/* ** 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; while( pTriggerStep ){ int saveNTab = pParse->nTab; orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin; pParse->trigStack->orconf = orconf; switch( pTriggerStep->op ){ case TK_SELECT: { Select * ss = sqliteSelectDup(pTriggerStep->pSelect); assert(ss); assert(ss->pSrc); sqliteSelect(pParse, ss, SRT_Discard, 0, 0, 0, 0); sqliteSelectDelete(ss); break; } case TK_UPDATE: { SrcList *pSrc; pSrc = targetSrcList(pParse, pTriggerStep); sqliteVdbeAddOp(pParse->pVdbe, OP_ListPush, 0, 0); sqliteUpdate(pParse, pSrc, sqliteExprListDup(pTriggerStep->pExprList), sqliteExprDup(pTriggerStep->pWhere), orconf); sqliteVdbeAddOp(pParse->pVdbe, OP_ListPop, 0, 0); break; } case TK_INSERT: { SrcList *pSrc; pSrc = targetSrcList(pParse, pTriggerStep); sqliteInsert(pParse, pSrc, sqliteExprListDup(pTriggerStep->pExprList), sqliteSelectDup(pTriggerStep->pSelect), sqliteIdListDup(pTriggerStep->pIdList), orconf); break; } case TK_DELETE: { SrcList *pSrc; sqliteVdbeAddOp(pParse->pVdbe, OP_ListPush, 0, 0); pSrc = targetSrcList(pParse, pTriggerStep); sqliteDeleteFrom(pParse, pSrc, sqliteExprDup(pTriggerStep->pWhere)); sqliteVdbeAddOp(pParse->pVdbe, OP_ListPop, 0, 0); break; } default: assert(0); } pParse->nTab = saveNTab; pTriggerStep = pTriggerStep->pNext; } return 0; }
/* ** Make a copy of all components of the given trigger step. This has ** the effect of copying all Expr.token.z values into memory obtained ** from sqliteMalloc(). As initially created, the Expr.token.z values ** all point to the input string that was fed to the parser. But that ** string is ephemeral - it will go away as soon as the sqlite_exec() ** call that started the parser exits. This routine makes a persistent ** copy of all the Expr.token.z strings so that the TriggerStep structure ** will be valid even after the sqlite_exec() call returns. */ static void sqlitePersistTriggerStep(TriggerStep *p){ if( p->target.z ){ p->target.z = sqliteStrNDup(p->target.z, p->target.n); p->target.dyn = 1; } if( p->pSelect ){ Select *pNew = sqliteSelectDup(p->pSelect); sqliteSelectDelete(p->pSelect); p->pSelect = pNew; } if( p->pWhere ){ Expr *pNew = sqliteExprDup(p->pWhere); sqliteExprDelete(p->pWhere); p->pWhere = pNew; } if( p->pExprList ){ ExprList *pNew = sqliteExprListDup(p->pExprList); sqliteExprListDelete(p->pExprList); p->pExprList = pNew; } if( p->pIdList ){ IdList *pNew = sqliteIdListDup(p->pIdList); sqliteIdListDelete(p->pIdList); p->pIdList = pNew; } }
ExprList *sqliteExprListDup(ExprList *p){ ExprList *pNew; struct ExprList_item *pItem; int i; if( p==0 ) return 0; pNew = sqliteMalloc( sizeof(*pNew) ); if( pNew==0 ) return 0; pNew->nExpr = pNew->nAlloc = p->nExpr; pNew->a = pItem = sqliteMalloc( p->nExpr*sizeof(p->a[0]) ); for(i=0; pItem && i<p->nExpr; i++, pItem++){ Expr *pNewExpr, *pOldExpr; pItem->pExpr = pNewExpr = sqliteExprDup(pOldExpr = p->a[i].pExpr); if( pOldExpr->span.z!=0 && pNewExpr ){ /* Always make a copy of the span for top-level expressions in the ** expression list. The logic in SELECT processing that determines ** the names of columns in the result set needs this information */ sqliteTokenCopy(&pNewExpr->span, &pOldExpr->span); } assert( pNewExpr==0 || pNewExpr->span.z!=0 || pOldExpr->span.z==0 || sqlite_malloc_failed ); pItem->zName = sqliteStrDup(p->a[i].zName); pItem->sortOrder = p->a[i].sortOrder; pItem->isAgg = p->a[i].isAgg; pItem->done = 0; } return pNew; }
