/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** Main file for the SQLite library. The routines in this file
** implement the programmer interface to the library. Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.94 2002/07/31 00:32:50 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
/*
** A pointer to this structure is used to communicate information
** from sqliteInit into the sqliteInitCallback.
*/
typedef struct {
sqlite *db; /* The database being initialized */
char **pzErrMsg; /* Error message stored here */
} InitData;
/*
** This is the callback routine for the code that initializes the
** database. See sqliteInit() below for additional information.
**
** Each callback contains the following information:
**
** argv[0] = "file-format" or "schema-cookie" or "table" or "index"
** argv[1] = table or index name or meta statement type.
** argv[2] = root page number for table or index. NULL for meta.
** argv[3] = SQL create statement for the table or index
** argv[4] = "1" for temporary files, "0" for main database
**
*/
static
int sqliteInitCallback(void *pInit, int argc, char **argv, char **azColName){
InitData *pData = (InitData*)pInit;
Parse sParse;
int nErr = 0;
/* TODO: Do some validity checks on all fields. In particular,
** make sure fields do not contain NULLs. Otherwise we might core
** when attempting to initialize from a corrupt database file. */
assert( argc==5 );
switch( argv[0][0] ){
case 'v':
case 'i':
case 't': { /* CREATE TABLE, CREATE INDEX, or CREATE VIEW statements */
if( argv[3] && argv[3][0] ){
/* Call the parser to process a CREATE TABLE, INDEX or VIEW.
** But because sParse.initFlag is set to 1, no VDBE code is generated
** or executed. All the parser does is build the internal data
** structures that describe the table, index, or view.
*/
memset(&sParse, 0, sizeof(sParse));
sParse.db = pData->db;
sParse.initFlag = 1;
sParse.isTemp = argv[4][0] - '0';
sParse.newTnum = atoi(argv[2]);
sqliteRunParser(&sParse, argv[3], pData->pzErrMsg);
}else{
/* If the SQL column is blank it means this is an index that
** was created to be the PRIMARY KEY or to fulfill a UNIQUE
** constraint for a CREATE TABLE. The index should have already
** been created when we processed the CREATE TABLE. All we have
** to do here is record the root page number for that index.
*/
Index *pIndex = sqliteFindIndex(pData->db, argv[1]);
if( pIndex==0 || pIndex->tnum!=0 ){
/* This can occur if there exists an index on a TEMP table which
** has the same name as another index on a permanent index. Since
** the permanent table is hidden by the TEMP table, we can also
** safely ignore the index on the permanent table.
*/
/* Do Nothing */;
}else{
pIndex->tnum = atoi(argv[2]);
}
}
break;
}
default: {
/* This can not happen! */
nErr = 1;
assert( nErr==0 );
}
}
return nErr;
}
/*
** This is a callback procedure used to reconstruct a table. The
** name of the table to be reconstructed is passed in as argv[0].
**
** This routine is used to automatically upgrade a database from
** format version 1 or 2 to version 3. The correct operation of
** this routine relys on the fact that no indices are used when
** copying a table out to a temporary file.
*/
static
int upgrade_3_callback(void *pInit, int argc, char **argv, char **NotUsed){
InitData *pData = (InitData*)pInit;
int rc;
Table *pTab;
Trigger *pTrig;
char *zErr = 0;
pTab = sqliteFindTable(pData->db, argv[0]);
assert( pTab!=0 );
assert( sqliteStrICmp(pTab->zName, argv[0])==0 );
if( pTab ){
pTrig = pTab->pTrigger;
pTab->pTrigger = 0; /* Disable all triggers before rebuilding the table */
}
rc = sqlite_exec_printf(pData->db,
"CREATE TEMP TABLE sqlite_x AS SELECT * FROM '%q'; "
"DELETE FROM '%q'; "
"INSERT INTO '%q' SELECT * FROM sqlite_x; "
"DROP TABLE sqlite_x;",
0, 0, &zErr, argv[0], argv[0], argv[0]);
if( zErr ){
sqliteSetString(pData->pzErrMsg, zErr, 0);
sqlite_freemem(zErr);
