/*
** Drop a trigger given a pointer to that trigger.
*/
void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
Table *pTable;
Vdbe *v;
sqlite3 *db = pParse->db;
int iDb;
iDb = sqlite3SchemaToIndex(pParse->db, pTrigger->pSchema);
assert( iDb>=0 && iDb<db->nDb );
pTable = tableOfTrigger(pTrigger);
assert( pTable );
assert( pTable->pSchema==pTrigger->pSchema || iDb==1 );
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_DROP_TRIGGER;
const char *zDb = db->aDb[iDb].zName;
const char *zTab = SCHEMA_TABLE(iDb);
if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;
if( sqlite3AuthCheck(pParse, code, pTrigger->zName, pTable->zName, zDb) ||
sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
return;
}
}
#endif
/* Generate code to destroy the database record of the trigger.
*/
assert( pTable!=0 );
if( (v = sqlite3GetVdbe(pParse))!=0 ){
int base;
static const int iLn = VDBE_OFFSET_LINENO(2);
static const VdbeOpList dropTrigger[] = {
{ OP_Rewind, 0, ADDR(9), 0},
{ OP_String8, 0, 1, 0}, /* 1 */
{ OP_Column, 0, 1, 2},
{ OP_Ne, 2, ADDR(8), 1},
{ OP_String8, 0, 1, 0}, /* 4: "trigger" */
{ OP_Column, 0, 0, 2},
{ OP_Ne, 2, ADDR(8), 1},
{ OP_Delete, 0, 0, 0},
{ OP_Next, 0, ADDR(1), 0}, /* 8 */
};
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3OpenMasterTable(pParse, iDb);
base = sqlite3VdbeAddOpList(v, ArraySize(dropTrigger), dropTrigger, iLn);
sqlite3VdbeChangeP4(v, base+1, pTrigger->zName, P4_TRANSIENT);
sqlite3VdbeChangeP4(v, base+4, "trigger", P4_STATIC);
sqlite3ChangeCookie(pParse, iDb);
sqlite3VdbeAddOp2(v, OP_Close, 0, 0);
sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->zName, 0);
if( pParse->nMem<3 ){
pParse->nMem = 3;
}
}
}
/*
** Drop a trigger given a pointer to that trigger. If nested is false,
** then also generate code to remove the trigger from the SQLITE_MASTER
** table.
*/
void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger, int nested){
Table *pTable;
Vdbe *v;
sqlite3 *db = pParse->db;
int iDb;
iDb = pTrigger->iDb;
assert( iDb>=0 && iDb<db->nDb );
pTable = tableOfTrigger(db, pTrigger);
assert(pTable);
assert( pTable->iDb==iDb || iDb==1 );
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_DROP_TRIGGER;
const char *zDb = db->aDb[iDb].zName;
const char *zTab = SCHEMA_TABLE(iDb);
if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;
if( sqlite3AuthCheck(pParse, code, pTrigger->name, pTable->zName, zDb) ||
sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
return;
}
}
#endif
/* Generate code to destroy the database record of the trigger.
*/
if( pTable!=0 && (v = sqlite3GetVdbe(pParse))!=0 ){
int base;
static const VdbeOpList dropTrigger[] = {
{ OP_Rewind, 0, ADDR(9), 0},
{ OP_String8, 0, 0, 0}, /* 1 */
{ OP_Column, 0, 1, 0},
{ OP_Ne, 0, ADDR(8), 0},
{ OP_String8, 0, 0, "trigger"},
{ OP_Column, 0, 0, 0},
{ OP_Ne, 0, ADDR(8), 0},
{ OP_Delete, 0, 0, 0},
{ OP_Next, 0, ADDR(1), 0}, /* 8 */
};
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3OpenMasterTable(v, iDb);
base = sqlite3VdbeAddOpList(v, ArraySize(dropTrigger), dropTrigger);
sqlite3VdbeChangeP3(v, base+1, pTrigger->name, 0);
sqlite3ChangeCookie(db, v, iDb);
sqlite3VdbeAddOp(v, OP_Close, 0, 0);
sqlite3VdbeOp3(v, OP_DropTrigger, iDb, 0, pTrigger->name, 0);
}
}
/*
** Drop a trigger given a pointer to that trigger.
*/
void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
Table *pTable;
Vdbe *v;
sqlite3 *db = pParse->db;
int iDb;
iDb = sqlite3SchemaToIndex(pParse->db, pTrigger->pSchema);
assert( iDb>=0 && iDb<db->nDb );
pTable = tableOfTrigger(pTrigger);
assert( pTable );
assert( pTable->pSchema==pTrigger->pSchema || iDb==1 );
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_DROP_TRIGGER;
const char *zDb = db->aDb[iDb].zName;
const char *zTab = SCHEMA_TABLE(iDb);
if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;
if( sqlite3AuthCheck(pParse, code, pTrigger->zName, pTable->zName, zDb) ||
sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
return;
}
}
#endif
/* Generate code to destroy the database record of the trigger.
*/
assert( pTable!=0 );
if( (v = sqlite3GetVdbe(pParse))!=0 ){
sqlite3NestedParse(pParse,
"DELETE FROM %Q.%s WHERE name=%Q AND type='trigger'",
db->aDb[iDb].zName, SCHEMA_TABLE(iDb), pTrigger->zName
);
sqlite3ChangeCookie(pParse, iDb);
sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->zName, 0);
}
}
/*
** This function is called after an "ALTER TABLE ... ADD" statement
** has been parsed. Argument pColDef contains the text of the new
** column definition.
**
** The Table structure pParse->pNewTable was extended to include
** the new column during parsing.
*/
void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
Table *pNew; /* Copy of pParse->pNewTable */
Table *pTab; /* Table being altered */
int iDb; /* Database number */
const char *zDb; /* Database name */
const char *zTab; /* Table name */
char *zCol; /* Null-terminated column definition */
Column *pCol; /* The new column */
Expr *pDflt; /* Default value for the new column */
sqlite3 *db; /* The database connection; */
Vdbe *v = pParse->pVdbe; /* The prepared statement under construction */
db = pParse->db;
if( pParse->nErr || db->mallocFailed ) return;
assert( v!=0 );
pNew = pParse->pNewTable;
assert( pNew );
assert( sqlite3BtreeHoldsAllMutexes(db) );
iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
zDb = db->aDb[iDb].zName;
zTab = &pNew->zName[16]; /* Skip the "sqlite_altertab_" prefix on the name */
pCol = &pNew->aCol[pNew->nCol-1];
pDflt = pCol->pDflt;
pTab = sqlite3FindTable(db, zTab, zDb);
assert( pTab );
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. */
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
return;
}
#endif
/* If the default value for the new column was specified with a
** literal NULL, then set pDflt to 0. This simplifies checking
** for an SQL NULL default below.
*/
if( pDflt && pDflt->op==TK_NULL ){
pDflt = 0;
}
/* Check that the new column is not specified as PRIMARY KEY or UNIQUE.
** If there is a NOT NULL constraint, then the default value for the
** column must not be NULL.
*/
if( pCol->colFlags & COLFLAG_PRIMKEY ){
sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
return;
}
if( pNew->pIndex ){
sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");
return;
}
if( (db->flags&SQLITE_ForeignKeys) && pNew->pFKey && pDflt ){
sqlite3ErrorMsg(pParse,
"Cannot add a REFERENCES column with non-NULL default value");
return;
}
if( pCol->notNull && !pDflt ){
sqlite3ErrorMsg(pParse,
"Cannot add a NOT NULL column with default value NULL");
return;
}
/* Ensure the default expression is something that sqlite3ValueFromExpr()
** can handle (i.e. not CURRENT_TIME etc.)
*/
if( pDflt ){
sqlite3_value *pVal = 0;
int rc;
rc = sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_BLOB, &pVal);
assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
if( rc!=SQLITE_OK ){
assert( db->mallocFailed == 1 );
return;
}
if( !pVal ){
sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");
return;
}
sqlite3ValueFree(pVal);
}
/* Modify the CREATE TABLE statement. */
zCol = sqlite3DbStrNDup(db, (char*)pColDef->z, pColDef->n);
if( zCol ){
char *zEnd = &zCol[pColDef->n-1];
int savedDbFlags = db->flags;
while( zEnd>zCol && (*zEnd==';' || sqlite3Isspace(*zEnd)) ){
*zEnd-- = '\0';
}
db->flags |= SQLITE_PreferBuiltin;
sqlite3NestedParse(pParse,
"UPDATE \"%w\".%s SET "
"sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
"WHERE type = 'table' AND name = %Q",
zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,
zTab
);
sqlite3DbFree(db, zCol);
db->flags = savedDbFlags;
}
/* If the default value of the new column is NULL, then the file
** format to 2. If the default value of the new column is not NULL,
** the file format be 3. Back when this feature was first added
** in 2006, we went to the trouble to upgrade the file format to the
** minimum support values. But 10-years on, we can assume that all
** extent versions of SQLite support file-format 4, so we always and
** unconditionally upgrade to 4.
*/
sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT,
SQLITE_MAX_FILE_FORMAT);
/* Reload the schema of the modified table. */
reloadTableSchema(pParse, pTab, pTab->zName);
}
/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy"
** command.
*/
void sqlite3AlterRenameTable(
Parse *pParse, /* Parser context. */
SrcList *pSrc, /* The table to rename. */
Token *pName /* The new table name. */
){
int iDb; /* Database that contains the table */
char *zDb; /* Name of database iDb */
Table *pTab; /* Table being renamed */
char *zName = 0; /* NULL-terminated version of pName */
sqlite3 *db = pParse->db; /* Database connection */
int nTabName; /* Number of UTF-8 characters in zTabName */
const char *zTabName; /* Original name of the table */
Vdbe *v;
#ifndef SQLITE_OMIT_TRIGGER
char *zWhere = 0; /* Where clause to locate temp triggers */
#endif
VTable *pVTab = 0; /* Non-zero if this is a v-tab with an xRename() */
int savedDbFlags; /* Saved value of db->flags */
savedDbFlags = db->flags;
if( NEVER(db->mallocFailed) ) goto exit_rename_table;
assert( pSrc->nSrc==1 );
assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);
if( !pTab ) goto exit_rename_table;
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
zDb = db->aDb[iDb].zName;
db->flags |= SQLITE_PreferBuiltin;
/* Get a NULL terminated version of the new table name. */
zName = sqlite3NameFromToken(db, pName);
if( !zName ) goto exit_rename_table;
/* Check that a table or index named 'zName' does not already exist
** in database iDb. If so, this is an error.
*/
if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
sqlite3ErrorMsg(pParse,
"there is already another table or index with this name: %s", zName);
goto exit_rename_table;
}
/* Make sure it is not a system table being altered, or a reserved name
** that the table is being renamed to.
*/
if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
goto exit_rename_table;
}
if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ goto
exit_rename_table;
}
#ifndef SQLITE_OMIT_VIEW
if( pTab->pSelect ){
sqlite3ErrorMsg(pParse, "view %s may not be altered", pTab->zName);
goto exit_rename_table;
}
#endif
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. */
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
goto exit_rename_table;
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto exit_rename_table;
}
if( IsVirtual(pTab) ){
pVTab = sqlite3GetVTable(db, pTab);
if( pVTab->pVtab->pModule->xRename==0 ){
pVTab = 0;
}
}
#endif
/* Begin a transaction for database iDb.
