824 lines
27 KiB
C
824 lines
27 KiB
C
/*
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**
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** The author disclaims copyright to this source code. In place of
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** a legal notice, here is a blessing:
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**
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** May you do good and not evil.
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** May you find forgiveness for yourself and forgive others.
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** May you share freely, never taking more than you give.
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**
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*************************************************************************
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*
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*/
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#include "sqliteInt.h"
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#ifndef SQLITE_OMIT_TRIGGER
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/*
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** Delete a linked list of TriggerStep structures.
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*/
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void sqlite3DeleteTriggerStep(TriggerStep *pTriggerStep){
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while( pTriggerStep ){
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TriggerStep * pTmp = pTriggerStep;
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pTriggerStep = pTriggerStep->pNext;
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if( pTmp->target.dyn ) sqliteFree((char*)pTmp->target.z);
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sqlite3ExprDelete(pTmp->pWhere);
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sqlite3ExprListDelete(pTmp->pExprList);
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sqlite3SelectDelete(pTmp->pSelect);
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sqlite3IdListDelete(pTmp->pIdList);
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sqliteFree(pTmp);
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}
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}
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/*
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** This is called by the parser when it sees a CREATE TRIGGER statement
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** up to the point of the BEGIN before the trigger actions. A Trigger
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** structure is generated based on the information available and stored
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** in pParse->pNewTrigger. After the trigger actions have been parsed, the
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** sqlite3FinishTrigger() function is called to complete the trigger
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** construction process.
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*/
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void sqlite3BeginTrigger(
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Parse *pParse, /* The parse context of the CREATE TRIGGER statement */
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Token *pName1, /* The name of the trigger */
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Token *pName2, /* The name of the trigger */
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int tr_tm, /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
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int op, /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
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IdList *pColumns, /* column list if this is an UPDATE OF trigger */
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SrcList *pTableName,/* The name of the table/view the trigger applies to */
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int foreach, /* One of TK_ROW or TK_STATEMENT */
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Expr *pWhen, /* WHEN clause */
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int isTemp, /* True if the TEMPORARY keyword is present */
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int noErr /* Suppress errors if the trigger already exists */
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){
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Trigger *pTrigger = 0;
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Table *pTab;
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char *zName = 0; /* Name of the trigger */
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sqlite3 *db = pParse->db;
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int iDb; /* The database to store the trigger in */
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Token *pName; /* The unqualified db name */
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DbFixer sFix;
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int iTabDb;
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assert( pName1!=0 ); /* pName1->z might be NULL, but not pName1 itself */
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assert( pName2!=0 );
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if( isTemp ){
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/* If TEMP was specified, then the trigger name may not be qualified. */
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if( pName2->n>0 ){
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sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name");
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goto trigger_cleanup;
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}
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iDb = 1;
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pName = pName1;
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}else{
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/* Figure out the db that the the trigger will be created in */
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iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
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if( iDb<0 ){
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goto trigger_cleanup;
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}
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}
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/* If the trigger name was unqualified, and the table is a temp table,
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** then set iDb to 1 to create the trigger in the temporary database.
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** If sqlite3SrcListLookup() returns 0, indicating the table does not
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** exist, the error is caught by the block below.
