diff -r 000000000000 -r 08ec8eefde2f persistentstorage/sql/SQLite364/trigger.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/persistentstorage/sql/SQLite364/trigger.c Fri Jan 22 11:06:30 2010 +0200 @@ -0,0 +1,852 @@ +/* +** +** 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. +** +************************************************************************* +** +** +** $Id: trigger.c,v 1.129 2008/08/20 16:35:10 drh Exp $ +*/ +#include "sqliteInt.h" + +#ifndef SQLITE_OMIT_TRIGGER +/* +** Delete a linked list of TriggerStep structures. +*/ +void sqlite3DeleteTriggerStep(sqlite3 *db, TriggerStep *pTriggerStep){ + while( pTriggerStep ){ + TriggerStep * pTmp = pTriggerStep; + pTriggerStep = pTriggerStep->pNext; + + if( pTmp->target.dyn ) sqlite3DbFree(db, (char*)pTmp->target.z); + sqlite3ExprDelete(db, pTmp->pWhere); + sqlite3ExprListDelete(db, pTmp->pExprList); + sqlite3SelectDelete(db, pTmp->pSelect); + sqlite3IdListDelete(db, pTmp->pIdList); + + sqlite3DbFree(db, pTmp); + } +} + +/* +** 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 */ + 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; + Table *pTab; + char *zName = 0; /* Name of the trigger */ + sqlite3 *db = pParse->db; + int iDb; /* The database to store the trigger in */ + Token *pName; /* The unqualified db name */ + DbFixer sFix; + int iTabDb; + + assert( pName1!=0 ); /* pName1->z might be NULL, but not pName1 itself */ + assert( pName2!=0 ); + 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 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 || db->mallocFailed ){ + goto trigger_cleanup; + } + pTab = sqlite3SrcListLookup(pParse, pTableName); + if( 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 ); + 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; + } + 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; + } + if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash), zName,strlen(zName)) ){ + if( !noErr ){ + sqlite3ErrorMsg(pParse, "trigger %T already exists", pName); + } + 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->name = zName; + zName = 0; + pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName); + pTrigger->pSchema = db->aDb[iDb].pSchema; + pTrigger->pTabSchema = pTab->pSchema; + pTrigger->op = op; + pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER; + pTrigger->pWhen = sqlite3ExprDup(db, pWhen); + pTrigger->pColumns = sqlite3IdListDup(db, pColumns); + sqlite3TokenCopy(db, &pTrigger->nameToken,pName); + 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 ); + } +} + +/* +** 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, strlen(pTrig->name), pTrig); + if( pDel ){ + assert( pDel==pTrig ); + db->mallocFailed = 1; + goto triggerfinish_cleanup; + } + n = strlen(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); +} + +/* +** Make a copy of all components of the given trigger step. This has +** the effect of copying all Expr.token.z values into memory obtained +** from sqlite3_malloc(). As initially created, the Expr.token.z values +** all point to the input string that was fed to the parser. But that +** string is ephemeral - it will go away as soon as the sqlite3_exec() +** call that started the parser exits. This routine makes a persistent +** copy of all the Expr.token.z strings so that the TriggerStep structure +** will be valid even after the sqlite3_exec() call returns. +*/ +static void sqlitePersistTriggerStep(sqlite3 *db, TriggerStep *p){ + if( p->target.z ){ + p->target.z = (u8*)sqlite3DbStrNDup(db, (char*)p->target.z, p->target.n); + p->target.dyn = 1; + } + if( p->pSelect ){ + Select *pNew = sqlite3SelectDup(db, p->pSelect); + sqlite3SelectDelete(db, p->pSelect); + p->pSelect = pNew; + } + if( p->pWhere ){ + Expr *pNew = sqlite3ExprDup(db, p->pWhere); + sqlite3ExprDelete(db, p->pWhere); + p->pWhere = pNew; + } + if( p->pExprList ){ + ExprList *pNew = sqlite3ExprListDup(db, p->pExprList); + sqlite3ExprListDelete(db, p->pExprList); + p->pExprList = pNew; + } + if( p->pIdList ){ + IdList *pNew = sqlite3IdListDup(db, p->pIdList); + sqlite3IdListDelete(db, p->pIdList); + p->pIdList = pNew; + } +} + +/* +** Turn a SELECT statement (that the pSelect parameter points to) into +** a trigger step. Return a pointer to a TriggerStep structure. +** +** The parser calls this routine when it finds a SELECT statement in +** body of a TRIGGER. +*/ +TriggerStep *sqlite3TriggerSelectStep(sqlite3 *db, Select *pSelect){ + TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep)); + if( pTriggerStep==0 ) { + sqlite3SelectDelete(db, pSelect); + return 0; + } + + pTriggerStep->op = TK_SELECT; + pTriggerStep->pSelect = pSelect; + pTriggerStep->orconf = OE_Default; + sqlitePersistTriggerStep(db, pTriggerStep); + + return pTriggerStep; +} + +/* +** Build a trigger step out of an INSERT statement. Return a pointer +** to the new trigger step. +** +** The parser calls this routine when it sees an INSERT inside the +** body of a trigger. +*/ +TriggerStep *sqlite3TriggerInsertStep( + sqlite3 *db, /* The database connection */ + Token *pTableName, /* Name of the table into which we insert */ + IdList *pColumn, /* List of columns in pTableName to insert into */ + ExprList *pEList, /* The VALUE clause: a list of values to be inserted */ + Select *pSelect, /* A SELECT statement that supplies values */ + int orconf /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */ +){ + TriggerStep *pTriggerStep; + + assert(pEList == 0 || pSelect == 0); + assert(pEList != 0 || pSelect != 0 || db->mallocFailed); + + pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep)); + if( pTriggerStep ){ + pTriggerStep->op = TK_INSERT; + pTriggerStep->pSelect = pSelect; + pTriggerStep->target = *pTableName; + pTriggerStep->pIdList = pColumn; + pTriggerStep->pExprList = pEList; + pTriggerStep->orconf = orconf; + sqlitePersistTriggerStep(db, pTriggerStep); + }else{ + sqlite3IdListDelete(db, pColumn); + sqlite3ExprListDelete(db, pEList); + sqlite3SelectDelete(db, pSelect); + } + + return pTriggerStep; +} + +/* +** Construct a trigger step that implements an UPDATE statement and return +** a pointer to that trigger step. The parser calls this routine when it +** sees an UPDATE statement inside the body of a CREATE TRIGGER. +*/ +TriggerStep *sqlite3TriggerUpdateStep( + sqlite3 *db, /* The database connection */ + Token *pTableName, /* Name of the table to be updated */ + ExprList *pEList, /* The SET clause: list of column and new values */ + Expr *pWhere, /* The WHERE clause */ + int orconf /* The conflict algorithm. (OE_Abort, OE_Ignore, etc) */ +){ + TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep)); + if( pTriggerStep==0 ){ + sqlite3ExprListDelete(db, pEList); + sqlite3ExprDelete(db, pWhere); + return 0; + } + + pTriggerStep->op = TK_UPDATE; + pTriggerStep->target = *pTableName; + pTriggerStep->pExprList = pEList; + pTriggerStep->pWhere = pWhere; + pTriggerStep->orconf = orconf; + sqlitePersistTriggerStep(db, pTriggerStep); + + return pTriggerStep; +} + +/* +** Construct a trigger step that implements a DELETE statement and return +** a pointer to that trigger step. The parser calls this routine when it +** sees a DELETE statement inside the body of a CREATE TRIGGER. +*/ +TriggerStep *sqlite3TriggerDeleteStep( + sqlite3 *db, /* Database connection */ + Token *pTableName, /* The table from which rows are deleted */ + Expr *pWhere /* The WHERE clause */ +){ + TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep)); + if( pTriggerStep==0 ){ + sqlite3ExprDelete(db, pWhere); + return 0; + } + + pTriggerStep->op = TK_DELETE; + pTriggerStep->target = *pTableName; + pTriggerStep->pWhere = pWhere; + pTriggerStep->orconf = OE_Default; + sqlitePersistTriggerStep(db, pTriggerStep); + + return pTriggerStep; +} + +/* +** Recursively delete a Trigger structure +*/ +void sqlite3DeleteTrigger(sqlite3 *db, Trigger *pTrigger){ + if( pTrigger==0 ) return; + sqlite3DeleteTriggerStep(db, pTrigger->step_list); + sqlite3DbFree(db, pTrigger->name); + sqlite3DbFree(db, pTrigger->table); + sqlite3ExprDelete(db, pTrigger->pWhen); + sqlite3IdListDelete(db, pTrigger->pColumns); + if( pTrigger->nameToken.dyn ) sqlite3DbFree(db, (char*)pTrigger->nameToken.z); + sqlite3DbFree(db, pTrigger); +} + +/* +** This function is called to drop a trigger from the database schema. +** +** This may be called directly from the parser and therefore identifies +** the trigger by name. The sqlite3DropTriggerPtr() routine does the +** same job as this routine except it takes a pointer to the trigger +** instead of the trigger name. +**/ +void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr){ + Trigger *pTrigger = 0; + int i; + const char *zDb; + const char *zName; + int nName; + sqlite3 *db = pParse->db; + + if( db->mallocFailed ) goto drop_trigger_cleanup; + if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){ + goto drop_trigger_cleanup; + } + + assert( pName->nSrc==1 ); + zDb = pName->a[0].zDatabase; + zName = pName->a[0].zName; + nName = strlen(zName); + for(i=OMIT_TEMPDB; inDb; i++){ + int j = (i<2) ? i^1 : i; /* Search TEMP before MAIN */ + if( zDb && sqlite3StrICmp(db->aDb[j].zName, zDb) ) continue; + pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName, nName); + if( pTrigger ) break; + } + if( !pTrigger ){ + if( !noErr ){ + sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0); + } + goto drop_trigger_cleanup; + } + sqlite3DropTriggerPtr(pParse, pTrigger); + +drop_trigger_cleanup: + sqlite3SrcListDelete(db, pName); +} + +/* +** Return a pointer to the Table structure for the table that a trigger +** is set on. +*/ +static Table *tableOfTrigger(Trigger *pTrigger){ + int n = strlen(pTrigger->table) + 1; + return sqlite3HashFind(&pTrigger->pTabSchema->tblHash, pTrigger->table, n); +} + + +/* +** 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 && iDbnDb ); + 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->name, 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 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); + sqlite3VdbeChangeP4(v, base+1, pTrigger->name, 0); + sqlite3VdbeChangeP4(v, base+4, "trigger", P4_STATIC); + sqlite3ChangeCookie(pParse, iDb); + sqlite3VdbeAddOp2(v, OP_Close, 0, 0); + sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->name, 0); + } +} + +/* +** Remove a trigger from the hash tables of the sqlite* pointer. +*/ +void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){ + Trigger *pTrigger; + int nName = strlen(zName); + pTrigger = sqlite3HashInsert(&(db->aDb[iDb].pSchema->trigHash), + zName, nName, 0); + if( pTrigger ){ + Table *pTable = tableOfTrigger(pTrigger); + assert( pTable!=0 ); + 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); + } + sqlite3DeleteTrigger(db, pTrigger); + db->flags |= SQLITE_InternChanges; + } +} + +/* +** pEList is the SET clause of an UPDATE statement. Each entry +** in pEList is of the format =. If any of the entries +** in pEList have an which matches an identifier in pIdList, +** then return TRUE. If pIdList==NULL, then it is considered a +** wildcard that matches anything. Likewise if pEList==NULL then +** it matches anything so always return true. Return false only +** if there is no match. +*/ +static int checkColumnOverLap(IdList *pIdList, ExprList *pEList){ + int e; + if( !pIdList || !pEList ) return 1; + for(e=0; enExpr; e++){ + if( sqlite3IdListIndex(pIdList, pEList->a[e].zName)>=0 ) return 1; + } + return 0; +} + +/* +** Return a bit vector to indicate what kind of triggers exist for operation +** "op" on table pTab. If pChanges is not NULL then it is a list of columns +** that are being updated. Triggers only match if the ON clause of the +** trigger definition overlaps the set of columns being updated. +** +** The returned bit vector is some combination of TRIGGER_BEFORE and +** TRIGGER_AFTER. +*/ +int sqlite3TriggersExist( + Parse *pParse, /* Used to check for recursive triggers */ + Table *pTab, /* The table the contains the triggers */ + int op, /* one of TK_DELETE, TK_INSERT, TK_UPDATE */ + ExprList *pChanges /* Columns that change in an UPDATE statement */ +){ + Trigger *pTrigger; + int mask = 0; + + pTrigger = IsVirtual(pTab) ? 