/*
** Evaluate a view and store its result in an ephemeral table. The
** pWhere argument is an optional WHERE clause that restricts the
** set of rows in the view that are to be added to the ephemeral table.
*/
void sqlite3MaterializeView(
Parse *pParse, /* Parsing context */
Table *pView, /* View definition */
Expr *pWhere, /* Optional WHERE clause to be added */
int iCur /* Cursor number for ephemerial table */
){
SelectDest dest;
Select *pDup;
sqlite3 *db = pParse->db;
pDup = sqlite3SelectDup(db, pView->pSelect, 0);
if( pWhere ){
SrcList *pFrom;
pWhere = sqlite3ExprDup(db, pWhere, 0);
pFrom = sqlite3SrcListAppend(db, 0, 0, 0);
if( pFrom ){
assert( pFrom->nSrc==1 );
pFrom->a[0].zAlias = sqlite3DbStrDup(db, pView->zName);
pFrom->a[0].pSelect = pDup;
assert( pFrom->a[0].pOn==0 );
assert( pFrom->a[0].pUsing==0 );
}else{
sqlite3SelectDelete(db, pDup);
}
pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
if( pDup ) pDup->selFlags |= SF_Materialize;
}
sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
sqlite3Select(pParse, pDup, &dest);
sqlite3SelectDelete(db, pDup);
}
/*
** Build a trigger step out of an INSERT statement. Return a pointer
** to the new trigger step.
**
** The parser calls this routine when it sees an INSERT inside the
** body of a trigger.
*/
TriggerStep *sqlite3TriggerInsertStep(
sqlite3 *db, /* The database connection */
Token *pTableName, /* Name of the table into which we insert */
IdList *pColumn, /* List of columns in pTableName to insert into */
ExprList *pEList, /* The VALUE clause: a list of values to be inserted */
Select *pSelect, /* A SELECT statement that supplies values */
int orconf /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */
){
TriggerStep *pTriggerStep;
assert(pEList == 0 || pSelect == 0);
assert(pEList != 0 || pSelect != 0 || db->mallocFailed);
pTriggerStep = (TriggerStep*)sqlite3DbMallocZero(db, sizeof(TriggerStep));
if( pTriggerStep ){
pTriggerStep->op = TK_INSERT;
pTriggerStep->pSelect = pSelect;
pTriggerStep->target = *pTableName;
pTriggerStep->pIdList = pColumn;
pTriggerStep->pExprList = pEList;
pTriggerStep->orconf = orconf;
sqlitePersistTriggerStep(db, pTriggerStep);
}else{
sqlite3IdListDelete(pColumn);
sqlite3ExprListDelete(pEList);
sqlite3SelectDelete(pSelect);
}
return pTriggerStep;
}
/*
** 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 sqlite3_malloc(). 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 sqlite3_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 sqlite3_exec() call returns.
*/
static void sqlitePersistTriggerStep(sqlite3 *db, TriggerStep *p){
if( p->target.z ){
p->target.z = (u8*)sqlite3DbStrNDup(db, (char*)p->target.z, p->target.n);
p->target.dyn = 1;
}
if( p->pSelect ){
Select *pNew = sqlite3SelectDup(db, p->pSelect);
sqlite3SelectDelete(db, p->pSelect);
p->pSelect = pNew;
}
if( p->pWhere ){
Expr *pNew = sqlite3ExprDup(db, p->pWhere);
sqlite3ExprDelete(db, p->pWhere);
p->pWhere = pNew;
}
if( p->pExprList ){
ExprList *pNew = sqlite3ExprListDup(db, p->pExprList);
sqlite3ExprListDelete(db, p->pExprList);
p->pExprList = pNew;
}
if( p->pIdList ){
IdList *pNew = sqlite3IdListDup(db, p->pIdList);
sqlite3IdListDelete(db, p->pIdList);
p->pIdList = pNew;
