/*
** Recursively delete an expression tree.
*/
void sqliteExprDelete(Expr *p){
if( p==0 ) return;
if( p->span.dyn ) sqliteFree((char*)p->span.z);
if( p->token.dyn ) sqliteFree((char*)p->token.z);
sqliteExprDelete(p->pLeft);
sqliteExprDelete(p->pRight);
sqliteExprListDelete(p->pList);
sqliteSelectDelete(p->pSelect);
sqliteFree(p);
}
/*
** Recursively delete a statement tree.
*/
void sqliteStmtDelete(Stmt *p){
if( p==0 ) return;
if( p->pExpr1 ) sqliteExprDelete(p->pExpr1);
if( p->pStmt1 ) sqliteStmtListDelete(p->pStmt1);
if( p->pStmt2 ) sqliteStmtDelete(p->pStmt2);
if( p->pBlock ) sqliteBlockDelete(p->pBlock);
}
/*
** 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;
}
}
/*
** Recursively delete a Trigger structure
*/
void sqliteDeleteTrigger(Trigger *pTrigger){
if( pTrigger==0 ) return;
sqliteDeleteTriggerStep(pTrigger->step_list);
sqliteFree(pTrigger->name);
sqliteFree(pTrigger->table);
sqliteExprDelete(pTrigger->pWhen);
sqliteIdListDelete(pTrigger->pColumns);
if( pTrigger->nameToken.dyn ) sqliteFree((char*)pTrigger->nameToken.z);
sqliteFree(pTrigger);
}
/*
** Delete an entire expression list.
*/
void sqliteExprListDelete(ExprList *pList){
int i;
if( pList==0 ) return;
for(i=0; i<pList->nExpr; i++){
sqliteExprDelete(pList->a[i].pExpr);
sqliteFree(pList->a[i].zName);
}
sqliteFree(pList->a);
sqliteFree(pList);
}
/*
** Delete a linked list of TriggerStep structures.
*/
void sqliteDeleteTriggerStep(TriggerStep *pTriggerStep){
while( pTriggerStep ){
TriggerStep * pTmp = pTriggerStep;
pTriggerStep = pTriggerStep->pNext;
if( pTmp->target.dyn ) sqliteFree((char*)pTmp->target.z);
sqliteExprDelete(pTmp->pWhere);
sqliteExprListDelete(pTmp->pExprList);
sqliteSelectDelete(pTmp->pSelect);
sqliteIdListDelete(pTmp->pIdList);
sqliteFree(pTmp);
}
}
/*
** Process an UPDATE statement.
**
** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;
** \_______/ \________/ \______/ \________________/
* onError pTabList pChanges pWhere
*/
void sqliteUpdate(
Parse *pParse, /* The parser context */
SrcList *pTabList, /* The table in which we should change things */
ExprList *pChanges, /* Things to be changed */
Expr *pWhere, /* The WHERE clause. May be null */
int onError /* How to handle constraint errors */
){
int i, j; /* Loop counters */
Table *pTab; /* The table to be updated */
int addr; /* VDBE instruction address of the start of the loop */
WhereInfo *pWInfo; /* Information about the WHERE clause */
Vdbe *v; /* The virtual database engine */
Index *pIdx; /* For looping over indices */
int nIdx; /* Number of indices that need updating */
int nIdxTotal; /* Total number of indices */
int iCur; /* VDBE Cursor number of pTab */
sqlite *db; /* The database structure */
Index **apIdx = 0; /* An array of indices that need updating too */
char *aIdxUsed = 0; /* aIdxUsed[i]==1 if the i-th index is used */
int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the
** an expression for the i-th column of the table.
** aXRef[i]==-1 if the i-th column is not changed. */
int chngRecno; /* True if the record number is being changed */
Expr *pRecnoExpr; /* Expression defining the new record number */
int openAll; /* True if all indices need to be opened */
int isView; /* Trying to update a view */
AuthContext sContext; /* The authorization context */
int before_triggers; /* True if there are any BEFORE triggers */
int after_triggers; /* True if there are any AFTER triggers */
int row_triggers_exist = 0; /* True if any row triggers exist */
int newIdx = -1; /* index of trigger "new" temp table */
int oldIdx = -1; /* index of trigger "old" temp table */
sContext.pParse = 0;
if( pParse->nErr || sqlite_malloc_failed ) goto update_cleanup;
db = pParse->db;
assert( pTabList->nSrc==1 );
/* Locate the table which we want to update.