}
/* If an error occurred in the SQL above, then the transaction will
** rollback which will delete the internal symbol tables. This will
** cause the structure that pTab points to be deleted. In case that
** happened, we need to refetch pTab.
*/
pTab = sqliteFindTable(pData->db, argv[0]);
if( pTab ){
assert( sqliteStrICmp(pTab->zName, argv[0])==0 );
pTab->pTrigger = pTrig; /* Re-enable triggers */
}
return rc!=SQLITE_OK;
}
/*
** Attempt to read the database schema and initialize internal
** data structures. Return one of the SQLITE_ error codes to
** indicate success or failure.
**
** After the database is initialized, the SQLITE_Initialized
** bit is set in the flags field of the sqlite structure. An
** attempt is made to initialize the database as soon as it
** is opened. If that fails (perhaps because another process
** has the sqlite_master table locked) than another attempt
** is made the first time the database is accessed.
*/
int sqliteInit(sqlite *db, char **pzErrMsg){
int rc;
BtCursor *curMain;
int size;
Table *pTab;
char *azArg[6];
int meta[SQLITE_N_BTREE_META];
Parse sParse;
InitData initData;
/*
** The master database table has a structure like this
*/
static char master_schema[] =
"CREATE TABLE sqlite_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
static char temp_master_schema[] =
"CREATE TEMP TABLE sqlite_temp_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
/* The following SQL will read the schema from the master tables.
** The first version works with SQLite file formats 2 or greater.
** The second version is for format 1 files.
**
** Beginning with file format 2, the rowid for new table entries
** (including entries in sqlite_master) is an increasing integer.
** So for file format 2 and later, we can play back sqlite_master
** and all the CREATE statements will appear in the right order.
** But with file format 1, table entries were random and so we
** have to make sure the CREATE TABLEs occur before their corresponding
** CREATE INDEXs. (We don't have to deal with CREATE VIEW or
** CREATE TRIGGER in file format 1 because those constructs did
** not exist then.)
*/
static char init_script[] =
"SELECT type, name, rootpage, sql, 1 FROM sqlite_temp_master "
"UNION ALL "
"SELECT type, name, rootpage, sql, 0 FROM sqlite_master";
static char older_init_script[] =
"SELECT type, name, rootpage, sql, 1 FROM sqlite_temp_master "
"UNION ALL "
"SELECT type, name, rootpage, sql, 0 FROM sqlite_master "
"WHERE type='table' "
"UNION ALL "
"SELECT type, name, rootpage, sql, 0 FROM sqlite_master "
"WHERE type='index'";
/* Construct the schema tables: sqlite_master and sqlite_temp_master
*/
azArg[0] = "table";
azArg[1] = MASTER_NAME;
azArg[2] = "2";
azArg[3] = master_schema;
azArg[4] = "0";
azArg[5] = 0;
initData.db = db;
initData.pzErrMsg = pzErrMsg;
sqliteInitCallback(&initData, 5, azArg, 0);
pTab = sqliteFindTable(db, MASTER_NAME);
if( pTab ){
pTab->readOnly = 1;
}
azArg[1] = TEMP_MASTER_NAME;
azArg[3] = temp_master_schema;
azArg[4] = "1";
sqliteInitCallback(&initData, 5, azArg, 0);
pTab = sqliteFindTable(db, TEMP_MASTER_NAME);
if( pTab ){
pTab->readOnly = 1;
}
/* Create a cursor to hold the database open
*/
if( db->pBe==0 ) return SQLITE_OK;
rc = sqliteBtreeCursor(db->pBe, 2, 0, &curMain);
if( rc ){
sqliteResetInternalSchema(db);
return rc;
}
/* Get the database meta information
*/
rc = sqliteBtreeGetMeta(db->pBe, meta);
if( rc ){
sqliteResetInternalSchema(db);
sqliteBtreeCloseCursor(curMain);
return rc;
}
db->schema_cookie = meta[1];
db->next_cookie = db->schema_cookie;
db->file_format = meta[2];
size = meta[3];
if( size==0 ){ size = MAX_PAGES; }
db->cache_size = size;
sqliteBtreeSetCacheSize(db->pBe, size);