/* ** The following group of routines make deep copies of expressions, ** expression lists, ID lists, and select statements. The copies can ** be deleted (by being passed to their respective ...Delete() routines) ** without effecting the originals. ** ** The expression list, ID, and source lists return by sqliteExprListDup(), ** sqliteIdListDup(), and sqliteSrcListDup() can not be further expanded ** by subsequent calls to sqlite*ListAppend() routines. ** ** Any tables that the SrcList might point to are not duplicated. */ Expr *sqliteExprDup(Expr *p){ Expr *pNew; if( p==0 ) return 0; pNew = sqliteMallocRaw( sizeof(*p) ); if( pNew==0 ) return 0; memcpy(pNew, p, sizeof(*pNew)); if( p->token.z!=0 ){ pNew->token.z = sqliteStrDup(p->token.z); pNew->token.dyn = 1; }else{ assert( pNew->token.z==0 ); } pNew->span.z = 0; pNew->pLeft = sqliteExprDup(p->pLeft); pNew->pRight = sqliteExprDup(p->pRight); pNew->pList = sqliteExprListDup(p->pList); pNew->pSelect = sqliteSelectDup(p->pSelect); return pNew; }
Select *sqliteSelectDup(Select *p){ Select *pNew; if( p==0 ) return 0; pNew = sqliteMallocRaw( sizeof(*p) ); if( pNew==0 ) return 0; pNew->isDistinct = p->isDistinct; pNew->pEList = sqliteExprListDup(p->pEList); pNew->pSrc = sqliteSrcListDup(p->pSrc); pNew->pWhere = sqliteExprDup(p->pWhere); pNew->pGroupBy = sqliteExprListDup(p->pGroupBy); pNew->pHaving = sqliteExprDup(p->pHaving); pNew->pOrderBy = sqliteExprListDup(p->pOrderBy); pNew->op = p->op; pNew->pPrior = sqliteSelectDup(p->pPrior); pNew->nLimit = p->nLimit; pNew->nOffset = p->nOffset; pNew->zSelect = 0; pNew->iLimit = -1; pNew->iOffset = -1; return pNew; }
SrcList *sqliteSrcListDup(SrcList *p){ SrcList *pNew; int i; int nByte; if( p==0 ) return 0; nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0); pNew = sqliteMallocRaw( nByte ); if( pNew==0 ) return 0; pNew->nSrc = pNew->nAlloc = p->nSrc; for(i=0; i<p->nSrc; i++){ struct SrcList_item *pNewItem = &pNew->a[i]; struct SrcList_item *pOldItem = &p->a[i]; pNewItem->zDatabase = sqliteStrDup(pOldItem->zDatabase); pNewItem->zName = sqliteStrDup(pOldItem->zName); pNewItem->zAlias = sqliteStrDup(pOldItem->zAlias); pNewItem->jointype = pOldItem->jointype; pNewItem->iCursor = pOldItem->iCursor; pNewItem->pTab = 0; pNewItem->pSelect = sqliteSelectDup(pOldItem->pSelect); pNewItem->pOn = sqliteExprDup(pOldItem->pOn); pNewItem->pUsing = sqliteIdListDup(pOldItem->pUsing); } return pNew; }
/* ** 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 sqliteCodeRowTrigger( 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 TK_BEFORE, TK_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 * pTrigger; TriggerStack * pTriggerStack; assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE); assert(tr_tm == TK_BEFORE || tr_tm == TK_AFTER ); assert(newIdx != -1 || oldIdx != -1); pTrigger = pTab->pTrigger; while( pTrigger ){ int fire_this = 0; /* determine whether we should code this trigger */ if( pTrigger->op == op && pTrigger->tr_tm == tr_tm && pTrigger->foreach == TK_ROW ){ fire_this = 1; pTriggerStack = pParse->trigStack; while( pTriggerStack ){ if( pTriggerStack->pTrigger == pTrigger ){ fire_this = 0; } pTriggerStack = pTriggerStack->pNext; } if( op == TK_UPDATE && pTrigger->pColumns && !checkColumnOverLap(pTrigger->pColumns, pChanges) ){ fire_this = 0; } } if( fire_this && (pTriggerStack = sqliteMalloc(sizeof(TriggerStack)))!=0 ){ int endTrigger; SrcList dummyTablist; Expr * whenExpr; AuthContext sContext; dummyTablist.nSrc = 0; /* Push an entry on to the trigger stack */ pTriggerStack->pTrigger = pTrigger; pTriggerStack->newIdx = newIdx; pTriggerStack->oldIdx = oldIdx; pTriggerStack->pTab = pTab; pTriggerStack->pNext = pParse->trigStack; pTriggerStack->ignoreJump = ignoreJump; pParse->trigStack = pTriggerStack; sqliteAuthContextPush(pParse, &sContext, pTrigger->name); /* code the WHEN clause */ endTrigger = sqliteVdbeMakeLabel(pParse->pVdbe); whenExpr = sqliteExprDup(pTrigger->pWhen); if( sqliteExprResolveIds(pParse, &dummyTablist, 0, whenExpr) ){ pParse->trigStack = pParse->trigStack->pNext; sqliteFree(pTriggerStack); sqliteExprDelete(whenExpr); return 1; } sqliteExprIfFalse(pParse, whenExpr, endTrigger, 1); sqliteExprDelete(whenExpr); sqliteVdbeAddOp(pParse->pVdbe, OP_ContextPush, 0, 0); codeTriggerProgram(pParse, pTrigger->step_list, orconf); sqliteVdbeAddOp(pParse->pVdbe, OP_ContextPop, 0, 0); /* Pop the entry off the trigger stack */ pParse->trigStack = pParse->trigStack->pNext; sqliteAuthContextPop(&sContext); sqliteFree(pTriggerStack); sqliteVdbeResolveLabel(pParse->pVdbe, endTrigger); } pTrigger = pTrigger->pNext; } return 0; }
/* ** This is called by the parser when it sees a CREATE TRIGGER statement ** up to the point of the BEGIN before the trigger actions. A Trigger ** structure is generated based on the information available and stored ** in pParse->pNewTrigger. After the trigger actions have been parsed, the ** sqliteFinishTrigger() function is called to complete the trigger ** construction process. */ void sqliteBeginTrigger( Parse *pParse, /* The parse context of the CREATE TRIGGER statement */ Token *pName, /* The name of the trigger */ int tr_tm, /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */ int op, /* One of TK_INSERT, TK_UPDATE, TK_DELETE */ IdList *pColumns, /* column list if this is an UPDATE OF trigger */ SrcList *pTableName,/* The name of the table/view the trigger applies to */ int foreach, /* One of TK_ROW or TK_STATEMENT */ Expr *pWhen, /* WHEN clause */ int isTemp /* True if the TEMPORARY keyword is present */ ){ Trigger *nt; Table *tab; char *zName = 0; /* Name of the trigger */ sqlite *db = pParse->db; int iDb; /* When database to store the trigger in */ DbFixer sFix; /* Check that: ** 1. the trigger name does not already exist. ** 2. the table (or view) does exist in the same database as the trigger. ** 3. that we are not trying to create a trigger on the sqlite_master table ** 4. That we are not trying to create an INSTEAD OF trigger on a table. ** 5. That we are not trying to create a BEFORE or AFTER trigger on a view. */ if( sqlite_malloc_failed ) goto trigger_cleanup; assert( pTableName->nSrc==1 ); if( db->init.busy && sqliteFixInit(&sFix, pParse, db->init.iDb, "trigger", pName) && sqliteFixSrcList(&sFix, pTableName) ){ goto trigger_cleanup; } tab = sqliteSrcListLookup(pParse, pTableName); if( !tab ){ goto trigger_cleanup; } iDb = isTemp ? 1 : tab->iDb; if( iDb>=2 && !db->init.busy ){ sqliteErrorMsg(pParse, "triggers may not be added to auxiliary " "database %s", db->aDb[tab->iDb].zName); goto trigger_cleanup; } zName = sqliteStrNDup(pName->z, pName->n); sqliteDequote(zName); if( sqliteHashFind(&(db->aDb[iDb].trigHash), zName,pName->n+1) ){ sqliteErrorMsg(pParse, "trigger %T already exists", pName); goto trigger_cleanup; } if( sqliteStrNICmp(tab->zName, "sqlite_", 7)==0 ){ sqliteErrorMsg(pParse, "cannot create trigger on system table"); pParse->nErr++; goto trigger_cleanup; } if( tab->pSelect && tr_tm != TK_INSTEAD ){ sqliteErrorMsg(pParse, "cannot create %s trigger on view: %S", (tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0); goto trigger_cleanup; } if( !tab->pSelect && tr_tm == TK_INSTEAD ){ sqliteErrorMsg(pParse, "cannot create INSTEAD OF" " trigger on table: %S", pTableName, 0); goto trigger_cleanup; } #ifndef SQLITE_OMIT_AUTHORIZATION { int code = SQLITE_CREATE_TRIGGER; const char *zDb = db->aDb[tab->iDb].zName; const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb; if( tab->iDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER; if( sqliteAuthCheck(pParse, code, zName, tab->zName, zDbTrig) ){ goto