*/
pTab = sqliteSrcListLookup(pParse, pTabList);
if( pTab==0 ) goto update_cleanup;
before_triggers = sqliteTriggersExist(pParse, pTab->pTrigger,
TK_UPDATE, TK_BEFORE, TK_ROW, pChanges);
after_triggers = sqliteTriggersExist(pParse, pTab->pTrigger,
TK_UPDATE, TK_AFTER, TK_ROW, pChanges);
row_triggers_exist = before_triggers || after_triggers;
isView = pTab->pSelect!=0;
if( sqliteIsReadOnly(pParse, pTab, before_triggers) ){
goto update_cleanup;
}
if( isView ){
if( sqliteViewGetColumnNames(pParse, pTab) ){
goto update_cleanup;
}
}
aXRef = sqliteMalloc( sizeof(int) * pTab->nCol );
if( aXRef==0 ) goto update_cleanup;
for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
/* If there are FOR EACH ROW triggers, allocate cursors for the
** special OLD and NEW tables
*/
if( row_triggers_exist ){
newIdx = pParse->nTab++;
oldIdx = pParse->nTab++;
}
/* Allocate a cursors for the main database table and for all indices.
** The index cursors might not be used, but if they are used they
** need to occur right after the database cursor. So go ahead and
** allocate enough space, just in case.
*/
pTabList->a[0].iCursor = iCur = pParse->nTab++;
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
pParse->nTab++;
}
/* Resolve the column names in all the expressions of the
** of the UPDATE statement. Also find the column index
** for each column to be updated in the pChanges array. For each
** column to be updated, make sure we have authorization to change
** that column.
*/
chngRecno = 0;
for(i=0; i<pChanges->nExpr; i++){
if( sqliteExprResolveIds(pParse, pTabList, 0, pChanges->a[i].pExpr) ){
goto update_cleanup;
}
if( sqliteExprCheck(pParse, pChanges->a[i].pExpr, 0, 0) ){
goto update_cleanup;
}
for(j=0; j<pTab->nCol; j++){
if( sqliteStrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){
if( j==pTab->iPKey ){
chngRecno = 1;
pRecnoExpr = pChanges->a[i].pExpr;
}
aXRef[j] = i;
break;
}
}
if( j>=pTab->nCol ){
if( sqliteIsRowid(pChanges->a[i].zName) ){
chngRecno = 1;
pRecnoExpr = pChanges->a[i].pExpr;
}else{
sqliteErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName);
goto update_cleanup;
}
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int rc;
rc = sqliteAuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
pTab->aCol[j].zName, db->aDb[pTab->iDb].zName);
if( rc==SQLITE_DENY ){
goto update_cleanup;
}else if( rc==SQLITE_IGNORE ){
aXRef[j] = -1;
}
}
#endif
}
/* Allocate memory for the array apIdx[] and fill it with pointers to every
** index that needs to be updated. Indices only need updating if their
** key includes one of the columns named in pChanges or if the record
** number of the original table entry is changing.
*/
for(nIdx=nIdxTotal=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdxTotal++){
if( chngRecno ){
i = 0;
}else {
for(i=0; i<pIdx->nColumn; i++){
if( aXRef[pIdx->aiColumn[i]]>=0 ) break;
}
}
if( i<pIdx->nColumn ) nIdx++;
}
if( nIdxTotal>0 ){
apIdx = sqliteMalloc( sizeof(Index*) * nIdx + nIdxTotal );
if( apIdx==0 ) goto update_cleanup;
aIdxUsed = (char*)&apIdx[nIdx];
}
for(nIdx=j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
if( chngRecno ){
i = 0;
}else{
for(i=0; i<pIdx->nColumn; i++){
if( aXRef[pIdx->aiColumn[i]]>=0 ) break;
}
}
if( i<pIdx->nColumn ){
apIdx[nIdx++] = pIdx;
aIdxUsed[j] = 1;
}else{
aIdxUsed[j] = 0;
}
}
/* Resolve the column names in all the expressions in the
** WHERE clause.
*/
if( pWhere ){
if( sqliteExprResolveIds(pParse, pTabList, 0, pWhere) ){
goto update_cleanup;
}
if( sqliteExprCheck(pParse, pWhere, 0, 0) ){
goto update_cleanup;
}
}
/* Start the view context
*/
if( isView ){
sqliteAuthContextPush(pParse, &sContext, pTab->zName);
}
/* Begin generating code.