** Then modify the schema cookie (since the ALTER TABLE modifies the
** schema). Open a statement transaction if the table is a virtual
** table.
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ){
goto exit_rename_table;
}
sqlite3BeginWriteOperation(pParse, pVTab!=0, iDb);
sqlite3ChangeCookie(pParse, iDb);
/* If this is a virtual table, invoke the xRename() function if
** one is defined. The xRename() callback will modify the names
** of any resources used by the v-table implementation (including other
** SQLite tables) that are identified by the name of the virtual table.
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( pVTab ){
int i = ++pParse->nMem;
sqlite3VdbeLoadString(v, i, zName);
sqlite3VdbeAddOp4(v, OP_VRename, i, 0, 0,(const char*)pVTab, P4_VTAB);
sqlite3MayAbort(pParse);
}
#endif
/* figure out how many UTF-8 characters are in zName */
zTabName = pTab->zName;
nTabName = sqlite3Utf8CharLen(zTabName, -1);
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
if( db->flags&SQLITE_ForeignKeys ){
/* If foreign-key support is enabled, rewrite the CREATE TABLE
** statements corresponding to all child tables of foreign key constraints
** for which the renamed table is the parent table. */
if( (zWhere=whereForeignKeys(pParse, pTab))!=0 ){
sqlite3NestedParse(pParse,
"UPDATE \"%w\".%s SET "
"sql = sqlite_rename_parent(sql, %Q, %Q) "
"WHERE %s;", zDb, SCHEMA_TABLE(iDb), zTabName, zName, zWhere);
sqlite3DbFree(db, zWhere);
}
}
#endif
/* Modify the sqlite_master table to use the new table name. */
sqlite3NestedParse(pParse,
"UPDATE %Q.%s SET "
#ifdef SQLITE_OMIT_TRIGGER
"sql = sqlite_rename_table(sql, %Q), "
#else
"sql = CASE "
"WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
"ELSE sqlite_rename_table(sql, %Q) END, "
#endif
"tbl_name = %Q, "
"name = CASE "
"WHEN type='table' THEN %Q "
"WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
"'sqlite_autoindex_' || %Q || substr(name,%d+18) "
"ELSE name END "
"WHERE tbl_name=%Q COLLATE nocase AND "
"(type='table' OR type='index' OR type='trigger');",
zDb, SCHEMA_TABLE(iDb), zName, zName, zName,
#ifndef SQLITE_OMIT_TRIGGER
zName,
#endif
zName, nTabName, zTabName
);
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* If the sqlite_sequence table exists in this database, then update
** it with the new table name.
*/
if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
sqlite3NestedParse(pParse,
"UPDATE \"%w\".sqlite_sequence set name = %Q WHERE name = %Q",
zDb, zName, pTab->zName);
}
#endif
#ifndef SQLITE_OMIT_TRIGGER
/* If there are TEMP triggers on this table, modify the sqlite_temp_master
** table. Don't do this if the table being ALTERed is itself located in
** the temp database.
*/
if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
sqlite3NestedParse(pParse,
"UPDATE sqlite_temp_master SET "
"sql = sqlite_rename_trigger(sql, %Q), "
"tbl_name = %Q "
"WHERE %s;", zName, zName, zWhere);
sqlite3DbFree(db, zWhere);
}
#endif
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
if( db->flags&SQLITE_ForeignKeys ){
FKey *p;
for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
Table *pFrom = p->pFrom;
if( pFrom!=pTab ){
reloadTableSchema(pParse, p->pFrom, pFrom->zName);
}
}
}
#endif
/* Drop and reload the internal table schema. */
reloadTableSchema(pParse, pTab, zName);
exit_rename_table:
sqlite3SrcListDelete(db, pSrc);
sqlite3DbFree(db, zName);
db->flags = savedDbFlags;
}
/*
** The parser calls this routine after the CREATE VIRTUAL TABLE statement
** has been completely parsed.
*/
void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
Table *pTab; /* The table being constructed */
sqlite3 *db; /* The database connection */
char *zModule; /* The module name of the table: USING modulename */
Module *pMod = 0;
addArgumentToVtab(pParse);
pParse->sArg.z = 0;
/* Lookup the module name. */
pTab = pParse->pNewTable;
if( pTab==0 ) return;
db = pParse->db;
if( pTab->nModuleArg<1 ) return;
zModule = pTab->azModuleArg[0];
pMod = (Module *)sqlite3HashFind(&db->aModule, zModule, strlen(zModule));
pTab->pMod = pMod;
/* If the CREATE VIRTUAL TABLE statement is being entered for the
** first time (in other words if the virtual table is actually being
** created now instead of just being read out of sqlite_master) then
** do additional initialization work and store the statement text
** in the sqlite_master table.
*/
if( !db->init.busy ){
char *zStmt;
char *zWhere;
int iDb;
Vdbe *v;
/* Compute the complete text of the CREATE VIRTUAL TABLE statement */
if( pEnd ){
pParse->sNameToken.n = pEnd->z - pParse->sNameToken.z + pEnd->n;
}
zStmt = sqlite3MPrintf("CREATE VIRTUAL TABLE %T", &pParse->sNameToken);
/* A slot for the record has already been allocated in the
** SQLITE_MASTER table. We just need to update that slot with all
** the information we've collected.
**
** The top of the stack is the rootpage allocated by sqlite3StartTable().
** This value is always 0 and is ignored, a virtual table does not have a
** rootpage. The next entry on the stack is the rowid of the record
** in the sqlite_master table.
*/
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
sqlite3NestedParse(pParse,
"UPDATE %Q.%s "
"SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
"WHERE rowid=#1",
db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
pTab->zName,
pTab->zName,
zStmt
);
sqliteFree(zStmt);
v = sqlite3GetVdbe(pParse);
sqlite3ChangeCookie(db, v, iDb);
sqlite3VdbeAddOp(v, OP_Expire, 0, 0);
zWhere = sqlite3MPrintf("name='%q'", pTab->zName);
sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 1, zWhere, P3_DYNAMIC);
sqlite3VdbeOp3(v, OP_VCreate, iDb, 0, pTab->zName, strlen(pTab->zName) + 1);
}
/* If we are rereading the sqlite_master table create the in-memory
** record of the table. If the module has already been registered,
** also call the xConnect method here.
*/
else {
Table *pOld;
Schema *pSchema = pTab->pSchema;
const char *zName = pTab->zName;
int nName = strlen(zName) + 1;
pOld = sqlite3HashInsert(&pSchema->tblHash, zName, nName, pTab);
if( pOld ){
assert( pTab==pOld ); /* Malloc must have failed inside HashInsert() */
return;
}
pSchema->db = pParse->db;
pParse->pNewTable = 0;
}
}
/*
** Attempt to read the database schema and initialize internal
** data structures for a single database file. The index of the
** database file is given by iDb. iDb==0 is used for the main
** database. iDb==1 should never be used. iDb>=2 is used for
** auxiliary databases. Return one of the SQLITE_ error codes to
** indicate success or failure.
*/
static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
int rc;
BtCursor *curMain;
int size;
Table *pTab;
Db *pDb;
char const *azArg[4];
int meta[10];
InitData initData;
char const *zMasterSchema;
char const *zMasterName = SCHEMA_TABLE(iDb);
/*
** The master database table has a structure like this
*/
static const char master_schema[] =
"CREATE TABLE sqlite_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
#ifndef SQLITE_OMIT_TEMPDB
static const 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"
")"
;
#else
#define temp_master_schema 0
#endif
assert( iDb>=0 && iDb<db->nDb );
assert( db->aDb[iDb].pSchema );
assert( sqlite3_mutex_held(db->mutex) );
assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
/* zMasterSchema and zInitScript are set to point at the master schema
** and initialisation script appropriate for the database being
** initialised. zMasterName is the name of the master table.
*/
if( !OMIT_TEMPDB && iDb==1 ){
zMasterSchema = temp_master_schema;
}else{
zMasterSchema = master_schema;
}
zMasterName = SCHEMA_TABLE(iDb);
/* Construct the schema tables. */
azArg[0] = zMasterName;
azArg[1] = "1";
azArg[2] = zMasterSchema;
azArg[3] = 0;
initData.db = db;
initData.iDb = iDb;
initData.rc = SQLITE_OK;
initData.pzErrMsg = pzErrMsg;
(void)sqlite3SafetyOff(db);
sqlite3InitCallback(&initData, 3, (char **)azArg, 0);
(void)sqlite3SafetyOn(db);
if( initData.rc ){
rc = initData.rc;
goto error_out;
}
pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
if( pTab ){
pTab->tabFlags |= TF_Readonly;
}
/* Create a cursor to hold the database open
*/
pDb = &db->aDb[iDb];
if( pDb->pBt==0 ){
if( !OMIT_TEMPDB && iDb==1 ){
DbSetProperty(db, 1, DB_SchemaLoaded);
}
return SQLITE_OK;
}
curMain = sqlite3MallocZero(sqlite3BtreeCursorSize());
if( !curMain ){
rc = SQLITE_NOMEM;
goto error_out;
}
sqlite3BtreeEnter(pDb->pBt);
rc = sqlite3BtreeCursor(pDb->pBt, MASTER_ROOT, 0, 0, curMain);
if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
sqlite3SetString(pzErrMsg, db, "%s", sqlite3ErrStr(rc));
goto initone_error_out;
}
/* Get the database meta information.