/*
** file_format==1 Version 2.1.0.
** file_format==2 Version 2.2.0. Add support for INTEGER PRIMARY KEY.
** file_format==3 Version 2.6.0. Fix empty-string index bug.
** file_format==4 Version 2.7.0. Add support for separate numeric and
** text datatypes.
*/
if( db->file_format==0 ){
/* This happens if the database was initially empty */
db->file_format = 3;
}else if( db->file_format>3 ){
sqliteBtreeCloseCursor(curMain);
sqliteSetString(pzErrMsg, "unsupported file format", 0);
return SQLITE_ERROR;
}
/* Read the schema information out of the schema tables
*/
memset(&sParse, 0, sizeof(sParse));
sParse.db = db;
sParse.pBe = db->pBe;
sParse.xCallback = sqliteInitCallback;
sParse.pArg = (void*)&initData;
sParse.initFlag = 1;
sqliteRunParser(&sParse,
db->file_format>=2 ? init_script : older_init_script,
pzErrMsg);
if( sqlite_malloc_failed ){
sqliteSetString(pzErrMsg, "out of memory", 0);
sParse.rc = SQLITE_NOMEM;
sqliteBtreeRollback(db->pBe);
sqliteResetInternalSchema(db);
}
if( sParse.rc==SQLITE_OK ){
db->flags |= SQLITE_Initialized;
sqliteCommitInternalChanges(db);
}else{
db->flags &= ~SQLITE_Initialized;
sqliteResetInternalSchema(db);
}
sqliteBtreeCloseCursor(curMain);
return sParse.rc;
}
/*
** The version of the library
*/
const char rcsid[] = "@(#) \044Id: SQLite version " SQLITE_VERSION " $";
const char sqlite_version[] = SQLITE_VERSION;
/*
** Does the library expect data to be encoded as UTF-8 or iso8859? The
** following global constant always lets us know.
*/
#ifdef SQLITE_UTF8
const char sqlite_encoding[] = "UTF-8";
#else
const char sqlite_encoding[] = "iso8859";
#endif
/*
** Open a new SQLite database. Construct an "sqlite" structure to define
** the state of this database and return a pointer to that structure.
**
** An attempt is made to initialize the in-memory data structures that
** hold the database schema. But if this fails (because the schema file
** is locked) then that step is deferred until the first call to
** sqlite_exec().
*/
sqlite *sqlite_open(const char *zFilename, int mode, char **pzErrMsg){
sqlite *db;
int rc;
/* Allocate the sqlite data structure */
db = sqliteMalloc( sizeof(sqlite) );
if( pzErrMsg ) *pzErrMsg = 0;
if( db==0 ) goto no_mem_on_open;
sqliteHashInit(&db->tblHash, SQLITE_HASH_STRING, 0);
sqliteHashInit(&db->idxHash, SQLITE_HASH_STRING, 0);
sqliteHashInit(&db->trigHash, SQLITE_HASH_STRING, 0);
sqliteHashInit(&db->aFunc, SQLITE_HASH_STRING, 1);
sqliteRegisterBuiltinFunctions(db);
db->onError = OE_Default;
db->priorNewRowid = 0;
db->magic = SQLITE_MAGIC_BUSY;
/* Open the backend database driver */
rc = sqliteBtreeOpen(zFilename, mode, MAX_PAGES, &db->pBe);
if( rc!=SQLITE_OK ){
switch( rc ){
default: {
sqliteSetString(pzErrMsg, "unable to open database: ", zFilename, 0);
}
}
sqliteFree(db);
sqliteStrRealloc(pzErrMsg);
return 0;
}
/* Attempt to read the schema */
rc = sqliteInit(db, pzErrMsg);
db->magic = SQLITE_MAGIC_OPEN;
if( sqlite_malloc_failed ){
sqlite_close(db);
goto no_mem_on_open;
}else if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){
sqlite_close(db);
sqliteStrRealloc(pzErrMsg);
return 0;
}else if( pzErrMsg ){
sqliteFree(*pzErrMsg);
*pzErrMsg = 0;
