also: [sqlite3_db_status()] 7376*/ 7377int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7378int sqlite3_status64( 7379 int op, 7380 sqlite3_int64 *pCurrent, 7381 sqlite3_int64 *pHighwater, 7382 int resetFlag 7383); 7384 7385 7386/* 7387** CAPI3REF: Status Parameters 7388** KEYWORDS: {status parameters} 7389** 7390** These integer constants designate various run-time status parameters 7391** that can be returned by [sqlite3_status()]. 7392** 7393** <dl> 7394** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7395** <dd>This parameter is the current amount of memory checked out 7396** using [sqlite3_malloc()], either directly or indirectly. The 7397** figure includes calls made to [sqlite3_malloc()] by the application 7398** and internal memory usage by the SQLite library. Auxiliary page-cache 7399** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7400** this parameter. The amount returned is the sum of the allocation 7401** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7402** 7403** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7404** <dd>This parameter records the largest memory allocation request 7405** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7406** internal equivalents). Only the value returned in the 7407** *pHighwater parameter to [sqlite3_status()] is of interest. 7408** The value written into the *pCurrent parameter is undefined.</dd>)^ 7409** 7410** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7411** <dd>This parameter records the number of separate memory allocations 7412** currently checked out.</dd>)^ 7413** 7414** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7415** <dd>This parameter returns the number of pages used out of the 7416** [pagecache memory allocator] that was configured using 7417** [SQLITE_CONFIG_PAGECACHE]. The 7418** value returned is in pages, not in bytes.</dd>)^ 7419** 7420** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7421** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7422** <dd>This parameter returns the number of bytes of page cache 7423** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7424** buffer and where forced to overflow to [sqlite3_malloc()]. The 7425** returned value includes allocations that overflowed because they 7426** where too large (they were larger than the "sz" parameter to 7427** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7428** no space was left in the page cache.</dd>)^ 7429** 7430** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7431** <dd>This parameter records the largest memory allocation request 7432** handed to [pagecache memory allocator]. Only the value returned in the 7433** *pHighwater parameter to [sqlite3_status()] is of interest. 7434** The value written into the *pCurrent parameter is undefined.</dd>)^ 7435** 7436** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7437** <dd>No longer used.</dd> 7438** 7439** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7440** <dd>No longer used.</dd> 7441** 7442** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7443** <dd>No longer used.</dd> 7444** 7445** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7446** <dd>The *pHighwater parameter records the deepest parser stack. 7447** The *pCurrent value is undefined. The *pHighwater value is only 7448** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7449** </dl> 7450** 7451** New status parameters may be added from time to time. 7452*/ 7453#define SQLITE_STATUS_MEMORY_USED 0 7454#define SQLITE_STATUS_PAGECACHE_USED 1 7455#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7456#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7457#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7458#define SQLITE_STATUS_MALLOC_SIZE 5 7459#define SQLITE_STATUS_PARSER_STACK 6 7460#define SQLITE_STATUS_PAGECACHE_SIZE 7 7461#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7462#define SQLITE_STATUS_MALLOC_COUNT 9 7463 7464/* 7465** CAPI3REF: Database Connection Status 7466** METHOD: sqlite3 7467** 7468** ^This interface is used to retrieve runtime status information 7469** about a single [database connection]. ^The first argument is the 7470** database connection object to be interrogated. ^The second argument 7471** is an integer constant, taken from the set of 7472** [SQLITE_DBSTATUS options], that 7473** determines the parameter to interrogate. The set of 7474** [SQLITE_DBSTATUS options] is likely 7475** to grow in future releases of SQLite. 7476** 7477** ^The current value of the requested parameter is written into *pCur 7478** and the highest instantaneous value is written into *pHiwtr. ^If 7479** the resetFlg is true, then the highest instantaneous value is 7480** reset back down to the current value. 7481** 7482** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7483** non-zero [error code] on failure. 7484** 7485** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7486*/ 7487int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7488 7489/* 7490** CAPI3REF: Status Parameters for database connections 7491** KEYWORDS: {SQLITE_DBSTATUS options} 7492** 7493** These constants are the available integer "verbs" that can be passed as 7494** the second argument to the [sqlite3_db_status()] interface. 7495** 7496** New verbs may be added in future releases of SQLite. Existing verbs 7497** might be discontinued. Applications should check the return code from 7498** [sqlite3_db_status()] to make sure that the call worked. 7499** The [sqlite3_db_status()] interface will return a non-zero error code 7500** if a discontinued or unsupported verb is invoked. 7501** 7502** <dl> 7503** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7504** <dd>This parameter returns the number of lookaside memory slots currently 7505** checked out.</dd>)^ 7506** 7507** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7508** <dd>This parameter returns the number malloc attempts that were 7509** satisfied using lookaside memory. Only the high-water value is meaningful; 7510** the current value is always zero.)^ 7511** 7512** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7513** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7514** <dd>This parameter returns the number malloc attempts that might have 7515** been satisfied using lookaside memory but failed due to the amount of 7516** memory requested being larger than the lookaside slot size. 7517** Only the high-water value is meaningful; 7518** the current value is always zero.)^ 7519** 7520** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7521** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7522** <dd>This parameter returns the number malloc attempts that might have 7523** been satisfied using lookaside memory but failed due to all lookaside 7524** memory already being in use. 7525** Only the high-water value is meaningful; 7526** the current value is always zero.)^ 7527** 7528** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7529** <dd>This parameter returns the approximate number of bytes of heap 7530** memory used by all pager caches associated with the database connection.)^ 7531** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7532** 7533** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7534** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7535** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7536** pager cache is shared between two or more connections the bytes of heap 7537** memory used by that pager cache is divided evenly between the attached 7538** connections.)^ In other words, if none of the pager caches associated 7539** with the database connection are shared, this request returns the same 7540** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7541** shared, the value returned by this call will be smaller than that returned 7542** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7543** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7544** 7545** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7546** <dd>This parameter returns the approximate number of bytes of heap 7547** memory used to store the schema for all databases associated 7548** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7549** ^The full amount of memory used by the schemas is reported, even if the 7550** schema memory is shared with other database connections due to 7551** [shared cache mode] being enabled. 7552** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7553** 7554** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7555** <dd>This parameter returns the approximate number of bytes of heap 7556** and lookaside memory used by all prepared statements associated with 7557** the database connection.)^ 7558** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7559** </dd> 7560** 7561** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7562** <dd>This parameter returns the number of pager cache hits that have 7563** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7564** is always 0. 7565** </dd> 7566** 7567** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7568** <dd>This parameter returns the number of pager cache misses that have 7569** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7570** is always 0. 7571** </dd> 7572** 7573** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7574** <dd>This parameter returns the number of dirty cache entries that have 7575** been written to disk. Specifically, the number of pages written to the 7576** wal file in wal mode databases, or the number of pages written to the 7577** database file in rollback mode databases. Any pages written as part of 7578** transaction rollback or database recovery operations are not included. 7579** If an IO or other error occurs while writing a page to disk, the effect 7580** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7581** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7582** </dd> 7583** 7584** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7585** <dd>This parameter returns the number of dirty cache entries that have 7586** been written to disk in the middle of a transaction due to the page 7587** cache overflowing. Transactions are more efficient if they are written 7588** to disk all at once. When pages spill mid-transaction, that introduces 7589** additional overhead. This parameter can be used help identify 7590** inefficiencies that can be resolve by increasing the cache size. 7591** </dd> 7592** 7593** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7594** <dd>This parameter returns zero for the current value if and only if 7595** all foreign key constraints (deferred or immediate) have been 7596** resolved.)^ ^The highwater mark is always 0. 7597** </dd> 7598** </dl> 7599*/ 7600#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7601#define SQLITE_DBSTATUS_CACHE_USED 1 7602#define SQLITE_DBSTATUS_SCHEMA_USED 2 7603#define SQLITE_DBSTATUS_STMT_USED 3 7604#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7605#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7606#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7607#define SQLITE_DBSTATUS_CACHE_HIT 7 7608#define SQLITE_DBSTATUS_CACHE_MISS 8 7609#define SQLITE_DBSTATUS_CACHE_WRITE 9 7610#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7611#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7612#define SQLITE_DBSTATUS_CACHE_SPILL 12 7613#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7614 7615 7616/* 7617** CAPI3REF: Prepared Statement Status 7618** METHOD: sqlite3_stmt 7619** 7620** ^(Each prepared statement maintains various 7621** [SQLITE_STMTSTATUS counters] that measure the number 7622** of times it has performed specific operations.)