1.1 --- a/extensions/sqlite/sqlite-source/trigger.c Fri Jul 11 06:51:21 2008 +0000
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,839 +0,0 @@
1.4 -/*
1.5 -**
1.6 -** The author disclaims copyright to this source code. In place of
1.7 -** a legal notice, here is a blessing:
1.8 -**
1.9 -** May you do good and not evil.
1.10 -** May you find forgiveness for yourself and forgive others.
1.11 -** May you share freely, never taking more than you give.
1.12 -**
1.13 -*************************************************************************
1.14 -*
1.15 -*/
1.16 -#include "sqliteInt.h"
1.17 -
1.18 -#ifndef SQLITE_OMIT_TRIGGER
1.19 -/*
1.20 -** Delete a linked list of TriggerStep structures.
1.21 -*/
1.22 -void sqlite3DeleteTriggerStep(TriggerStep *pTriggerStep){
1.23 - while( pTriggerStep ){
1.24 - TriggerStep * pTmp = pTriggerStep;
1.25 - pTriggerStep = pTriggerStep->pNext;
1.26 -
1.27 - if( pTmp->target.dyn ) sqlite3_free((char*)pTmp->target.z);
1.28 - sqlite3ExprDelete(pTmp->pWhere);
1.29 - sqlite3ExprListDelete(pTmp->pExprList);
1.30 - sqlite3SelectDelete(pTmp->pSelect);
1.31 - sqlite3IdListDelete(pTmp->pIdList);
1.32 -
1.33 - sqlite3_free(pTmp);
1.34 - }
1.35 -}
1.36 -
1.37 -/*
1.38 -** This is called by the parser when it sees a CREATE TRIGGER statement
1.39 -** up to the point of the BEGIN before the trigger actions. A Trigger
1.40 -** structure is generated based on the information available and stored
1.41 -** in pParse->pNewTrigger. After the trigger actions have been parsed, the
1.42 -** sqlite3FinishTrigger() function is called to complete the trigger
1.43 -** construction process.
1.44 -*/
1.45 -void sqlite3BeginTrigger(
1.46 - Parse *pParse, /* The parse context of the CREATE TRIGGER statement */
1.47 - Token *pName1, /* The name of the trigger */
1.48 - Token *pName2, /* The name of the trigger */
1.49 - int tr_tm, /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
1.50 - int op, /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
1.51 - IdList *pColumns, /* column list if this is an UPDATE OF trigger */
1.52 - SrcList *pTableName,/* The name of the table/view the trigger applies to */
1.53 - Expr *pWhen, /* WHEN clause */
1.54 - int isTemp, /* True if the TEMPORARY keyword is present */
1.55 - int noErr /* Suppress errors if the trigger already exists */
1.56 -){
1.57 - Trigger *pTrigger = 0;
1.58 - Table *pTab;
1.59 - char *zName = 0; /* Name of the trigger */
1.60 - sqlite3 *db = pParse->db;
1.61 - int iDb; /* The database to store the trigger in */
1.62 - Token *pName; /* The unqualified db name */
1.63 - DbFixer sFix;
1.64 - int iTabDb;
1.65 -
1.66 - assert( pName1!=0 ); /* pName1->z might be NULL, but not pName1 itself */
1.67 - assert( pName2!=0 );
1.68 - if( isTemp ){
1.69 - /* If TEMP was specified, then the trigger name may not be qualified. */
1.70 - if( pName2->n>0 ){
1.71 - sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name");
1.72 - goto trigger_cleanup;
1.73 - }
1.74 - iDb = 1;
1.75 - pName = pName1;
1.76 - }else{
1.77 - /* Figure out the db that the the trigger will be created in */
1.78 - iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
1.79 - if( iDb<0 ){
1.80 - goto trigger_cleanup;
1.81 - }
1.82 - }
1.83 -
1.84 - /* If the trigger name was unqualified, and the table is a temp table,
1.85 - ** then set iDb to 1 to create the trigger in the temporary database.
1.86 - ** If sqlite3SrcListLookup() returns 0, indicating the table does not
1.87 - ** exist, the error is caught by the block below.