}
/* If the database is in formats 1 or 2, then upgrade it to
** version 3. This will reconstruct all indices. If the
** upgrade fails for any reason (ex: out of disk space, database
** is read only, interrupt receive, etc.) then refuse to open.
*/
if( rc==SQLITE_OK && db->file_format<3 ){
char *zErr = 0;
InitData initData;
int meta[SQLITE_N_BTREE_META];
initData.db = db;
initData.pzErrMsg = &zErr;
db->file_format = 3;
rc = sqlite_exec(db,
"BEGIN; SELECT name FROM sqlite_master WHERE type='table';",
upgrade_3_callback,
&initData,
&zErr);
if( rc==SQLITE_OK ){
sqliteBtreeGetMeta(db->pBe, meta);
meta[2] = 3;
sqliteBtreeUpdateMeta(db->pBe, meta);
sqlite_exec(db, "COMMIT", 0, 0, 0);
}
if( rc!=SQLITE_OK ){
sqliteSetString(pzErrMsg,
"unable to upgrade database to the version 2.6 format",
zErr ? ": " : 0, zErr, 0);
sqlite_freemem(zErr);
sqliteStrRealloc(pzErrMsg);
sqlite_close(db);
return 0;
}
sqlite_freemem(zErr);
}
/* Return a pointer to the newly opened database structure */
return db;
no_mem_on_open:
sqliteSetString(pzErrMsg, "out of memory", 0);
sqliteStrRealloc(pzErrMsg);
return 0;
}
/*
** Return the ROWID of the most recent insert
*/
int sqlite_last_insert_rowid(sqlite *db){
return db->lastRowid;
}
/*
** Return the number of changes in the most recent call to sqlite_exec().
*/
int sqlite_changes(sqlite *db){
return db->nChange;
}
/*
** Close an existing SQLite database
*/
void sqlite_close(sqlite *db){
HashElem *i;
if( sqliteSafetyCheck(db) || sqliteSafetyOn(db) ){ return; }
db->magic = SQLITE_MAGIC_CLOSED;
sqliteBtreeClose(db->pBe);
sqliteResetInternalSchema(db);
if( db->pBeTemp ){
sqliteBtreeClose(db->pBeTemp);
}
for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
FuncDef *pFunc, *pNext;
for(pFunc = (FuncDef*)sqliteHashData(i); pFunc; pFunc=pNext){
pNext = pFunc->pNext;
sqliteFree(pFunc);
}
}
sqliteHashClear(&db->aFunc);
sqliteFree(db);