0 : pTab->pTrigger; + while( pTrigger ){ + if( pTrigger->op==op && checkColumnOverLap(pTrigger->pColumns, pChanges) ){ + mask |= pTrigger->tr_tm; + } + pTrigger = pTrigger->pNext; + } + return mask; +} + +/* +** Convert the pStep->target token into a SrcList and return a pointer +** to that SrcList. +** +** This routine adds a specific database name, if needed, to the target when +** forming the SrcList. This prevents a trigger in one database from +** referring to a target in another database. An exception is when the +** trigger is in TEMP in which case it can refer to any other database it +** wants. +*/ +static SrcList *targetSrcList( + Parse *pParse, /* The parsing context */ + TriggerStep *pStep /* The trigger containing the target token */ +){ + Token sDb; /* Dummy database name token */ + int iDb; /* Index of the database to use */ + SrcList *pSrc; /* SrcList to be returned */ + + iDb = sqlite3SchemaToIndex(pParse->db, pStep->pTrig->pSchema); + if( iDb==0 || iDb>=2 ){ + assert( iDbdb->nDb ); + sDb.z = (u8*)pParse->db->aDb[iDb].zName; + sDb.n = strlen((char*)sDb.z); + pSrc = sqlite3SrcListAppend(pParse->db, 0, &sDb, &pStep->target); + } else { + pSrc = sqlite3SrcListAppend(pParse->db, 0, &pStep->target, 0); + } + return pSrc; +} + +/* +** Generate VDBE code for zero or more statements inside the body of a +** trigger. +*/ +static int codeTriggerProgram( + Parse *pParse, /* The parser context */ + TriggerStep *pStepList, /* List of statements inside the trigger body */ + int orconfin /* Conflict algorithm. (OE_Abort, etc) */ +){ + TriggerStep * pTriggerStep = pStepList; + int orconf; + Vdbe *v = pParse->pVdbe; + sqlite3 *db = pParse->db; + + assert( pTriggerStep!=0 ); + assert( v!=0 ); + sqlite3VdbeAddOp2(v, OP_ContextPush, 0, 0); + VdbeComment((v, "begin trigger %s", pStepList->pTrig->name)); + while( pTriggerStep ){ + orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin; + pParse->trigStack->orconf = orconf; + switch( pTriggerStep->op ){ + case TK_SELECT: { + Select *ss = sqlite3SelectDup(db, pTriggerStep->pSelect); + if( ss ){ + SelectDest dest; + + sqlite3SelectDestInit(&dest, SRT_Discard, 0); + sqlite3Select(pParse, ss, &dest); + sqlite3SelectDelete(db, ss); + } + break; + } + case TK_UPDATE: { + SrcList *pSrc; + pSrc = targetSrcList(pParse, pTriggerStep); + sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0); + sqlite3Update(pParse, pSrc, + sqlite3ExprListDup(db, pTriggerStep->pExprList), + sqlite3ExprDup(db, pTriggerStep->pWhere), orconf); + sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0); + break; + } + case TK_INSERT: { + SrcList *pSrc; + pSrc = targetSrcList(pParse, pTriggerStep); + sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0); + sqlite3Insert(pParse, pSrc, + sqlite3ExprListDup(db, pTriggerStep->pExprList), + sqlite3SelectDup(db, pTriggerStep->pSelect), + sqlite3IdListDup(db, pTriggerStep->pIdList), orconf); + sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0); + break; + } + case TK_DELETE: { + SrcList *pSrc; + sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0); + pSrc = targetSrcList(pParse, pTriggerStep); + sqlite3DeleteFrom(pParse, pSrc, + sqlite3ExprDup(db, pTriggerStep->pWhere)); + sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0); + break; + } + default: + assert(0); + } + pTriggerStep = pTriggerStep->pNext; + } + sqlite3VdbeAddOp2(v, OP_ContextPop, 0, 0); + VdbeComment((v, "end trigger %s", pStepList->pTrig->name)); + + return 0; +} + +/* +** This is called to code FOR EACH ROW triggers. +** +** When the code that this function generates is executed, the following +** must be true: +** +** 1. No cursors may be open in the main database. (But newIdx and oldIdx +** can be indices of cursors in temporary tables. See below.) +** +** 2. If the triggers being coded are ON INSERT or ON UPDATE triggers, then +** a temporary vdbe cursor (index newIdx) must be open and pointing at +** a row containing values to be substituted for new.