1.88 - */
1.89 - if( !pTableName || db->mallocFailed ){
1.90 - goto trigger_cleanup;
1.91 - }
1.92 - pTab = sqlite3SrcListLookup(pParse, pTableName);
1.93 - if( pName2->n==0 && pTab && pTab->pSchema==db->aDb[1].pSchema ){
1.94 - iDb = 1;
1.95 - }
1.96 -
1.97 - /* Ensure the table name matches database name and that the table exists */
1.98 - if( db->mallocFailed ) goto trigger_cleanup;
1.99 - assert( pTableName->nSrc==1 );
1.100 - if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName) &&
1.101 - sqlite3FixSrcList(&sFix, pTableName) ){
1.102 - goto trigger_cleanup;
1.103 - }
1.104 - pTab = sqlite3SrcListLookup(pParse, pTableName);
1.105 - if( !pTab ){
1.106 - /* The table does not exist. */
1.107 - goto trigger_cleanup;
1.108 - }
1.109 - if( IsVirtual(pTab) ){
1.110 - sqlite3ErrorMsg(pParse, "cannot create triggers on virtual tables");
1.111 - goto trigger_cleanup;
1.112 - }
1.113 -
1.114 - /* Check that the trigger name is not reserved and that no trigger of the
1.115 - ** specified name exists */
1.116 - zName = sqlite3NameFromToken(db, pName);
1.117 - if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
1.118 - goto trigger_cleanup;
1.119 - }
1.120 - if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash), zName,strlen(zName)) ){
1.121 - if( !noErr ){
1.122 - sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
1.123 - }
1.124 - goto trigger_cleanup;
1.125 - }
1.126 -
1.127 - /* Do not create a trigger on a system table */
1.128 - if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
1.129 - sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
1.130 - pParse->nErr++;
1.131 - goto trigger_cleanup;
1.132 - }
1.133 -
1.134 - /* INSTEAD of triggers are only for views and views only support INSTEAD
1.135 - ** of triggers.
1.136 - */
1.137 - if( pTab->pSelect && tr_tm!=TK_INSTEAD ){
1.138 - sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S",
1.139 - (tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
1.140 - goto trigger_cleanup;
1.141 - }
1.142 - if( !pTab->pSelect && tr_tm==TK_INSTEAD ){
1.143 - sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
1.144 - " trigger on table: %S", pTableName, 0);
1.145 - goto trigger_cleanup;
1.146 - }
1.147 - iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
1.148 -
1.149 -#ifndef SQLITE_OMIT_AUTHORIZATION
1.150 - {
1.151 - int code = SQLITE_CREATE_TRIGGER;
1.152 - const char *zDb = db->aDb[iTabDb].zName;
1.153 - const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
1.154 - if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
1.155 - if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
1.156 - goto trigger_cleanup;
1.157 - }
1.158 - if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iTabDb),0,zDb)){
1.159 - goto trigger_cleanup;
1.160 - }
1.161 - }
1.162 -#endif
1.163 -
1.164 - /* INSTEAD OF triggers can only appear on views and BEFORE triggers
1.165 - ** cannot appear on views. So we might as well translate every
1.166 - ** INSTEAD OF trigger into a BEFORE trigger. It simplifies code
1.167 - ** elsewhere.
1.168 - */
1.169 - if (tr_tm == TK_INSTEAD){
1.170 - tr_tm = TK_BEFORE;
1.171 - }
1.172 -
1.173 - /* Build the Trigger object */
1.174 - pTrigger = (Trigger*)sqlite3DbMallocZero(db, sizeof(Trigger));
1.175 - if( pTrigger==0 ) goto trigger_cleanup;
1.176 - pTrigger->name = zName;
1.177 - zName = 0;
1.178 - pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName);
1.179 - pTrigger->pSchema = db->aDb[iDb].pSchema;
1.180 - pTrigger->pTabSchema = pTab->pSchema;
1.181 - pTrigger->op = op;
1.182 - pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER;
1.183 - pTrigger->pWhen = sqlite3ExprDup(db, pWhen);
1.184 - pTrigger->pColumns = sqlite3IdListDup(db, pColumns);
1.185 - sqlite3TokenCopy(db, &pTrigger->nameToken,pName);
1.186 - assert( pParse->pNewTrigger==0 );
1.187 - pParse->pNewTrigger = pTrigger;
1.188 -
1.189 -trigger_cleanup:
1.190 - sqlite3_free(zName);
1.191 - sqlite3SrcListDelete(pTableName);
1.192 - sqlite3IdListDelete(pColumns);
1.193 - sqlite3ExprDelete(pWhen);
1.194 - if( !pParse->pNewTrigger ){
1.195 - sqlite3DeleteTrigger(pTrigger);
1.196 - }else{
1.197 - assert( pParse->pNewTrigger==pTrigger );
1.198 - }
1.199 -}
1.200 -
1.201 -/*
1.202 -** This routine is called after all of the trigger actions have been parsed
1.203 -** in order to complete the process of building the trigger.