}
/*
** Return TRUE if the given SQL string ends in a semicolon.
**
** Special handling is require for CREATE TRIGGER statements.
** Whenever the CREATE TRIGGER keywords are seen, the statement
** must end with ";END;".
*/
int sqlite_complete(const char *zSql){
int isComplete = 1;
int requireEnd = 0;
int seenText = 0;
int seenCreate = 0;
while( *zSql ){
switch( *zSql ){
case ';': {
isComplete = 1;
seenText = 1;
seenCreate = 0;
break;
}
case ' ':
case '\t':
case '\n':
case '\f': {
break;
}
case '[': {
isComplete = 0;
seenText = 1;
seenCreate = 0;
zSql++;
while( *zSql && *zSql!=']' ){ zSql++; }
if( *zSql==0 ) return 0;
break;
}
case '"':
case '\'': {
int c = *zSql;
isComplete = 0;
seenText = 1;
seenCreate = 0;
zSql++;
while( *zSql && *zSql!=c ){ zSql++; }
if( *zSql==0 ) return 0;
break;
}
case '-': {
if( zSql[1]!='-' ){
isComplete = 0;
seenCreate = 0;
break;
}
while( *zSql && *zSql!='\n' ){ zSql++; }
if( *zSql==0 ) return seenText && isComplete && requireEnd==0;
break;
}
case 'c':
case 'C': {
seenText = 1;
if( !isComplete ) break;
isComplete = 0;
if( sqliteStrNICmp(zSql, "create", 6)!=0 ) break;
if( !isspace(zSql[6]) ) break;
zSql += 5;
seenCreate = 1;
while( isspace(zSql[1]) ) zSql++;
if( sqliteStrNICmp(&zSql[1],"trigger", 7)!=0 ) break;
zSql += 7;
requireEnd++;
break;
}
case 't':
case 'T': {
seenText = 1;
if( !seenCreate ) break;
seenCreate = 0;
isComplete = 0;
if( sqliteStrNICmp(zSql, "trigger", 7)!=0 ) break;
if( !isspace(zSql[7]) ) break;
zSql += 6;
requireEnd++;
break;
}
case 'e':
case 'E': {
seenCreate = 0;
seenText = 1;
if( !isComplete ) break;
isComplete = 0;
if( requireEnd==0 ) break;
if( sqliteStrNICmp(zSql, "end", 3)!=0 ) break;
zSql += 2;
while( isspace(zSql[1]) ) zSql++;
if( zSql[1]==';' ){
zSql++;
isComplete = 1;
requireEnd--;
}
break;
}
default: {
seenCreate = 0;
seenText = 1;
isComplete = 0;
break;
}
}
zSql++;
}
return seenText && isComplete && requireEnd==0;
}
/*
** Execute SQL code. Return one of the SQLITE_ success/failure
** codes. Also write an error message into memory obtained from
** malloc() and make *pzErrMsg point to that message.
**
** If the SQL is a query, then for each row in the query result
** the xCallback() function is called. pArg becomes the first
** argument to xCallback(). If xCallback=NULL then no callback
** is invoked, even for queries.
*/
int sqlite_exec(
sqlite *db, /* The database on which the SQL executes */
const char *zSql, /* The SQL to be executed */
sqlite_callback xCallback, /* Invoke this callback routine */
void *pArg, /* First argument to xCallback() */
char **pzErrMsg /* Write error messages here */
){
Parse sParse;
if( pzErrMsg ) *pzErrMsg = 0;
if( sqliteSafetyOn(db) ) goto exec_misuse;
if( (db->flags & SQLITE_InTrans)!=0 && db->pid!=sqliteOsProcessId() ){
goto exec_misuse;
}
if( (db->flags & SQLITE_Initialized)==0 ){
int rc = sqliteInit(db, pzErrMsg);
if( rc!=SQLITE_OK ){
sqliteStrRealloc(pzErrMsg);
sqliteSafetyOff(db);
return rc;
}
}
if( db->file_format<3 ){
sqliteSafetyOff(db);
sqliteSetString(pzErrMsg, "obsolete database file format", 0);
return SQLITE_ERROR;
}
if( db->recursionDepth==0 ){ db->nChange = 0; }
db->recursionDepth++;
memset(&sParse, 0, sizeof(sParse));
sParse.db = db;
sParse.pBe = db->pBe;
sParse.xCallback = xCallback;
sParse.pArg = pArg;
sqliteRunParser(&sParse, zSql, pzErrMsg);
if( sqlite_malloc_failed ){
sqliteSetString(pzErrMsg, "out of memory", 0);
sParse.rc = SQLITE_NOMEM;
sqliteBtreeRollback(db->pBe);
if( db->pBeTemp ) sqliteBtreeRollback(db->pBeTemp);
db->flags &= ~SQLITE_InTrans;
sqliteResetInternalSchema(db);
}
sqliteStrRealloc(pzErrMsg);
if( sParse.rc==SQLITE_SCHEMA ){
sqliteResetInternalSchema(db);
}
db->recursionDepth--;
if( sqliteSafetyOff(db) ) goto exec_misuse;
return sParse.rc;
exec_misuse:
if( pzErrMsg ){
*pzErrMsg = 0;
sqliteSetString(pzErrMsg, sqlite_error_string(SQLITE_MISUSE), 0);
sqliteStrRealloc(pzErrMsg);
}
return SQLITE_MISUSE;