^ These counters can 7623** be used to monitor the performance characteristics of the prepared 7624** statements. For example, if the number of table steps greatly exceeds 7625** the number of table searches or result rows, that would tend to indicate 7626** that the prepared statement is using a full table scan rather than 7627** an index. 7628** 7629** ^(This interface is used to retrieve and reset counter values from 7630** a [prepared statement]. The first argument is the prepared statement 7631** object to be interrogated. The second argument 7632** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7633** to be interrogated.)^ 7634** ^The current value of the requested counter is returned. 7635** ^If the resetFlg is true, then the counter is reset to zero after this 7636** interface call returns. 7637** 7638** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7639*/ 7640int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7641 7642/* 7643** CAPI3REF: Status Parameters for prepared statements 7644** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7645** 7646** These preprocessor macros define integer codes that name counter 7647** values associated with the [sqlite3_stmt_status()] interface. 7648** The meanings of the various counters are as follows: 7649** 7650** <dl> 7651** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7652** <dd>^This is the number of times that SQLite has stepped forward in 7653** a table as part of a full table scan. Large numbers for this counter 7654** may indicate opportunities for performance improvement through 7655** careful use of indices.</dd> 7656** 7657** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7658** <dd>^This is the number of sort operations that have occurred. 7659** A non-zero value in this counter may indicate an opportunity to 7660** improvement performance through careful use of indices.</dd> 7661** 7662** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7663** <dd>^This is the number of rows inserted into transient indices that 7664** were created automatically in order to help joins run faster. 7665** A non-zero value in this counter may indicate an opportunity to 7666** improvement performance by adding permanent indices that do not 7667** need to be reinitialized each time the statement is run.</dd> 7668** 7669** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7670** <dd>^This is the number of virtual machine operations executed 7671** by the prepared statement if that number is less than or equal 7672** to 2147483647. The number of virtual machine operations can be 7673** used as a proxy for the total work done by the prepared statement. 7674** If the number of virtual machine operations exceeds 2147483647 7675** then the value returned by this statement status code is undefined. 7676** 7677** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7678** <dd>^This is the number of times that the prepare statement has been 7679** automatically regenerated due to schema changes or change to 7680** [bound parameters] that might affect the query plan. 7681** 7682** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7683** <dd>^This is the number of times that the prepared statement has 7684** been run. A single "run" for the purposes of this counter is one 7685** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7686** The counter is incremented on the first [sqlite3_step()] call of each 7687** cycle. 7688** 7689** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7690** <dd>^This is the approximate number of bytes of heap memory 7691** used to store the prepared statement. ^This value is not actually 7692** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7693** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7694** </dd> 7695** </dl> 7696*/ 7697#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7698#define SQLITE_STMTSTATUS_SORT 2 7699#define SQLITE_STMTSTATUS_AUTOINDEX 3 7700#define SQLITE_STMTSTATUS_VM_STEP 4 7701#define SQLITE_STMTSTATUS_REPREPARE 5 7702#define SQLITE_STMTSTATUS_RUN 6 7703#define SQLITE_STMTSTATUS_MEMUSED 99 7704 7705/* 7706** CAPI3REF: Custom Page Cache Object 7707** 7708** The sqlite3_pcache type is opaque. It is implemented by 7709** the pluggable module. The SQLite core has no knowledge of 7710** its size or internal structure and never deals with the 7711** sqlite3_pcache object except by holding and passing pointers 7712** to the object. 7713** 7714** See [sqlite3_pcache_methods2] for additional information. 7715*/ 7716typedef struct sqlite3_pcache sqlite3_pcache; 7717 7718/* 7719** CAPI3REF: Custom Page Cache Object 7720** 7721** The sqlite3_pcache_page object represents a single page in the 7722** page cache. The page cache will allocate instances of this 7723** object. Various methods of the page cache use pointers to instances 7724** of this object as parameters or as their return value. 7725** 7726** See [sqlite3_pcache_methods2] for additional information. 7727*/ 7728typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7729struct sqlite3_pcache_page { 7730 void *pBuf; /* The content of the page */ 7731 void *pExtra; /* Extra information associated with the page */ 7732}; 7733 7734/* 7735** CAPI3REF: Application Defined Page Cache. 7736** KEYWORDS: {page cache} 7737** 7738** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7739** register an alternative page cache implementation by passing in an 7740** instance of the sqlite3_pcache_methods2 structure.)^ 7741** In many applications, most of the heap memory allocated by 7742** SQLite is used for the page cache. 7743** By implementing a 7744** custom page cache using this API, an application can better control 7745** the amount of memory consumed by SQLite, the way in which 7746** that memory is allocated and released, and the policies used to 7747** determine exactly which parts of a database file are cached and for 7748** how long. 7749** 7750** The alternative page cache mechanism is an 7751** extreme measure that is only needed by the most demanding applications. 7752** The built-in page cache is recommended for most uses. 7753** 7754** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7755** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7756** the application may discard the parameter after the call to 7757** [sqlite3_config()] returns.)^ 7758** 7759** [[the xInit() page cache method]] 7760** ^(The xInit() method is called once for each effective 7761** call to [sqlite3_initialize()])^ 7762** (usually only once during the lifetime of the process). ^(The xInit() 7763** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7764** The intent of the xInit() method is to set up global data structures 7765** required by the custom page cache implementation. 7766** ^(If the xInit() method is NULL, then the 7767** built-in default page cache is used instead of the application defined 7768** page cache.)^ 7769** 7770** [[the xShutdown() page cache method]] 7771** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7772** It can be used to clean up 7773** any outstanding resources before process shutdown, if required. 7774** ^The xShutdown() method may be NULL. 7775** 7776** ^SQLite automatically serializes calls to the xInit method, 7777** so the xInit method need not be threadsafe. ^The 7778** xShutdown method is only called from [sqlite3_shutdown()] so it does 7779** not need to be threadsafe either. All other methods must be threadsafe 7780** in multithreaded applications. 7781** 7782** ^SQLite will never invoke xInit() more than once without an intervening 7783** call to xShutdown(). 7784** 7785** [[the xCreate() page cache methods]] 7786** ^SQLite invokes the xCreate() method to construct a new cache instance. 7787** SQLite will typically create one cache instance for each open database file, 7788** though this is not guaranteed. ^The 7789** first parameter, szPage, is the size in bytes of the pages that must 7790** be allocated by the cache. ^szPage will always a power of two. ^The 7791** second parameter szExtra is a number of bytes of extra storage 7792** associated with each page cache entry. ^The szExtra parameter will 7793** a number less than 250. SQLite will use the 7794** extra szExtra bytes on each page to store metadata about the underlying 7795** database page on disk. The value passed into szExtra depends 7796** on the SQLite version, the target platform, and how SQLite was compiled. 7797** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7798** created will be used to cache database pages of a file stored on disk, or 7799** false if it is used for an in-memory database. The cache implementation 7800** does not have to do anything special based with the value of bPurgeable; 7801** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7802** never invoke xUnpin() except to deliberately delete a page. 7803** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7804** false will always have the "discard" flag set to true. 7805** ^Hence, a cache created with bPurgeable false will 7806** never contain any unpinned pages. 7807** 7808** [[the xCachesize() page cache method]] 7809** ^(The xCachesize() method may be called at any time by SQLite to set the 7810** suggested maximum cache-size (number of pages stored by) the cache 7811** instance passed as the first argument. This is the value configured using 7812** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7813** parameter, the implementation is not required to do anything with this 7814** value; it is advisory only. 7815** 7816** [[the xPagecount() page cache methods]] 7817** The xPagecount() method must return the number of pages currently 7818** stored in the cache, both pinned and unpinned. 7819** 7820** [[the xFetch() page cache methods]] 7821** The xFetch() method locates a page in the cache and returns a pointer to 7822** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7823** The pBuf element of the returned sqlite3_pcache_page object will be a 7824** pointer to a buffer of szPage bytes used to store the content of a 7825** single database page. The pExtra element of sqlite3_pcache_page will be 7826** a pointer to the szExtra bytes of extra storage that SQLite has requested 7827** for each entry in the page cache. 7828** 7829** The page to be fetched is determined by the key. ^The minimum key value 7830** is 1. After it has been retrieved using xFetch, the page is considered 7831** to be "pinned". 