trigger_cleanup; } if( sqliteAuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(tab->iDb), 0, zDb)){ goto trigger_cleanup; } } #endif /* INSTEAD OF triggers can only appear on views and BEGIN triggers ** cannot appear on views. So we might as well translate every ** INSTEAD OF trigger into a BEFORE trigger. It simplifies code ** elsewhere. */ if (tr_tm == TK_INSTEAD){ tr_tm = TK_BEFORE; } /* Build the Trigger object */ nt = (Trigger*)sqliteMalloc(sizeof(Trigger)); if( nt==0 ) goto trigger_cleanup; nt->name = zName; zName = 0; nt->table = sqliteStrDup(pTableName->a[0].zName); if( sqlite_malloc_failed ) goto trigger_cleanup; nt->iDb = iDb; nt->iTabDb = tab->iDb; nt->op = op; nt->tr_tm = tr_tm; nt->pWhen = sqliteExprDup(pWhen); nt->pColumns = sqliteIdListDup(pColumns); nt->foreach = foreach; sqliteTokenCopy(&nt->nameToken,pName); assert( pParse->pNewTrigger==0 ); pParse->pNewTrigger = nt; trigger_cleanup: sqliteFree(zName); sqliteSrcListDelete(pTableName); sqliteIdListDelete(pColumns); sqliteExprDelete(pWhen); }
/* ** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up ** that name in the set of source tables in pSrcList and make the pExpr ** expression node refer back to that source column. The following changes ** are made to pExpr: ** ** pExpr->iDb Set the index in db->aDb[] of the database holding ** the table. ** pExpr->iTable Set to the cursor number for the table obtained ** from pSrcList. ** pExpr->iColumn Set to the column number within the table. ** pExpr->dataType Set to the appropriate data type for the column. ** pExpr->op Set to TK_COLUMN. ** pExpr->pLeft Any expression this points to is deleted ** pExpr->pRight Any expression this points to is deleted. ** ** The pDbToken is the name of the database (the "X"). This value may be ** NULL meaning that name is of the form Y.Z or Z. Any available database ** can be used. The pTableToken is the name of the table (the "Y"). This ** value can be NULL if pDbToken is also NULL. If pTableToken is NULL it ** means that the form of the name is Z and that columns from any table ** can be used. ** ** If the name cannot be resolved unambiguously, leave an error message ** in pParse and return non-zero. Return zero on success. */ static int lookupName( Parse *pParse, /* The parsing context */ Token *pDbToken, /* Name of the database containing table, or NULL */ Token *pTableToken, /* Name of table containing column, or NULL */ Token *pColumnToken, /* Name of the column. */ SrcList *pSrcList, /* List of tables used to resolve column names */ ExprList *pEList, /* List of expressions used to resolve "AS" */ Expr *pExpr /* Make this EXPR node point to the selected column */ ){ char *zDb = 0; /* Name of the database. The "X" in X.Y.Z */ char *zTab = 0; /* Name of the table. The "Y" in X.Y.Z or Y.Z */ char *zCol = 0; /* Name of the column. The "Z" */ int i, j; /* Loop counters */ int cnt = 0; /* Number of matching column names */ int cntTab = 0; /* Number of matching table names */ sqlite *db = pParse->db; /* The database */ assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */ if( pDbToken && pDbToken->z ){ zDb = sqliteStrNDup(pDbToken->z, pDbToken->n); sqliteDequote(zDb); }else{ zDb = 0; } if( pTableToken && pTableToken->z ){ zTab = sqliteStrNDup(pTableToken->z, pTableToken->n); sqliteDequote(zTab); }else{ assert( zDb==0 ); zTab = 0; } zCol = sqliteStrNDup(pColumnToken->z, pColumnToken->n); sqliteDequote(zCol); if( sqlite_malloc_failed ){ return 1; /* Leak memory (zDb and zTab) if malloc fails */ } assert( zTab==0 || pEList==0 ); pExpr->iTable = -1; for(i=0; i<pSrcList->nSrc; i++){ struct SrcList_item *pItem = &pSrcList->a[i]; Table *pTab = pItem->pTab; Column *pCol; if( pTab==0 ) continue; assert( pTab->nCol>0 ); if( zTab ){ if( pItem->zAlias ){ char *zTabName = pItem->zAlias; if( sqliteStrICmp(zTabName, zTab)!