}
}
/*
** Build a trigger step out of an INSERT statement. Return a pointer
** to the new trigger step.
**
** The parser calls this routine when it sees an INSERT inside the
** body of a trigger.
*/
SQLITE_PRIVATE TriggerStep *sqlite3TriggerInsertStep(
sqlite3 *db, /* The database connection */
Token *pTableName, /* Name of the table into which we insert */
IdList *pColumn, /* List of columns in pTableName to insert into */
ExprList *pEList, /* The VALUE clause: a list of values to be inserted */
Select *pSelect, /* A SELECT statement that supplies values */
u8 orconf /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */
){
TriggerStep *pTriggerStep;
assert(pEList == 0 || pSelect == 0);
assert(pEList != 0 || pSelect != 0 || db->mallocFailed);
pTriggerStep = triggerStepAllocate(db, TK_INSERT, pTableName);
if( pTriggerStep ){
pTriggerStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
pTriggerStep->pIdList = pColumn;
pTriggerStep->pExprList = sqlite3ExprListDup(db, pEList, EXPRDUP_REDUCE);
pTriggerStep->orconf = orconf;
}else{
sqlite3IdListDelete(db, pColumn);
}
sqlite3ExprListDelete(db, pEList);
sqlite3SelectDelete(db, pSelect);
return pTriggerStep;
}
/*
** 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 sqlite3_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 sqlite3_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 = sqlite3SelectDup(p->pSelect);
sqlite3SelectDelete(p->pSelect);
p->pSelect = pNew;
}
if( p->pWhere ){
Expr *pNew = sqlite3ExprDup(p->pWhere);
sqlite3ExprDelete(p->pWhere);
p->pWhere = pNew;
}
if( p->pExprList ){
ExprList *pNew = sqlite3ExprListDup(p->pExprList);
sqlite3ExprListDelete(p->pExprList);
p->pExprList = pNew;
}
if( p->pIdList ){
IdList *pNew = sqlite3IdListDup(p->pIdList);
sqlite3IdListDelete(p->pIdList);
p->pIdList = pNew;
}
}
/*
** Evaluate a view and store its result in an ephemeral table. The
** pWhere argument is an optional WHERE clause that restricts the
** set of rows in the view that are to be added to the ephemeral table.
*/
void sqlite3MaterializeView(
Parse *pParse, /* Parsing context */
Table *pView, /* View definition */
Expr *pWhere, /* Optional WHERE clause to be added */
int iCur /* Cursor number for ephemerial table */
){
SelectDest dest;
Select *pDup;
sqlite3 *db = pParse->db;
pDup = sqlite3SelectDup(db, pView->pSelect);
if( pWhere ){
SrcList *pFrom;
Token viewName;
pWhere = sqlite3ExprDup(db, pWhere);
viewName.z = (u8*)pView->zName;
viewName.n = (unsigned int)sqlite3Strlen30((const char*)viewName.z);
pFrom = sqlite3SrcListAppendFromTerm(pParse, 0, 0, 0, &viewName, pDup, 0,0);
pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
}
sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
sqlite3Select(pParse, pDup, &dest);
sqlite3SelectDelete(db, pDup);
}
/*
** Evaluate a view and store its result in an ephemeral table. The
** pWhere argument is an optional WHERE clause that restricts the
** set of rows in the view that are to be added to the ephemeral table.
*/
void sqlite3MaterializeView(
Parse *pParse, /* Parsing context */
Table *pView, /* View definition */
Expr *pWhere, /* Optional WHERE clause to be added */
int iCur /* Cursor number for ephemeral table */
){
SelectDest dest;
Select *pSel;
SrcList *pFrom;
sqlite3 *db = pParse->db;
int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
pWhere = sqlite3ExprDup(db, pWhere, 0);
pFrom = sqlite3SrcListAppend(db, 0, 0, 0);
if( pFrom ){
assert( pFrom->nSrc==1 );
pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
assert( pFrom->a[0].pOn==0 );
assert( pFrom->a[0].pUsing==0 );
}
pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0,
SF_IncludeHidden, 0, 0);
sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
sqlite3Select(pParse, pSel, &dest);
sqlite3SelectDelete(db, pSel);