7832** 7833** If the requested page is already in the page cache, then the page cache 7834** implementation must return a pointer to the page buffer with its content 7835** intact. If the requested page is not already in the cache, then the 7836** cache implementation should use the value of the createFlag 7837** parameter to help it determined what action to take: 7838** 7839** <table border=1 width=85% align=center> 7840** <tr><th> createFlag <th> Behavior when page is not already in cache 7841** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7842** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7843** Otherwise return NULL. 7844** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7845** NULL if allocating a new page is effectively impossible. 7846** </table> 7847** 7848** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7849** will only use a createFlag of 2 after a prior call with a createFlag of 1 7850** failed.)^ In between the to xFetch() calls, SQLite may 7851** attempt to unpin one or more cache pages by spilling the content of 7852** pinned pages to disk and synching the operating system disk cache. 7853** 7854** [[the xUnpin() page cache method]] 7855** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7856** as its second argument. If the third parameter, discard, is non-zero, 7857** then the page must be evicted from the cache. 7858** ^If the discard parameter is 7859** zero, then the page may be discarded or retained at the discretion of 7860** page cache implementation. ^The page cache implementation 7861** may choose to evict unpinned pages at any time. 7862** 7863** The cache must not perform any reference counting. A single 7864** call to xUnpin() unpins the page regardless of the number of prior calls 7865** to xFetch(). 7866** 7867** [[the xRekey() page cache methods]] 7868** The xRekey() method is used to change the key value associated with the 7869** page passed as the second argument. If the cache 7870** previously contains an entry associated with newKey, it must be 7871** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7872** to be pinned. 7873** 7874** When SQLite calls the xTruncate() method, the cache must discard all 7875** existing cache entries with page numbers (keys) greater than or equal 7876** to the value of the iLimit parameter passed to xTruncate(). If any 7877** of these pages are pinned, they are implicitly unpinned, meaning that 7878** they can be safely discarded. 7879** 7880** [[the xDestroy() page cache method]] 7881** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7882** All resources associated with the specified cache should be freed. ^After 7883** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7884** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7885** functions. 7886** 7887** [[the xShrink() page cache method]] 7888** ^SQLite invokes the xShrink() method when it wants the page cache to 7889** free up as much of heap memory as possible. The page cache implementation 7890** is not obligated to free any memory, but well-behaved implementations should 7891** do their best. 7892*/ 7893typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7894struct sqlite3_pcache_methods2 { 7895 int iVersion; 7896 void *pArg; 7897 int (*xInit)(void*); 7898 void (*xShutdown)(void*); 7899 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7900 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7901 int (*xPagecount)(sqlite3_pcache*); 7902 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7903 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7904 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7905 unsigned oldKey, unsigned newKey); 7906 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7907 void (*xDestroy)(sqlite3_pcache*); 7908 void (*xShrink)(sqlite3_pcache*); 7909}; 7910 7911/* 7912** This is the obsolete pcache_methods object that has now been replaced 7913** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7914** retained in the header file for backwards compatibility only. 7915*/ 7916typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7917struct sqlite3_pcache_methods { 7918 void *pArg; 7919 int (*xInit)(void*); 7920 void (*xShutdown)(void*); 7921 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7922 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7923 int (*xPagecount)(sqlite3_pcache*); 7924 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7925 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7926 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7927 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7928 void (*xDestroy)(sqlite3_pcache*); 7929}; 7930 7931 7932/* 7933** CAPI3REF: Online Backup Object 7934** 7935** The sqlite3_backup object records state information about an ongoing 7936** online backup operation. ^The sqlite3_backup object is created by 7937** a call to [sqlite3_backup_init()] and is destroyed by a call to 7938** [sqlite3_backup_finish()]. 7939** 7940** See Also: [Using the SQLite Online Backup API] 7941*/ 7942typedef struct sqlite3_backup sqlite3_backup; 7943 7944/* 7945** CAPI3REF: Online Backup API. 7946** 7947** The backup API copies the content of one database into another. 7948** It is useful either for creating backups of databases or 7949** for copying in-memory databases to or from persistent files. 7950** 7951** See Also: [Using the SQLite Online Backup API] 7952** 7953** ^SQLite holds a write transaction open on the destination database file 7954** for the duration of the backup operation. 7955** ^The source database is read-locked only while it is being read; 7956** it is not locked continuously for the entire backup operation. 7957** ^Thus, the backup may be performed on a live source database without 7958** preventing other database connections from 7959** reading or writing to the source database while the backup is underway. 7960** 7961** ^(To perform a backup operation: 7962** <ol> 7963** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7964** backup, 7965** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7966** the data between the two databases, and finally 7967** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7968** associated with the backup operation. 7969** </ol>)^ 7970** There should be exactly one call to sqlite3_backup_finish() for each 7971** successful call to sqlite3_backup_init(). 7972** 7973** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7974** 7975** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7976** [database connection] associated with the destination database 7977** and the database name, respectively. 7978** ^The database name is "main" for the main database, "temp" for the 7979** temporary database, or the name specified after the AS keyword in 7980** an [ATTACH] statement for an attached database. 7981** ^The S and M arguments passed to 7982** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7983** and database name of the source database, respectively. 7984** ^The source and destination [database connections] (parameters S and D) 7985** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7986** an error. 7987** 7988** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7989** there is already a read or read-write transaction open on the 7990** destination database. 7991** 7992** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7993** returned and an error code and error message are stored in the 7994** destination [database connection] D. 7995** ^The error code and message for the failed call to sqlite3_backup_init() 7996** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7997** [sqlite3_errmsg16()] functions. 7998** ^A successful call to sqlite3_backup_init() returns a pointer to an 7999** [sqlite3_backup] object. 8000** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8001** sqlite3_backup_finish() functions to perform the specified backup 8002** operation. 8003** 8004** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8005** 8006** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8007** the source and destination databases specified by [sqlite3_backup] object B. 8008** ^If N is negative, all remaining source pages are copied. 8009** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8010** are still more pages to be copied, then the function returns [SQLITE_OK]. 8011** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8012** from source to destination, then it returns [SQLITE_DONE]. 8013** ^If an error occurs while running sqlite3_backup_step(B,N), 8014** then an [error code] is returned. ^As well as [SQLITE_OK] and 8015** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8016** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8017** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8018** 8019** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8020** <ol> 8021** <li> the destination database was opened read-only, or 8022** <li> the destination database is using write-ahead-log journaling 8023** and the destination and source page sizes differ, or 8024** <li> the destination database is an in-memory database and the 8025** destination and source page sizes differ. 8026** </ol>)^ 8027** 8028** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8029** the [sqlite3_busy_handler | busy-handler function] 8030** is invoked (if one is specified). ^If the 8031** busy-handler returns non-zero before the lock is available, then 8032** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8033** sqlite3_backup_step() can be retried later. ^If the source 8034** [database connection] 8035** is being used to write to the source database when sqlite3_backup_step() 8036** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8037** case the call to sqlite3_backup_step() can be retried later on. ^(If 8038** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8039** [SQLITE_READONLY] is returned, then 8040** there is no point in retrying the call to sqlite3_backup_step(). These 8041** errors are considered fatal.)^ The application must accept 8042** that the backup operation has failed and pass the backup operation handle 8043** to the sqlite3_backup_finish() to release associated resources. 8044** 8045** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8046** on the destination file. ^The exclusive lock is not released until either 8047** sqlite3_backup_finish() is called or the backup operation is complete 8048** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8049** sqlite3_backup_step() obtains a [shared lock] on the source database that 8050** lasts for the duration of the sqlite3_backup_step() call. 8051** ^Because the source database is not locked between calls to 8052** sqlite3_backup_step(), the source database may be modified mid-way 8053** through the backup process. ^If the source database is modified by an 8054** external process or via a database connection other than the one being 8055** used by the backup operation, then the backup will be automatically 8056** restarted by the next call to sqlite3_backup_step(). ^If the source 8057** database is modified by the using the same database connection as is used 8058** by the backup operation, then the backup database is automatically 8059** updated at the same time. 8060** 8061** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8062** 8063** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8064** application wishes to abandon the backup operation, the application 8065** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8066** ^The sqlite3_backup_finish() interfaces releases all 8067** resources associated with the [sqlite3_backup] object. 