}
/*
** Return a static string that describes the kind of error specified in the
** argument.
*/
const char *sqlite_error_string(int rc){
const char *z;
switch( rc ){
case SQLITE_OK: z = "not an error"; break;
case SQLITE_ERROR: z = "SQL logic error or missing database"; break;
case SQLITE_INTERNAL: z = "internal SQLite implementation flaw"; break;
case SQLITE_PERM: z = "access permission denied"; break;
case SQLITE_ABORT: z = "callback requested query abort"; break;
case SQLITE_BUSY: z = "database is locked"; break;
case SQLITE_LOCKED: z = "database table is locked"; break;
case SQLITE_NOMEM: z = "out of memory"; break;
case SQLITE_READONLY: z = "attempt to write a readonly database"; break;
case SQLITE_INTERRUPT: z = "interrupted"; break;
case SQLITE_IOERR: z = "disk I/O error"; break;
case SQLITE_CORRUPT: z = "database disk image is malformed"; break;
case SQLITE_NOTFOUND: z = "table or record not found"; break;
case SQLITE_FULL: z = "database is full"; break;
case SQLITE_CANTOPEN: z = "unable to open database file"; break;
case SQLITE_PROTOCOL: z = "database locking protocol failure"; break;
case SQLITE_EMPTY: z = "table contains no data"; break;
case SQLITE_SCHEMA: z = "database schema has changed"; break;
case SQLITE_TOOBIG: z = "too much data for one table row"; break;
case SQLITE_CONSTRAINT: z = "constraint failed"; break;
case SQLITE_MISMATCH: z = "datatype mismatch"; break;
case SQLITE_MISUSE: z = "library routine called out of sequence";break;
default: z = "unknown error"; break;
}
return z;
}
/*
** This routine implements a busy callback that sleeps and tries
** again until a timeout value is reached. The timeout value is
** an integer number of milliseconds passed in as the first
** argument.
*/
static int sqliteDefaultBusyCallback(
void *Timeout, /* Maximum amount of time to wait */
const char *NotUsed, /* The name of the table that is busy */
int count /* Number of times table has been busy */
){
#if SQLITE_MIN_SLEEP_MS==1
int delay = 10;
int prior_delay = 0;
int timeout = (int)Timeout;
int i;
for(i=1; i<count; i++){
prior_delay += delay;
delay = delay*2;
if( delay>=1000 ){
delay = 1000;
prior_delay += 1000*(count - i - 1);
break;
}
}
if( prior_delay + delay > timeout ){
delay = timeout - prior_delay;
if( delay<=0 ) return 0;
}
sqliteOsSleep(delay);
return 1;
#else
int timeout = (int)Timeout;
if( (count+1)*1000 > timeout ){
return 0;
}
sqliteOsSleep(1000);
return 1;
#endif
}
/*
** This routine sets the busy callback for an Sqlite database to the
** given callback function with the given argument.
*/
void sqlite_busy_handler(
sqlite *db,
int (*xBusy)(void*,const char*,int),
void *pArg
){
db->xBusyCallback = xBusy;
db->pBusyArg = pArg;
}
/*
** This routine installs a default busy handler that waits for the
** specified number of milliseconds before returning 0.
*/
void sqlite_busy_timeout(sqlite *db, int ms){
if( ms>0 ){
sqlite_busy_handler(db, sqliteDefaultBusyCallback, (void*)ms);
}else{
sqlite_busy_handler(db, 0, 0);
}
}
/*
** Cause any pending operation to stop at its earliest opportunity.
*/
void sqlite_interrupt(sqlite *db){
db->flags |= SQLITE_Interrupt;