**
** Meta values are as follows:
** meta[0] Schema cookie. Changes with each schema change.
** meta[1] File format of schema layer.
** meta[2] Size of the page cache.
** meta[3] Use freelist if 0. Autovacuum if greater than zero.
** meta[4] Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE
** meta[5] The user cookie. Used by the application.
** meta[6] Incremental-vacuum flag.
** meta[7]
** meta[8]
** meta[9]
**
** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to
** the possible values of meta[4].
*/
if( rc==SQLITE_OK ){
int i;
for(i=0; i<ArraySize(meta); i++){
rc = sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
if( rc ){
sqlite3SetString(pzErrMsg, db, "%s", sqlite3ErrStr(rc));
goto initone_error_out;
}
}
}else{
memset(meta, 0, sizeof(meta));
}
pDb->pSchema->schema_cookie = meta[0];
/* If opening a non-empty database, check the text encoding. For the
** main database, set sqlite3.enc to the encoding of the main database.
** For an attached db, it is an error if the encoding is not the same
** as sqlite3.enc.
*/
if( meta[4] ){ /* text encoding */
if( iDb==0 ){
/* If opening the main database, set ENC(db). */
ENC(db) = (u8)meta[4];
db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0);
}else{
/* If opening an attached database, the encoding much match ENC(db) */
if( meta[4]!=ENC(db) ){
sqlite3SetString(pzErrMsg, db, "attached databases must use the same"
" text encoding as main database");
rc = SQLITE_ERROR;
goto initone_error_out;
}
}
}else{
DbSetProperty(db, iDb, DB_Empty);
}
pDb->pSchema->enc = ENC(db);
if( pDb->pSchema->cache_size==0 ){
size = meta[2];
if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; }
if( size<0 ) size = -size;
pDb->pSchema->cache_size = size;
sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
}
/*
** file_format==1 Version 3.0.0.
** file_format==2 Version 3.1.3. // ALTER TABLE ADD COLUMN
** file_format==3 Version 3.1.4. // ditto but with non-NULL defaults
** file_format==4 Version 3.3.0. // DESC indices. Boolean constants
*/
pDb->pSchema->file_format = (u8)meta[1];
if( pDb->pSchema->file_format==0 ){
pDb->pSchema->file_format = 1;
}
if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
sqlite3SetString(pzErrMsg, db, "unsupported file format");
rc = SQLITE_ERROR;
goto initone_error_out;
}
/* Ticket #2804: When we open a database in the newer file format,
** clear the legacy_file_format pragma flag so that a VACUUM will
** not downgrade the database and thus invalidate any descending
** indices that the user might have created.
*/
if( iDb==0 && meta[1]>=4 ){
db->flags &= ~SQLITE_LegacyFileFmt;
}
/* Read the schema information out of the schema tables
*/
assert( db->init.busy );
if( rc==SQLITE_EMPTY ){
/* For an empty database, there is nothing to read */
rc = SQLITE_OK;
}else{
char *zSql;
zSql = sqlite3MPrintf(db,
"SELECT name, rootpage, sql FROM '%q'.%s",
db->aDb[iDb].zName, zMasterName);
(void)sqlite3SafetyOff(db);
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
xAuth = db->xAuth;
db->xAuth = 0;
#endif
rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
#ifndef SQLITE_OMIT_AUTHORIZATION
db->xAuth = xAuth;
}
#endif
if( rc==SQLITE_OK ) rc = initData.rc;
(void)sqlite3SafetyOn(db);
sqlite3DbFree(db, zSql);
#ifndef SQLITE_OMIT_ANALYZE
if( rc==SQLITE_OK ){
sqlite3AnalysisLoad(db, iDb);
}
#endif
}
if( db->mallocFailed ){
rc = SQLITE_NOMEM;
sqlite3ResetInternalSchema(db, 0);
}
if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){
/* Black magic: If the SQLITE_RecoveryMode flag is set, then consider
** the schema loaded, even if errors occurred. In this situation the
** current sqlite3_prepare() operation will fail, but the following one
** will attempt to compile the supplied statement against whatever subset
** of the schema was loaded before the error occurred. The primary
** purpose of this is to allow access to the sqlite_master table
** even when its contents have been corrupted.
*/
DbSetProperty(db, iDb, DB_SchemaLoaded);
rc = SQLITE_OK;
}
/* Jump here for an error that occurs after successfully allocating
** curMain and calling sqlite3BtreeEnter(). For an error that occurs
** before that point, jump to error_out.
*/
initone_error_out:
sqlite3BtreeCloseCursor(curMain);
sqlite3_free(curMain);
sqlite3BtreeLeave(pDb->pBt);
error_out:
if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
db->mallocFailed = 1;
}
return rc;
}
/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy"
** command. 生成代码来实现“ALTER TABLE xxx重命名yyy”命令。
*/
void sqlite3AlterRenameTable(
Parse *pParse, /* Parser context. 语法分析器上下文*/
SrcList *pSrc, /* The table to rename. 重命名的表*/
Token *pName /* The new table name. 新表名*/
){
int iDb; /* Database that contains the table 包含表的数据库*/
char *zDb; /* Name of database iDb 数据库iDb 的名称*/
Table *pTab; /* Table being renamed 正在重命名的表*/
char *zName = 0; /* NULL-terminated version of pName pName的空值终止版本*/
sqlite3 *db = pParse->db; /* Database connection 数据库的连接*/
int nTabName; /* Number of UTF-8 characters in zTabName 在 zTabName里的UTF-8类型的数目*/
const char *zTabName; /* Original name of the table 最初的数据库名称*/
Vdbe *v;
#ifndef SQLITE_OMIT_TRIGGER
char *zWhere = 0; /* Where clause to locate temp triggers Where 子句位于temp触发器*/
#endif
VTable *pVTab = 0; /* Non-zero if this is a v-tab with an xRename() 如果是 一个v-tab 和一个xRename() ，则为零*/
int savedDbFlags; /* Saved value of db->flags db->flags的保留值*/
savedDbFlags = db->flags;
if( NEVER(db->mallocFailed) ) goto exit_rename_table;
assert( pSrc->nSrc==1 );
assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
pTab = sqlite3LocateTable(pParse, 0, pSrc->a[0].zName, pSrc->a[0].zDatabase);
if( !pTab ) goto exit_rename_table;
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
zDb = db->aDb[iDb].zName;
db->flags |= SQLITE_PreferBuiltin;
/* Get a NULL terminated version of the new table name. 得到一个空终止版本的新表的名称。*/
zName = sqlite3NameFromToken(db, pName);
if( !zName ) goto exit_rename_table;
/* Check that a table or index named 'zName' does not already exist
** in database iDb. If so, this is an error.检查一个表或索引名叫“zName”不存在数据库iDb。
如果是这样,这是一个错误。
*/
if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
sqlite3ErrorMsg(pParse,
"there is already another table or index with this name: %s", zName);
goto exit_rename_table;
}
/* Make sure it is not a system table being altered, or a reserved name
** that the table is being renamed to.
确保它不是一个正在被修改的系统表或者一个正在被重命名的保留的名称表
*/
if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
goto exit_rename_table;
}
if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ goto
exit_rename_table;
}
#ifndef SQLITE_OMIT_VIEW
if( pTab->pSelect ){
sqlite3ErrorMsg(pParse, "view %s may not be altered", pTab->zName);
goto exit_rename_table;
}
#endif
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. 调用授权回调。*/
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
goto exit_rename_table;
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto exit_rename_table;
}
if( IsVirtual(pTab) ){
pVTab = sqlite3GetVTable(db, pTab);
if( pVTab->pVtab->pModule->xRename==0 ){
pVTab = 0;
}
}
#endif
/* Begin a transaction and code the VerifyCookie for database iDb.
** Then modify the schema cookie (since the ALTER TABLE modifies the
** schema). Open a statement transaction if the table is a virtual
** table.
对于iDb数据库开始一个事务和代码的VerifyCookie。
然后修改模式cookie(因为ALTER TABLE修改模式)。
如果表是一个虚拟表打开一个声明事务。
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ){
goto exit_rename_table;
}
sqlite3BeginWriteOperation(pParse, pVTab!=0, iDb);
sqlite3ChangeCookie(pParse, iDb);
/* If this is a virtual table, invoke the xRename() function if
** one is defined. The xRename() callback will modify the names
** of any resources used by the v-table implementation (including other
** SQLite tables) that are identified by the name of the virtual table.、
如果这是一个虚拟表,调用xRename()函数如果一个定义。
xRename()回调将修改使用v-table实现的任何资源的名字(包括其他SQLite表)，
这个v-table实现是确定的虚拟表的名称。
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( pVTab ){
int i = ++pParse->nMem;
sqlite3VdbeAddOp4(v, OP_String8, 0, i, 0, zName, 0);
sqlite3VdbeAddOp4(v, OP_VRename, i, 0, 0,(const char*)pVTab, P4_VTAB);
sqlite3MayAbort(pParse);
}
#endif
/* figure out how many UTF-8 characters are in zName 算出在zName里有多少utf - 8字符*/
zTabName = pTab->zName;
nTabName = sqlite3Utf8CharLen(zTabName, -1);
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
if( db->flags&SQLITE_ForeignKeys ){
/* If foreign-key support is enabled, rewrite the CREATE TABLE
** statements corresponding to all child tables of foreign key constraints
** for which the renamed table is the parent table.
如果启用了外键的支持,重写CREATE TABLE语句对应的所有子表的外键约束重命名表的父表。*/
if( (zWhere=whereForeignKeys(pParse, pTab))!=0 ){
sqlite3NestedParse(pParse,
"UPDATE \"%w\".%s SET "
"sql = sqlite_rename_parent(sql, %Q, %Q) "
"WHERE %s;", zDb, SCHEMA_TABLE(iDb), zTabName, zName, zWhere);
sqlite3DbFree(db, zWhere);
}
}
#endif
/* Modify the sqlite_master table to use the new table name. 修改sqlite_master表来使用新的表名。*/
sqlite3NestedParse(pParse,
"UPDATE %Q.%s SET "
#ifdef SQLITE_OMIT_TRIGGER
"sql = sqlite_rename_table(sql, %Q), "
#else
"sql = CASE "
"WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
"ELSE sqlite_rename_table(sql, %Q) END, "
#endif
"tbl_name = %Q, "
"name = CASE "
"WHEN type='table' THEN %Q "
"WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
"'sqlite_autoindex_' || %Q || substr(name,%d+18) "
"ELSE name END "
"WHERE tbl_name=%Q COLLATE nocase AND "
"(type='table' OR type='index' OR type='trigger');",
zDb, SCHEMA_TABLE(iDb), zName, zName, zName,
#ifndef SQLITE_OMIT_TRIGGER
zName,
#endif
zName, nTabName, zTabName
);
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* If the sqlite_sequence table exists in this database, then update
** it with the new table name.
如果sqlite_sequence表存在于这个数据库中,那么用新表的名称更新它
*/
if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
sqlite3NestedParse(pParse,
"UPDATE \"%w\".sqlite_sequence set name = %Q WHERE name = %Q",
zDb, zName, pTab->zName);
}
#endif
#ifndef SQLITE_OMIT_TRIGGER
/* If there are TEMP triggers on this table, modify the sqlite_temp_master
** table. Don't do this if the table being ALTERed is itself located in
** the temp database.
如果在这个表上有临时触发器，修改sqlite_temp_master表，
如果表被修改本身就是位于临时数据库，不要做这些。
*/
if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
sqlite3NestedParse(pParse,
"UPDATE sqlite_temp_master SET "
"sql = sqlite_rename_trigger(sql, %Q), "
"tbl_name = %Q "
"WHERE %s;", zName, zName, zWhere);
sqlite3DbFree(db, zWhere);
}
#endif
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
if( db->flags&SQLITE_ForeignKeys ){
FKey *p;
for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
Table *pFrom = p->pFrom;
if( pFrom!=pTab ){
reloadTableSchema(pParse, p->pFrom, pFrom->zName);
}
}
}
#endif
/* Drop and reload the internal table schema. 删除和重新加载内部表模式。*/
reloadTableSchema(pParse, pTab, zName);
exit_rename_table:
sqlite3SrcListDelete(db, pSrc);
sqlite3DbFree(db, zName);
db->flags = savedDbFlags;