8068** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8069** active write-transaction on the destination database is rolled back. 8070** The [sqlite3_backup] object is invalid 8071** and may not be used following a call to sqlite3_backup_finish(). 8072** 8073** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8074** sqlite3_backup_step() errors occurred, regardless or whether or not 8075** sqlite3_backup_step() completed. 8076** ^If an out-of-memory condition or IO error occurred during any prior 8077** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8078** sqlite3_backup_finish() returns the corresponding [error code]. 8079** 8080** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8081** is not a permanent error and does not affect the return value of 8082** sqlite3_backup_finish(). 8083** 8084** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8085** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8086** 8087** ^The sqlite3_backup_remaining() routine returns the number of pages still 8088** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8089** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8090** in the source database at the conclusion of the most recent 8091** sqlite3_backup_step(). 8092** ^(The values returned by these functions are only updated by 8093** sqlite3_backup_step(). If the source database is modified in a way that 8094** changes the size of the source database or the number of pages remaining, 8095** those changes are not reflected in the output of sqlite3_backup_pagecount() 8096** and sqlite3_backup_remaining() until after the next 8097** sqlite3_backup_step().)^ 8098** 8099** <b>Concurrent Usage of Database Handles</b> 8100** 8101** ^The source [database connection] may be used by the application for other 8102** purposes while a backup operation is underway or being initialized. 8103** ^If SQLite is compiled and configured to support threadsafe database 8104** connections, then the source database connection may be used concurrently 8105** from within other threads. 8106** 8107** However, the application must guarantee that the destination 8108** [database connection] is not passed to any other API (by any thread) after 8109** sqlite3_backup_init() is called and before the corresponding call to 8110** sqlite3_backup_finish(). SQLite does not currently check to see 8111** if the application incorrectly accesses the destination [database connection] 8112** and so no error code is reported, but the operations may malfunction 8113** nevertheless. Use of the destination database connection while a 8114** backup is in progress might also also cause a mutex deadlock. 8115** 8116** If running in [shared cache mode], the application must 8117** guarantee that the shared cache used by the destination database 8118** is not accessed while the backup is running. In practice this means 8119** that the application must guarantee that the disk file being 8120** backed up to is not accessed by any connection within the process, 8121** not just the specific connection that was passed to sqlite3_backup_init(). 8122** 8123** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8124** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8125** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8126** APIs are not strictly speaking threadsafe. If they are invoked at the 8127** same time as another thread is invoking sqlite3_backup_step() it is 8128** possible that they return invalid values. 8129*/ 8130sqlite3_backup *sqlite3_backup_init( 8131 sqlite3 *pDest, /* Destination database handle */ 8132 const char *zDestName, /* Destination database name */ 8133 sqlite3 *pSource, /* Source database handle */ 8134 const char *zSourceName /* Source database name */ 8135); 8136int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8137int sqlite3_backup_finish(sqlite3_backup *p); 8138int sqlite3_backup_remaining(sqlite3_backup *p); 8139int sqlite3_backup_pagecount(sqlite3_backup *p); 8140 8141/* 8142** CAPI3REF: Unlock Notification 8143** METHOD: sqlite3 8144** 8145** ^When running in shared-cache mode, a database operation may fail with 8146** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8147** individual tables within the shared-cache cannot be obtained. See 8148** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8149** ^This API may be used to register a callback that SQLite will invoke 8150** when the connection currently holding the required lock relinquishes it. 8151** ^This API is only available if the library was compiled with the 8152** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8153** 8154** See Also: [Using the SQLite Unlock Notification Feature]. 8155** 8156** ^Shared-cache locks are released when a database connection concludes 8157** its current transaction, either by committing it or rolling it back. 8158** 8159** ^When a connection (known as the blocked connection) fails to obtain a 8160** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8161** identity of the database connection (the blocking connection) that 8162** has locked the required resource is stored internally. ^After an 8163** application receives an SQLITE_LOCKED error, it may call the 8164** sqlite3_unlock_notify() method with the blocked connection handle as 8165** the first argument to register for a callback that will be invoked 8166** when the blocking connections current transaction is concluded. ^The 8167** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8168** call that concludes the blocking connections transaction. 8169** 8170** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8171** there is a chance that the blocking connection will have already 8172** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8173** If this happens, then the specified callback is invoked immediately, 8174** from within the call to sqlite3_unlock_notify().)^ 8175** 8176** ^If the blocked connection is attempting to obtain a write-lock on a 8177** shared-cache table, and more than one other connection currently holds 8178** a read-lock on the same table, then SQLite arbitrarily selects one of 8179** the other connections to use as the blocking connection. 8180** 8181** ^(There may be at most one unlock-notify callback registered by a 8182** blocked connection. If sqlite3_unlock_notify() is called when the 8183** blocked connection already has a registered unlock-notify callback, 8184** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8185** called with a NULL pointer as its second argument, then any existing 8186** unlock-notify callback is canceled. ^The blocked connections 8187** unlock-notify callback may also be canceled by closing the blocked 8188** connection using [sqlite3_close()]. 8189** 8190** The unlock-notify callback is not reentrant. If an application invokes 8191** any sqlite3_xxx API functions from within an unlock-notify callback, a 8192** crash or deadlock may be the result. 8193** 8194** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8195** returns SQLITE_OK. 8196** 8197** <b>Callback Invocation Details</b> 8198** 8199** When an unlock-notify callback is registered, the application provides a 8200** single void* pointer that is passed to the callback when it is invoked. 8201** However, the signature of the callback function allows SQLite to pass 8202** it an array of void* context pointers. The first argument passed to 8203** an unlock-notify callback is a pointer to an array of void* pointers, 8204** and the second is the number of entries in the array. 8205** 8206** When a blocking connections transaction is concluded, there may be 8207** more than one blocked connection that has registered for an unlock-notify 8208** callback. ^If two or more such blocked connections have specified the 8209** same callback function, then instead of invoking the callback function 8210** multiple times, it is invoked once with the set of void* context pointers 8211** specified by the blocked connections bundled together into an array. 8212** This gives the application an opportunity to prioritize any actions 8213** related to the set of unblocked database connections. 8214** 8215** <b>Deadlock Detection</b> 8216** 8217** Assuming that after registering for an unlock-notify callback a 8218** database waits for the callback to be issued before taking any further 8219** action (a reasonable assumption), then using this API may cause the 8220** application to deadlock. For example, if connection X is waiting for 8221** connection Y's transaction to be concluded, and similarly connection 8222** Y is waiting on connection X's transaction, then neither connection 8223** will proceed and the system may remain deadlocked indefinitely. 8224** 8225** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8226** detection. ^If a given call to sqlite3_unlock_notify() would put the 8227** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8228** unlock-notify callback is registered. The system is said to be in 8229** a deadlocked state if connection A has registered for an unlock-notify 8230** callback on the conclusion of connection B's transaction, and connection 8231** B has itself registered for an unlock-notify callback when connection 8232** A's transaction is concluded. ^Indirect deadlock is also detected, so 8233** the system is also considered to be deadlocked if connection B has 8234** registered for an unlock-notify callback on the conclusion of connection 8235** C's transaction, where connection C is waiting on connection A. ^Any 8236** number of levels of indirection are allowed. 8237** 8238** <b>The "DROP TABLE" Exception</b> 8239** 8240** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8241** always appropriate to call sqlite3_unlock_notify(). There is however, 8242** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8243** SQLite checks if there are any currently executing SELECT statements 8244** that belong to the same connection. If there are, SQLITE_LOCKED is 8245** returned. In this case there is no "blocking connection", so invoking 8246** sqlite3_unlock_notify() results in the unlock-notify callback being 8247** invoked immediately. If the application then re-attempts the "DROP TABLE" 8248** or "DROP INDEX" query, an infinite loop might be the result. 8249** 8250** One way around this problem is to check the extended error code returned 8251** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8252** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8253** the special "DROP TABLE/INDEX" case, the extended error code is just 8254** SQLITE_LOCKED.)^ 8255*/ 8256int sqlite3_unlock_notify( 8257 sqlite3 *pBlocked, /* Waiting connection */ 8258 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8259 void *pNotifyArg /* Argument to pass to xNotify */ 8260); 8261 8262 8263/* 8264** CAPI3REF: String Comparison 8265** 8266** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8267** and extensions to compare the contents of two buffers containing UTF-8 8268** strings in a case-independent fashion, using the same definition of "case 8269** independence" that SQLite uses internally when comparing identifiers. 