}
/*
** The second argument is a Trigger structure allocated by the
** fkActionTrigger() routine. This function deletes the Trigger structure
** and all of its sub-components.
**
** The Trigger structure or any of its sub-components may be allocated from
** the lookaside buffer belonging to database handle dbMem.
*/
static void fkTriggerDelete(sqlite3 *dbMem, Trigger *p){
if( p ){
TriggerStep *pStep = p->step_list;
sqlite3ExprDelete(dbMem, pStep->pWhere);
sqlite3ExprListDelete(dbMem, pStep->pExprList);
sqlite3SelectDelete(dbMem, pStep->pSelect);
sqlite3ExprDelete(dbMem, p->pWhen);
sqlite3DbFree(dbMem, p);
}
}
/*
** Turn a SELECT statement (that the pSelect parameter points to) into
** a trigger step. Return a pointer to a TriggerStep structure.
**
** The parser calls this routine when it finds a SELECT statement in
** body of a TRIGGER.
*/
SQLITE_PRIVATE TriggerStep *sqlite3TriggerSelectStep(sqlite3 *db, Select *pSelect){
TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
if( pTriggerStep==0 ) {
sqlite3SelectDelete(db, pSelect);
return 0;
}
pTriggerStep->op = TK_SELECT;
pTriggerStep->pSelect = pSelect;
pTriggerStep->orconf = OE_Default;
return pTriggerStep;
}
/*
** Delete a linked list of TriggerStep structures.
*/
SQLITE_PRIVATE void sqlite3DeleteTriggerStep(sqlite3 *db, TriggerStep *pTriggerStep){
while( pTriggerStep ){
TriggerStep * pTmp = pTriggerStep;
pTriggerStep = pTriggerStep->pNext;
sqlite3ExprDelete(db, pTmp->pWhere);
sqlite3ExprListDelete(db, pTmp->pExprList);
sqlite3SelectDelete(db, pTmp->pSelect);
sqlite3IdListDelete(db, pTmp->pIdList);
sqlite3DbFree(db, pTmp);
}
}
/*
** Turn a SELECT statement (that the pSelect parameter points to) into
** a trigger step. Return a pointer to a TriggerStep structure.
**
** The parser calls this routine when it finds a SELECT statement in
** body of a TRIGGER.
*/
TriggerStep *sqlite3TriggerSelectStep(Select *pSelect){
TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep));
if( pTriggerStep==0 ) {
sqlite3SelectDelete(pSelect);
return 0;
}
pTriggerStep->op = TK_SELECT;
pTriggerStep->pSelect = pSelect;
pTriggerStep->orconf = OE_Default;
sqlitePersistTriggerStep(pTriggerStep);
return pTriggerStep;
}
/*
** Delete a linked list of TriggerStep structures.
*/
void sqlite3DeleteTriggerStep(TriggerStep *pTriggerStep){
while( pTriggerStep ){
TriggerStep * pTmp = pTriggerStep;
pTriggerStep = pTriggerStep->pNext;
if( pTmp->target.dyn ) sqliteFree((char*)pTmp->target.z);
sqlite3ExprDelete(pTmp->pWhere);
sqlite3ExprListDelete(pTmp->pExprList);
sqlite3SelectDelete(pTmp->pSelect);
sqlite3IdListDelete(pTmp->pIdList);
sqliteFree(pTmp);