=0 ) continue; }else{ char *zTabName = pTab->zName; if( zTabName==0 || sqliteStrICmp(zTabName, zTab)!=0 ) continue; if( zDb!=0 && sqliteStrICmp(db->aDb[pTab->iDb].zName, zDb)!=0 ){ continue; } } } if( 0==(cntTab++) ){ pExpr->iTable = pItem->iCursor; pExpr->iDb = pTab->iDb; } for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){ if( sqliteStrICmp(pCol->zName, zCol)==0 ){ cnt++; pExpr->iTable = pItem->iCursor; pExpr->iDb = pTab->iDb; /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */ pExpr->iColumn = j==pTab->iPKey ? -1 : j; pExpr->dataType = pCol->sortOrder & SQLITE_SO_TYPEMASK; break; } } } /* If we have not already resolved the name, then maybe ** it is a new.* or old.* trigger argument reference */ if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){ TriggerStack *pTriggerStack = pParse->trigStack; Table *pTab = 0; if( pTriggerStack->newIdx != -1 && sqliteStrICmp("new", zTab) == 0 ){ pExpr->iTable = pTriggerStack->newIdx; assert( pTriggerStack->pTab ); pTab = pTriggerStack->pTab; }else if( pTriggerStack->oldIdx != -1 && sqliteStrICmp("old", zTab) == 0 ){ pExpr->iTable = pTriggerStack->oldIdx; assert( pTriggerStack->pTab ); pTab = pTriggerStack->pTab; } if( pTab ){ int j; Column *pCol = pTab->aCol; pExpr->iDb = pTab->iDb; cntTab++; for(j=0; j < pTab->nCol; j++, pCol++) { if( sqliteStrICmp(pCol->zName, zCol)==0 ){ cnt++; pExpr->iColumn = j==pTab->iPKey ? -1 : j; pExpr->dataType = pCol->sortOrder & SQLITE_SO_TYPEMASK; break; } } } } /* ** Perhaps the name is a reference to the ROWID */ if( cnt==0 && cntTab==1 && sqliteIsRowid(zCol) ){ cnt = 1; pExpr->iColumn = -1; pExpr->dataType = SQLITE_SO_NUM; } /* ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z ** might refer to an result-set alias. This happens, for example, when ** we are resolving names in the WHERE clause of the following command: ** ** SELECT a+b AS x FROM table WHERE x<10; ** ** In cases like this, replace pExpr with a copy of the expression that ** forms the result set entry ("a+b" in the example) and return immediately. ** Note that the expression in the result set should have already been ** resolved by the time the WHERE clause is resolved. */ if( cnt==0 && pEList!=0 ){ for(j=0; j<pEList->nExpr; j++){ char *zAs = pEList->a[j].zName; if( zAs!=0 && sqliteStrICmp(zAs, zCol)==0 ){ assert( pExpr->pLeft==0 && pExpr->pRight==0 ); pExpr->op = TK_AS; pExpr->iColumn = j; pExpr->pLeft = sqliteExprDup(pEList->a[j].pExpr); sqliteFree(zCol); assert( zTab==0 && zDb==0 ); return 0; } } } /* ** If X and Y are NULL (in other words if only the column name Z is ** supplied) and the value of Z is enclosed in double-quotes, then ** Z is a string literal if it doesn't match any column names. In that ** case, we need to return right away and not make any changes to ** pExpr. */ if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){ sqliteFree(zCol); return 0; } /* ** cnt==0 means there was not match. cnt>1 means there were two or ** more matches. Either way, we have an error. */ if( cnt!=1 ){ char *z = 0; char *zErr; zErr = cnt==0 ? "no such column: %s" : "ambiguous column name: %s"; if( zDb ){ sqliteSetString(&z, zDb, ".", zTab, ".", zCol, 0); }else if( zTab ){ sqliteSetString(&z, zTab, ".", zCol, 0); }else{ z = sqliteStrDup(zCol); } sqliteErrorMsg(pParse, zErr, z); sqliteFree(z); } /* Clean up and return */ sqliteFree(zDb); sqliteFree(zTab); sqliteFree(zCol); sqliteExprDelete(pExpr->pLeft); pExpr->pLeft = 0; sqliteExprDelete(pExpr->pRight); pExpr->pRight = 0; pExpr->op = TK_COLUMN; sqliteAuthRead(pParse, pExpr, pSrcList); return cnt!=1; }