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*/
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if( !pTableName || sqlite3MallocFailed() ){
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goto trigger_cleanup;
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}
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pTab = sqlite3SrcListLookup(pParse, pTableName);
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if( pName2->n==0 && pTab && pTab->pSchema==db->aDb[1].pSchema ){
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iDb = 1;
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}
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/* Ensure the table name matches database name and that the table exists */
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if( sqlite3MallocFailed() ) goto trigger_cleanup;
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assert( pTableName->nSrc==1 );
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if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName) &&
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sqlite3FixSrcList(&sFix, pTableName) ){
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goto trigger_cleanup;
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}
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pTab = sqlite3SrcListLookup(pParse, pTableName);
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if( !pTab ){
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/* The table does not exist. */
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goto trigger_cleanup;
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}
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if( IsVirtual(pTab) ){
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sqlite3ErrorMsg(pParse, "cannot create triggers on virtual tables");
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goto trigger_cleanup;
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}
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/* Check that the trigger name is not reserved and that no trigger of the
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** specified name exists */
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zName = sqlite3NameFromToken(pName);
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if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
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goto trigger_cleanup;
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}
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if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash), zName,strlen(zName)) ){
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if( !noErr ){
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sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
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}
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goto trigger_cleanup;
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}
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/* Do not create a trigger on a system table */
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if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
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sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
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pParse->nErr++;
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goto trigger_cleanup;
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}
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/* INSTEAD of triggers are only for views and views only support INSTEAD
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** of triggers.
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*/
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if( pTab->pSelect && tr_tm!=TK_INSTEAD ){
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sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S",
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(tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
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goto trigger_cleanup;
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}
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if( !pTab->pSelect && tr_tm==TK_INSTEAD ){
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sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
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" trigger on table: %S", pTableName, 0);
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goto trigger_cleanup;
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}
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iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
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#ifndef SQLITE_OMIT_AUTHORIZATION
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{
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int code = SQLITE_CREATE_TRIGGER;
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const char *zDb = db->aDb[iTabDb].zName;
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const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
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if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
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if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
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goto trigger_cleanup;
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}
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if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iTabDb),0,zDb)){
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goto trigger_cleanup;
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}
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}
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#endif
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/* INSTEAD OF triggers can only appear on views and BEFORE triggers
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** cannot appear on views. So we might as well translate every
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** INSTEAD OF trigger into a BEFORE trigger. It simplifies code
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** elsewhere.
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*/
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if (tr_tm == TK_INSTEAD){
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tr_tm = TK_BEFORE;
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}
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/* Build the Trigger object */
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pTrigger = (Trigger*)sqliteMalloc(sizeof(Trigger));
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if( pTrigger==0 ) goto trigger_cleanup;
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pTrigger->name = zName;
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zName = 0;
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pTrigger->table = sqliteStrDup(pTableName->a[0].zName);
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pTrigger->pSchema = db->aDb[iDb].pSchema;
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pTrigger->pTabSchema = pTab->pSchema;
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pTrigger->op = op;
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pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER;
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pTrigger->pWhen = sqlite3ExprDup(pWhen);
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pTrigger->pColumns = sqlite3IdListDup(pColumns);
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pTrigger->foreach = foreach;
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sqlite3TokenCopy(&pTrigger->nameToken,pName);
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assert( pParse->pNewTrigger==0 );
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pParse->pNewTrigger = pTrigger;
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trigger_cleanup:
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sqliteFree(zName);
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sqlite3SrcListDelete(pTableName);
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sqlite3IdListDelete(pColumns);
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sqlite3ExprDelete(pWhen);
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if( !pParse->pNewTrigger ){
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sqlite3DeleteTrigger(pTrigger);
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}else{
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assert( pParse->pNewTrigger==pTrigger );
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}
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}
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/*
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** This routine is called after all of the trigger actions have been parsed
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** in order to complete the process of building the trigger.