}
/*
** This is called by the parser when it sees a CREATE TRIGGER statement
** up to the point of the BEGIN before the trigger actions. A Trigger
** structure is generated based on the information available and stored
** in pParse->pNewTrigger. After the trigger actions have been parsed, the
** sqlite3FinishTrigger() function is called to complete the trigger
** construction process.
*/
void sqlite3BeginTrigger(
Parse *pParse, /* The parse context of the CREATE TRIGGER statement */
Token *pName1, /* The name of the trigger */
Token *pName2, /* The name of the trigger */
int tr_tm, /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
int op, /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
IdList *pColumns, /* column list if this is an UPDATE OF trigger */
SrcList *pTableName,/* The name of the table/view the trigger applies to */
int foreach, /* One of TK_ROW or TK_STATEMENT */
Expr *pWhen, /* WHEN clause */
int isTemp /* True if the TEMPORARY keyword is present */
){
Trigger *pTrigger;
Table *pTab;
char *zName = 0; /* Name of the trigger */
sqlite *db = pParse->db;
int iDb; /* The database to store the trigger in */
Token *pName; /* The unqualified db name */
DbFixer sFix;
if( isTemp ){
/* If TEMP was specified, then the trigger name may not be qualified. */
if( pName2 && pName2->n>0 ){
sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name");
goto trigger_cleanup;
}
iDb = 1;
pName = pName1;
}else{
/* Figure out the db that the the trigger will be created in */
iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
if( iDb<0 ){
goto trigger_cleanup;
}
}
/* If the trigger name was unqualified, and the table is a temp table,
** then set iDb to 1 to create the trigger in the temporary database.
** If sqlite3SrcListLookup() returns 0, indicating the table does not
** exist, the error is caught by the block below.
*/
if( !pTableName || sqlite3_malloc_failed ) goto trigger_cleanup;
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( pName2->n==0 && pTab && pTab->iDb==1 ){
iDb = 1;
}
/* Ensure the table name matches database name and that the table exists */
if( sqlite3_malloc_failed ) goto trigger_cleanup;
assert( pTableName->nSrc==1 );
if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName) &&
sqlite3FixSrcList(&sFix, pTableName) ){
goto trigger_cleanup;
}
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( !pTab ){
/* The table does not exist. */
goto trigger_cleanup;
}
/* Check that the trigger name is not reserved and that no trigger of the
** specified name exists */
zName = sqlite3NameFromToken(pName);
if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
goto trigger_cleanup;
}
if( sqlite3HashFind(&(db->aDb[iDb].trigHash), zName,pName->n+1) ){
sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
goto trigger_cleanup;
}
/* Do not create a trigger on a system table */
if( (iDb!=1 && sqlite3StrICmp(pTab->zName, MASTER_NAME)==0) ||
(iDb==1 && sqlite3StrICmp(pTab->zName, TEMP_MASTER_NAME)==0)
){
sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
pParse->nErr++;
goto trigger_cleanup;
}
/* INSTEAD of triggers are only for views and views only support INSTEAD
** of triggers.
*/
if( pTab->pSelect && tr_tm!=TK_INSTEAD ){
sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S",
(tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
goto trigger_cleanup;
}
if( !pTab->pSelect && tr_tm==TK_INSTEAD ){
sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
" trigger on table: %S", pTableName, 0);
goto trigger_cleanup;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_CREATE_TRIGGER;
const char *zDb = db->aDb[pTab->iDb].zName;
const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
if( pTab->iDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
goto trigger_cleanup;
}
if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(pTab->iDb), 0, zDb)){
goto trigger_cleanup;
}
}
#endif
/* INSTEAD OF triggers can only appear on views and BEFORE triggers
** cannot appear on views. So we might as well translate every
** INSTEAD OF trigger into a BEFORE trigger. It simplifies code
** elsewhere.
*/
if (tr_tm == TK_INSTEAD){
tr_tm = TK_BEFORE;
}
/* Build the Trigger object */
pTrigger = (Trigger*)sqliteMalloc(sizeof(Trigger));
if( pTrigger==0 ) goto trigger_cleanup;
pTrigger->name = zName;
zName = 0;
pTrigger->table = sqliteStrDup(pTableName->a[0].zName);
if( sqlite3_malloc_failed ) goto trigger_cleanup;
pTrigger->iDb = iDb;
pTrigger->iTabDb = pTab->iDb;
pTrigger->op = op;
pTrigger->tr_tm = tr_tm;
pTrigger->pWhen = sqlite3ExprDup(pWhen);
pTrigger->pColumns = sqlite3IdListDup(pColumns);
pTrigger->foreach = foreach;
sqlite3TokenCopy(&pTrigger->nameToken,pName);
assert( pParse->pNewTrigger==0 );
pParse->pNewTrigger = pTrigger;
trigger_cleanup:
sqliteFree(zName);
sqlite3SrcListDelete(pTableName);
sqlite3IdListDelete(pColumns);
sqlite3ExprDelete(pWhen);
}
/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy"
** command.
*/
void sqlite3AlterRenameTable(
Parse *pParse, /* Parser context. */
SrcList *pSrc, /* The table to rename. */
Token *pName /* The new table name. */
){
int iDb; /* Database that contains the table */
char *zDb; /* Name of database iDb */
Table *pTab; /* Table being renamed */
char *zName = 0; /* NULL-terminated version of pName */
sqlite3 *db = pParse->db; /* Database connection */
int nTabName; /* Number of UTF-8 characters in zTabName */
const char *zTabName; /* Original name of the table */
Vdbe *v;
#ifndef SQLITE_OMIT_TRIGGER
char *zWhere = 0; /* Where clause to locate temp triggers */
#endif
int isVirtualRename = 0; /* True if this is a v-table with an xRename() */
if( sqlite3MallocFailed() ) goto exit_rename_table;
assert( pSrc->nSrc==1 );
pTab = sqlite3LocateTable(pParse, pSrc->a[0].zName, pSrc->a[0].zDatabase);
if( !pTab ) goto exit_rename_table;
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
zDb = db->aDb[iDb].zName;
/* Get a NULL terminated version of the new table name. */
zName = sqlite3NameFromToken(pName);
if( !zName ) goto exit_rename_table;
/* Check that a table or index named 'zName' does not already exist
** in database iDb. If so, this is an error.
*/
if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
sqlite3ErrorMsg(pParse,
"there is already another table or index with this name: %s", zName);
goto exit_rename_table;
}
/* Make sure it is not a system table being altered, or a reserved name
** that the table is being renamed to.
*/
if( strlen(pTab->zName)>6 && 0==sqlite3StrNICmp(pTab->zName, "sqlite_", 7) ){
sqlite3ErrorMsg(pParse, "table %s may not be altered", pTab->zName);
goto exit_rename_table;
}
if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
goto exit_rename_table;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. */
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
goto exit_rename_table;
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto exit_rename_table;
}
if( IsVirtual(pTab) && pTab->pMod->pModule->xRename ){
isVirtualRename = 1;
}
#endif
/* Begin a transaction and code the VerifyCookie for database iDb.
** Then modify the schema cookie (since the ALTER TABLE modifies the
** schema). Open a statement transaction if the table is a virtual
** table.
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ){
goto exit_rename_table;
}
sqlite3BeginWriteOperation(pParse, isVirtualRename, iDb);
sqlite3ChangeCookie(db, v, iDb);
/* If this is a virtual table, invoke the xRename() function if
** one is defined. The xRename() callback will modify the names
** of any resources used by the v-table implementation (including other
** SQLite tables) that are identified by the name of the virtual table.
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( isVirtualRename ){
sqlite3VdbeOp3(v, OP_String8, 0, 0, zName, 0);
sqlite3VdbeOp3(v, OP_VRename, 0, 0, (const char*)pTab->pVtab, P3_VTAB);
}
#endif
/* figure out how many UTF-8 characters are in zName */
zTabName = pTab->zName;
nTabName = sqlite3Utf8CharLen(zTabName, -1);
/* Modify the sqlite_master table to use the new table name. */
sqlite3NestedParse(pParse,
"UPDATE %Q.%s SET "
#ifdef SQLITE_OMIT_TRIGGER
"sql = sqlite_rename_table(sql, %Q), "
#else
"sql = CASE "
"WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
"ELSE sqlite_rename_table(sql, %Q) END, "
#endif
"tbl_name = %Q, "
"name = CASE "
"WHEN type='table' THEN %Q "
"WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
"'sqlite_autoindex_' || %Q || substr(name,%d+18,10) "
"ELSE name END "
"WHERE tbl_name=%Q AND "
"(type='table' OR type='index' OR type='trigger');",
zDb, SCHEMA_TABLE(iDb), zName, zName, zName,
#ifndef SQLITE_OMIT_TRIGGER
zName,
#endif
zName, nTabName, zTabName
);
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* If the sqlite_sequence table exists in this database, then update
** it with the new table name.
*/
if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
sqlite3NestedParse(pParse,
"UPDATE %Q.sqlite_sequence set name = %Q WHERE name = %Q",
zDb, zName, pTab->zName);
}
#endif
#ifndef SQLITE_OMIT_TRIGGER
/* If there are TEMP triggers on this table, modify the sqlite_temp_master
** table. Don't do this if the table being ALTERed is itself located in
** the temp database.
*/
if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
sqlite3NestedParse(pParse,
"UPDATE sqlite_temp_master SET "
"sql = sqlite_rename_trigger(sql, %Q), "
"tbl_name = %Q "
"WHERE %s;", zName, zName, zWhere);
sqliteFree(zWhere);
}
#endif
/* Drop and reload the internal table schema. */
reloadTableSchema(pParse, pTab, zName);
exit_rename_table:
sqlite3SrcListDelete(pSrc);
sqliteFree(zName);
}
/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy"
** command.
*/
void sqlite3AlterRenameTable(
Parse *pParse, /* Parser context. */
SrcList *pSrc, /* The table to rename. */
Token *pName /* The new table name. */
){
int iDb; /* Database that contains the table */
char *zDb; /* Name of database iDb */
Table *pTab; /* Table being renamed */
char *zName = 0; /* NULL-terminated version of pName */
sqlite3 *db = pParse->db; /* Database connection */
Vdbe *v;
#ifndef SQLITE_OMIT_TRIGGER
char *zWhere = 0; /* Where clause to locate temp triggers */
#endif
if( sqlite3_malloc_failed ) goto exit_rename_table;
assert( pSrc->nSrc==1 );
pTab = sqlite3LocateTable(pParse, pSrc->a[0].zName, pSrc->a[0].zDatabase);
if( !pTab ) goto exit_rename_table;
iDb = pTab->iDb;
zDb = db->aDb[iDb].zName;
/* Get a NULL terminated version of the new table name. */
zName = sqlite3NameFromToken(pName);
if( !zName ) goto exit_rename_table;
/* Check that a table or index named 'zName' does not already exist
** in database iDb. If so, this is an error.
*/
if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
sqlite3ErrorMsg(pParse,
"there is already another table or index with this name: %s", zName);
goto exit_rename_table;
}
/* Make sure it is not a system table being altered, or a reserved name
** that the table is being renamed to.
*/
if( strlen(pTab->zName)>6 && 0==sqlite3StrNICmp(pTab->zName, "sqlite_", 7) ){
sqlite3ErrorMsg(pParse, "table %s may not be altered", pTab->zName);
goto exit_rename_table;
}
if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
goto exit_rename_table;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. */
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
goto exit_rename_table;
}
#endif
/* Begin a transaction and code the VerifyCookie for database iDb.