}
/*
** Windows systems should call this routine to free memory that
** is returned in the in the errmsg parameter of sqlite_open() when
** SQLite is a DLL. For some reason, it does not work to call free()
** directly.
**
** Note that we need to call free() not sqliteFree() here, since every
** string that is exported from SQLite should have already passed through
** sqliteStrRealloc().
*/
void sqlite_freemem(void *p){ free(p); }
/*
** Windows systems need functions to call to return the sqlite_version
** and sqlite_encoding strings.
*/
const char *sqlite_libversion(void){ return sqlite_version; }
const char *sqlite_libencoding(void){ return sqlite_encoding; }
/*
** Create new user-defined functions. The sqlite_create_function()
** routine creates a regular function and sqlite_create_aggregate()
** creates an aggregate function.
**
** Passing a NULL xFunc argument or NULL xStep and xFinalize arguments
** disables the function. Calling sqlite_create_function() with the
** same name and number of arguments as a prior call to
** sqlite_create_aggregate() disables the prior call to
** sqlite_create_aggregate(), and vice versa.
**
** If nArg is -1 it means that this function will accept any number
** of arguments, including 0.
*/
int sqlite_create_function(
sqlite *db, /* Add the function to this database connection */
const char *zName, /* Name of the function to add */
int nArg, /* Number of arguments */
void (*xFunc)(sqlite_func*,int,const char**), /* The implementation */
void *pUserData /* User data */
){
FuncDef *p;
if( db==0 || zName==0 || sqliteSafetyCheck(db) ) return 1;
p = sqliteFindFunction(db, zName, strlen(zName), nArg, 1);
if( p==0 ) return 1;
p->xFunc = xFunc;
p->xStep = 0;
p->xFinalize = 0;
p->pUserData = pUserData;
return 0;
}
int sqlite_create_aggregate(
sqlite *db, /* Add the function to this database connection */
const char *zName, /* Name of the function to add */
int nArg, /* Number of arguments */
void (*xStep)(sqlite_func*,int,const char**), /* The step function */
void (*xFinalize)(sqlite_func*), /* The finalizer */
void *pUserData /* User data */
){
FuncDef *p;
if( db==0 || zName==0 || sqliteSafetyCheck(db) ) return 1;
p = sqliteFindFunction(db, zName, strlen(zName), nArg, 1);
if( p==0 ) return 1;
p->xFunc = 0;
p->xStep = xStep;
p->xFinalize = xFinalize;
p->pUserData = pUserData;
return 0;
}
/*
** Change the datatype for all functions with a given name. See the
** header comment for the prototype of this function in sqlite.h for
** additional information.
*/
int sqlite_function_type(sqlite *db, const char *zName, int dataType){
FuncDef *p = (FuncDef*)sqliteHashFind(&db->aFunc, zName, strlen(zName));
while( p ){
p->dataType = dataType;
p = p->pNext;
}
return SQLITE_OK;
}
/*
** Attempt to open the file named in the argument as the auxiliary database
** file. The auxiliary database file is used to store TEMP tables. But
** by using this API, it is possible to trick SQLite into opening two
** separate databases and acting on them as if they were one.
**
** This routine closes the existing auxiliary database file, which will
** cause any previously created TEMP tables to be created.
**
** The zName parameter can be a NULL pointer or an empty string to cause
** a temporary file to be opened and automatically deleted when closed.
*/
int sqlite_open_aux_file(sqlite *db, const char *zName, char **pzErrMsg){
int rc;
if( zName && zName[0]==0 ) zName = 0;
if( sqliteSafetyOn(db) ) goto openaux_misuse;
sqliteResetInternalSchema(db);
if( db->pBeTemp!=0 ){
sqliteBtreeClose(db->pBeTemp);
}
rc = sqliteBtreeOpen(zName, 0, MAX_PAGES, &db->pBeTemp);
if( rc ){
if( zName==0 ) zName = "a temporary file";
sqliteSetString(pzErrMsg, "unable to open ", zName,
": ", sqlite_error_string(rc), 0);
sqliteStrRealloc(pzErrMsg);
sqliteSafetyOff(db);
return rc;
}
rc = sqliteInit(db, pzErrMsg);
if( sqliteSafetyOff(db) ) goto openaux_misuse;
sqliteStrRealloc(pzErrMsg);
return rc;
openaux_misuse:
sqliteSetString(pzErrMsg, sqlite_error_string(SQLITE_MISUSE), 0);
sqliteStrRealloc(pzErrMsg);
return SQLITE_MISUSE;
}