1.204 -*/
1.205 -void sqlite3FinishTrigger(
1.206 - Parse *pParse, /* Parser context */
1.207 - TriggerStep *pStepList, /* The triggered program */
1.208 - Token *pAll /* Token that describes the complete CREATE TRIGGER */
1.209 -){
1.210 - Trigger *pTrig = 0; /* The trigger whose construction is finishing up */
1.211 - sqlite3 *db = pParse->db; /* The database */
1.212 - DbFixer sFix;
1.213 - int iDb; /* Database containing the trigger */
1.214 -
1.215 - pTrig = pParse->pNewTrigger;
1.216 - pParse->pNewTrigger = 0;
1.217 - if( pParse->nErr || !pTrig ) goto triggerfinish_cleanup;
1.218 - iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
1.219 - pTrig->step_list = pStepList;
1.220 - while( pStepList ){
1.221 - pStepList->pTrig = pTrig;
1.222 - pStepList = pStepList->pNext;
1.223 - }
1.224 - if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", &pTrig->nameToken)
1.225 - && sqlite3FixTriggerStep(&sFix, pTrig->step_list) ){
1.226 - goto triggerfinish_cleanup;
1.227 - }
1.228 -
1.229 - /* if we are not initializing, and this trigger is not on a TEMP table,
1.230 - ** build the sqlite_master entry
1.231 - */
1.232 - if( !db->init.busy ){
1.233 - static const VdbeOpList insertTrig[] = {
1.234 - { OP_NewRowid, 0, 0, 0 },
1.235 - { OP_String8, 0, 0, "trigger" },
1.236 - { OP_String8, 0, 0, 0 }, /* 2: trigger name */
1.237 - { OP_String8, 0, 0, 0 }, /* 3: table name */
1.238 - { OP_Integer, 0, 0, 0 },
1.239 - { OP_String8, 0, 0, "CREATE TRIGGER "},
1.240 - { OP_String8, 0, 0, 0 }, /* 6: SQL */
1.241 - { OP_Concat, 0, 0, 0 },
1.242 - { OP_MakeRecord, 5, 0, "aaada" },
1.243 - { OP_Insert, 0, 0, 0 },
1.244 - };
1.245 - int addr;
1.246 - Vdbe *v;
1.247 -
1.248 - /* Make an entry in the sqlite_master table */
1.249 - v = sqlite3GetVdbe(pParse);
1.250 - if( v==0 ) goto triggerfinish_cleanup;
1.251 - sqlite3BeginWriteOperation(pParse, 0, iDb);
1.252 - sqlite3OpenMasterTable(pParse, iDb);
1.253 - addr = sqlite3VdbeAddOpList(v, ArraySize(insertTrig), insertTrig);
1.254 - sqlite3VdbeChangeP3(v, addr+2, pTrig->name, 0);
1.255 - sqlite3VdbeChangeP3(v, addr+3, pTrig->table, 0);
1.256 - sqlite3VdbeChangeP3(v, addr+6, (char*)pAll->z, pAll->n);
1.257 - sqlite3ChangeCookie(db, v, iDb);
1.258 - sqlite3VdbeAddOp(v, OP_Close, 0, 0);
1.259 - sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0, sqlite3MPrintf(
1.260 - db, "type='trigger' AND name='%q'", pTrig->name), P3_DYNAMIC
1.261 - );
1.262 - }
1.263 -
1.264 - if( db->init.busy ){
1.265 - int n;
1.266 - Table *pTab;
1.267 - Trigger *pDel;
1.268 - pDel = sqlite3HashInsert(&db->aDb[iDb].pSchema->trigHash,
1.269 - pTrig->name, strlen(pTrig->name), pTrig);
1.270 - if( pDel ){
1.271 - assert( pDel==pTrig );
1.272 - db->mallocFailed = 1;
1.273 - goto triggerfinish_cleanup;
1.274 - }
1.275 - n = strlen(pTrig->table) + 1;
1.276 - pTab = sqlite3HashFind(&pTrig->pTabSchema->tblHash, pTrig->table, n);
1.277 - assert( pTab!=0 );
1.278 - pTrig->pNext = pTab->pTrigger;
1.279 - pTab->pTrigger = pTrig;
1.280 - pTrig = 0;
1.281 - }
1.282 -
1.283 -triggerfinish_cleanup:
1.284 - sqlite3DeleteTrigger(pTrig);
1.285 - assert( !pParse->pNewTrigger );
1.286 - sqlite3DeleteTriggerStep(pStepList);
1.287 -}
1.288 -
1.289 -/*
1.290 -** Make a copy of all components of the given trigger step. This has
1.291 -** the effect of copying all Expr.token.z values into memory obtained
1.292 -** from sqlite3_malloc(). As initially created, the Expr.token.z values
1.293 -** all point to the input string that was fed to the parser. But that
1.294 -** string is ephemeral - it will go away as soon as the sqlite3_exec()
1.295 -** call that started the parser exits. This routine makes a persistent
1.296 -** copy of all the Expr.token.z strings so that the TriggerStep structure
1.297 -** will be valid even after the sqlite3_exec() call returns.