** Then modify the schema cookie (since the ALTER TABLE modifies the
** schema).
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ){
goto exit_rename_table;
}
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3ChangeCookie(db, v, iDb);
/* Modify the sqlite_master table to use the new table name. */
sqlite3NestedParse(pParse,
"UPDATE %Q.%s SET "
#ifdef SQLITE_OMIT_TRIGGER
"sql = sqlite_rename_table(sql, %Q), "
#else
"sql = CASE "
"WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
"ELSE sqlite_rename_table(sql, %Q) END, "
#endif
"tbl_name = %Q, "
"name = CASE "
"WHEN type='table' THEN %Q "
"WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
"'sqlite_autoindex_' || %Q || substr(name, %d+18,10) "
"ELSE name END "
"WHERE tbl_name=%Q AND "
"(type='table' OR type='index' OR type='trigger');",
zDb, SCHEMA_TABLE(iDb), zName, zName, zName,
#ifndef SQLITE_OMIT_TRIGGER
zName,
#endif
zName, strlen(pTab->zName), pTab->zName
);
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* If the sqlite_sequence table exists in this database, then update
** it with the new table name.
*/
if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
sqlite3NestedParse(pParse,
"UPDATE %Q.sqlite_sequence set name = %Q WHERE name = %Q",
zDb, zName, pTab->zName);
}
#endif
#ifndef SQLITE_OMIT_TRIGGER
/* If there are TEMP triggers on this table, modify the sqlite_temp_master
** table. Don't do this if the table being ALTERed is itself located in
** the temp database.
*/
if( (zWhere=whereTempTriggers(pParse, pTab)) ){
sqlite3NestedParse(pParse,
"UPDATE sqlite_temp_master SET "
"sql = sqlite_rename_trigger(sql, %Q), "
"tbl_name = %Q "
"WHERE %s;", zName, zName, zWhere);
sqliteFree(zWhere);
}
#endif
/* Drop and reload the internal table schema. */
reloadTableSchema(pParse, pTab, zName);
exit_rename_table:
sqlite3SrcListDelete(pSrc);
sqliteFree(zName);
}
/*
** This is called by the parser when it sees a CREATE TRIGGER statement
** up to the point of the BEGIN before the trigger actions. A Trigger
** structure is generated based on the information available and stored
** in pParse->pNewTrigger. After the trigger actions have been parsed, the
** sqliteFinishTrigger() function is called to complete the trigger
** construction process.
*/
void sqliteBeginTrigger(
Parse *pParse, /* The parse context of the CREATE TRIGGER statement */
Token *pName, /* The name of the trigger */
int tr_tm, /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
int op, /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
IdList *pColumns, /* column list if this is an UPDATE OF trigger */
SrcList *pTableName,/* The name of the table/view the trigger applies to */
int foreach, /* One of TK_ROW or TK_STATEMENT */
Expr *pWhen, /* WHEN clause */
int isTemp /* True if the TEMPORARY keyword is present */
){
Trigger *nt;
Table *tab;
char *zName = 0; /* Name of the trigger */
sqlite *db = pParse->db;
int iDb; /* When database to store the trigger in */
DbFixer sFix;
/* Check that:
** 1. the trigger name does not already exist.
** 2. the table (or view) does exist in the same database as the trigger.
** 3. that we are not trying to create a trigger on the sqlite_master table
** 4. That we are not trying to create an INSTEAD OF trigger on a table.
** 5. That we are not trying to create a BEFORE or AFTER trigger on a view.
*/
if( sqlite_malloc_failed ) goto trigger_cleanup;
assert( pTableName->nSrc==1 );
if( db->init.busy
&& sqliteFixInit(&sFix, pParse, db->init.iDb, "trigger", pName)
&& sqliteFixSrcList(&sFix, pTableName)
){
goto trigger_cleanup;
}
tab = sqliteSrcListLookup(pParse, pTableName);
if( !tab ){
goto trigger_cleanup;
}
iDb = isTemp ? 1 : tab->iDb;
if( iDb>=2 && !db->init.busy ){
sqliteErrorMsg(pParse, "triggers may not be added to auxiliary "
"database %s", db->aDb[tab->iDb].zName);
goto trigger_cleanup;
}
zName = sqliteStrNDup(pName->z, pName->n);
sqliteDequote(zName);
if( sqliteHashFind(&(db->aDb[iDb].trigHash), zName,pName->n+1) ){
sqliteErrorMsg(pParse, "trigger %T already exists", pName);
goto trigger_cleanup;
}
if( sqliteStrNICmp(tab->zName, "sqlite_", 7)==0 ){
sqliteErrorMsg(pParse, "cannot create trigger on system table");
pParse->nErr++;
goto trigger_cleanup;
}
if( tab->pSelect && tr_tm != TK_INSTEAD ){
sqliteErrorMsg(pParse, "cannot create %s trigger on view: %S",
(tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
goto trigger_cleanup;
}
if( !tab->pSelect && tr_tm == TK_INSTEAD ){
sqliteErrorMsg(pParse, "cannot create INSTEAD OF"
" trigger on table: %S", pTableName, 0);
goto trigger_cleanup;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_CREATE_TRIGGER;
const char *zDb = db->aDb[tab->iDb].zName;
const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
if( tab->iDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
if( sqliteAuthCheck(pParse, code, zName, tab->zName, zDbTrig) ){
goto trigger_cleanup;
}
if( sqliteAuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(tab->iDb), 0, zDb)){
goto trigger_cleanup;
}
}
#endif
/* INSTEAD OF triggers can only appear on views and BEGIN triggers
** cannot appear on views. So we might as well translate every
** INSTEAD OF trigger into a BEFORE trigger. It simplifies code
** elsewhere.
*/
if (tr_tm == TK_INSTEAD){
tr_tm = TK_BEFORE;
}
/* Build the Trigger object */
nt = (Trigger*)sqliteMalloc(sizeof(Trigger));
if( nt==0 ) goto trigger_cleanup;
nt->name = zName;
zName = 0;
nt->table = sqliteStrDup(pTableName->a[0].zName);
if( sqlite_malloc_failed ) goto trigger_cleanup;
nt->iDb = iDb;
nt->iTabDb = tab->iDb;
nt->op = op;
nt->tr_tm = tr_tm;
nt->pWhen = sqliteExprDup(pWhen);
nt->pColumns = sqliteIdListDup(pColumns);
nt->foreach = foreach;
sqliteTokenCopy(&nt->nameToken,pName);
assert( pParse->pNewTrigger==0 );
pParse->pNewTrigger = nt;
trigger_cleanup:
sqliteFree(zName);
sqliteSrcListDelete(pTableName);
sqliteIdListDelete(pColumns);
sqliteExprDelete(pWhen);
}
/*
** This routine is called after all of the trigger actions have been parsed
** in order to complete the process of building the trigger.
*/
void sqlite3FinishTrigger(
Parse *pParse, /* Parser context */
TriggerStep *pStepList, /* The triggered program */
Token *pAll /* Token that describes the complete CREATE TRIGGER */
){
Trigger *pTrig = 0; /* The trigger whose construction is finishing up */
sqlite3 *db = pParse->db; /* The database */
DbFixer sFix;
int iDb; /* Database containing the trigger */
pTrig = pParse->pNewTrigger;
pParse->pNewTrigger = 0;
if( pParse->nErr || !pTrig ) goto triggerfinish_cleanup;
iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
pTrig->step_list = pStepList;
while( pStepList ){
pStepList->pTrig = pTrig;
pStepList = pStepList->pNext;
}
if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", &pTrig->nameToken)
&& sqlite3FixTriggerStep(&sFix, pTrig->step_list) ){
goto triggerfinish_cleanup;
}
/* if we are not initializing, and this trigger is not on a TEMP table,
** build the sqlite_master entry
*/
if( !db->init.busy ){
Vdbe *v;
char *z;
/* Make an entry in the sqlite_master table */
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto triggerfinish_cleanup;
sqlite3BeginWriteOperation(pParse, 0, iDb);
z = sqlite3DbStrNDup(db, (char*)pAll->z, pAll->n);
sqlite3NestedParse(pParse,
"INSERT INTO %Q.%s VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')",
db->aDb[iDb].zName, SCHEMA_TABLE(iDb), pTrig->name,
pTrig->table, z);
sqlite3DbFree(db, z);
sqlite3ChangeCookie(pParse, iDb);
sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0, sqlite3MPrintf(
db, "type='trigger' AND name='%q'", pTrig->name), P4_DYNAMIC
);
}
if( db->init.busy ){
int n;
Table *pTab;
Trigger *pDel;
pDel = sqlite3HashInsert(&db->aDb[iDb].pSchema->trigHash,
pTrig->name, sqlite3Strlen30(pTrig->name), pTrig);
if( pDel ){
assert( pDel==pTrig );
db->mallocFailed = 1;
goto triggerfinish_cleanup;
}
n = sqlite3Strlen30(pTrig->table) + 1;
pTab = sqlite3HashFind(&pTrig->pTabSchema->tblHash, pTrig->table, n);
assert( pTab!=0 );
pTrig->pNext = pTab->pTrigger;
pTab->pTrigger = pTrig;
pTrig = 0;
}
triggerfinish_cleanup:
sqlite3DeleteTrigger(db, pTrig);
assert( !pParse->pNewTrigger );
sqlite3DeleteTriggerStep(db, pStepList);
}
/*
** This function is called after an "ALTER TABLE ... ADD" statement
** has been parsed. Argument pColDef contains the text of the new
** column definition.
**
** The Table structure pParse->pNewTable was extended to include
** the new column during parsing.
在“ALTER TABLE…添加“声明解析后这个函数被调用。
参数pColDef包含新列定义的文本。
表结构pParse - > pNewTable扩大到包括在解析新列。
*/
void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
Table *pNew; /* Copy of pParse->pNewTable pParse->pNew表的副本*/
Table *pTab; /* Table being altered 被修改的表*/
int iDb; /* Database number 数据库数*/
const char *zDb; /* Database name 数据库名*/
const char *zTab; /* Table name 表名*/
char *zCol; /* Null-terminated column definition 空值终止列定义*/
Column *pCol; /* The new column 新列*/
Expr *pDflt; /* Default value for the new column 为新列默认数值*/
sqlite3 *db; /* The database connection; 数据库的连接*/
db = pParse->db;
if( pParse->nErr || db->mallocFailed ) return;
pNew = pParse->pNewTable;
assert( pNew );
assert( sqlite3BtreeHoldsAllMutexes(db) );
iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
zDb = db->aDb[iDb].zName;
zTab = &pNew->zName[16]; /* Skip the "sqlite_altertab_" prefix on the name 跳过“sqlite_altertab_”前缀的名称*/
pCol = &pNew->aCol[pNew->nCol-1];
pDflt = pCol->pDflt;
pTab = sqlite3FindTable(db, zTab, zDb);
assert( pTab );
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. 调用授权回调*/
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
return;
}
#endif
/* If the default value for the new column was specified with a
** literal NULL, then set pDflt to 0. This simplifies checking
** for an SQL NULL default below.
如果新列的默认值是用文字指定NULL,那么pDflt设置为0。
这简化了检查SQL空下面的默认。
*/
if( pDflt && pDflt->op==TK_NULL ){
pDflt = 0;
}
/* Check that the new column is not specified as PRIMARY KEY or UNIQUE.