8270*/ 8271int sqlite3_stricmp(const char *, const char *); 8272int sqlite3_strnicmp(const char *, const char *, int); 8273 8274/* 8275** CAPI3REF: String Globbing 8276* 8277** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8278** string X matches the [GLOB] pattern P. 8279** ^The definition of [GLOB] pattern matching used in 8280** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8281** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8282** is case sensitive. 8283** 8284** Note that this routine returns zero on a match and non-zero if the strings 8285** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8286** 8287** See also: [sqlite3_strlike()]. 8288*/ 8289int sqlite3_strglob(const char *zGlob, const char *zStr); 8290 8291/* 8292** CAPI3REF: String LIKE Matching 8293* 8294** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8295** string X matches the [LIKE] pattern P with escape character E. 8296** ^The definition of [LIKE] pattern matching used in 8297** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8298** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8299** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8300** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8301** insensitive - equivalent upper and lower case ASCII characters match 8302** one another. 8303** 8304** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8305** only ASCII characters are case folded. 8306** 8307** Note that this routine returns zero on a match and non-zero if the strings 8308** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8309** 8310** See also: [sqlite3_strglob()]. 8311*/ 8312int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8313 8314/* 8315** CAPI3REF: Error Logging Interface 8316** 8317** ^The [sqlite3_log()] interface writes a message into the [error log] 8318** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8319** ^If logging is enabled, the zFormat string and subsequent arguments are 8320** used with [sqlite3_snprintf()] to generate the final output string. 8321** 8322** The sqlite3_log() interface is intended for use by extensions such as 8323** virtual tables, collating functions, and SQL functions. While there is 8324** nothing to prevent an application from calling sqlite3_log(), doing so 8325** is considered bad form. 8326** 8327** The zFormat string must not be NULL. 8328** 8329** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8330** will not use dynamically allocated memory. The log message is stored in 8331** a fixed-length buffer on the stack. If the log message is longer than 8332** a few hundred characters, it will be truncated to the length of the 8333** buffer. 8334*/ 8335void sqlite3_log(int iErrCode, const char *zFormat, ...); 8336 8337/* 8338** CAPI3REF: Write-Ahead Log Commit Hook 8339** METHOD: sqlite3 8340** 8341** ^The [sqlite3_wal_hook()] function is used to register a callback that 8342** is invoked each time data is committed to a database in wal mode. 8343** 8344** ^(The callback is invoked by SQLite after the commit has taken place and 8345** the associated write-lock on the database released)^, so the implementation 8346** may read, write or [checkpoint] the database as required. 8347** 8348** ^The first parameter passed to the callback function when it is invoked 8349** is a copy of the third parameter passed to sqlite3_wal_hook() when 8350** registering the callback. ^The second is a copy of the database handle. 8351** ^The third parameter is the name of the database that was written to - 8352** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8353** is the number of pages currently in the write-ahead log file, 8354** including those that were just committed. 8355** 8356** The callback function should normally return [SQLITE_OK]. ^If an error 8357** code is returned, that error will propagate back up through the 8358** SQLite code base to cause the statement that provoked the callback 8359** to report an error, though the commit will have still occurred. If the 8360** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8361** that does not correspond to any valid SQLite error code, the results 8362** are undefined. 8363** 8364** A single database handle may have at most a single write-ahead log callback 8365** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8366** previously registered write-ahead log callback. ^Note that the 8367** [sqlite3_wal_autocheckpoint()] interface and the 8368** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8369** overwrite any prior [sqlite3_wal_hook()] settings. 8370*/ 8371void *sqlite3_wal_hook( 8372 sqlite3*, 8373 int(*)(void *,sqlite3*,const char*,int), 8374 void* 8375); 8376 8377/* 8378** CAPI3REF: Configure an auto-checkpoint 8379** METHOD: sqlite3 8380** 8381** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8382** [sqlite3_wal_hook()] that causes any database on [database connection] D 8383** to automatically [checkpoint] 8384** after committing a transaction if there are N or 8385** more frames in the [write-ahead log] file. ^Passing zero or 8386** a negative value as the nFrame parameter disables automatic 8387** checkpoints entirely. 8388** 8389** ^The callback registered by this function replaces any existing callback 8390** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8391** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8392** configured by this function. 8393** 8394** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8395** from SQL. 8396** 8397** ^Checkpoints initiated by this mechanism are 8398** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8399** 8400** ^Every new [database connection] defaults to having the auto-checkpoint 8401** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8402** pages. The use of this interface 8403** is only necessary if the default setting is found to be suboptimal 8404** for a particular application. 8405*/ 8406int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8407 8408/* 8409** CAPI3REF: Checkpoint a database 8410** METHOD: sqlite3 8411** 8412** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8413** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8414** 8415** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8416** [write-ahead log] for database X on [database connection] D to be 8417** transferred into the database file and for the write-ahead log to 8418** be reset. See the [checkpointing] documentation for addition 8419** information. 8420** 8421** This interface used to be the only way to cause a checkpoint to 8422** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8423** interface was added. This interface is retained for backwards 8424** compatibility and as a convenience for applications that need to manually 8425** start a callback but which do not need the full power (and corresponding 8426** complication) of [sqlite3_wal_checkpoint_v2()]. 8427*/ 8428int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8429 8430/* 8431** CAPI3REF: Checkpoint a database 8432** METHOD: sqlite3 8433** 8434** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8435** operation on database X of [database connection] D in mode M. Status 8436** information is written back into integers pointed to by L and C.)^ 8437** ^(The M parameter must be a valid [checkpoint mode]:)^ 8438** 8439** <dl> 8440** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8441** ^Checkpoint as many frames as possible without waiting for any database 8442** readers or writers to finish, then sync the database file if all frames 8443** in the log were checkpointed. ^The [busy-handler callback] 8444** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8445** ^On the other hand, passive mode might leave the checkpoint unfinished 8446** if there are concurrent readers or writers. 8447** 8448** <dt>SQLITE_CHECKPOINT_FULL<dd> 8449** ^This mode blocks (it invokes the 8450** [sqlite3_busy_handler|busy-handler callback]) until there is no 8451** database writer and all readers are reading from the most recent database 8452** snapshot. ^It then checkpoints all frames in the log file and syncs the 8453** database file. ^This mode blocks new database writers while it is pending, 8454** but new database readers are allowed to continue unimpeded. 8455** 8456** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8457** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8458** that after checkpointing the log file it blocks (calls the 8459** [busy-handler callback]) 8460** until all readers are reading from the database file only. ^This ensures 8461** that the next writer will restart the log file from the beginning. 8462** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8463** database writer attempts while it is pending, but does not impede readers. 8464** 8465** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8466** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8467** addition that it also truncates the log file to zero bytes just prior 8468** to a successful return. 8469** </dl> 8470** 8471** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8472** the log file or to -1 if the checkpoint could not run because 8473** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8474** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8475** log file (including any that were already checkpointed before the function 8476** was called) or to -1 if the checkpoint could not run due to an error or 8477** because the database is not in WAL mode. ^Note that upon successful 8478** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8479** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8480** 8481** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8482** any other process is running a checkpoint operation at the same time, the 8483** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8484** busy-handler configured, it will not be invoked in this case. 8485** 8486** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8487** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8488** obtained immediately, and a busy-handler is configured, it is invoked and 8489** the writer lock retried until either the busy-handler returns 0 or the lock 8490** is successfully obtained. ^The busy-handler is also invoked while waiting for 8491** database readers as described above. ^If the busy-handler returns 0 before 8492** the writer lock is obtained or while waiting for database readers, the 8493** checkpoint operation proceeds from that point in the same way as 8494** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8495** without blocking any further. ^SQLITE_BUSY is returned in this case. 8496** 8497** ^If parameter zDb is NULL or points to a zero length string, then the 8498** specified operation is attempted on all WAL databases [attached] to 8499** [database connection] db. In this case the 8500** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8501** an SQLITE_BUSY error is encountered when processing one or more of the 8502** attached WAL databases, the operation is still attempted on any remaining 8503** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8504** error occurs while processing an attached database, processing is abandoned 8505** and the error code is returned to the caller immediately. ^If no error 8506** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8507** databases, SQLITE_OK is returned. 