1.298 -*/
1.299 -static void sqlitePersistTriggerStep(sqlite3 *db, TriggerStep *p){
1.300 - if( p->target.z ){
1.301 - p->target.z = (u8*)sqlite3DbStrNDup(db, (char*)p->target.z, p->target.n);
1.302 - p->target.dyn = 1;
1.303 - }
1.304 - if( p->pSelect ){
1.305 - Select *pNew = sqlite3SelectDup(db, p->pSelect);
1.306 - sqlite3SelectDelete(p->pSelect);
1.307 - p->pSelect = pNew;
1.308 - }
1.309 - if( p->pWhere ){
1.310 - Expr *pNew = sqlite3ExprDup(db, p->pWhere);
1.311 - sqlite3ExprDelete(p->pWhere);
1.312 - p->pWhere = pNew;
1.313 - }
1.314 - if( p->pExprList ){
1.315 - ExprList *pNew = sqlite3ExprListDup(db, p->pExprList);
1.316 - sqlite3ExprListDelete(p->pExprList);
1.317 - p->pExprList = pNew;
1.318 - }
1.319 - if( p->pIdList ){
1.320 - IdList *pNew = sqlite3IdListDup(db, p->pIdList);
1.321 - sqlite3IdListDelete(p->pIdList);
1.322 - p->pIdList = pNew;
1.323 - }
1.324 -}
1.325 -
1.326 -/*
1.327 -** Turn a SELECT statement (that the pSelect parameter points to) into
1.328 -** a trigger step. Return a pointer to a TriggerStep structure.
1.329 -**
1.330 -** The parser calls this routine when it finds a SELECT statement in
1.331 -** body of a TRIGGER.
1.332 -*/
1.333 -TriggerStep *sqlite3TriggerSelectStep(sqlite3 *db, Select *pSelect){
1.334 - TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
1.335 - if( pTriggerStep==0 ) {
1.336 - sqlite3SelectDelete(pSelect);
1.337 - return 0;
1.338 - }
1.339 -
1.340 - pTriggerStep->op = TK_SELECT;
1.341 - pTriggerStep->pSelect = pSelect;
1.342 - pTriggerStep->orconf = OE_Default;
1.343 - sqlitePersistTriggerStep(db, pTriggerStep);
1.344 -
1.345 - return pTriggerStep;
1.346 -}
1.347 -
1.348 -/*
1.349 -** Build a trigger step out of an INSERT statement. Return a pointer
1.350 -** to the new trigger step.
1.351 -**
1.352 -** The parser calls this routine when it sees an INSERT inside the
1.353 -** body of a trigger.
1.354 -*/
1.355 -TriggerStep *sqlite3TriggerInsertStep(
1.356 - sqlite3 *db, /* The database connection */
1.357 - Token *pTableName, /* Name of the table into which we insert */
1.358 - IdList *pColumn, /* List of columns in pTableName to insert into */
1.359 - ExprList *pEList, /* The VALUE clause: a list of values to be inserted */
1.360 - Select *pSelect, /* A SELECT statement that supplies values */
1.361 - int orconf /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */
1.362 -){
1.363 - TriggerStep *pTriggerStep;
1.364 -
1.365 - assert(pEList == 0 || pSelect == 0);
1.366 - assert(pEList != 0 || pSelect != 0 || db->mallocFailed);
1.367 -
1.368 - pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
1.369 - if( pTriggerStep ){
1.370 - pTriggerStep->op = TK_INSERT;
1.371 - pTriggerStep->pSelect = pSelect;
1.372 - pTriggerStep->target = *pTableName;
1.373 - pTriggerStep->pIdList = pColumn;
1.374 - pTriggerStep->pExprList = pEList;
1.375 - pTriggerStep->orconf = orconf;
1.376 - sqlitePersistTriggerStep(db, pTriggerStep);
1.377 - }else{
1.378 - sqlite3IdListDelete(pColumn);
1.379 - sqlite3ExprListDelete(pEList);
1.380 - sqlite3SelectDelete(pSelect);
1.381 - }
1.382 -
1.383 - return pTriggerStep;
1.384 -}
1.385 -
1.386 -/*
1.387 -** Construct a trigger step that implements an UPDATE statement and return
1.388 -** a pointer to that trigger step. The parser calls this routine when it
1.389 -** sees an UPDATE statement inside the body of a CREATE TRIGGER.
1.390 -*/
1.391 -TriggerStep *sqlite3TriggerUpdateStep(
1.392 - sqlite3 *db, /* The database connection */
1.393 - Token *pTableName, /* Name of the table to be updated */
1.394 - ExprList *pEList, /* The SET clause: list of column and new values */
1.395 - Expr *pWhere, /* The WHERE clause */
1.396 - int orconf /* The conflict algorithm. (OE_Abort, OE_Ignore, etc) */
1.397 -){
1.398 - TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
1.399 - if( pTriggerStep==0 ){
1.400 - sqlite3ExprListDelete(pEList);
1.401 - sqlite3ExprDelete(pWhere);
1.402 - return 0;
1.403 - }
1.404 -
1.405 - pTriggerStep->op = TK_UPDATE;
1.406 - pTriggerStep->target = *pTableName;
1.407 - pTriggerStep->pExprList = pEList;
1.408 - pTriggerStep->pWhere = pWhere;
1.409 - pTriggerStep->orconf = orconf;
1.410 - sqlitePersistTriggerStep(db, pTriggerStep);
1.411 -
1.412 - return pTriggerStep;
1.413 -}
1.414 -
1.415 -/*
1.416 -** Construct a trigger step that implements a DELETE statement and return
1.417 -** a pointer to that trigger step. The parser calls this routine when it
1.418 -** sees a DELETE statement inside the body of a CREATE TRIGGER.