** If there is a NOT NULL constraint, then the default value for the
** column must not be NULL.
检查新列没有指定主键或唯一的。
如果有一个非空约束,然后列的默认值不能为空。
*/
if( pCol->isPrimKey ){
sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
return;
}
if( pNew->pIndex ){
sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");
return;
}
if( (db->flags&SQLITE_ForeignKeys) && pNew->pFKey && pDflt ){
sqlite3ErrorMsg(pParse,
"Cannot add a REFERENCES column with non-NULL default value");
return;
}
if( pCol->notNull && !pDflt ){
sqlite3ErrorMsg(pParse,
"Cannot add a NOT NULL column with default value NULL");
return;
}
/* Ensure the default expression is something that sqlite3ValueFromExpr()
** can handle (i.e. not CURRENT_TIME etc.)
确保默认表达式是sqlite3ValueFromExpr()可以处理的事(即不是当前时间等。)
*/
if( pDflt ){
sqlite3_value *pVal;
if( sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_NONE, &pVal) ){
db->mallocFailed = 1;
return;
}
if( !pVal ){
sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");
return;
}
sqlite3ValueFree(pVal);
}
/* Modify the CREATE TABLE statement. 修改CREATE TABLE语句。*/
zCol = sqlite3DbStrNDup(db, (char*)pColDef->z, pColDef->n);
if( zCol ){
char *zEnd = &zCol[pColDef->n-1];
int savedDbFlags = db->flags;
while( zEnd>zCol && (*zEnd==';' || sqlite3Isspace(*zEnd)) ){
*zEnd-- = '\0';
}
db->flags |= SQLITE_PreferBuiltin;
sqlite3NestedParse(pParse,
"UPDATE \"%w\".%s SET "
"sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
"WHERE type = 'table' AND name = %Q",
zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,
zTab
);
sqlite3DbFree(db, zCol);
db->flags = savedDbFlags;
}
/* If the default value of the new column is NULL, then set the file
** format to 2. If the default value of the new column is not NULL,
** the file format becomes 3.
如果新列的默认值为空,那么将文件格式设置为2。如果新列的默认值不为空,文件格式变成3。
*/
sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);
/* Reload the schema of the modified table. 重新加载修改后的表的模式。*/
reloadTableSchema(pParse, pTab, pTab->zName);
}
/*
** Attempt to read the database schema and initialize internal
** data structures for a single database file. The index of the
** database file is given by iDb. iDb==0 is used for the main
** database. iDb==1 should never be used. iDb>=2 is used for
** auxiliary databases. Return one of the SQLITE_ error codes to
** indicate success or failure.
*/
static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
int rc;
BtCursor *curMain;
int size;
Table *pTab;
Db *pDb;
char const *azArg[4];
int meta[10];
InitData initData;
char const *zMasterSchema;
char const *zMasterName = SCHEMA_TABLE(iDb);
/*
** The master database table has a structure like this
*/
static const char master_schema[] =
"CREATE TABLE sqlite_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
#ifndef SQLITE_OMIT_TEMPDB
static const 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"
")"
;
#else
#define temp_master_schema 0
#endif
assert( iDb>=0 && iDb<db->nDb );
assert( db->aDb[iDb].pSchema );
/* zMasterSchema and zInitScript are set to point at the master schema
** and initialisation script appropriate for the database being
** initialised. zMasterName is the name of the master table.
*/
if( !OMIT_TEMPDB && iDb==1 ){
zMasterSchema = temp_master_schema;
}else{
zMasterSchema = master_schema;
}
zMasterName = SCHEMA_TABLE(iDb);
/* Construct the schema tables. */
sqlite3SafetyOff(db);
azArg[0] = zMasterName;
azArg[1] = "1";
azArg[2] = zMasterSchema;
azArg[3] = 0;
initData.db = db;
initData.iDb = iDb;
initData.pzErrMsg = pzErrMsg;
rc = sqlite3InitCallback(&initData, 3, (char **)azArg, 0);
if( rc ){
sqlite3SafetyOn(db);
return initData.rc;
}
pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
if( pTab ){
pTab->readOnly = 1;
}
sqlite3SafetyOn(db);
/* Create a cursor to hold the database open
*/
pDb = &db->aDb[iDb];
if( pDb->pBt==0 ){
if( !OMIT_TEMPDB && iDb==1 ){
DbSetProperty(db, 1, DB_SchemaLoaded);
}
return SQLITE_OK;
}
rc = sqlite3BtreeCursor(pDb->pBt, MASTER_ROOT, 0, 0, 0, &curMain);
if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
return rc;
}
/* Get the database meta information.
**
** Meta values are as follows:
** meta[0] Schema cookie. Changes with each schema change.
** meta[1] File format of schema layer.
** meta[2] Size of the page cache.
** meta[3] Use freelist if 0. Autovacuum if greater than zero.
** meta[4] Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE
** meta[5] The user cookie. Used by the application.
** meta[6]
** meta[7]
** meta[8]
** meta[9]
**
** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to
** the possible values of meta[4].
*/
if( rc==SQLITE_OK ){
int i;
for(i=0; rc==SQLITE_OK && i<sizeof(meta)/sizeof(meta[0]); i++){
rc = sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
}
if( rc ){
sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
sqlite3BtreeCloseCursor(curMain);
return rc;
}
}else{
memset(meta, 0, sizeof(meta));
}
pDb->pSchema->schema_cookie = meta[0];
/* If opening a non-empty database, check the text encoding. For the
** main database, set sqlite3.enc to the encoding of the main database.
** For an attached db, it is an error if the encoding is not the same
** as sqlite3.enc.
*/
if( meta[4] ){ /* text encoding */
if( iDb==0 ){
/* If opening the main database, set ENC(db). */
ENC(db) = (u8)meta[4];
db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0);
}else{
/* If opening an attached database, the encoding much match ENC(db) */
if( meta[4]!=ENC(db) ){
sqlite3BtreeCloseCursor(curMain);
sqlite3SetString(pzErrMsg, "attached databases must use the same"
" text encoding as main database", (char*)0);
return SQLITE_ERROR;
}
}
}else{
DbSetProperty(db, iDb, DB_Empty);
}
pDb->pSchema->enc = ENC(db);
size = meta[2];
if( size==0 ){ size = MAX_PAGES; }
pDb->pSchema->cache_size = size;
sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
/*
** file_format==1 Version 3.0.0.
** file_format==2 Version 3.1.3. // ALTER TABLE ADD COLUMN
** file_format==3 Version 3.1.4. // ditto but with non-NULL defaults
** file_format==4 Version 3.3.0. // DESC indices. Boolean constants
*/
pDb->pSchema->file_format = meta[1];
if( pDb->pSchema->file_format==0 ){
pDb->pSchema->file_format = 1;
}
if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
sqlite3BtreeCloseCursor(curMain);
sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0);
return SQLITE_ERROR;
}
/* Read the schema information out of the schema tables
*/
assert( db->init.busy );
if( rc==SQLITE_EMPTY ){
/* For an empty database, there is nothing to read */
rc = SQLITE_OK;
}else{
char *zSql;
zSql = sqlite3MPrintf(
"SELECT name, rootpage, sql FROM '%q'.%s",
db->aDb[iDb].zName, zMasterName);
sqlite3SafetyOff(db);
rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
if( rc==SQLITE_ABORT ) rc = initData.rc;
sqlite3SafetyOn(db);
sqliteFree(zSql);
#ifndef SQLITE_OMIT_ANALYZE
if( rc==SQLITE_OK ){
sqlite3AnalysisLoad(db, iDb);
}
#endif
sqlite3BtreeCloseCursor(curMain);
}
if( sqlite3MallocFailed() ){
/* sqlite3SetString(pzErrMsg, "out of memory", (char*)0); */
rc = SQLITE_NOMEM;
sqlite3ResetInternalSchema(db, 0);
}
if( rc==SQLITE_OK ){
DbSetProperty(db, iDb, DB_SchemaLoaded);
}else{
sqlite3ResetInternalSchema(db, iDb);
}
return rc;
}
/*
** The parser calls this routine after the CREATE VIRTUAL TABLE statement
** has been completely parsed.
*/
void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
Table *pTab = pParse->pNewTable; /* The table being constructed */
sqlite3 *db = pParse->db; /* The database connection */
if( pTab==0 ) return;
addArgumentToVtab(pParse);
pParse->sArg.z = 0;
if( pTab->nModuleArg<1 ) return;
/* If the CREATE VIRTUAL TABLE statement is being entered for the
** first time (in other words if the virtual table is actually being
** created now instead of just being read out of sqlite_master) then
** do additional initialization work and store the statement text
** in the sqlite_master table.
*/
if( !db->init.busy ){
char *zStmt;
char *zWhere;
int iDb;
Vdbe *v;
/* Compute the complete text of the CREATE VIRTUAL TABLE statement */
if( pEnd ){
pParse->sNameToken.n = (int)(pEnd->z - pParse->sNameToken.z) + pEnd->n;
}
zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken);