8508** 8509** ^If database zDb is the name of an attached database that is not in WAL 8510** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8511** zDb is not NULL (or a zero length string) and is not the name of any 8512** attached database, SQLITE_ERROR is returned to the caller. 8513** 8514** ^Unless it returns SQLITE_MISUSE, 8515** the sqlite3_wal_checkpoint_v2() interface 8516** sets the error information that is queried by 8517** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8518** 8519** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8520** from SQL. 8521*/ 8522int sqlite3_wal_checkpoint_v2( 8523 sqlite3 *db, /* Database handle */ 8524 const char *zDb, /* Name of attached database (or NULL) */ 8525 int eMode, /* SQLITE_CHECKPOINT_* value */ 8526 int *pnLog, /* OUT: Size of WAL log in frames */ 8527 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8528); 8529 8530/* 8531** CAPI3REF: Checkpoint Mode Values 8532** KEYWORDS: {checkpoint mode} 8533** 8534** These constants define all valid values for the "checkpoint mode" passed 8535** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8536** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8537** meaning of each of these checkpoint modes. 8538*/ 8539#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8540#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8541#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8542#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8543 8544/* 8545** CAPI3REF: Virtual Table Interface Configuration 8546** 8547** This function may be called by either the [xConnect] or [xCreate] method 8548** of a [virtual table] implementation to configure 8549** various facets of the virtual table interface. 8550** 8551** If this interface is invoked outside the context of an xConnect or 8552** xCreate virtual table method then the behavior is undefined. 8553** 8554** At present, there is only one option that may be configured using 8555** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8556** may be added in the future. 8557*/ 8558int sqlite3_vtab_config(sqlite3*, int op, ...); 8559 8560/* 8561** CAPI3REF: Virtual Table Configuration Options 8562** 8563** These macros define the various options to the 8564** [sqlite3_vtab_config()] interface that [virtual table] implementations 8565** can use to customize and optimize their behavior. 8566** 8567** <dl> 8568** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8569** <dd>Calls of the form 8570** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8571** where X is an integer. If X is zero, then the [virtual table] whose 8572** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8573** support constraints. In this configuration (which is the default) if 8574** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8575** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8576** specified as part of the users SQL statement, regardless of the actual 8577** ON CONFLICT mode specified. 8578** 8579** If X is non-zero, then the virtual table implementation guarantees 8580** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8581** any modifications to internal or persistent data structures have been made. 8582** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8583** is able to roll back a statement or database transaction, and abandon 8584** or continue processing the current SQL statement as appropriate. 8585** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8586** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8587** had been ABORT. 8588** 8589** Virtual table implementations that are required to handle OR REPLACE 8590** must do so within the [xUpdate] method. If a call to the 8591** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8592** CONFLICT policy is REPLACE, the virtual table implementation should 8593** silently replace the appropriate rows within the xUpdate callback and 8594** return SQLITE_OK. Or, if this is not possible, it may return 8595** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8596** constraint handling. 8597** </dl> 8598*/ 8599#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8600 8601/* 8602** CAPI3REF: Determine The Virtual Table Conflict Policy 8603** 8604** This function may only be called from within a call to the [xUpdate] method 8605** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8606** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8607** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8608** of the SQL statement that triggered the call to the [xUpdate] method of the 8609** [virtual table]. 8610*/ 8611int sqlite3_vtab_on_conflict(sqlite3 *); 8612 8613/* 8614** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8615** 8616** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8617** method of a [virtual table], then it returns true if and only if the 8618** column is being fetched as part of an UPDATE operation during which the 8619** column value will not change. Applications might use this to substitute 8620** a return value that is less expensive to compute and that the corresponding 8621** [xUpdate] method understands as a "no-change" value. 8622** 8623** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8624** the column is not changed by the UPDATE statement, then the xColumn 8625** method can optionally return without setting a result, without calling 8626** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8627** In that case, [sqlite3_value_nochange(X)] will return true for the 8628** same column in the [xUpdate] method. 8629*/ 8630int sqlite3_vtab_nochange(sqlite3_context*); 8631 8632/* 8633** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8634** 8635** This function may only be called from within a call to the [xBestIndex] 8636** method of a [virtual table]. 8637** 8638** The first argument must be the sqlite3_index_info object that is the 8639** first parameter to the xBestIndex() method. The second argument must be 8640** an index into the aConstraint[] array belonging to the sqlite3_index_info 8641** structure passed to xBestIndex. This function returns a pointer to a buffer 8642** containing the name of the collation sequence for the corresponding 8643** constraint. 8644*/ 8645SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8646 8647/* 8648** CAPI3REF: Conflict resolution modes 8649** KEYWORDS: {conflict resolution mode} 8650** 8651** These constants are returned by [sqlite3_vtab_on_conflict()] to 8652** inform a [virtual table] implementation what the [ON CONFLICT] mode 8653** is for the SQL statement being evaluated. 8654** 8655** Note that the [SQLITE_IGNORE] constant is also used as a potential 8656** return value from the [sqlite3_set_authorizer()] callback and that 8657** [SQLITE_ABORT] is also a [result code]. 8658*/ 8659#define SQLITE_ROLLBACK 1 8660/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8661#define SQLITE_FAIL 3 8662/* #define SQLITE_ABORT 4 // Also an error code */ 8663#define SQLITE_REPLACE 5 8664 8665/* 8666** CAPI3REF: Prepared Statement Scan Status Opcodes 8667** KEYWORDS: {scanstatus options} 8668** 8669** The following constants can be used for the T parameter to the 8670** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8671** different metric for sqlite3_stmt_scanstatus() to return. 8672** 8673** When the value returned to V is a string, space to hold that string is 8674** managed by the prepared statement S and will be automatically freed when 8675** S is finalized. 8676** 8677** <dl> 8678** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8679** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8680** set to the total number of times that the X-th loop has run.</dd> 8681** 8682** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8683** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8684** to the total number of rows examined by all iterations of the X-th loop.</dd> 8685** 8686** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8687** <dd>^The "double" variable pointed to by the T parameter will be set to the 8688** query planner's estimate for the average number of rows output from each 8689** iteration of the X-th loop. If the query planner's estimates was accurate, 8690** then this value will approximate the quotient NVISIT/NLOOP and the 8691** product of this value for all prior loops with the same SELECTID will 8692** be the NLOOP value for the current loop. 8693** 8694** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8695** <dd>^The "const char *" variable pointed to by the T parameter will be set 8696** to a zero-terminated UTF-8 string containing the name of the index or table 8697** used for the X-th loop. 8698** 8699** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8700** <dd>^The "const char *" variable pointed to by the T parameter will be set 8701** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8702** description for the X-th loop. 8703** 8704** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8705** <dd>^The "int" variable pointed to by the T parameter will be set to the 8706** "select-id" for the X-th loop. The select-id identifies which query or 8707** subquery the loop is part of. The main query has a select-id of zero. 8708** The select-id is the same value as is output in the first column 8709** of an [EXPLAIN QUERY PLAN] query. 8710** </dl> 8711*/ 8712#define SQLITE_SCANSTAT_NLOOP 0 8713#define SQLITE_SCANSTAT_NVISIT 1 8714#define SQLITE_SCANSTAT_EST 2 8715#define SQLITE_SCANSTAT_NAME 3 8716#define SQLITE_SCANSTAT_EXPLAIN 4 8717#define SQLITE_SCANSTAT_SELECTID 5 8718 8719/* 8720** CAPI3REF: Prepared Statement Scan Status 8721** METHOD: sqlite3_stmt 8722** 8723** This interface returns information about the predicted and measured 8724** performance for pStmt. Advanced applications can use this 8725** interface to compare the predicted and the measured performance and 8726** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8727** 8728** Since this interface is expected to be rarely used, it is only 8729** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8730** compile-time option. 8731** 8732** The "iScanStatusOp" parameter determines which status information to return. 8733** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8734** of this interface is undefined. 8735** ^The requested measurement is written into a variable pointed to by 8736** the "pOut" parameter. 8737** Parameter "idx" identifies the specific loop to retrieve statistics for. 8738** Loops are numbered starting from zero. ^If idx is out of range - less than 8739** zero or greater than or equal to the total number of loops used to implement 8740** the statement - a non-zero value is returned and the variable that pOut 8741** points to is unchanged. 