}
}
/*
** Turn a SELECT statement (that the pSelect parameter points to) into
** a trigger step. Return a pointer to a TriggerStep structure.
**
** The parser calls this routine when it finds a SELECT statement in
** body of a TRIGGER.
*/
TriggerStep *sqlite3TriggerSelectStep(sqlite3 *db, Select *pSelect){
TriggerStep *pTriggerStep = (TriggerStep*)sqlite3DbMallocZero(db, sizeof(TriggerStep));
if( pTriggerStep==0 ) {
sqlite3SelectDelete(pSelect);
return 0;
}
pTriggerStep->op = TK_SELECT;
pTriggerStep->pSelect = pSelect;
pTriggerStep->orconf = OE_Default;
sqlitePersistTriggerStep(db, pTriggerStep);
return pTriggerStep;
}
/*
** Turn a SELECT statement (that the pSelect parameter points to) into
** a trigger step. Return a pointer to a TriggerStep structure.
**
** The parser calls this routine when it finds a SELECT statement in
** body of a TRIGGER.
*/
TriggerStep *sqlite3TriggerSelectStep(
sqlite3 *db, /* Database connection */
Select *pSelect, /* The SELECT statement */
const char *zStart, /* Start of SQL text */
const char *zEnd /* End of SQL text */
){
TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
if( pTriggerStep==0 ) {
sqlite3SelectDelete(db, pSelect);
return 0;
}
pTriggerStep->op = TK_SELECT;
pTriggerStep->pSelect = pSelect;
pTriggerStep->orconf = OE_Default;
pTriggerStep->zSpan = triggerSpanDup(db, zStart, zEnd);
return pTriggerStep;
}
/*
** Evaluate a view and store its result in an ephemeral table. The
** pWhere argument is an optional WHERE clause that restricts the
** set of rows in the view that are to be added to the ephemeral table.
*/
void sqlite3MaterializeView(
Parse *pParse, /* Parsing context */
Select *pView, /* View definition */
Expr *pWhere, /* Optional WHERE clause to be added */
int iCur /* Cursor number for ephemerial table */
){
SelectDest dest;
Select *pDup;
sqlite3 *db = pParse->db;
pDup = sqlite3SelectDup(db, pView);
if( pWhere ){
SrcList *pFrom;
pWhere = sqlite3ExprDup(db, pWhere);
pFrom = sqlite3SrcListAppendFromTerm(pParse, 0, 0, 0, 0, pDup, 0, 0);
pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
}
sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
sqlite3Select(pParse, pDup, &dest, 0, 0, 0);
sqlite3SelectDelete(db, pDup);
}
/*
** Build a trigger step out of an INSERT statement. Return a pointer
** to the new trigger step.
**
** The parser calls this routine when it sees an INSERT inside the
** body of a trigger.
*/
TriggerStep *sqlite3TriggerInsertStep(
Parse *pParse, /* Parser */
Token *pTableName, /* Name of the table into which we insert */
IdList *pColumn, /* List of columns in pTableName to insert into */
Select *pSelect, /* A SELECT statement that supplies values */
u8 orconf, /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */
Upsert *pUpsert, /* ON CONFLICT clauses for upsert */
const char *zStart, /* Start of SQL text */
const char *zEnd /* End of SQL text */
){
sqlite3 *db = pParse->db;
TriggerStep *pTriggerStep;
assert(pSelect != 0 || db->mallocFailed);
pTriggerStep = triggerStepAllocate(pParse, TK_INSERT, pTableName,zStart,zEnd);
if( pTriggerStep ){
if( IN_RENAME_OBJECT ){
pTriggerStep->pSelect = pSelect;
pSelect = 0;
}else{
pTriggerStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
}
pTriggerStep->pIdList = pColumn;
pTriggerStep->pUpsert = pUpsert;
pTriggerStep->orconf = orconf;
}else{
testcase( pColumn );
sqlite3IdListDelete(db, pColumn);
testcase( pUpsert );
sqlite3UpsertDelete(db, pUpsert);
}
sqlite3SelectDelete(db, pSelect);
return pTriggerStep;
