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Diffstat (limited to 'lib/libsqlite3/src/trigger.c')
| -rw-r--r-- | lib/libsqlite3/src/trigger.c | 1119 |
1 files changed, 0 insertions, 1119 deletions
diff --git a/lib/libsqlite3/src/trigger.c b/lib/libsqlite3/src/trigger.c deleted file mode 100644 index 2eba0cf92cd..00000000000 --- a/lib/libsqlite3/src/trigger.c +++ /dev/null @@ -1,1119 +0,0 @@ -/* -** -** 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. -** -************************************************************************* -** This file contains the implementation for TRIGGERs -*/ -#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; - - sqlite3ExprDelete(db, pTmp->pWhere); - sqlite3ExprListDelete(db, pTmp->pExprList); - sqlite3SelectDelete(db, pTmp->pSelect); - sqlite3IdListDelete(db, pTmp->pIdList); - - sqlite3DbFree(db, pTmp); - } -} - -/* -** Given table pTab, return a list of all the triggers attached to -** the table. The list is connected by Trigger.pNext pointers. -** -** All of the triggers on pTab that are in the same database as pTab -** are already attached to pTab->pTrigger. But there might be additional -** triggers on pTab in the TEMP schema. This routine prepends all -** TEMP triggers on pTab to the beginning of the pTab->pTrigger list -** and returns the combined list. -** -** To state it another way: This routine returns a list of all triggers -** that fire off of pTab. The list will include any TEMP triggers on -** pTab as well as the triggers lised in pTab->pTrigger. -*/ -Trigger *sqlite3TriggerList(Parse *pParse, Table *pTab){ - Schema * const pTmpSchema = pParse->db->aDb[1].pSchema; - Trigger *pList = 0; /* List of triggers to return */ - - if( pParse->disableTriggers ){ - return 0; - } - - if( pTmpSchema!=pTab->pSchema ){ - HashElem *p; - assert( sqlite3SchemaMutexHeld(pParse->db, 0, pTmpSchema) ); - for(p=sqliteHashFirst(&pTmpSchema->trigHash); p; p=sqliteHashNext(p)){ - Trigger *pTrig = (Trigger *)sqliteHashData(p); - if( pTrig->pTabSchema==pTab->pSchema - && 0==sqlite3StrICmp(pTrig->table, pTab->zName) - ){ - pTrig->pNext = (pList ? pList : pTab->pTrigger); - pList = pTrig; - } - } - } - - return (pList ? pList : pTab->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. -*/ -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 out 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) ){ - 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"); - 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 ); - } -} - -/* -** 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 = 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, pTrig); - if( pTrig ){ - db->mallocFailed = 1; - }else if( pLink->pSchema==pLink->pTabSchema ){ - Table *pTab; - pTab = sqlite3HashFind(&pLink->pTabSchema->tblHash, pLink->table); - assert( pTab!=0 ); - pLink->pNext = pTab->pTrigger; - pTab->pTrigger = pLink; - } - } - -triggerfinish_cleanup: - sqlite3DeleteTrigger(db, pTrig); - assert( !pParse->pNewTrigger ); - sqlite3DeleteTriggerStep(db, pStepList); -} - -/* -** 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; - return pTriggerStep; -} - -/* -** Allocate space to hold a new trigger step. The allocated space -** holds both the TriggerStep object and the TriggerStep.target.z string. -** -** If an OOM error occurs, NULL is returned and db->mallocFailed is set. -*/ -static TriggerStep *triggerStepAllocate( - sqlite3 *db, /* Database connection */ - u8 op, /* Trigger opcode */ - Token *pName /* The target name */ -){ - TriggerStep *pTriggerStep; - - pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep) + pName->n + 1); - if( pTriggerStep ){ - char *z = (char*)&pTriggerStep[1]; - memcpy(z, pName->z, pName->n); - sqlite3Dequote(z); - pTriggerStep->zTarget = z; - pTriggerStep->op = op; - } - 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 */ - Select *pSelect, /* A SELECT statement that supplies values */ - u8 orconf /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */ -){ - TriggerStep *pTriggerStep; - - assert(pSelect != 0 || db->mallocFailed); - - pTriggerStep = triggerStepAllocate(db, TK_INSERT, pTableName); - if( pTriggerStep ){ - pTriggerStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE); - pTriggerStep->pIdList = pColumn; - pTriggerStep->orconf = orconf; - }else{ - sqlite3IdListDelete(db, pColumn); - } - 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 */ - u8 orconf /* The conflict algorithm. (OE_Abort, OE_Ignore, etc) */ -){ - TriggerStep *pTriggerStep; - - pTriggerStep = triggerStepAllocate(db, TK_UPDATE, pTableName); - if( pTriggerStep ){ - pTriggerStep->pExprList = sqlite3ExprListDup(db, pEList, EXPRDUP_REDUCE); - pTriggerStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE); - pTriggerStep->orconf = orconf; - } - sqlite3ExprListDelete(db, pEList); - sqlite3ExprDelete(db, pWhere); - 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; - - pTriggerStep = triggerStepAllocate(db, TK_DELETE, pTableName); - if( pTriggerStep ){ - pTriggerStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE); - pTriggerStep->orconf = OE_Default; - } - sqlite3ExprDelete(db, pWhere); - 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->zName); - sqlite3DbFree(db, pTrigger->table); - sqlite3ExprDelete(db, pTrigger->pWhen); - sqlite3IdListDelete(db, pTrigger->pColumns); - 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; - 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; - assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) ); - for(i=OMIT_TEMPDB; i<db->nDb; i++){ - int j = (i<2) ? i^1 : i; /* Search TEMP before MAIN */ - if( zDb && sqlite3StrICmp(db->aDb[j].zName, zDb) ) continue; - assert( sqlite3SchemaMutexHeld(db, j, 0) ); - pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName); - if( pTrigger ) break; - } - if( !pTrigger ){ - if( !noErr ){ - sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0); - }else{ - sqlite3CodeVerifyNamedSchema(pParse, zDb); - } - pParse->checkSchema = 1; - 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){ - return sqlite3HashFind(&pTrigger->pTabSchema->tblHash, pTrigger->table); -} - - -/* -** 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; - } - } -} - -/* -** Remove a trigger from the hash tables of the sqlite* pointer. -*/ -void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){ - Trigger *pTrigger; - Hash *pHash; - - assert( sqlite3SchemaMutexHeld(db, iDb, 0) ); - pHash = &(db->aDb[iDb].pSchema->trigHash); - pTrigger = sqlite3HashInsert(pHash, zName, 0); - if( ALWAYS(pTrigger) ){ - if( pTrigger->pSchema==pTrigger->pTabSchema ){ - Table *pTab = tableOfTrigger(pTrigger); - Trigger **pp; - for(pp=&pTab->pTrigger; *pp!=pTrigger; pp=&((*pp)->pNext)); - *pp = (*pp)->pNext; - } - sqlite3DeleteTrigger(db, pTrigger); - db->flags |= SQLITE_InternChanges; - } -} - -/* -** pEList is the SET clause of an UPDATE statement. Each entry -** in pEList is of the format <id>=<expr>. If any of the entries -** in pEList have an <id> 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==0 || NEVER(pEList==0) ) return 1; - for(e=0; e<pEList->nExpr; e++){ - if( sqlite3IdListIndex(pIdList, pEList->a[e].zName)>=0 ) return 1; - } - return 0; -} - -/* -** Return a list of all triggers on table pTab if there exists at least -** one trigger that must be fired when an operation of type 'op' is -** performed on the table, and, if that operation is an UPDATE, if at -** least one of the columns in pChanges is being modified. -*/ -Trigger *sqlite3TriggersExist( - Parse *pParse, /* Parse context */ - 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 */ - int *pMask /* OUT: Mask of TRIGGER_BEFORE|TRIGGER_AFTER */ -){ - int mask = 0; - Trigger *pList = 0; - Trigger *p; - - if( (pParse->db->flags & SQLITE_EnableTrigger)!