8742** 8743** ^Statistics might not be available for all loops in all statements. ^In cases 8744** where there exist loops with no available statistics, this function behaves 8745** as if the loop did not exist - it returns non-zero and leave the variable 8746** that pOut points to unchanged. 8747** 8748** See also: [sqlite3_stmt_scanstatus_reset()] 8749*/ 8750int sqlite3_stmt_scanstatus( 8751 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8752 int idx, /* Index of loop to report on */ 8753 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8754 void *pOut /* Result written here */ 8755); 8756 8757/* 8758** CAPI3REF: Zero Scan-Status Counters 8759** METHOD: sqlite3_stmt 8760** 8761** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8762** 8763** This API is only available if the library is built with pre-processor 8764** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8765*/ 8766void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8767 8768/* 8769** CAPI3REF: Flush caches to disk mid-transaction 8770** 8771** ^If a write-transaction is open on [database connection] D when the 8772** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8773** pages in the pager-cache that are not currently in use are written out 8774** to disk. A dirty page may be in use if a database cursor created by an 8775** active SQL statement is reading from it, or if it is page 1 of a database 8776** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8777** interface flushes caches for all schemas - "main", "temp", and 8778** any [attached] databases. 8779** 8780** ^If this function needs to obtain extra database locks before dirty pages 8781** can be flushed to disk, it does so. ^If those locks cannot be obtained 8782** immediately and there is a busy-handler callback configured, it is invoked 8783** in the usual manner. ^If the required lock still cannot be obtained, then 8784** the database is skipped and an attempt made to flush any dirty pages 8785** belonging to the next (if any) database. ^If any databases are skipped 8786** because locks cannot be obtained, but no other error occurs, this 8787** function returns SQLITE_BUSY. 8788** 8789** ^If any other error occurs while flushing dirty pages to disk (for 8790** example an IO error or out-of-memory condition), then processing is 8791** abandoned and an SQLite [error code] is returned to the caller immediately. 8792** 8793** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8794** 8795** ^This function does not set the database handle error code or message 8796** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8797*/ 8798int sqlite3_db_cacheflush(sqlite3*); 8799 8800/* 8801** CAPI3REF: The pre-update hook. 8802** 8803** ^These interfaces are only available if SQLite is compiled using the 8804** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8805** 8806** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8807** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8808** on a database table. 8809** ^At most one preupdate hook may be registered at a time on a single 8810** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8811** the previous setting. 8812** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8813** with a NULL pointer as the second parameter. 8814** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8815** the first parameter to callbacks. 8816** 8817** ^The preupdate hook only fires for changes to real database tables; the 8818** preupdate hook is not invoked for changes to [virtual tables] or to 8819** system tables like sqlite_master or sqlite_stat1. 8820** 8821** ^The second parameter to the preupdate callback is a pointer to 8822** the [database connection] that registered the preupdate hook. 8823** ^The third parameter to the preupdate callback is one of the constants 8824** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8825** kind of update operation that is about to occur. 8826** ^(The fourth parameter to the preupdate callback is the name of the 8827** database within the database connection that is being modified. This 8828** will be "main" for the main database or "temp" for TEMP tables or 8829** the name given after the AS keyword in the [ATTACH] statement for attached 8830** databases.)^ 8831** ^The fifth parameter to the preupdate callback is the name of the 8832** table that is being modified. 8833** 8834** For an UPDATE or DELETE operation on a [rowid table], the sixth 8835** parameter passed to the preupdate callback is the initial [rowid] of the 8836** row being modified or deleted. For an INSERT operation on a rowid table, 8837** or any operation on a WITHOUT ROWID table, the value of the sixth 8838** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8839** seventh parameter is the final rowid value of the row being inserted 8840** or updated. The value of the seventh parameter passed to the callback 8841** function is not defined for operations on WITHOUT ROWID tables, or for 8842** INSERT operations on rowid tables. 8843** 8844** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8845** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8846** provide additional information about a preupdate event. These routines 8847** may only be called from within a preupdate callback. Invoking any of 8848** these routines from outside of a preupdate callback or with a 8849** [database connection] pointer that is different from the one supplied 8850** to the preupdate callback results in undefined and probably undesirable 8851** behavior. 8852** 8853** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8854** in the row that is being inserted, updated, or deleted. 8855** 8856** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8857** a [protected sqlite3_value] that contains the value of the Nth column of 8858** the table row before it is updated. The N parameter must be between 0 8859** and one less than the number of columns or the behavior will be 8860** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8861** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8862** behavior is undefined. The [sqlite3_value] that P points to 8863** will be destroyed when the preupdate callback returns. 8864** 8865** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8866** a [protected sqlite3_value] that contains the value of the Nth column of 8867** the table row after it is updated. The N parameter must be between 0 8868** and one less than the number of columns or the behavior will be 8869** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8870** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8871** behavior is undefined. The [sqlite3_value] that P points to 8872** will be destroyed when the preupdate callback returns. 8873** 8874** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8875** callback was invoked as a result of a direct insert, update, or delete 8876** operation; or 1 for inserts, updates, or deletes invoked by top-level 8877** triggers; or 2 for changes resulting from triggers called by top-level 8878** triggers; and so forth. 8879** 8880** See also: [sqlite3_update_hook()] 8881*/ 8882#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8883void *sqlite3_preupdate_hook( 8884 sqlite3 *db, 8885 void(*xPreUpdate)( 8886 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8887 sqlite3 *db, /* Database handle */ 8888 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8889 char const *zDb, /* Database name */ 8890 char const *zName, /* Table name */ 8891 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8892 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8893 ), 8894 void* 8895); 8896int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8897int sqlite3_preupdate_count(sqlite3 *); 8898int sqlite3_preupdate_depth(sqlite3 *); 8899int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8900#endif 8901 8902/* 8903** CAPI3REF: Low-level system error code 8904** 8905** ^Attempt to return the underlying operating system error code or error 8906** number that caused the most recent I/O error or failure to open a file. 8907** The return value is OS-dependent. For example, on unix systems, after 8908** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8909** called to get back the underlying "errno" that caused the problem, such 8910** as ENOSPC, EAUTH, EISDIR, and so forth. 8911*/ 8912int sqlite3_system_errno(sqlite3*); 8913 8914/* 8915** CAPI3REF: Database Snapshot 8916** KEYWORDS: {snapshot} {sqlite3_snapshot} 8917** EXPERIMENTAL 8918** 8919** An instance of the snapshot object records the state of a [WAL mode] 8920** database for some specific point in history. 8921** 8922** In [WAL mode], multiple [database connections] that are open on the 8923** same database file can each be reading a different historical version 8924** of the database file. When a [database connection] begins a read 8925** transaction, that connection sees an unchanging copy of the database 8926** as it existed for the point in time when the transaction first started. 8927** Subsequent changes to the database from other connections are not seen 8928** by the reader until a new read transaction is started. 8929** 8930** The sqlite3_snapshot object records state information about an historical 8931** version of the database file so that it is possible to later open a new read 8932** transaction that sees that historical version of the database rather than 8933** the most recent version. 8934** 8935** The constructor for this object is [sqlite3_snapshot_get()]. The 8936** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8937** to an historical snapshot (if possible). The destructor for 8938** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8939*/ 8940typedef struct sqlite3_snapshot { 8941 unsigned char hidden[48]; 8942} sqlite3_snapshot; 8943 8944/* 8945** CAPI3REF: Record A Database Snapshot 8946** EXPERIMENTAL 8947** 8948** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8949** new [sqlite3_snapshot] object that records the current state of 8950** schema S in database connection D. ^On success, the 8951** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8952** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8953** If there is not already a read-transaction open on schema S when 8954** this function is called, one is opened automatically. 8955** 8956** The following must be true for this function to succeed. If any of 8957** the following statements are false when sqlite3_snapshot_get() is 8958** called, SQLITE_ERROR is returned. The final value of *P is undefined 8959** in this case. 8960** 8961** <ul> 8962** <li> The database handle must be in [autocommit mode]. 8963** 8964** <li> Schema S of [database connection] D must be a [WAL mode] database. 8965** 8966** <li> There must not be a write transaction open on schema S of database 8967** connection D. 8968** 8969** <li> One or more transactions must have been written to the current wal 8970** file since it was created on disk (by any connection). This means 8971** that a snapshot cannot be taken on a wal mode database with no wal 8972** file immediately after it is first opened. At least one transaction 8973** must be written to it first. 8974** </ul> 8975** 8976** This function may also return SQLITE_NOMEM. If it is called with the 8977** database handle in autocommit mode but fails for some other reason, 8978** whether or not a read transaction is opened on schema S is undefined. 