}
/*
** Generate code for a DELETE FROM statement.
**
** DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
** \________/ \________________/
** pTabList pWhere
*/
void sqlite3DeleteFrom(
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 = 0; /* 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 */
sqlite3 *db; /* Main database structure */
AuthContext sContext; /* Authorization context */
int oldIdx = -1; /* Cursor for the OLD table of AFTER triggers */
NameContext sNC; /* Name context to resolve expressions in */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True if attempting to delete from a view */
int triggers_exist = 0; /* True if any triggers exist */
#endif
sContext.pParse = 0;
if( pParse->nErr || sqlite3_malloc_failed ){
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 = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ) goto delete_from_cleanup;
/* Figure out if we have any triggers and if the table being
** deleted from is a view
*/
#ifndef SQLITE_OMIT_TRIGGER
triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0);
isView = pTab->pSelect!=0;
#else
# define triggers_exist 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
goto delete_from_cleanup;
}
assert( pTab->iDb<db->nDb );
zDb = db->aDb[pTab->iDb].zName;
if( sqlite3AuthCheck(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 && sqlite3ViewGetColumnNames(pParse, pTab) ){
goto delete_from_cleanup;
}
/* Allocate a cursor used to store the old.* data for a trigger.
*/
if( triggers_exist ){
oldIdx = pParse->nTab++;
}
/* Resolve the column names in the WHERE clause.
*/
assert( pTabList->nSrc==1 );
iCur = pTabList->a[0].iCursor = pParse->nTab++;
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
if( sqlite3ExprResolveNames(&sNC, pWhere) ){
goto delete_from_cleanup;
}
/* Start the view context
*/
if( isView ){
sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
}
/* Begin generating code.
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ){
goto delete_from_cleanup;
}
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, triggers_exist, pTab->iDb);
/* If we are trying to delete from a view, construct that view into
** a temporary table.
*/
if( isView ){
Select *pView = sqlite3SelectDup(pTab->pSelect);
sqlite3Select(pParse, pView, SRT_TempTable, iCur, 0, 0, 0, 0);
sqlite3SelectDelete(pView);
}
/* Initialize the counter of the number of rows deleted, if
** we are counting rows.
*/
if( db->flags & SQLITE_CountRows ){
sqlite3VdbeAddOp(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 && !triggers_exist ){
if( db->flags & SQLITE_CountRows ){
/* If counting rows deleted, just count the total number of
** entries in the table. */
int endOfLoop = sqlite3VdbeMakeLabel(v);
int addr;
if( !isView ){
sqlite3OpenTableForReading(v, iCur, pTab);
}
sqlite3VdbeAddOp(v, OP_Rewind, iCur, sqlite3VdbeCurrentAddr(v)+2);
addr = sqlite3VdbeAddOp(v, OP_AddImm, 1, 0);
sqlite3VdbeAddOp(v, OP_Next, iCur, addr);
sqlite3VdbeResolveLabel(v, endOfLoop);
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
if( !isView ){
sqlite3VdbeAddOp(v, OP_Clear, pTab->tnum, pTab->iDb);
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
sqlite3VdbeAddOp(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{
/* Ensure all required collation sequences are available. */
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( sqlite3CheckIndexCollSeq(pParse, pIdx) ){
goto delete_from_cleanup;
}
}
/* Begin the database scan
*/
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0);
if( pWInfo==0 ) goto delete_from_cleanup;
/* Remember the rowid of every item to be deleted.
*/
sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
sqlite3VdbeAddOp(v, OP_ListWrite, 0, 0);
if( db->flags & SQLITE_CountRows ){
sqlite3VdbeAddOp(v, OP_AddImm, 1, 0);
}
/* End the database scan loop.
*/
sqlite3WhereEnd(pWInfo);
/* Open the pseudo-table used to store OLD if there are triggers.
*/
if( triggers_exist ){
sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol);
}
/* 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.