1.419 -*/
1.420 -TriggerStep *sqlite3TriggerDeleteStep(
1.421 - sqlite3 *db, /* Database connection */
1.422 - Token *pTableName, /* The table from which rows are deleted */
1.423 - Expr *pWhere /* The WHERE clause */
1.424 -){
1.425 - TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
1.426 - if( pTriggerStep==0 ){
1.427 - sqlite3ExprDelete(pWhere);
1.428 - return 0;
1.429 - }
1.430 -
1.431 - pTriggerStep->op = TK_DELETE;
1.432 - pTriggerStep->target = *pTableName;
1.433 - pTriggerStep->pWhere = pWhere;
1.434 - pTriggerStep->orconf = OE_Default;
1.435 - sqlitePersistTriggerStep(db, pTriggerStep);
1.436 -
1.437 - return pTriggerStep;
1.438 -}
1.439 -
1.440 -/*
1.441 -** Recursively delete a Trigger structure
1.442 -*/
1.443 -void sqlite3DeleteTrigger(Trigger *pTrigger){
1.444 - if( pTrigger==0 ) return;
1.445 - sqlite3DeleteTriggerStep(pTrigger->step_list);
1.446 - sqlite3_free(pTrigger->name);
1.447 - sqlite3_free(pTrigger->table);
1.448 - sqlite3ExprDelete(pTrigger->pWhen);
1.449 - sqlite3IdListDelete(pTrigger->pColumns);
1.450 - if( pTrigger->nameToken.dyn ) sqlite3_free((char*)pTrigger->nameToken.z);
1.451 - sqlite3_free(pTrigger);
1.452 -}
1.453 -
1.454 -/*
1.455 -** This function is called to drop a trigger from the database schema.
1.456 -**
1.457 -** This may be called directly from the parser and therefore identifies
1.458 -** the trigger by name. The sqlite3DropTriggerPtr() routine does the
1.459 -** same job as this routine except it takes a pointer to the trigger
1.460 -** instead of the trigger name.
1.461 -**/
1.462 -void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr){
1.463 - Trigger *pTrigger = 0;
1.464 - int i;
1.465 - const char *zDb;
1.466 - const char *zName;
1.467 - int nName;
1.468 - sqlite3 *db = pParse->db;
1.469 -
1.470 - if( db->mallocFailed ) goto drop_trigger_cleanup;
1.471 - if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
1.472 - goto drop_trigger_cleanup;
1.473 - }
1.474 -
1.475 - assert( pName->nSrc==1 );
1.476 - zDb = pName->a[0].zDatabase;
1.477 - zName = pName->a[0].zName;
1.478 - nName = strlen(zName);
1.479 - for(i=OMIT_TEMPDB; i<db->nDb; i++){
1.480 - int j = (i<2) ? i^1 : i; /* Search TEMP before MAIN */
1.481 - if( zDb && sqlite3StrICmp(db->aDb[j].zName, zDb) ) continue;
1.482 - pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName, nName);
1.483 - if( pTrigger ) break;
1.484 - }
1.485 - if( !pTrigger ){
1.486 - if( !noErr ){
1.487 - sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0);
1.488 - }
1.489 - goto drop_trigger_cleanup;
1.490 - }
1.491 - sqlite3DropTriggerPtr(pParse, pTrigger);
1.492 -
1.493 -drop_trigger_cleanup:
1.494 - sqlite3SrcListDelete(pName);
1.495 -}
1.496 -
1.497 -/*
1.498 -** Return a pointer to the Table structure for the table that a trigger
1.499 -** is set on.
1.500 -*/
1.501 -static Table *tableOfTrigger(Trigger *pTrigger){
1.502 - int n = strlen(pTrigger->table) + 1;
1.503 - return sqlite3HashFind(&pTrigger->pTabSchema->tblHash, pTrigger->table, n);
1.504 -}
1.505 -
1.506 -
1.507 -/*
1.508 -** Drop a trigger given a pointer to that trigger.
1.509 -*/
1.510 -void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
1.511 - Table *pTable;
1.512 - Vdbe *v;
1.513 - sqlite3 *db = pParse->db;
1.514 - int iDb;
1.515 -
1.516 - iDb = sqlite3SchemaToIndex(pParse->db, pTrigger->pSchema);
1.517 - assert( iDb>=0 && iDb<db->nDb );
1.518 - pTable = tableOfTrigger(pTrigger);
1.519 - assert( pTable );
1.520 - assert( pTable->pSchema==pTrigger->pSchema || iDb==1 );
1.521 -#ifndef SQLITE_OMIT_AUTHORIZATION
1.522 - {
1.523 - int code = SQLITE_DROP_TRIGGER;
1.524 - const char *zDb = db->aDb[iDb].zName;
1.525 - const char *zTab = SCHEMA_TABLE(iDb);
1.526 - if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;
1.527 - if( sqlite3AuthCheck(pParse, code, pTrigger->name, pTable->zName, zDb) ||
1.528 - sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
1.529 - return;
1.530 - }
1.531 - }
1.532 -#endif
1.533 -
1.534 - /* Generate code to destroy the database record of the trigger.