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*/
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void sqlite3FinishTrigger(
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Parse *pParse, /* Parser context */
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TriggerStep *pStepList, /* The triggered program */
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Token *pAll /* Token that describes the complete CREATE TRIGGER */
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){
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Trigger *pTrig = 0; /* The trigger whose construction is finishing up */
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sqlite3 *db = pParse->db; /* The database */
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DbFixer sFix;
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int iDb; /* Database containing the trigger */
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pTrig = pParse->pNewTrigger;
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pParse->pNewTrigger = 0;
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if( pParse->nErr || !pTrig ) goto triggerfinish_cleanup;
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iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
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pTrig->step_list = pStepList;
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while( pStepList ){
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pStepList->pTrig = pTrig;
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pStepList = pStepList->pNext;
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}
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if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", &pTrig->nameToken)
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&& sqlite3FixTriggerStep(&sFix, pTrig->step_list) ){
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goto triggerfinish_cleanup;
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}
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/* if we are not initializing, and this trigger is not on a TEMP table,
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** build the sqlite_master entry
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*/
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if( !db->init.busy ){
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static const VdbeOpList insertTrig[] = {
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{ OP_NewRowid, 0, 0, 0 },
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{ OP_String8, 0, 0, "trigger" },
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{ OP_String8, 0, 0, 0 }, /* 2: trigger name */
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{ OP_String8, 0, 0, 0 }, /* 3: table name */
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{ OP_Integer, 0, 0, 0 },
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{ OP_String8, 0, 0, "CREATE TRIGGER "},
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{ OP_String8, 0, 0, 0 }, /* 6: SQL */
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{ OP_Concat, 0, 0, 0 },
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{ OP_MakeRecord, 5, 0, "aaada" },
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{ OP_Insert, 0, 0, 0 },
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};
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int addr;
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Vdbe *v;
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/* Make an entry in the sqlite_master table */
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v = sqlite3GetVdbe(pParse);
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if( v==0 ) goto triggerfinish_cleanup;
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sqlite3BeginWriteOperation(pParse, 0, iDb);
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sqlite3OpenMasterTable(pParse, iDb);
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addr = sqlite3VdbeAddOpList(v, ArraySize(insertTrig), insertTrig);
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sqlite3VdbeChangeP3(v, addr+2, pTrig->name, 0);
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sqlite3VdbeChangeP3(v, addr+3, pTrig->table, 0);
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sqlite3VdbeChangeP3(v, addr+6, (char*)pAll->z, pAll->n);
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sqlite3ChangeCookie(db, v, iDb);
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sqlite3VdbeAddOp(v, OP_Close, 0, 0);
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sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0,
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sqlite3MPrintf("type='trigger' AND name='%q'", pTrig->name), P3_DYNAMIC);
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}
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if( db->init.busy ){
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int n;
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Table *pTab;
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Trigger *pDel;
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pDel = sqlite3HashInsert(&db->aDb[iDb].pSchema->trigHash,
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pTrig->name, strlen(pTrig->name), pTrig);
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if( pDel ){
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assert( sqlite3MallocFailed() && pDel==pTrig );
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goto triggerfinish_cleanup;
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}
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n = strlen(pTrig->table) + 1;
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pTab = sqlite3HashFind(&pTrig->pTabSchema->tblHash, pTrig->table, n);
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assert( pTab!=0 );
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pTrig->pNext = pTab->pTrigger;
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pTab->pTrigger = pTrig;
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pTrig = 0;
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}
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triggerfinish_cleanup:
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sqlite3DeleteTrigger(pTrig);
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assert( !pParse->pNewTrigger );
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sqlite3DeleteTriggerStep(pStepList);
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}
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/*
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** Make a copy of all components of the given trigger step. This has
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** the effect of copying all Expr.token.z values into memory obtained
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** from sqliteMalloc(). As initially created, the Expr.token.z values
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** all point to the input string that was fed to the parser. But that
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** string is ephemeral - it will go away as soon as the sqlite3_exec()
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** call that started the parser exits. This routine makes a persistent
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** copy of all the Expr.token.z strings so that the TriggerStep structure
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** will be valid even after the sqlite3_exec() call returns.