*/
v = sqliteGetVdbe(pParse);
if( v==0 ) goto update_cleanup;
sqliteBeginWriteOperation(pParse, 1, pTab->iDb);
/* If we are trying to update a view, construct that view into
** a temporary table.
*/
if( isView ){
Select *pView;
pView = sqliteSelectDup(pTab->pSelect);
sqliteSelect(pParse, pView, SRT_TempTable, iCur, 0, 0, 0);
sqliteSelectDelete(pView);
}
/* Begin the database scan
*/
pWInfo = sqliteWhereBegin(pParse, pTabList, pWhere, 1, 0);
if( pWInfo==0 ) goto update_cleanup;
/* Remember the index of every item to be updated.
*/
sqliteVdbeAddOp(v, OP_ListWrite, 0, 0);
/* End the database scan loop.
*/
sqliteWhereEnd(pWInfo);
/* Initialize the count of updated rows
*/
if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
sqliteVdbeAddOp(v, OP_Integer, 0, 0);
}
if( row_triggers_exist ){
/* Create pseudo-tables for NEW and OLD
*/
sqliteVdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
sqliteVdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
/* The top of the update loop for when there are triggers.
*/
sqliteVdbeAddOp(v, OP_ListRewind, 0, 0);
addr = sqliteVdbeAddOp(v, OP_ListRead, 0, 0);
sqliteVdbeAddOp(v, OP_Dup, 0, 0);
/* Open a cursor and make it point to the record that is
** being updated.
*/
sqliteVdbeAddOp(v, OP_Dup, 0, 0);
if( !isView ){
sqliteVdbeAddOp(v, OP_Integer, pTab->iDb, 0);
sqliteVdbeAddOp(v, OP_OpenRead, iCur, pTab->tnum);
}
sqliteVdbeAddOp(v, OP_MoveTo, iCur, 0);
/* Generate the OLD table
*/
sqliteVdbeAddOp(v, OP_Recno, iCur, 0);
sqliteVdbeAddOp(v, OP_RowData, iCur, 0);
sqliteVdbeAddOp(v, OP_PutIntKey, oldIdx, 0);
/* Generate the NEW table
*/
if( chngRecno ){
sqliteExprCode(pParse, pRecnoExpr);
}else{
sqliteVdbeAddOp(v, OP_Recno, iCur, 0);
}
for(i=0; i<pTab->nCol; i++){
if( i==pTab->iPKey ){
sqliteVdbeAddOp(v, OP_String, 0, 0);
continue;
}
j = aXRef[i];
if( j<0 ){
sqliteVdbeAddOp(v, OP_Column, iCur, i);
}else{
sqliteExprCode(pParse, pChanges->a[j].pExpr);
}
}
sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);
if( !isView ){
sqliteVdbeAddOp(v, OP_Close, iCur, 0);
}
/* Fire the BEFORE and INSTEAD OF triggers
*/
if( sqliteCodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_BEFORE, pTab,
newIdx, oldIdx, onError, addr) ){
goto update_cleanup;
}
}
if( !isView ){
/*
** Open every index that needs updating. Note that if any
** index could potentially invoke a REPLACE conflict resolution
** action, then we need to open all indices because we might need
** to be deleting some records.
*/
sqliteVdbeAddOp(v, OP_Integer, pTab->iDb, 0);
sqliteVdbeAddOp(v, OP_OpenWrite, iCur, pTab->tnum);
if( onError==OE_Replace ){
openAll = 1;
}else{
openAll = 0;
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( pIdx->onError==OE_Replace ){
openAll = 1;
break;
}
}
}
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
if( openAll || aIdxUsed[i] ){
sqliteVdbeAddOp(v, OP_Integer, pIdx->iDb, 0);
sqliteVdbeAddOp(v, OP_OpenWrite, iCur+i+1, pIdx->tnum);
assert( pParse->nTab>iCur+i+1 );
}
}
/* Loop over every record that needs updating. We have to load
** the old data for each record to be updated because some columns
** might not change and we will need to copy the old value.
** Also, the old data is needed to delete the old index entires.
** So make the cursor point at the old record.
*/
if( !row_triggers_exist ){
sqliteVdbeAddOp(v, OP_ListRewind, 0, 0);
addr = sqliteVdbeAddOp(v, OP_ListRead, 0, 0);
sqliteVdbeAddOp(v, OP_Dup, 0, 0);
}
sqliteVdbeAddOp(v, OP_NotExists, iCur, addr);
/* If the record number will change, push the record number as it
** will be after the update. (The old record number is currently
** on top of the stack.)
*/
if( chngRecno ){
sqliteExprCode(pParse, pRecnoExpr);
sqliteVdbeAddOp(v, OP_MustBeInt, 0, 0);
}
/* Compute new data for this record.