*/
sqlite3VdbeAddOp(v, OP_ListRewind, 0, 0);
end = sqlite3VdbeMakeLabel(v);
/* This is the beginning of the delete loop when there are
** row triggers.
*/
if( triggers_exist ){
addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, end);
if( !isView ){
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
sqlite3OpenTableForReading(v, iCur, pTab);
}
sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
sqlite3VdbeAddOp(v, OP_PutIntKey, oldIdx, 0);
if( !isView ){
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
(void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_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.
*/
sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);
/* This is the beginning of the delete loop when there are no
** row triggers */
if( !triggers_exist ){
addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, end);
}
/* Delete the row */
sqlite3GenerateRowDelete(db, v, pTab, iCur, pParse->nested==0);
}
/* If there are row triggers, close all cursors then invoke
** the AFTER triggers
*/
if( triggers_exist ){
if( !isView ){
for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
sqlite3VdbeAddOp(v, OP_Close, iCur + i, pIdx->tnum);
}
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
(void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_AFTER, pTab, -1,
oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
addr);
}
/* End of the delete loop */
sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
sqlite3VdbeResolveLabel(v, end);
sqlite3VdbeAddOp(v, OP_ListReset, 0, 0);
/* Close the cursors after the loop if there are no row triggers */
if( !triggers_exist ){
for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
sqlite3VdbeAddOp(v, OP_Close, iCur + i, pIdx->tnum);
}
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
}
/*
** Return the number of rows that were deleted. If this routine is
** generating code because of a call to sqlite3NestedParse(), do not
** invoke the callback function.
*/
if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, "rows deleted", P3_STATIC);
}
delete_from_cleanup:
sqlite3AuthContextPop(&sContext);
sqlite3SrcListDelete(pTabList);
sqlite3ExprDelete(pWhere);
return;