1.535 - */
1.536 - assert( pTable!=0 );
1.537 - if( (v = sqlite3GetVdbe(pParse))!=0 ){
1.538 - int base;
1.539 - static const VdbeOpList dropTrigger[] = {
1.540 - { OP_Rewind, 0, ADDR(9), 0},
1.541 - { OP_String8, 0, 0, 0}, /* 1 */
1.542 - { OP_Column, 0, 1, 0},
1.543 - { OP_Ne, 0, ADDR(8), 0},
1.544 - { OP_String8, 0, 0, "trigger"},
1.545 - { OP_Column, 0, 0, 0},
1.546 - { OP_Ne, 0, ADDR(8), 0},
1.547 - { OP_Delete, 0, 0, 0},
1.548 - { OP_Next, 0, ADDR(1), 0}, /* 8 */
1.549 - };
1.550 -
1.551 - sqlite3BeginWriteOperation(pParse, 0, iDb);
1.552 - sqlite3OpenMasterTable(pParse, iDb);
1.553 - base = sqlite3VdbeAddOpList(v, ArraySize(dropTrigger), dropTrigger);
1.554 - sqlite3VdbeChangeP3(v, base+1, pTrigger->name, 0);
1.555 - sqlite3ChangeCookie(db, v, iDb);
1.556 - sqlite3VdbeAddOp(v, OP_Close, 0, 0);
1.557 - sqlite3VdbeOp3(v, OP_DropTrigger, iDb, 0, pTrigger->name, 0);
1.558 - }
1.559 -}
1.560 -
1.561 -/*
1.562 -** Remove a trigger from the hash tables of the sqlite* pointer.
1.563 -*/
1.564 -void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){
1.565 - Trigger *pTrigger;
1.566 - int nName = strlen(zName);
1.567 - pTrigger = sqlite3HashInsert(&(db->aDb[iDb].pSchema->trigHash),
1.568 - zName, nName, 0);
1.569 - if( pTrigger ){
1.570 - Table *pTable = tableOfTrigger(pTrigger);
1.571 - assert( pTable!=0 );
1.572 - if( pTable->pTrigger == pTrigger ){
1.573 - pTable->pTrigger = pTrigger->pNext;
1.574 - }else{
1.575 - Trigger *cc = pTable->pTrigger;
1.576 - while( cc ){
1.577 - if( cc->pNext == pTrigger ){
1.578 - cc->pNext = cc->pNext->pNext;
1.579 - break;
1.580 - }
1.581 - cc = cc->pNext;
1.582 - }
1.583 - assert(cc);
1.584 - }
1.585 - sqlite3DeleteTrigger(pTrigger);
1.586 - db->flags |= SQLITE_InternChanges;
1.587 - }
1.588 -}
1.589 -
1.590 -/*
1.591 -** pEList is the SET clause of an UPDATE statement. Each entry
1.592 -** in pEList is of the format <id>=<expr>. If any of the entries
1.593 -** in pEList have an <id> which matches an identifier in pIdList,
1.594 -** then return TRUE. If pIdList==NULL, then it is considered a
1.595 -** wildcard that matches anything. Likewise if pEList==NULL then
1.596 -** it matches anything so always return true. Return false only
1.597 -** if there is no match.
1.598 -*/
1.599 -static int checkColumnOverLap(IdList *pIdList, ExprList *pEList){
1.600 - int e;
1.601 - if( !pIdList || !pEList ) return 1;
1.602 - for(e=0; e<pEList->nExpr; e++){
1.603 - if( sqlite3IdListIndex(pIdList, pEList->a[e].zName)>=0 ) return 1;
1.604 - }
1.605 - return 0;
1.606 -}
1.607 -
1.608 -/*
1.609 -** Return a bit vector to indicate what kind of triggers exist for operation
1.610 -** "op" on table pTab. If pChanges is not NULL then it is a list of columns
1.611 -** that are being updated. Triggers only match if the ON clause of the
1.612 -** trigger definition overlaps the set of columns being updated.
1.613 -**
1.614 -** The returned bit vector is some combination of TRIGGER_BEFORE and
1.615 -** TRIGGER_AFTER.
1.616 -*/
1.617 -int sqlite3TriggersExist(
1.618 - Parse *pParse, /* Used to check for recursive triggers */
1.619 - Table *pTab, /* The table the contains the triggers */
1.620 - int op, /* one of TK_DELETE, TK_INSERT, TK_UPDATE */
1.621 - ExprList *pChanges /* Columns that change in an UPDATE statement */
1.622 -){
1.623 - Trigger *pTrigger;
1.624 - int mask = 0;
1.625 -
1.626 - pTrigger = IsVirtual(pTab) ? 0 : pTab->pTrigger;
1.627 - while( pTrigger ){
1.628 - if( pTrigger->op==op && checkColumnOverLap(pTrigger->pColumns, pChanges) ){
1.629 - mask |= pTrigger->tr_tm;
1.630 - }
1.631 - pTrigger = pTrigger->pNext;
1.632 - }
1.633 - return mask;
1.634 -}
1.635 -
1.636 -/*
1.637 -** Convert the pStep->target token into a SrcList and return a pointer
1.638 -** to that SrcList.