/* A slot for the record has already been allocated in the
** SQLITE_MASTER table. We just need to update that slot with all
** the information we've collected.
**
** The VM register number pParse->regRowid holds the rowid of an
** entry in the sqlite_master table tht was created for this vtab
** by sqlite3StartTable().
*/
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
sqlite3NestedParse(pParse,
"UPDATE %Q.%s "
"SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
"WHERE rowid=#%d",
db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
pTab->zName,
pTab->zName,
zStmt,
pParse->regRowid
);
sqlite3DbFree(db, zStmt);
v = sqlite3GetVdbe(pParse);
sqlite3ChangeCookie(pParse, iDb);
sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
zWhere = sqlite3MPrintf(db, "name='%q' AND type='table'", pTab->zName);
sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere);
sqlite3VdbeAddOp4(v, OP_VCreate, iDb, 0, 0,
pTab->zName, sqlite3Strlen30(pTab->zName) + 1);
}
/* If we are rereading the sqlite_master table create the in-memory
** record of the table. The xConnect() method is not called until
** the first time the virtual table is used in an SQL statement. This
** allows a schema that contains virtual tables to be loaded before
** the required virtual table implementations are registered. */
else {
Table *pOld;
Schema *pSchema = pTab->pSchema;
const char *zName = pTab->zName;
assert( sqlite3SchemaMutexHeld(db, 0, pSchema) );
pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab);
if( pOld ){
db->mallocFailed = 1;
assert( pTab==pOld ); /* Malloc must have failed inside HashInsert() */
return;
}
pParse->pNewTable = 0;
}
}
/*
** Attempt to read the database schema and initialize internal
** data structures for a single database file. The index of the
** database file is given by iDb. iDb==0 is used for the main
** database. iDb==1 should never be used. iDb>=2 is used for
** auxiliary databases. Return one of the SQLITE_ error codes to
** indicate success or failure.
*/
static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
int rc;
BtCursor *curMain;
int size;
Table *pTab;
char const *azArg[5];
char zDbNum[30];
int meta[10];
InitData initData;
char const *zMasterSchema;
char const *zMasterName = SCHEMA_TABLE(iDb);
/*
** The master database table has a structure like this
*/
static const char master_schema[] =
"CREATE TABLE sqlite_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
#ifndef SQLITE_OMIT_TEMPDB
static const 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"
")"
;
#else
#define temp_master_schema 0
#endif
assert( iDb>=0 && iDb<db->nDb );
/* zMasterSchema and zInitScript are set to point at the master schema
** and initialisation script appropriate for the database being
** initialised. zMasterName is the name of the master table.
*/
if( !OMIT_TEMPDB && iDb==1 ){
zMasterSchema = temp_master_schema;
}else{
zMasterSchema = master_schema;
}
zMasterName = SCHEMA_TABLE(iDb);
/* Construct the schema tables. */
sqlite3SafetyOff(db);
azArg[0] = zMasterName;
azArg[1] = "1";
azArg[2] = zMasterSchema;
sprintf(zDbNum, "%d", iDb);
azArg[3] = zDbNum;
azArg[4] = 0;
initData.db = db;
initData.pzErrMsg = pzErrMsg;
rc = sqlite3InitCallback(&initData, 4, (char **)azArg, 0);
if( rc!=SQLITE_OK ){
sqlite3SafetyOn(db);
return rc;
}
pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
if( pTab ){
pTab->readOnly = 1;
}
sqlite3SafetyOn(db);
/* Create a cursor to hold the database open
*/
if( db->aDb[iDb].pBt==0 ){
if( !OMIT_TEMPDB && iDb==1 ) DbSetProperty(db, 1, DB_SchemaLoaded);
return SQLITE_OK;
}
rc = sqlite3BtreeCursor(db->aDb[iDb].pBt, MASTER_ROOT, 0, 0, 0, &curMain);
if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
return rc;
}
/* Get the database meta information.
**
** Meta values are as follows:
** meta[0] Schema cookie. Changes with each schema change.
** meta[1] File format of schema layer.
** meta[2] Size of the page cache.
** meta[3] Use freelist if 0. Autovacuum if greater than zero.
** meta[4] Db text encoding. 1:UTF-8 3:UTF-16 LE 4:UTF-16 BE
** meta[5] The user cookie. Used by the application.
** meta[6]
** meta[7]
** meta[8]
** meta[9]
**
** Note: The hash defined SQLITE_UTF* symbols in sqliteInt.h correspond to
** the possible values of meta[4].
*/
if( rc==SQLITE_OK ){
int i;
for(i=0; rc==SQLITE_OK && i<sizeof(meta)/sizeof(meta[0]); i++){
rc = sqlite3BtreeGetMeta(db->aDb[iDb].pBt, i+1, (u32 *)&meta[i]);
}
if( rc ){
sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
sqlite3BtreeCloseCursor(curMain);
return rc;
}
}else{
memset(meta, 0, sizeof(meta));
}
db->aDb[iDb].schema_cookie = meta[0];
/* If opening a non-empty database, check the text encoding. For the
** main database, set sqlite3.enc to the encoding of the main database.
** For an attached db, it is an error if the encoding is not the same
** as sqlite3.enc.
*/
if( meta[4] ){ /* text encoding */
if( iDb==0 ){
/* If opening the main database, set db->enc. */
db->enc = (u8)meta[4];
db->pDfltColl = sqlite3FindCollSeq(db, db->enc, "BINARY", 6, 0);
}else{
/* If opening an attached database, the encoding much match db->enc */
if( meta[4]!=db->enc ){
sqlite3BtreeCloseCursor(curMain);
sqlite3SetString(pzErrMsg, "attached databases must use the same"
" text encoding as main database", (char*)0);
return SQLITE_ERROR;
}
}
}
size = meta[2];
if( size==0 ){ size = MAX_PAGES; }
db->aDb[iDb].cache_size = size;
if( iDb==0 ){
db->file_format = meta[1];
if( db->file_format==0 ){
/* This happens if the database was initially empty */
db->file_format = 1;
}
if( db->file_format==2 || db->file_format==3 ){
/* File format 2 is treated exactly as file format 1. New
** databases are created with file format 1.
*/
db->file_format = 1;
}
}
/*
** file_format==1 Version 3.0.0.
** file_format==2 Version 3.1.3.
** file_format==3 Version 3.1.4.
**
** Version 3.0 can only use files with file_format==1. Version 3.1.3
** can read and write files with file_format==1 or file_format==2.
** Version 3.1.4 can read and write file formats 1, 2 and 3.
*/
if( meta[1]>3 ){
sqlite3BtreeCloseCursor(curMain);
sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0);
return SQLITE_ERROR;
}
sqlite3BtreeSetCacheSize(db->aDb[iDb].pBt, db->aDb[iDb].cache_size);
/* Read the schema information out of the schema tables
*/
assert( db->init.busy );
if( rc==SQLITE_EMPTY ){
/* For an empty database, there is nothing to read */
rc = SQLITE_OK;
}else{
char *zSql;
zSql = sqlite3MPrintf(
"SELECT name, rootpage, sql, '%s' FROM '%q'.%s",
zDbNum, db->aDb[iDb].zName, zMasterName);
sqlite3SafetyOff(db);
rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
sqlite3SafetyOn(db);
sqliteFree(zSql);
sqlite3BtreeCloseCursor(curMain);
}
if( sqlite3_malloc_failed ){
sqlite3SetString(pzErrMsg, "out of memory", (char*)0);
rc = SQLITE_NOMEM;
sqlite3ResetInternalSchema(db, 0);
}
if( rc==SQLITE_OK ){
DbSetProperty(db, iDb, DB_SchemaLoaded);
}else{
sqlite3ResetInternalSchema(db, iDb);
}
return rc;
}
/*
** This function is called after an "ALTER TABLE ... ADD" statement
** has been parsed. Argument pColDef contains the text of the new
** column definition.
**
** The Table structure pParse->pNewTable was extended to include
** the new column during parsing.
*/
void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
Table *pNew; /* Copy of pParse->pNewTable */
Table *pTab; /* Table being altered */
int iDb; /* Database number */
const char *zDb; /* Database name */
const char *zTab; /* Table name */
char *zCol; /* Null-terminated column definition */
Column *pCol; /* The new column */
Expr *pDflt; /* Default value for the new column */
if( pParse->nErr ) return;
pNew = pParse->pNewTable;
assert( pNew );
iDb = sqlite3SchemaToIndex(pParse->db, pNew->pSchema);
zDb = pParse->db->aDb[iDb].zName;
zTab = pNew->zName;
pCol = &pNew->aCol[pNew->nCol-1];
pDflt = pCol->pDflt;
pTab = sqlite3FindTable(pParse->db, zTab, zDb);
assert( pTab );
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. */
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
return;
}
#endif
/* If the default value for the new column was specified with a
** literal NULL, then set pDflt to 0. This simplifies checking
** for an SQL NULL default below.
*/
if( pDflt && pDflt->op==TK_NULL ){
pDflt = 0;
}
/* Check that the new column is not specified as PRIMARY KEY or UNIQUE.
** If there is a NOT NULL constraint, then the default value for the
** column must not be NULL.
*/
if( pCol->isPrimKey ){
sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
return;
}
if( pNew->pIndex ){
sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");
return;
}
if( pCol->notNull && !pDflt ){
sqlite3ErrorMsg(pParse,
"Cannot add a NOT NULL column with default value NULL");
return;
}
/* Ensure the default expression is something that sqlite3ValueFromExpr()
** can handle (i.e. not CURRENT_TIME etc.)
*/
if( pDflt ){
sqlite3_value *pVal;
if( sqlite3ValueFromExpr(pDflt, SQLITE_UTF8, SQLITE_AFF_NONE, &pVal) ){
/* malloc() has failed */
return;
}
if( !pVal ){
sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");
return;
}
sqlite3ValueFree(pVal);
}
/* Modify the CREATE TABLE statement. */
zCol = sqliteStrNDup((char*)pColDef->z, pColDef->n);
if( zCol ){
char *zEnd = &zCol[pColDef->n-1];
while( (zEnd>zCol && *zEnd==';') || isspace(*(unsigned char *)zEnd) ){
*zEnd-- = '\0';
}
sqlite3NestedParse(pParse,
"UPDATE %Q.%s SET "
"sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d,length(sql)) "
"WHERE type = 'table' AND name = %Q",
zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,
zTab
);
sqliteFree(zCol);
}
/* If the default value of the new column is NULL, then set the file
** format to 2. If the default value of the new column is not NULL,
** the file format becomes 3.
*/
sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);
/* Reload the schema of the modified table. */
reloadTableSchema(pParse, pTab, pTab->zName);