=0 ){ - pList = sqlite3TriggerList(pParse, pTab); - } - assert( pList==0 || IsVirtual(pTab)==0 ); - for(p=pList; p; p=p->pNext){ - if( p->op==op && checkColumnOverlap(p->pColumns, pChanges) ){ - mask |= p->tr_tm; - } - } - if( pMask ){ - *pMask = mask; - } - return (mask ? pList : 0); -} - -/* -** Convert the pStep->zTarget string 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 */ -){ - sqlite3 *db = pParse->db; - int iDb; /* Index of the database to use */ - SrcList *pSrc; /* SrcList to be returned */ - - pSrc = sqlite3SrcListAppend(db, 0, 0, 0); - if( pSrc ){ - assert( pSrc->nSrc>0 ); - pSrc->a[pSrc->nSrc-1].zName = sqlite3DbStrDup(db, pStep->zTarget); - iDb = sqlite3SchemaToIndex(db, pStep->pTrig->pSchema); - if( iDb==0 || iDb>=2 ){ - assert( iDb<db->nDb ); - pSrc->a[pSrc->nSrc-1].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zName); - } - } - return pSrc; -} - -/* -** Generate VDBE code for the statements inside the body of a single -** trigger. -*/ -static int codeTriggerProgram( - Parse *pParse, /* The parser context */ - TriggerStep *pStepList, /* List of statements inside the trigger body */ - int orconf /* Conflict algorithm. (OE_Abort, etc) */ -){ - TriggerStep *pStep; - Vdbe *v = pParse->pVdbe; - sqlite3 *db = pParse->db; - - assert( pParse->pTriggerTab && pParse->pToplevel ); - assert( pStepList ); - assert( v!=0 ); - for(pStep=pStepList; pStep; pStep=pStep->pNext){ - /* Figure out the ON CONFLICT policy that will be used for this step - ** of the trigger program. If the statement that caused this trigger - ** to fire had an explicit ON CONFLICT, then use it. Otherwise, use - ** the ON CONFLICT policy that was specified as part of the trigger - ** step statement. Example: - ** - ** CREATE TRIGGER AFTER INSERT ON t1 BEGIN; - ** INSERT OR REPLACE INTO t2 VALUES(new.a, new.b); - ** END; - ** - ** INSERT INTO t1 ... ; -- insert into t2 uses REPLACE policy - ** INSERT OR IGNORE INTO t1 ... ; -- insert into t2 uses IGNORE policy - */ - pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf; - assert( pParse->okConstFactor==0 ); - - switch( pStep->op ){ - case TK_UPDATE: { - sqlite3Update(pParse, - targetSrcList(pParse, pStep), - sqlite3ExprListDup(db, pStep->pExprList, 0), - sqlite3ExprDup(db, pStep->pWhere, 0), - pParse->eOrconf - ); - break; - } - case TK_INSERT: { - sqlite3Insert(pParse, - targetSrcList(pParse, pStep), - sqlite3SelectDup(db, pStep->pSelect, 0), - sqlite3IdListDup(db, pStep->pIdList), - pParse->eOrconf - ); - break; - } - case TK_DELETE: { - sqlite3DeleteFrom(pParse, - targetSrcList(pParse, pStep), - sqlite3ExprDup(db, pStep->pWhere, 0) - ); - break; - } - default: assert( pStep->op==TK_SELECT ); { - SelectDest sDest; - Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0); - sqlite3SelectDestInit(&sDest, SRT_Discard, 0); - sqlite3Select(pParse, pSelect, &sDest); - sqlite3SelectDelete(db, pSelect); - break; - } - } - if( pStep->op!=TK_SELECT ){ - sqlite3VdbeAddOp0(v, OP_ResetCount); - } - } - - return 0; -} - -#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS -/* -** This function is used to add VdbeComment() annotations to a VDBE -** program. It is not used in production code, only for debugging. -*/ -static const char *onErrorText(int onError){ - switch( onError ){ - case OE_Abort: return "abort"; - case OE_Rollback: return "rollback"; - case OE_Fail: return "fail"; - case OE_Replace: return "replace"; - case OE_Ignore: return "ignore"; - case OE_Default: return "default"; - } - return "n/a"; -} -#endif - -/* -** Parse context structure pFrom has just been used to create a sub-vdbe -** (trigger program). If an error has occurred, transfer error information -** from pFrom to pTo. -*/ -static void transferParseError(Parse *pTo, Parse *pFrom){ - assert( pFrom->zErrMsg==0 || pFrom->nErr ); - assert( pTo->zErrMsg==0 || pTo->nErr ); - if( pTo->nErr==0 ){ - pTo->zErrMsg = pFrom->zErrMsg; - pTo->nErr = pFrom->nErr; - pTo->rc = pFrom->rc; - }else{ - sqlite3DbFree(pFrom->db, pFrom->zErrMsg); - } -} - -/* -** Create and populate a new TriggerPrg object with a sub-program -** implementing trigger pTrigger with ON CONFLICT policy orconf. -*/ -static TriggerPrg *codeRowTrigger( - Parse *pParse, /* Current parse