1.639 -**
1.640 -** This routine adds a specific database name, if needed, to the target when
1.641 -** forming the SrcList. This prevents a trigger in one database from
1.642 -** referring to a target in another database. An exception is when the
1.643 -** trigger is in TEMP in which case it can refer to any other database it
1.644 -** wants.
1.645 -*/
1.646 -static SrcList *targetSrcList(
1.647 - Parse *pParse, /* The parsing context */
1.648 - TriggerStep *pStep /* The trigger containing the target token */
1.649 -){
1.650 - Token sDb; /* Dummy database name token */
1.651 - int iDb; /* Index of the database to use */
1.652 - SrcList *pSrc; /* SrcList to be returned */
1.653 -
1.654 - iDb = sqlite3SchemaToIndex(pParse->db, pStep->pTrig->pSchema);
1.655 - if( iDb==0 || iDb>=2 ){
1.656 - assert( iDb<pParse->db->nDb );
1.657 - sDb.z = (u8*)pParse->db->aDb[iDb].zName;
1.658 - sDb.n = strlen((char*)sDb.z);
1.659 - pSrc = sqlite3SrcListAppend(pParse->db, 0, &sDb, &pStep->target);
1.660 - } else {
1.661 - pSrc = sqlite3SrcListAppend(pParse->db, 0, &pStep->target, 0);
1.662 - }
1.663 - return pSrc;
1.664 -}
1.665 -
1.666 -/*
1.667 -** Generate VDBE code for zero or more statements inside the body of a
1.668 -** trigger.
1.669 -*/
1.670 -static int codeTriggerProgram(
1.671 - Parse *pParse, /* The parser context */
1.672 - TriggerStep *pStepList, /* List of statements inside the trigger body */
1.673 - int orconfin /* Conflict algorithm. (OE_Abort, etc) */
1.674 -){
1.675 - TriggerStep * pTriggerStep = pStepList;
1.676 - int orconf;
1.677 - Vdbe *v = pParse->pVdbe;
1.678 - sqlite3 *db = pParse->db;
1.679 -
1.680 - assert( pTriggerStep!=0 );
1.681 - assert( v!=0 );
1.682 - sqlite3VdbeAddOp(v, OP_ContextPush, 0, 0);
1.683 - VdbeComment((v, "# begin trigger %s", pStepList->pTrig->name));
1.684 - while( pTriggerStep ){
1.685 - orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin;
1.686 - pParse->trigStack->orconf = orconf;
1.687 - switch( pTriggerStep->op ){
1.688 - case TK_SELECT: {
1.689 - Select *ss = sqlite3SelectDup(db, pTriggerStep->pSelect);
1.690 - if( ss ){
1.691 - sqlite3SelectResolve(pParse, ss, 0);
1.692 - sqlite3Select(pParse, ss, SRT_Discard, 0, 0, 0, 0, 0);
1.693 - sqlite3SelectDelete(ss);
1.694 - }
1.695 - break;
1.696 - }
1.697 - case TK_UPDATE: {
1.698 - SrcList *pSrc;
1.699 - pSrc = targetSrcList(pParse, pTriggerStep);
1.700 - sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
1.701 - sqlite3Update(pParse, pSrc,
1.702 - sqlite3ExprListDup(db, pTriggerStep->pExprList),
1.703 - sqlite3ExprDup(db, pTriggerStep->pWhere), orconf);
1.704 - sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
1.705 - break;
1.706 - }
1.707 - case TK_INSERT: {
1.708 - SrcList *pSrc;
1.709 - pSrc = targetSrcList(pParse, pTriggerStep);
1.710 - sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
1.711 - sqlite3Insert(pParse, pSrc,
1.712 - sqlite3ExprListDup(db, pTriggerStep->pExprList),
1.713 - sqlite3SelectDup(db, pTriggerStep->pSelect),
1.714 - sqlite3IdListDup(db, pTriggerStep->pIdList), orconf);
1.715 - sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
1.716 - break;
1.717 - }
1.718 - case TK_DELETE: {
1.719 - SrcList *pSrc;
1.720 - sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
1.721 - pSrc = targetSrcList(pParse, pTriggerStep);
1.722 - sqlite3DeleteFrom(pParse, pSrc,
1.723 - sqlite3ExprDup(db, pTriggerStep->pWhere));
1.724 - sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
1.725 - break;
1.726 - }
1.727 - default:
1.728 - assert(0);
1.729 - }
1.730 - pTriggerStep = pTriggerStep->pNext;
1.731 - }
1.732 - sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0);
1.733 - VdbeComment((v, "# end trigger %s", pStepList->pTrig->name));
1.734 -
1.735 - return 0;
1.736 -}
1.737 -
1.738 -/*
1.739 -** This is called to code FOR EACH ROW triggers.