}
/*
** This routine is called after all of the trigger actions have been parsed
** in order to complete the process of building the trigger.
*/
SQLITE_PRIVATE void sqlite3FinishTrigger(
Parse *pParse, /* Parser context */
TriggerStep *pStepList, /* The triggered program */
Token *pAll /* Token that describes the complete CREATE TRIGGER */
){
Trigger *pTrig = pParse->pNewTrigger; /* Trigger being finished */
char *zName; /* Name of trigger */
sqlite3 *db = pParse->db; /* The database */
DbFixer sFix; /* Fixer object */
int iDb; /* Database containing the trigger */
Token nameToken; /* Trigger name for error reporting */
pParse->pNewTrigger = 0;
if( NEVER(pParse->nErr) || !pTrig ) goto triggerfinish_cleanup;
zName = pTrig->zName;
iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
pTrig->step_list = pStepList;
while( pStepList ){
pStepList->pTrig = pTrig;
pStepList = pStepList->pNext;
}
nameToken.z = pTrig->zName;
nameToken.n = sqlite3Strlen30(nameToken.z);
sqlite3FixInit(&sFix, pParse, iDb, "trigger", &nameToken);
if( sqlite3FixTriggerStep(&sFix, pTrig->step_list)
|| sqlite3FixExpr(&sFix, pTrig->pWhen)
){
goto triggerfinish_cleanup;
}
/* if we are not initializing,
** build the sqlite_master entry
*/
if( !db->init.busy ){
Vdbe *v;
char *z;
/* Make an entry in the sqlite_master table */
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto triggerfinish_cleanup;
sqlite3BeginWriteOperation(pParse, 0, iDb);
z = sqlite3DbStrNDup(db, (char*)pAll->z, pAll->n);
sqlite3NestedParse(pParse,
"INSERT INTO %Q.%s VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')",
db->aDb[iDb].zName, SCHEMA_TABLE(iDb), zName,
pTrig->table, z);
sqlite3DbFree(db, z);
sqlite3ChangeCookie(pParse, iDb);
sqlite3VdbeAddParseSchemaOp(v, iDb,
sqlite3MPrintf(db, "type='trigger' AND name='%q'", zName));
}
if( db->init.busy ){
Trigger *pLink = pTrig;
Hash *pHash = &db->aDb[iDb].pSchema->trigHash;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
pTrig = sqlite3HashInsert(pHash, zName, sqlite3Strlen30(zName), pTrig);
if( pTrig ){
db->mallocFailed = 1;
}else if( pLink->pSchema==pLink->pTabSchema ){
Table *pTab;
int n = sqlite3Strlen30(pLink->table);
pTab = sqlite3HashFind(&pLink->pTabSchema->tblHash, pLink->table, n);
assert( pTab!=0 );
pLink->pNext = pTab->pTrigger;
pTab->pTrigger = pLink;
}
}
triggerfinish_cleanup:
sqlite3DeleteTrigger(db, pTrig);
assert( !pParse->pNewTrigger );
sqlite3DeleteTriggerStep(db, pStepList);
}
/*
** Drop a trigger given a pointer to that trigger. If nested is false,
** then also generate code to remove the trigger from the SQLITE_MASTER
** table.
*/
void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger, int nested){
Table *pTable;
Vdbe *v;
sqlite *db = pParse->db;
assert( pTrigger->iDb<db->nDb );
pTable = sqlite3FindTable(db,pTrigger->table,db->aDb[pTrigger->iTabDb].zName);
assert(pTable);
assert( pTable->iDb==pTrigger->iDb || pTrigger->iDb==1 );
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_DROP_TRIGGER;
const char *zDb = db->aDb[pTrigger->iDb].zName;
const char *zTab = SCHEMA_TABLE(pTrigger->iDb);
if( pTrigger->iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;
if( sqlite3AuthCheck(pParse, code, pTrigger->name, pTable->zName, zDb) ||
sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
return;
}
}
#endif
/* Generate code to destroy the database record of the trigger.
*/
if( pTable!=0 && (v = sqlite3GetVdbe(pParse))!=0 ){
int base;
static VdbeOpList dropTrigger[] = {
{ OP_Rewind, 0, ADDR(9), 0},
{ OP_String8, 0, 0, 0}, /* 1 */
{ OP_Column, 0, 1, 0},
{ OP_Ne, 0, ADDR(8), 0},
{ OP_String8, 0, 0, "trigger"},
{ OP_Column, 0, 0, 0},
{ OP_Ne, 0, ADDR(8), 0},
{ OP_Delete, 0, 0, 0},
{ OP_Next, 0, ADDR(1), 0}, /* 8 */
};
sqlite3BeginWriteOperation(pParse, 0, pTrigger->iDb);
sqlite3OpenMasterTable(v, pTrigger->iDb);
base = sqlite3VdbeAddOpList(v, ArraySize(dropTrigger), dropTrigger);
sqlite3VdbeChangeP3(v, base+1, pTrigger->name, 0);
sqlite3ChangeCookie(db, v, pTrigger->iDb);
sqlite3VdbeAddOp(v, OP_Close, 0, 0);
}
/*
** If this is not an "explain", then delete the trigger structure.
*/
if( !pParse->explain ){
const char *zName = pTrigger->name;
int nName = strlen(zName);
if( pTable->pTrigger == pTrigger ){
pTable->pTrigger = pTrigger->pNext;
}else{
Trigger *cc = pTable->pTrigger;
while( cc ){
if( cc->pNext == pTrigger ){
cc->pNext = cc->pNext->pNext;
break;
}
cc = cc->pNext;
}
assert(cc);
}
sqlite3HashInsert(&(db->aDb[pTrigger->iDb].trigHash), zName, nName+1, 0);
sqlite3DeleteTrigger(pTrigger);
}
}
/*
** This is called by the parser when it sees a CREATE TRIGGER statement
** up to the point of the BEGIN before the trigger actions. A Trigger
** structure is generated based on the information available and stored
** in pParse->pNewTrigger. After the trigger actions have been parsed, the
** sqlite3FinishTrigger() function is called to complete the trigger
** construction process.
*/
SQLITE_PRIVATE void sqlite3BeginTrigger(
Parse *pParse, /* The parse context of the CREATE TRIGGER statement */
Token *pName1, /* The name of the trigger */
Token *pName2, /* The name of the trigger */
int tr_tm, /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
int op, /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
IdList *pColumns, /* column list if this is an UPDATE OF trigger */
SrcList *pTableName,/* The name of the table/view the trigger applies to */
Expr *pWhen, /* WHEN clause */
int isTemp, /* True if the TEMPORARY keyword is present */
int noErr /* Suppress errors if the trigger already exists */
){
Trigger *pTrigger = 0; /* The new trigger */
Table *pTab; /* Table that the trigger fires off of */
char *zName = 0; /* Name of the trigger */
sqlite3 *db = pParse->db; /* The database connection */
int iDb; /* The database to store the trigger in */
Token *pName; /* The unqualified db name */
DbFixer sFix; /* State vector for the DB fixer */
int iTabDb; /* Index of the database holding pTab */
assert( pName1!=0 ); /* pName1->z might be NULL, but not pName1 itself */
assert( pName2!=0 );
assert( op==TK_INSERT || op==TK_UPDATE || op==TK_DELETE );
assert( op>0 && op<0xff );
if( isTemp ){
/* If TEMP was specified, then the trigger name may not be qualified. */
if( pName2->n>0 ){
sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name");
goto trigger_cleanup;
}
iDb = 1;
pName = pName1;
}else{
/* Figure out the db that the trigger will be created in */
iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
if( iDb<0 ){
goto trigger_cleanup;
}
}
if( !pTableName || db->mallocFailed ){
goto trigger_cleanup;
}
/* A long-standing parser bug is that this syntax was allowed:
**
** CREATE TRIGGER attached.demo AFTER INSERT ON attached.tab ....
** ^^^^^^^^
**
** To maintain backwards compatibility, ignore the database
** name on pTableName if we are reparsing our of SQLITE_MASTER.
*/
if( db->init.busy && iDb!=1 ){
sqlite3DbFree(db, pTableName->a[0].zDatabase);
pTableName->a[0].zDatabase = 0;
}
/* If the trigger name was unqualified, and the table is a temp table,
** then set iDb to 1 to create the trigger in the temporary database.
** If sqlite3SrcListLookup() returns 0, indicating the table does not
** exist, the error is caught by the block below.
*/
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( db->init.busy==0 && pName2->n==0 && pTab
&& pTab->pSchema==db->aDb[1].pSchema ){
iDb = 1;
}
/* Ensure the table name matches database name and that the table exists */
if( db->mallocFailed ) goto trigger_cleanup;
assert( pTableName->nSrc==1 );
sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName);
if( sqlite3FixSrcList(&sFix, pTableName) ){
goto trigger_cleanup;
}
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( !pTab ){
/* The table does not exist. */
if( db->init.iDb==1 ){
/* Ticket #3810.
** Normally, whenever a table is dropped, all associated triggers are
** dropped too. But if a TEMP trigger is created on a non-TEMP table
** and the table is dropped by a different database connection, the
** trigger is not visible to the database connection that does the
** drop so the trigger cannot be dropped. This results in an
** "orphaned trigger" - a trigger whose associated table is missing.
*/
db->init.orphanTrigger = 1;
}
goto trigger_cleanup;
}
if( IsVirtual(pTab) ){
sqlite3ErrorMsg(pParse, "cannot create triggers on virtual tables");
goto trigger_cleanup;
}
/* Check that the trigger name is not reserved and that no trigger of the
** specified name exists */
zName = sqlite3NameFromToken(db, pName);
if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
goto trigger_cleanup;
}
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),
zName, sqlite3Strlen30(zName)) ){
if( !noErr ){
sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
}else{
assert( !db->init.busy );
sqlite3CodeVerifySchema(pParse, iDb);
}
goto trigger_cleanup;
}
/* Do not create a trigger on a system table */
if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
pParse->nErr++;
goto trigger_cleanup;
}
/* INSTEAD of triggers are only for views and views only support INSTEAD
** of triggers.
*/
if( pTab->pSelect && tr_tm!=TK_INSTEAD ){
sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S",
(tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
goto trigger_cleanup;
}
if( !pTab->pSelect && tr_tm==TK_INSTEAD ){
sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
" trigger on table: %S", pTableName, 0);
goto trigger_cleanup;
}
iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_CREATE_TRIGGER;
const char *zDb = db->aDb[iTabDb].zName;
const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
goto trigger_cleanup;
}
if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iTabDb),0,zDb)){
goto trigger_cleanup;
}
}
#endif
/* INSTEAD OF triggers can only appear on views and BEFORE triggers
** cannot appear on views. So we might as well translate every
** INSTEAD OF trigger into a BEFORE trigger. It simplifies code
** elsewhere.
*/
if (tr_tm == TK_INSTEAD){
tr_tm = TK_BEFORE;
}
/* Build the Trigger object */
pTrigger = (Trigger*)sqlite3DbMallocZero(db, sizeof(Trigger));
if( pTrigger==0 ) goto trigger_cleanup;
pTrigger->zName = zName;
zName = 0;
pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName);
pTrigger->pSchema = db->aDb[iDb].pSchema;
pTrigger->pTabSchema = pTab->pSchema;
pTrigger->op = (u8)op;
pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER;
pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
pTrigger->pColumns = sqlite3IdListDup(db, pColumns);
assert( pParse->pNewTrigger==0 );
pParse->pNewTrigger = pTrigger;
trigger_cleanup:
sqlite3DbFree(db, zName);
sqlite3SrcListDelete(db, pTableName);
sqlite3IdListDelete(db, pColumns);
sqlite3ExprDelete(db, pWhen);
if( !pParse->pNewTrigger ){
sqlite3DeleteTrigger(db, pTrigger);
}else{
assert( pParse->pNewTrigger==pTrigger );
}
}