context */ - Trigger *pTrigger, /* Trigger to code */ - Table *pTab, /* The table pTrigger is attached to */ - int orconf /* ON CONFLICT policy to code trigger program with */ -){ - Parse *pTop = sqlite3ParseToplevel(pParse); - sqlite3 *db = pParse->db; /* Database handle */ - TriggerPrg *pPrg; /* Value to return */ - Expr *pWhen = 0; /* Duplicate of trigger WHEN expression */ - Vdbe *v; /* Temporary VM */ - NameContext sNC; /* Name context for sub-vdbe */ - SubProgram *pProgram = 0; /* Sub-vdbe for trigger program */ - Parse *pSubParse; /* Parse context for sub-vdbe */ - int iEndTrigger = 0; /* Label to jump to if WHEN is false */ - - assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) ); - assert( pTop->pVdbe ); - - /* Allocate the TriggerPrg and SubProgram objects. To ensure that they - ** are freed if an error occurs, link them into the Parse.pTriggerPrg - ** list of the top-level Parse object sooner rather than later. */ - pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg)); - if( !pPrg ) return 0; - pPrg->pNext = pTop->pTriggerPrg; - pTop->pTriggerPrg = pPrg; - pPrg->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram)); - if( !pProgram ) return 0; - sqlite3VdbeLinkSubProgram(pTop->pVdbe, pProgram); - pPrg->pTrigger = pTrigger; - pPrg->orconf = orconf; - pPrg->aColmask[0] = 0xffffffff; - pPrg->aColmask[1] = 0xffffffff; - - /* Allocate and populate a new Parse context to use for coding the - ** trigger sub-program. */ - pSubParse = sqlite3StackAllocZero(db, sizeof(Parse)); - if( !pSubParse ) return 0; - memset(&sNC, 0, sizeof(sNC)); - sNC.pParse = pSubParse; - pSubParse->db = db; - pSubParse->pTriggerTab = pTab; - pSubParse->pToplevel = pTop; - pSubParse->zAuthContext = pTrigger->zName; - pSubParse->eTriggerOp = pTrigger->op; - pSubParse->nQueryLoop = pParse->nQueryLoop; - - v = sqlite3GetVdbe(pSubParse); - if( v ){ - VdbeComment((v, "Start: %s.%s (%s %s%s%s ON %s)", - pTrigger->zName, onErrorText(orconf), - (pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"), - (pTrigger->op==TK_UPDATE ? "UPDATE" : ""), - (pTrigger->op==TK_INSERT ? "INSERT" : ""), - (pTrigger->op==TK_DELETE ? "DELETE" : ""), - pTab->zName - )); -#ifndef SQLITE_OMIT_TRACE - sqlite3VdbeChangeP4(v, -1, - sqlite3MPrintf(db, "-- TRIGGER %s", pTrigger->zName), P4_DYNAMIC - ); -#endif - - /* If one was specified, code the WHEN clause. If it evaluates to false - ** (or NULL) the sub-vdbe is immediately halted by jumping to the - ** OP_Halt inserted at the end of the program. */ - if( pTrigger->pWhen ){ - pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0); - if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen) - && db->mallocFailed==0 - ){ - iEndTrigger = sqlite3VdbeMakeLabel(v); - sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL); - } - sqlite3ExprDelete(db, pWhen); - } - - /* Code the trigger program into the sub-vdbe. */ - codeTriggerProgram(pSubParse, pTrigger->step_list, orconf); - - /* Insert an OP_Halt at the end of the sub-program. */ - if( iEndTrigger ){ - sqlite3VdbeResolveLabel(v, iEndTrigger); - } - sqlite3VdbeAddOp0(v, OP_Halt); - VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf))); - - transferParseError(pParse, pSubParse); - if( db->mallocFailed==0 ){ - pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg); - } - pProgram->nMem = pSubParse->nMem; - pProgram->nCsr = pSubParse->nTab; - pProgram->nOnce = pSubParse->nOnce; - pProgram->token = (void *)pTrigger; - pPrg->aColmask[0] = pSubParse->oldmask; - pPrg->aColmask[1] = pSubParse->newmask; - sqlite3VdbeDelete(v); - } - - assert( !pSubParse->pAinc && !pSubParse->pZombieTab ); - assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg ); - sqlite3ParserReset(pSubParse); - sqlite3StackFree(db, pSubParse); - - return pPrg; -} - -/* -** Return a pointer to a TriggerPrg object containing the sub-program for -** trigger pTrigger with default ON CONFLICT algorithm orconf. If no such -** TriggerPrg object exists, a new object is allocated and populated