1.740 -**
1.741 -** When the code that this function generates is executed, the following
1.742 -** must be true:
1.743 -**
1.744 -** 1. No cursors may be open in the main database. (But newIdx and oldIdx
1.745 -** can be indices of cursors in temporary tables. See below.)
1.746 -**
1.747 -** 2. If the triggers being coded are ON INSERT or ON UPDATE triggers, then
1.748 -** a temporary vdbe cursor (index newIdx) must be open and pointing at
1.749 -** a row containing values to be substituted for new.* expressions in the
1.750 -** trigger program(s).
1.751 -**
1.752 -** 3. If the triggers being coded are ON DELETE or ON UPDATE triggers, then
1.753 -** a temporary vdbe cursor (index oldIdx) must be open and pointing at
1.754 -** a row containing values to be substituted for old.* expressions in the
1.755 -** trigger program(s).
1.756 -**
1.757 -*/
1.758 -int sqlite3CodeRowTrigger(
1.759 - Parse *pParse, /* Parse context */
1.760 - int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
1.761 - ExprList *pChanges, /* Changes list for any UPDATE OF triggers */
1.762 - int tr_tm, /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
1.763 - Table *pTab, /* The table to code triggers from */
1.764 - int newIdx, /* The indice of the "new" row to access */
1.765 - int oldIdx, /* The indice of the "old" row to access */
1.766 - int orconf, /* ON CONFLICT policy */
1.767 - int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */
1.768 -){
1.769 - Trigger *p;
1.770 - TriggerStack trigStackEntry;
1.771 -
1.772 - assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE);
1.773 - assert(tr_tm == TRIGGER_BEFORE || tr_tm == TRIGGER_AFTER );
1.774 -
1.775 - assert(newIdx != -1 || oldIdx != -1);
1.776 -
1.777 - for(p=pTab->pTrigger; p; p=p->pNext){
1.778 - int fire_this = 0;
1.779 -
1.780 - /* Determine whether we should code this trigger */
1.781 - if(
1.782 - p->op==op &&
1.783 - p->tr_tm==tr_tm &&
1.784 - (p->pSchema==p->pTabSchema || p->pSchema==pParse->db->aDb[1].pSchema) &&
1.785 - (op!=TK_UPDATE||!p->pColumns||checkColumnOverLap(p->pColumns,pChanges))
1.786 - ){
1.787 - TriggerStack *pS; /* Pointer to trigger-stack entry */
1.788 - for(pS=pParse->trigStack; pS && p!=pS->pTrigger; pS=pS->pNext){}
1.789 - if( !pS ){
1.790 - fire_this = 1;
1.791 - }
1.792 -#if 0 /* Give no warning for recursive triggers. Just do not do them */
1.793 - else{
1.794 - sqlite3ErrorMsg(pParse, "recursive triggers not supported (%s)",
1.795 - p->name);
1.796 - return SQLITE_ERROR;
1.797 - }
1.798 -#endif
1.799 - }
1.800 -
1.801 - if( fire_this ){
1.802 - int endTrigger;
1.803 - Expr * whenExpr;
1.804 - AuthContext sContext;
1.805 - NameContext sNC;
1.806 -
1.807 - memset(&sNC, 0, sizeof(sNC));
1.808 - sNC.pParse = pParse;
1.809 -
1.810 - /* Push an entry on to the trigger stack */
1.811 - trigStackEntry.pTrigger = p;
1.812 - trigStackEntry.newIdx = newIdx;
1.813 - trigStackEntry.oldIdx = oldIdx;
1.814 - trigStackEntry.pTab = pTab;
1.815 - trigStackEntry.pNext = pParse->trigStack;
1.816 - trigStackEntry.ignoreJump = ignoreJump;
1.817 - pParse->trigStack = &trigStackEntry;
1.818 - sqlite3AuthContextPush(pParse, &sContext, p->name);
1.819 -
1.820 - /* code the WHEN clause */
1.821 - endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe);
1.822 - whenExpr = sqlite3ExprDup(pParse->db, p->pWhen);
1.823 - if( sqlite3ExprResolveNames(&sNC, whenExpr) ){
1.824 - pParse->trigStack = trigStackEntry.pNext;
1.825 - sqlite3ExprDelete(whenExpr);
1.826 - return 1;
1.827 - }
1.828 - sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, 1);
1.829 - sqlite3ExprDelete(whenExpr);
1.830 -
1.831 - codeTriggerProgram(pParse, p->step_list, orconf);
1.832 -
1.833 - /* Pop the entry off the trigger stack */
1.834 - pParse->trigStack = trigStackEntry.pNext;
1.835 - sqlite3AuthContextPop(&sContext);
1.836 -
1.837 - sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger);
1.838 - }
1.839 - }
1.840 - return 0;
1.841 -}
1.842 -#endif /* !defined(SQLITE_OMIT_TRIGGER) */