*/
for(i=0; i<pTab->nCol; i++){
if( i==pTab->iPKey ){
sqliteVdbeAddOp(v, OP_String, 0, 0);
continue;
}
j = aXRef[i];
if( j<0 ){
sqliteVdbeAddOp(v, OP_Column, iCur, i);
}else{
sqliteExprCode(pParse, pChanges->a[j].pExpr);
}
}
/* Do constraint checks
*/
sqliteGenerateConstraintChecks(pParse, pTab, iCur, aIdxUsed, chngRecno, 1,
onError, addr);
/* Delete the old indices for the current record.
*/
sqliteGenerateRowIndexDelete(db, v, pTab, iCur, aIdxUsed);
/* If changing the record number, delete the old record.
*/
if( chngRecno ){
sqliteVdbeAddOp(v, OP_Delete, iCur, 0);
}
/* Create the new index entries and the new record.
*/
sqliteCompleteInsertion(pParse, pTab, iCur, aIdxUsed, chngRecno, 1, -1);
}
/* Increment the row counter
*/
if( db->flags & SQLITE_CountRows && !pParse->trigStack){
sqliteVdbeAddOp(v, OP_AddImm, 1, 0);
}
/* If there are triggers, close all the cursors after each iteration
** through the loop. The fire the after triggers.
*/
if( row_triggers_exist ){
if( !isView ){
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
if( openAll || aIdxUsed[i] )
sqliteVdbeAddOp(v, OP_Close, iCur+i+1, 0);
}
sqliteVdbeAddOp(v, OP_Close, iCur, 0);
pParse->nTab = iCur;
}
if( sqliteCodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_AFTER, pTab,
newIdx, oldIdx, onError, addr) ){
goto update_cleanup;
}
}
/* Repeat the above with the next record to be updated, until
** all record selected by the WHERE clause have been updated.
*/
sqliteVdbeAddOp(v, OP_Goto, 0, addr);
sqliteVdbeChangeP2(v, addr, sqliteVdbeCurrentAddr(v));
sqliteVdbeAddOp(v, OP_ListReset, 0, 0);
/* Close all tables if there were no FOR EACH ROW triggers */
if( !row_triggers_exist ){
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
if( openAll || aIdxUsed[i] ){
sqliteVdbeAddOp(v, OP_Close, iCur+i+1, 0);
}
}
sqliteVdbeAddOp(v, OP_Close, iCur, 0);
pParse->nTab = iCur;
}else{
sqliteVdbeAddOp(v, OP_Close, newIdx, 0);
sqliteVdbeAddOp(v, OP_Close, oldIdx, 0);
}
sqliteVdbeAddOp(v, OP_SetCounts, 0, 0);
sqliteEndWriteOperation(pParse);
/*
** Return the number of rows that were changed.
*/
if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
sqliteVdbeOp3(v, OP_ColumnName, 0, 1, "rows updated", P3_STATIC);
sqliteVdbeAddOp(v, OP_Callback, 1, 0);
}
update_cleanup:
sqliteAuthContextPop(&sContext);
sqliteFree(apIdx);
sqliteFree(aXRef);
sqliteSrcListDelete(pTabList);
sqliteExprListDelete(pChanges);
sqliteExprDelete(pWhere);
return;