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*/
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static void sqlitePersistTriggerStep(TriggerStep *p){
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if( p->target.z ){
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p->target.z = (u8*)sqliteStrNDup((char*)p->target.z, p->target.n);
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p->target.dyn = 1;
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}
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if( p->pSelect ){
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Select *pNew = sqlite3SelectDup(p->pSelect);
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sqlite3SelectDelete(p->pSelect);
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p->pSelect = pNew;
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}
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if( p->pWhere ){
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Expr *pNew = sqlite3ExprDup(p->pWhere);
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sqlite3ExprDelete(p->pWhere);
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p->pWhere = pNew;
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}
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if( p->pExprList ){
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ExprList *pNew = sqlite3ExprListDup(p->pExprList);
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sqlite3ExprListDelete(p->pExprList);
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p->pExprList = pNew;
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}
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if( p->pIdList ){
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IdList *pNew = sqlite3IdListDup(p->pIdList);
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sqlite3IdListDelete(p->pIdList);
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p->pIdList = pNew;
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}
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}
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/*
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** Turn a SELECT statement (that the pSelect parameter points to) into
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** a trigger step. Return a pointer to a TriggerStep structure.
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**
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** The parser calls this routine when it finds a SELECT statement in
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** body of a TRIGGER.
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*/
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TriggerStep *sqlite3TriggerSelectStep(Select *pSelect){
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TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep));
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if( pTriggerStep==0 ) {
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sqlite3SelectDelete(pSelect);
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return 0;
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}
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pTriggerStep->op = TK_SELECT;
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pTriggerStep->pSelect = pSelect;
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pTriggerStep->orconf = OE_Default;
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sqlitePersistTriggerStep(pTriggerStep);
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return pTriggerStep;
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}
|
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|
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/*
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** Build a trigger step out of an INSERT statement. Return a pointer
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** to the new trigger step.
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**
|
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** The parser calls this routine when it sees an INSERT inside the
|
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** body of a trigger.
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*/
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TriggerStep *sqlite3TriggerInsertStep(
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Token *pTableName, /* Name of the table into which we insert */
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IdList *pColumn, /* List of columns in pTableName to insert into */
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ExprList *pEList, /* The VALUE clause: a list of values to be inserted */
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Select *pSelect, /* A SELECT statement that supplies values */
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int orconf /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */
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){
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TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep));
|
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|
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assert(pEList == 0 || pSelect == 0);
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assert(pEList != 0 || pSelect != 0);
|
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|
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if( pTriggerStep ){
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pTriggerStep->op = TK_INSERT;
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pTriggerStep->pSelect = pSelect;