before -** being returned. -*/ -static TriggerPrg *getRowTrigger( - Parse *pParse, /* Current parse context */ - Trigger *pTrigger, /* Trigger to code */ - Table *pTab, /* The table trigger pTrigger is attached to */ - int orconf /* ON CONFLICT algorithm. */ -){ - Parse *pRoot = sqlite3ParseToplevel(pParse); - TriggerPrg *pPrg; - - assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) ); - - /* It may be that this trigger has already been coded (or is in the - ** process of being coded). If this is the case, then an entry with - ** a matching TriggerPrg.pTrigger field will be present somewhere - ** in the Parse.pTriggerPrg list. Search for such an entry. */ - for(pPrg=pRoot->pTriggerPrg; - pPrg && (pPrg->pTrigger!=pTrigger || pPrg->orconf!=orconf); - pPrg=pPrg->pNext - ); - - /* If an existing TriggerPrg could not be located, create a new one. */ - if( !pPrg ){ - pPrg = codeRowTrigger(pParse, pTrigger, pTab, orconf); - } - - return pPrg; -} - -/* -** Generate code for the trigger program associated with trigger p on -** table pTab. The reg, orconf and ignoreJump parameters passed to this -** function are the same as those described in the header function for -** sqlite3CodeRowTrigger() -*/ -void sqlite3CodeRowTriggerDirect( - Parse *pParse, /* Parse context */ - Trigger *p, /* Trigger to code */ - Table *pTab, /* The table to code triggers from */ - int reg, /* Reg array containing OLD.* and NEW.* values */ - int orconf, /* ON CONFLICT policy */ - int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */ -){ - Vdbe *v = sqlite3GetVdbe(pParse); /* Main VM */ - TriggerPrg *pPrg; - pPrg = getRowTrigger(pParse, p, pTab, orconf); - assert( pPrg || pParse->nErr || pParse->db->mallocFailed ); - - /* Code the OP_Program opcode in the parent VDBE. P4 of the OP_Program - ** is a pointer to the sub-vdbe containing the trigger program. */ - if( pPrg ){ - int bRecursive = (p->zName && 0==(pParse->db->flags&SQLITE_RecTriggers)); - - sqlite3VdbeAddOp3(v, OP_Program, reg, ignoreJump, ++pParse->nMem); - sqlite3VdbeChangeP4(v, -1, (const char *)pPrg->pProgram, P4_SUBPROGRAM); - VdbeComment( - (v, "Call: %s.%s", (p->zName?p->zName:"fkey"), onErrorText(orconf))); - - /* Set the P5 operand of the OP_Program instruction to non-zero if - ** recursive invocation of this trigger program is disallowed. Recursive - ** invocation is disallowed if (a) the sub-program is really a trigger, - ** not a foreign key action, and (b) the flag to enable recursive triggers - ** is clear. */ - sqlite3VdbeChangeP5(v, (u8)bRecursive); - } -} - -/* -** This is called to code the required FOR EACH ROW triggers for an operation -** on table pTab. The operation to code triggers for (INSERT, UPDATE or DELETE) -** is given by the op parameter. The tr_tm parameter determines whether the -** BEFORE or AFTER triggers are coded. If the operation is an UPDATE, then -** parameter pChanges is passed the list of columns being modified. -** -** If there are no triggers that fire at the specified time for the specified -** operation on pTab, this function is a no-op. -** -** The reg argument is the address of the first in an array of registers -** that contain the values substituted for the new.* and old.* references -** in the trigger program. If N is the number of columns in table pTab -** (a copy of pTab->nCol), then registers are populated as follows: -** -** Register Contains -** ------------------------------------------------------ -** reg+0 OLD.rowid -** reg+1 OLD.* value of left-most column of pTab -** ... ... -** reg+N OLD.* value of right-most column of pTab -** reg+N+1 NEW.rowid -** reg+N+2 OLD.* value of left-most column of pTab -** ... ... -** reg+N+N+1 NEW.* value of right-most column of pTab -** -** For ON DELETE triggers, the registers containing the NEW.* values will -** never be accessed by the trigger program, so they are not allocated or -** populated by the caller (there is no data to populate them with anyway). -** Similarly, for ON INSERT triggers the values stored in the OLD.