}
/*
** Process a DELETE FROM statement.
*/
void sqliteDeleteFrom(
Parse *pParse, /* The parser context */
SrcList *pTabList, /* The table from which we should delete things */
Expr *pWhere /* The WHERE clause. May be null */
){
Vdbe *v; /* The virtual database engine */
Table *pTab; /* The table from which records will be deleted */
const char *zDb; /* Name of database holding pTab */
int end, addr; /* A couple addresses of generated code */
int i; /* Loop counter */
WhereInfo *pWInfo; /* Information about the WHERE clause */
Index *pIdx; /* For looping over indices of the table */
int iCur; /* VDBE Cursor number for pTab */
sqlite *db; /* Main database structure */
int isView; /* True if attempting to delete from a view */
AuthContext sContext; /* Authorization context */
int row_triggers_exist = 0; /* True if any triggers exist */
int before_triggers; /* True if there are BEFORE triggers */
int after_triggers; /* True if there are AFTER triggers */
int oldIdx = -1; /* Cursor for the OLD table of AFTER triggers */
sContext.pParse = 0;
if( pParse->nErr || sqlite_malloc_failed ){
pTabList = 0;
goto delete_from_cleanup;
}
db = pParse->db;
assert( pTabList->nSrc==1 );
/* Locate the table which we want to delete. This table has to be
** put in an SrcList structure because some of the subroutines we
** will be calling are designed to work with multiple tables and expect
** an SrcList* parameter instead of just a Table* parameter.
*/
pTab = sqliteSrcListLookup(pParse, pTabList);
if( pTab==0 ) goto delete_from_cleanup;
before_triggers = sqliteTriggersExist(pParse, pTab->pTrigger,
TK_DELETE, TK_BEFORE, TK_ROW, 0);
after_triggers = sqliteTriggersExist(pParse, pTab->pTrigger,
TK_DELETE, TK_AFTER, TK_ROW, 0);
row_triggers_exist = before_triggers || after_triggers;
isView = pTab->pSelect!=0;
if( sqliteIsReadOnly(pParse, pTab, before_triggers) ){
goto delete_from_cleanup;
}
assert( pTab->iDb<db->nDb );
zDb = db->aDb[pTab->iDb].zName;
if( sqliteAuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){
goto delete_from_cleanup;
}
/* If pTab is really a view, make sure it has been initialized.
*/
if( isView && sqliteViewGetColumnNames(pParse, pTab) ){
goto delete_from_cleanup;
}
/* Allocate a cursor used to store the old.* data for a trigger.
*/
if( row_triggers_exist ){
oldIdx = pParse->nTab++;
}
/* Resolve the column names in all the expressions.
*/
assert( pTabList->nSrc==1 );
iCur = pTabList->a[0].iCursor = pParse->nTab++;
if( pWhere ){
if( sqliteExprResolveIds(pParse, pTabList, 0, pWhere) ){
goto delete_from_cleanup;
}
if( sqliteExprCheck(pParse, pWhere, 0, 0) ){
goto delete_from_cleanup;
}
}
/* Start the view context
*/
if( isView ){
sqliteAuthContextPush(pParse, &sContext, pTab->zName);
}
/* Begin generating code.
*/
v = sqliteGetVdbe(pParse);
if( v==0 ){
goto delete_from_cleanup;
}
sqliteBeginWriteOperation(pParse, row_triggers_exist, pTab->iDb);
/* If we are trying to delete from a view, construct that view into
** a temporary table.
*/
if( isView ){
Select *pView = sqliteSelectDup(pTab->pSelect);
sqliteSelect(pParse, pView, SRT_TempTable, iCur, 0, 0, 0);
sqliteSelectDelete(pView);
}
/* Initialize the counter of the number of rows deleted, if
** we are counting rows.
*/
if( db->flags & SQLITE_CountRows ){
sqliteVdbeAddOp(v, OP_Integer, 0, 0);
}
/* Special case: A DELETE without a WHERE clause deletes everything.
** It is easier just to erase the whole table. Note, however, that
** this means that the row change count will be incorrect.
*/
if( pWhere==0 && !row_triggers_exist ){
if( db->flags & SQLITE_CountRows ){
/* If counting rows deleted, just count the total number of
** entries in the table. */
int endOfLoop = sqliteVdbeMakeLabel(v);
int addr;
if( !isView ){
sqliteVdbeAddOp(v, OP_Integer, pTab->iDb, 0);
sqliteVdbeAddOp(v, OP_OpenRead, iCur, pTab->tnum);
}
sqliteVdbeAddOp(v, OP_Rewind, iCur, sqliteVdbeCurrentAddr(v)+2);
addr = sqliteVdbeAddOp(v, OP_AddImm, 1, 0);
sqliteVdbeAddOp(v, OP_Next, iCur, addr);
sqliteVdbeResolveLabel(v, endOfLoop);
sqliteVdbeAddOp(v, OP_Close, iCur, 0);
}
if( !isView ){
sqliteVdbeAddOp(v, OP_Clear, pTab->tnum, pTab->iDb);
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
sqliteVdbeAddOp(v, OP_Clear, pIdx->tnum, pIdx->iDb);
}
}
}
/* The usual case: There is a WHERE clause so we have to scan through
** the table and pick which records to delete.
*/
else{
/* Begin the database scan
*/
pWInfo = sqliteWhereBegin(pParse, pTabList, pWhere, 1, 0);
if( pWInfo==0 ) goto delete_from_cleanup;
/* Remember the key of every item to be deleted.