8979** 8980** The [sqlite3_snapshot] object returned from a successful call to 8981** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8982** to avoid a memory leak. 8983** 8984** The [sqlite3_snapshot_get()] interface is only available when the 8985** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8986*/ 8987SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8988 sqlite3 *db, 8989 const char *zSchema, 8990 sqlite3_snapshot **ppSnapshot 8991); 8992 8993/* 8994** CAPI3REF: Start a read transaction on an historical snapshot 8995** EXPERIMENTAL 8996** 8997** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8998** read transaction for schema S of 8999** [database connection] D such that the read transaction 9000** refers to historical [snapshot] P, rather than the most 9001** recent change to the database. 9002** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 9003** or an appropriate [error code] if it fails. 9004** 9005** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 9006** the first operation following the [BEGIN] that takes the schema S 9007** out of [autocommit mode]. 9008** ^In other words, schema S must not currently be in 9009** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 9010** database connection D must be out of [autocommit mode]. 9011** ^A [snapshot] will fail to open if it has been overwritten by a 9012** [checkpoint]. 9013** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9014** database connection D does not know that the database file for 9015** schema S is in [WAL mode]. A database connection might not know 9016** that the database file is in [WAL mode] if there has been no prior 9017** I/O on that database connection, or if the database entered [WAL mode] 9018** after the most recent I/O on the database connection.)^ 9019** (Hint: Run "[PRAGMA application_id]" against a newly opened 9020** database connection in order to make it ready to use snapshots.) 9021** 9022** The [sqlite3_snapshot_open()] interface is only available when the 9023** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 9024*/ 9025SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9026 sqlite3 *db, 9027 const char *zSchema, 9028 sqlite3_snapshot *pSnapshot 9029); 9030 9031/* 9032** CAPI3REF: Destroy a snapshot 9033** EXPERIMENTAL 9034** 9035** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9036** The application must eventually free every [sqlite3_snapshot] object 9037** using this routine to avoid a memory leak. 9038** 9039** The [sqlite3_snapshot_free()] interface is only available when the 9040** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 9041*/ 9042SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9043 9044/* 9045** CAPI3REF: Compare the ages of two snapshot handles. 9046** EXPERIMENTAL 9047** 9048** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9049** of two valid snapshot handles. 9050** 9051** If the two snapshot handles are not associated with the same database 9052** file, the result of the comparison is undefined. 9053** 9054** Additionally, the result of the comparison is only valid if both of the 9055** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9056** last time the wal file was deleted. The wal file is deleted when the 9057** database is changed back to rollback mode or when the number of database 9058** clients drops to zero. If either snapshot handle was obtained before the 9059** wal file was last deleted, the value returned by this function 9060** is undefined. 9061** 9062** Otherwise, this API returns a negative value if P1 refers to an older 9063** snapshot than P2, zero if the two handles refer to the same database 9064** snapshot, and a positive value if P1 is a newer snapshot than P2. 9065*/ 9066SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9067 sqlite3_snapshot *p1, 9068 sqlite3_snapshot *p2 9069); 9070 9071/* 9072** CAPI3REF: Recover snapshots from a wal file 9073** EXPERIMENTAL 9074** 9075** If all connections disconnect from a database file but do not perform 9076** a checkpoint, the existing wal file is opened along with the database 9077** file the next time the database is opened. At this point it is only 9078** possible to successfully call sqlite3_snapshot_open() to open the most 9079** recent snapshot of the database (the one at the head of the wal file), 9080** even though the wal file may contain other valid snapshots for which 9081** clients have sqlite3_snapshot handles. 9082** 9083** This function attempts to scan the wal file associated with database zDb 9084** of database handle db and make all valid snapshots available to 9085** sqlite3_snapshot_open(). It is an error if there is already a read 9086** transaction open on the database, or if the database is not a wal mode 9087** database. 9088** 9089** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9090*/ 9091SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9092 9093/* 9094** CAPI3REF: Serialize a database 9095** 9096** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9097** that is a serialization of the S database on [database connection] D. 9098** If P is not a NULL pointer, then the size of the database in bytes 9099** is written into *P. 9100** 9101** For an ordinary on-disk database file, the serialization is just a 9102** copy of the disk file. For an in-memory database or a "TEMP" database, 9103** the serialization is the same sequence of bytes which would be written 9104** to disk if that database where backed up to disk. 9105** 9106** The usual case is that sqlite3_serialize() copies the serialization of 9107** the database into memory obtained from [sqlite3_malloc64()] and returns 9108** a pointer to that memory. The caller is responsible for freeing the 9109** returned value to avoid a memory leak. However, if the F argument 9110** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9111** are made, and the sqlite3_serialize() function will return a pointer 9112** to the contiguous memory representation of the database that SQLite 9113** is currently using for that database, or NULL if the no such contiguous 9114** memory representation of the database exists. A contiguous memory 9115** representation of the database will usually only exist if there has 9116** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9117** values of D and S. 9118** The size of the database is written into *P even if the 9119** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9120** of the database exists. 9121** 9122** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9123** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9124** allocation error occurs. 9125** 9126** This interface is only available if SQLite is compiled with the 9127** [SQLITE_ENABLE_DESERIALIZE] option. 9128*/ 9129unsigned char *sqlite3_serialize( 9130 sqlite3 *db, /* The database connection */ 9131 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9132 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9133 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9134); 9135 9136/* 9137** CAPI3REF: Flags for sqlite3_serialize 9138** 9139** Zero or more of the following constants can be OR-ed together for 9140** the F argument to [sqlite3_serialize(D,S,P,F)]. 9141** 9142** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9143** a pointer to contiguous in-memory database that it is currently using, 9144** without making a copy of the database. If SQLite is not currently using 9145** a contiguous in-memory database, then this option causes 9146** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9147** using a contiguous in-memory database if it has been initialized by a 9148** prior call to [sqlite3_deserialize()]. 9149*/ 9150#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9151 9152/* 9153** CAPI3REF: Deserialize a database 9154** 9155** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9156** [database connection] D to disconnect from database S and then 9157** reopen S as an in-memory database based on the serialization contained 9158** in P. The serialized database P is N bytes in size. M is the size of 9159** the buffer P, which might be larger than N. If M is larger than N, and 9160** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9161** permitted to add content to the in-memory database as long as the total 9162** size does not exceed M bytes. 9163** 9164** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9165** invoke sqlite3_free() on the serialization buffer when the database 9166** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9167** SQLite will try to increase the buffer size using sqlite3_realloc64() 9168** if writes on the database cause it to grow larger than M bytes. 9169** 9170** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9171** database is currently in a read transaction or is involved in a backup 9172** operation. 9173** 9174** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9175** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9176** [sqlite3_free()] is invoked on argument P prior to returning. 9177** 9178** This interface is only available if SQLite is compiled with the 9179** [SQLITE_ENABLE_DESERIALIZE] option. 9180*/ 9181int sqlite3_deserialize( 9182 sqlite3 *db, /* The database connection */ 9183 const char *zSchema, /* Which DB to reopen with the deserialization */ 9184 unsigned char *pData, /* The serialized database content */ 9185 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9186 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9187 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9188); 9189 9190/* 9191** CAPI3REF: Flags for sqlite3_deserialize() 9192** 9193** The following are allowed values for 6th argument (the F argument) to 9194** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9195** 9196** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9197** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9198** and that SQLite should take ownership of this memory and automatically 9199** free it when it has finished using it. Without this flag, the caller 9200** is resposible for freeing any dynamically allocated memory. 9201** 9202** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9203** grow the size of the database using calls to [sqlite3_realloc64()]. This 9204** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9205** Without this flag, the deserialized database cannot increase in size beyond 9206** the number of bytes specified by the M parameter. 9207** 9208** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9209** should be treated as read-only. 9210*/ 9211#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9212#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9213#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9214 9215/* 9216** Undo the hack that converts floating point types to integer for 9217** builds on processors without floating point support. 9218*/ 9219#ifdef SQLITE_OMIT_FLOATING_POINT 9220# undef double 9221#endif 9222 9223#ifdef __cplusplus 9224} /* End of the 'extern "C"' block */ 9225#endif 9226#endif /* SQLITE3_H */ 9227