}
/*
** This routine is call to handle SQL of the following forms:
**
** insert into TABLE (IDLIST) values(EXPRLIST)
** insert into TABLE (IDLIST) select
**
** The IDLIST following the table name is always optional. If omitted,
** then a list of all columns for the table is substituted. The IDLIST
** appears in the pColumn parameter. pColumn is NULL if IDLIST is omitted.
**
** The pList parameter holds EXPRLIST in the first form of the INSERT
** statement above, and pSelect is NULL. For the second form, pList is
** NULL and pSelect is a pointer to the select statement used to generate
** data for the insert.
**
** The code generated follows one of three templates. For a simple
** select with data coming from a VALUES clause, the code executes
** once straight down through. The template looks like this:
**
** open write cursor to <table> and its indices
** puts VALUES clause expressions onto the stack
** write the resulting record into <table>
** cleanup
**
** If the statement is of the form
**
** INSERT INTO <table> SELECT ...
**
** And the SELECT clause does not read from <table> at any time, then
** the generated code follows this template:
**
** goto B
** A: setup for the SELECT
** loop over the tables in the SELECT
** gosub C
** end loop
** cleanup after the SELECT
** goto D
** B: open write cursor to <table> and its indices
** goto A
** C: insert the select result into <table>
** return
** D: cleanup
**
** The third template is used if the insert statement takes its
** values from a SELECT but the data is being inserted into a table
** that is also read as part of the SELECT. In the third form,
** we have to use a intermediate table to store the results of
** the select. The template is like this:
**
** goto B
** A: setup for the SELECT
** loop over the tables in the SELECT
** gosub C
** end loop
** cleanup after the SELECT
** goto D
** C: insert the select result into the intermediate table
** return
** B: open a cursor to an intermediate table
** goto A
** D: open write cursor to <table> and its indices
** loop over the intermediate table
** transfer values form intermediate table into <table>
** end the loop
** cleanup
*/
void sqlite3Insert(
Parse *pParse, /* Parser context */
SrcList *pTabList, /* Name of table into which we are inserting */
ExprList *pList, /* List of values to be inserted */
Select *pSelect, /* A SELECT statement to use as the data source */
IdList *pColumn, /* Column names corresponding to IDLIST. */
int onError /* How to handle constraint errors */
){
Table *pTab; /* The table to insert into */
char *zTab; /* Name of the table into which we are inserting */
const char *zDb; /* Name of the database holding this table */
int i, j, idx; /* Loop counters */
Vdbe *v; /* Generate code into this virtual machine */
Index *pIdx; /* For looping over indices of the table */
int nColumn; /* Number of columns in the data */
int base = 0; /* VDBE Cursor number for pTab */
int iCont=0,iBreak=0; /* Beginning and end of the loop over srcTab */
sqlite3 *db; /* The main database structure */
int keyColumn = -1; /* Column that is the INTEGER PRIMARY KEY */
int endOfLoop; /* Label for the end of the insertion loop */
int useTempTable = 0; /* Store SELECT results in intermediate table */
int srcTab = 0; /* Data comes from this temporary cursor if >=0 */
int iSelectLoop = 0; /* Address of code that implements the SELECT */
int iCleanup = 0; /* Address of the cleanup code */
int iInsertBlock = 0; /* Address of the subroutine used to insert data */
int iCntMem = 0; /* Memory cell used for the row counter */
int newIdx = -1; /* Cursor for the NEW table */
Db *pDb; /* The database containing table being inserted into */
int counterMem = 0; /* Memory cell holding AUTOINCREMENT counter */
int iDb;
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True if attempting to insert into a view */
int triggers_exist = 0; /* True if there are FOR EACH ROW triggers */
#endif
#ifndef SQLITE_OMIT_AUTOINCREMENT
int counterRowid = 0; /* Memory cell holding rowid of autoinc counter */
#endif
if( pParse->nErr || sqlite3MallocFailed() ){
goto insert_cleanup;
}
db = pParse->db;
/* Locate the table into which we will be inserting new information.
*/
assert( pTabList->nSrc==1 );
zTab = pTabList->a[0].zName;
if( zTab==0 ) goto insert_cleanup;
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ){
goto insert_cleanup;
}
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
assert( iDb<db->nDb );
pDb = &db->aDb[iDb];
zDb = pDb->zName;
if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb) ){
goto insert_cleanup;
}
/* Figure out if we have any triggers and if the table being
** inserted into is a view
*/
#ifndef SQLITE_OMIT_TRIGGER
triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0);
isView = pTab->pSelect!=0;
#else
# define triggers_exist 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
/* Ensure that:
* (a) the table is not read-only,
* (b) that if it is a view then ON INSERT triggers exist
*/
if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
goto insert_cleanup;
}
assert( pTab!=0 );
/* If pTab is really a view, make sure it has been initialized.
*/
if( isView && sqlite3ViewGetColumnNames(pParse, pTab) ){
goto insert_cleanup;
}
/* Allocate a VDBE
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto insert_cleanup;
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, pSelect || triggers_exist, iDb);
/* if there are row triggers, allocate a temp table for new.* references. */
if( triggers_exist ){
newIdx = pParse->nTab++;
}
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* If this is an AUTOINCREMENT table, look up the sequence number in the