*/
sqliteVdbeAddOp(v, OP_ListWrite, 0, 0);
if( db->flags & SQLITE_CountRows ){
sqliteVdbeAddOp(v, OP_AddImm, 1, 0);
}
/* End the database scan loop.
*/
sqliteWhereEnd(pWInfo);
/* Open the pseudo-table used to store OLD if there are triggers.
*/
if( row_triggers_exist ){
sqliteVdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
}
/* Delete every item whose key was written to the list during the
** database scan. We have to delete items after the scan is complete
** because deleting an item can change the scan order.
*/
sqliteVdbeAddOp(v, OP_ListRewind, 0, 0);
end = sqliteVdbeMakeLabel(v);
/* This is the beginning of the delete loop when there are
** row triggers.
*/
if( row_triggers_exist ){
addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end);
sqliteVdbeAddOp(v, OP_Dup, 0, 0);
if( !isView ){
sqliteVdbeAddOp(v, OP_Integer, pTab->iDb, 0);
sqliteVdbeAddOp(v, OP_OpenRead, iCur, pTab->tnum);
}
sqliteVdbeAddOp(v, OP_MoveTo, iCur, 0);
sqliteVdbeAddOp(v, OP_Recno, iCur, 0);
sqliteVdbeAddOp(v, OP_RowData, iCur, 0);
sqliteVdbeAddOp(v, OP_PutIntKey, oldIdx, 0);
if( !isView ){
sqliteVdbeAddOp(v, OP_Close, iCur, 0);
}
sqliteCodeRowTrigger(pParse, TK_DELETE, 0, TK_BEFORE, pTab, -1,
oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
addr);
}
if( !isView ){
/* Open cursors for the table we are deleting from and all its
** indices. If there are row triggers, this happens inside the
** OP_ListRead loop because the cursor have to all be closed
** before the trigger fires. If there are no row triggers, the
** cursors are opened only once on the outside the loop.
*/
pParse->nTab = iCur + 1;
sqliteOpenTableAndIndices(pParse, pTab, iCur);
/* This is the beginning of the delete loop when there are no
** row triggers */
if( !row_triggers_exist ){
addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end);
}
/* Delete the row */
sqliteGenerateRowDelete(db, v, pTab, iCur, pParse->trigStack==0);
}
/* If there are row triggers, close all cursors then invoke
** the AFTER triggers
*/
if( row_triggers_exist ){
if( !isView ){
for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
sqliteVdbeAddOp(v, OP_Close, iCur + i, pIdx->tnum);
}
sqliteVdbeAddOp(v, OP_Close, iCur, 0);
}
sqliteCodeRowTrigger(pParse, TK_DELETE, 0, TK_AFTER, pTab, -1,
oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
addr);
}
/* End of the delete loop */
sqliteVdbeAddOp(v, OP_Goto, 0, addr);
sqliteVdbeResolveLabel(v, end);
sqliteVdbeAddOp(v, OP_ListReset, 0, 0);
/* Close the cursors after the loop if there are no row triggers */
if( !row_triggers_exist ){
for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
sqliteVdbeAddOp(v, OP_Close, iCur + i, pIdx->tnum);
}
sqliteVdbeAddOp(v, OP_Close, iCur, 0);
pParse->nTab = iCur;
}
}
sqliteVdbeAddOp(v, OP_SetCounts, 0, 0);
sqliteEndWriteOperation(pParse);
/*
** Return the number of rows that were deleted.
*/
if( db->flags & SQLITE_CountRows ){
sqliteVdbeAddOp(v, OP_ColumnName, 0, 1);
sqliteVdbeChangeP3(v, -1, "rows deleted", P3_STATIC);
sqliteVdbeAddOp(v, OP_Callback, 1, 0);
}
delete_from_cleanup:
sqliteAuthContextPop(&sContext);
sqliteSrcListDelete(pTabList);
sqliteExprDelete(pWhere);
return;
}
/*
** 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;
}