|
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pTriggerStep->target = *pTableName;
|
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pTriggerStep->pIdList = pColumn;
|
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pTriggerStep->pExprList = pEList;
|
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pTriggerStep->orconf = orconf;
|
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sqlitePersistTriggerStep(pTriggerStep);
|
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}else{
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sqlite3IdListDelete(pColumn);
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sqlite3ExprListDelete(pEList);
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sqlite3SelectDup(pSelect);
|
|
}
|
|
|
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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
|
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** sees an UPDATE statement inside the body of a CREATE TRIGGER.
|
|
*/
|
|
TriggerStep *sqlite3TriggerUpdateStep(
|
|
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 = sqliteMalloc(sizeof(TriggerStep));
|
|
if( pTriggerStep==0 ) return 0;
|
|
|
|
pTriggerStep->op = TK_UPDATE;
|
|
pTriggerStep->target = *pTableName;
|
|
pTriggerStep->pExprList = pEList;
|
|
pTriggerStep->pWhere = pWhere;
|
|
pTriggerStep->orconf = orconf;
|
|
sqlitePersistTriggerStep(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(Token *pTableName, Expr *pWhere){
|
|
TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep));
|
|
if( pTriggerStep==0 ) return 0;
|
|
|
|
pTriggerStep->op = TK_DELETE;
|
|
pTriggerStep->target = *pTableName;
|
|
pTriggerStep->pWhere = pWhere;
|
|
pTriggerStep->orconf = OE_Default;
|
|
sqlitePersistTriggerStep(pTriggerStep);
|
|
|
|
return pTriggerStep;
|
|
}
|
|
|
|
/*
|
|
** Recursively delete a Trigger structure
|
|
*/
|
|
void sqlite3DeleteTrigger(Trigger *pTrigger){
|
|
if( pTrigger==0 ) return;
|
|
sqlite3DeleteTriggerStep(pTrigger->step_list);
|
|
sqliteFree(pTrigger->name);
|
|
sqliteFree(pTrigger->table);
|
|
sqlite3ExprDelete(pTrigger->pWhen);
|
|
sqlite3IdListDelete(pTrigger->pColumns);
|
|
if( pTrigger->nameToken.dyn ) sqliteFree((char*)pTrigger->nameToken.z);
|
|
sqliteFree(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( sqlite3MallocFailed() ) 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; i<db->nDb; 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(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 && 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->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, 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(pParse, 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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** 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(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 || !pEList ) return 1;
|
|
for(e=0; e<pEList->nExpr; 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( iDb<pParse->db->nDb );
|
|
sDb.z = (u8*)pParse->db->aDb[iDb].zName;
|
|
sDb.n = strlen((char*)sDb.z);
|
|
pSrc = sqlite3SrcListAppend(0, &sDb, &pStep->target);
|
|
} else {
|
|
pSrc = sqlite3SrcListAppend(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;
|
|
|
|
assert( pTriggerStep!=0 );
|
|
assert( v!=0 );
|
|
sqlite3VdbeAddOp(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(pTriggerStep->pSelect);
|
|
if( ss ){
|
|
sqlite3SelectResolve(pParse, ss, 0);
|
|
sqlite3Select(pParse, ss, SRT_Discard, 0, 0, 0, 0, 0);
|
|
sqlite3SelectDelete(ss);
|
|
}
|
|
break;
|
|
}
|
|
case TK_UPDATE: {
|
|
SrcList *pSrc;
|
|
pSrc = targetSrcList(pParse, pTriggerStep);
|
|
sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
|
|
sqlite3Update(pParse, pSrc,
|
|
sqlite3ExprListDup(pTriggerStep->pExprList),
|
|
sqlite3ExprDup(pTriggerStep->pWhere), orconf);
|
|
sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
|
|
break;
|
|
}
|
|
case TK_INSERT: {
|
|
SrcList *pSrc;
|
|
pSrc = targetSrcList(pParse, pTriggerStep);
|
|
sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
|
|
sqlite3Insert(pParse, pSrc,
|
|
sqlite3ExprListDup(pTriggerStep->pExprList),
|
|
sqlite3SelectDup(pTriggerStep->pSelect),
|
|
sqlite3IdListDup(pTriggerStep->pIdList), orconf);
|
|
sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
|
|
break;
|
|
}
|
|
case TK_DELETE: {
|
|
SrcList *pSrc;
|
|
sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
|
|
pSrc = targetSrcList(pParse, pTriggerStep);
|
|
sqlite3DeleteFrom(pParse, pSrc, sqlite3ExprDup(pTriggerStep->pWhere));
|
|
sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
|
|
break;
|
|
}
|
|
default:
|
|
assert(0);
|
|
}
|
|
pTriggerStep = pTriggerStep->pNext;
|
|
}
|
|
sqlite3VdbeAddOp(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).
|
|
**
|
|
*/
|
|
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) */
|
|
){
|
|
Trigger *p;
|
|
TriggerStack trigStackEntry;
|
|
|
|
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==pParse->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;
|
|
|
|
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(p->pWhen);
|
|
if( sqlite3ExprResolveNames(&sNC, whenExpr) ){
|
|
pParse->trigStack = trigStackEntry.pNext;
|
|
sqlite3ExprDelete(whenExpr);
|
|
return 1;
|
|
}
|
|
sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, 1);
|
|
sqlite3ExprDelete(whenExpr);
|
|
|
|
codeTriggerProgram(pParse, p->step_list, orconf);
|
|
|
|
/* Pop the entry off the trigger stack */
|
|
pParse->trigStack = trigStackEntry.pNext;
|
|
sqlite3AuthContextPop(&sContext);
|
|
|
|
sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
#endif /* !defined(SQLITE_OMIT_TRIGGER) */
|