* registers -** are never accessed, and so are not allocated by the caller. So, for an -** ON INSERT trigger, the value passed to this function as parameter reg -** is not a readable register, although registers (reg+N) through -** (reg+N+N+1) are. -** -** Parameter orconf is the default conflict resolution algorithm for the -** trigger program to use (REPLACE, IGNORE etc.). Parameter ignoreJump -** is the instruction that control should jump to if a trigger program -** raises an IGNORE exception. -*/ -void sqlite3CodeRowTrigger( - Parse *pParse, /* Parse context */ - Trigger *pTrigger, /* List of triggers on table pTab */ - 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 reg, /* The first in an array of registers (see above) */ - int orconf, /* ON CONFLICT policy */ - int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */ -){ - Trigger *p; /* Used to iterate through pTrigger list */ - - assert( op==TK_UPDATE || op==TK_INSERT || op==TK_DELETE ); - assert( tr_tm==TRIGGER_BEFORE || tr_tm==TRIGGER_AFTER ); - assert( (op==TK_UPDATE)==(pChanges!=0) ); - - for(p=pTrigger; p; p=p->pNext){ - - /* Sanity checking: The schema for the trigger and for the table are - ** always defined. The trigger must be in the same schema as the table - ** or else it must be a TEMP trigger. */ - assert( p->pSchema!=0 ); - assert( p->pTabSchema!=0 ); - assert( p->pSchema==p->pTabSchema - || p->pSchema==pParse->db->aDb[1].pSchema ); - - /* Determine whether we should code this trigger */ - if( p->op==op - && p->tr_tm==tr_tm - && checkColumnOverlap(p->pColumns, pChanges) - ){ - sqlite3CodeRowTriggerDirect(pParse, p, pTab, reg, orconf, ignoreJump); - } - } -} - -/* -** Triggers may access values stored in the old.* or new.* pseudo-table. -** This function returns a 32-bit bitmask indicating which columns of the -** old.* or new.* tables actually are used by triggers. This information -** may be used by the caller, for example, to avoid having to load the entire -** old.* record into memory when executing an UPDATE or DELETE command. -** -** Bit 0 of the returned mask is set if the left-most column of the -** table may be accessed using an [old|new].<col> reference. Bit 1 is set if -** the second leftmost column value is required, and so on. If there -** are more than 32 columns in the table, and at least one of the columns -** with an index greater than 32 may be accessed, 0xffffffff is returned. -** -** It is not possible to determine if the old.rowid or new.rowid column is -** accessed by triggers. The caller must always assume that it is. -** -** Parameter isNew must be either 1 or 0. If it is 0, then the mask returned -** applies to the old.* table. If 1, the new.* table. -** -** Parameter tr_tm must be a mask with one or both of the TRIGGER_BEFORE -** and TRIGGER_AFTER bits set. Values accessed by BEFORE triggers are only -** included in the returned mask if the TRIGGER_BEFORE bit is set in the -** tr_tm parameter. Similarly, values accessed by AFTER triggers are only -** included in the returned mask if the TRIGGER_AFTER bit is set in tr_tm. -*/ -u32 sqlite3TriggerColmask( - Parse *pParse, /* Parse context */ - Trigger *pTrigger, /* List of triggers on table pTab */ - ExprList *pChanges, /* Changes list for any UPDATE OF triggers */ - int isNew, /* 1 for new.* ref mask, 0 for old.* ref mask */ - int tr_tm, /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */ - Table *pTab, /* The table to code triggers from */ - int orconf /* Default ON CONFLICT policy for trigger steps */ -){ - const int op = pChanges ? TK_UPDATE : TK_DELETE; - u32 mask = 0; - Trigger *p; - - assert( isNew==1 || isNew==0 ); - for(p=pTrigger; p; p=p->pNext){ - if( p->op==op && (tr_tm&p->tr_tm) - && checkColumnOverlap(p->pColumns,pChanges) - ){ - TriggerPrg *pPrg; - pPrg = getRowTrigger(pParse, p, pTab, orconf); - if( pPrg ){ - mask |= pPrg->aColmask[isNew]; - } - } - } - - return mask; -} - -#endif /* !defined(SQLITE_OMIT_TRIGGER) */ |