* expressions in the +** trigger program(s). +** +** 3. If the triggers being coded are ON DELETE or ON UPDATE triggers, then +** a temporary vdbe cursor (index oldIdx) must be open and pointing at +** a row containing values to be substituted for old.* expressions in the +** trigger program(s). +** +** If they are not NULL, the piOldColMask and piNewColMask output variables +** are set to values that describe the columns used by the trigger program +** in the OLD.* and NEW.* tables respectively. If column N of the +** pseudo-table is read at least once, the corresponding bit of the output +** mask is set. If a column with an index greater than 32 is read, the +** output mask is set to the special value 0xffffffff. +** +*/ +int sqlite3CodeRowTrigger( + Parse *pParse, /* Parse context */ + int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */ + ExprList *pChanges, /* Changes list for any UPDATE OF triggers */ + int tr_tm, /* One of TRIGGER_BEFORE, TRIGGER_AFTER */ + Table *pTab, /* The table to code triggers from */ + int newIdx, /* The indice of the "new" row to access */ + int oldIdx, /* The indice of the "old" row to access */ + int orconf, /* ON CONFLICT policy */ + int ignoreJump, /* Instruction to jump to for RAISE(IGNORE) */ + u32 *piOldColMask, /* OUT: Mask of columns used from the OLD.* table */ + u32 *piNewColMask /* OUT: Mask of columns used from the NEW.* table */ +){ + Trigger *p; + sqlite3 *db = pParse->db; + TriggerStack trigStackEntry; + + trigStackEntry.oldColMask = 0; + trigStackEntry.newColMask = 0; + + assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE); + assert(tr_tm == TRIGGER_BEFORE || tr_tm == TRIGGER_AFTER ); + + assert(newIdx != -1 || oldIdx != -1); + + for(p=pTab->pTrigger; p; p=p->pNext){ + int fire_this = 0; + + /* Determine whether we should code this trigger */ + if( + p->op==op && + p->tr_tm==tr_tm && + (p->pSchema==p->pTabSchema || p->pSchema==db->aDb[1].pSchema) && + (op!=TK_UPDATE||!p->pColumns||checkColumnOverLap(p->pColumns,pChanges)) + ){ + TriggerStack *pS; /* Pointer to trigger-stack entry */ + for(pS=pParse->trigStack; pS && p!=pS->pTrigger; pS=pS->pNext){} + if( !pS ){ + fire_this = 1; + } +#if 0 /* Give no warning for recursive triggers. Just do not do them */ + else{ + sqlite3ErrorMsg(pParse, "recursive triggers not supported (%s)", + p->name); + return SQLITE_ERROR; + } +#endif + } + + if( fire_this ){ + int endTrigger; + Expr * whenExpr; + AuthContext sContext; + NameContext sNC; + +#ifndef SQLITE_OMIT_TRACE + sqlite3VdbeAddOp4(pParse->pVdbe, OP_Trace, 0, 0, 0, + sqlite3MPrintf(db, "-- TRIGGER %s", p->name), + P4_DYNAMIC); +#endif + memset(&sNC, 0, sizeof(sNC)); + sNC.pParse = pParse; + + /* Push an entry on to the trigger stack */ + trigStackEntry.pTrigger = p; + trigStackEntry.newIdx = newIdx; + trigStackEntry.oldIdx = oldIdx; + trigStackEntry.pTab = pTab; + trigStackEntry.pNext = pParse->trigStack; + trigStackEntry.ignoreJump = ignoreJump; + pParse->trigStack = &trigStackEntry; + sqlite3AuthContextPush(pParse, &sContext, p->name); + + /* code the WHEN clause */ + endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe); + whenExpr = sqlite3ExprDup(db, p->pWhen); + if( db->mallocFailed || sqlite3ResolveExprNames(&sNC, whenExpr) ){ + pParse->trigStack = trigStackEntry.pNext; + sqlite3ExprDelete(db, whenExpr); + return 1; + } + sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, SQLITE_JUMPIFNULL); + sqlite3ExprDelete(db, whenExpr); + + codeTriggerProgram(pParse, p->step_list, orconf); + + /* Pop the entry off the trigger stack */ + pParse->trigStack = trigStackEntry.pNext; + sqlite3AuthContextPop(&sContext); + + sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger); + } + } + if( piOldColMask ) *piOldColMask |= trigStackEntry.oldColMask; + if( piNewColMask ) *piNewColMask |= trigStackEntry.newColMask; + return 0; +} +#endif /* !defined(SQLITE_OMIT_TRIGGER) */