** sqlite_sequence table and store it in memory cell counterMem. Also
** remember the rowid of the sqlite_sequence table entry in memory cell
** counterRowid.
*/
if( pTab->autoInc ){
int iCur = pParse->nTab;
int addr = sqlite3VdbeCurrentAddr(v);
counterRowid = pParse->nMem++;
counterMem = pParse->nMem++;
sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
sqlite3VdbeAddOp(v, OP_Rewind, iCur, addr+13);
sqlite3VdbeAddOp(v, OP_Column, iCur, 0);
sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0);
sqlite3VdbeAddOp(v, OP_Ne, 0x100, addr+12);
sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
sqlite3VdbeAddOp(v, OP_MemStore, counterRowid, 1);
sqlite3VdbeAddOp(v, OP_Column, iCur, 1);
sqlite3VdbeAddOp(v, OP_MemStore, counterMem, 1);
sqlite3VdbeAddOp(v, OP_Goto, 0, addr+13);
sqlite3VdbeAddOp(v, OP_Next, iCur, addr+4);
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */
/* Figure out how many columns of data are supplied. If the data
** is coming from a SELECT statement, then this step also generates
** all the code to implement the SELECT statement and invoke a subroutine
** to process each row of the result. (Template 2.) If the SELECT
** statement uses the the table that is being inserted into, then the
** subroutine is also coded here. That subroutine stores the SELECT
** results in a temporary table. (Template 3.)
*/
if( pSelect ){
/* Data is coming from a SELECT. Generate code to implement that SELECT
*/
int rc, iInitCode;
iInitCode = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
iSelectLoop = sqlite3VdbeCurrentAddr(v);
iInsertBlock = sqlite3VdbeMakeLabel(v);
/* Resolve the expressions in the SELECT statement and execute it. */
rc = sqlite3Select(pParse, pSelect, SRT_Subroutine, iInsertBlock,0,0,0,0);
if( rc || pParse->nErr || sqlite3MallocFailed() ){
goto insert_cleanup;
}
iCleanup = sqlite3VdbeMakeLabel(v);
sqlite3VdbeAddOp(v, OP_Goto, 0, iCleanup);
assert( pSelect->pEList );
nColumn = pSelect->pEList->nExpr;
/* Set useTempTable to TRUE if the result of the SELECT statement
** should be written into a temporary table. Set to FALSE if each
** row of the SELECT can be written directly into the result table.
**
** A temp table must be used if the table being updated is also one
** of the tables being read by the SELECT statement. Also use a
** temp table in the case of row triggers.
*/
if( triggers_exist || selectReadsTable(pSelect,pTab->pSchema,pTab->tnum) ){
useTempTable = 1;
}
if( useTempTable ){
/* Generate the subroutine that SELECT calls to process each row of
** the result. Store the result in a temporary table
*/
srcTab = pParse->nTab++;
sqlite3VdbeResolveLabel(v, iInsertBlock);
sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
sqlite3VdbeAddOp(v, OP_NewRowid, srcTab, 0);
sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
sqlite3VdbeAddOp(v, OP_Insert, srcTab, 0);
sqlite3VdbeAddOp(v, OP_Return, 0, 0);
/* The following code runs first because the GOTO at the very top
** of the program jumps to it. Create the temporary table, then jump
** back up and execute the SELECT code above.
*/
sqlite3VdbeJumpHere(v, iInitCode);
sqlite3VdbeAddOp(v, OP_OpenVirtual, srcTab, 0);
sqlite3VdbeAddOp(v, OP_SetNumColumns, srcTab, nColumn);
sqlite3VdbeAddOp(v, OP_Goto, 0, iSelectLoop);
sqlite3VdbeResolveLabel(v, iCleanup);
}else{
sqlite3VdbeJumpHere(v, iInitCode);
}
}else{
/* This is the case if the data for the INSERT is coming from a VALUES
** clause
*/
NameContext sNC;
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
assert( pList!=0 );
srcTab = -1;
useTempTable = 0;
assert( pList );
nColumn = pList->nExpr;
for(i=0; i<nColumn; i++){
if( sqlite3ExprResolveNames(&sNC, pList->a[i].pExpr) ){
goto insert_cleanup;
}
}
}
/* Make sure the number of columns in the source data matches the number
** of columns to be inserted into the table.
*/
if( pColumn==0 && nColumn!=pTab->nCol ){
sqlite3ErrorMsg(pParse,
"table %S has %d columns but %d values were supplied",
pTabList, 0, pTab->nCol, nColumn);
goto insert_cleanup;
}
if( pColumn!=0 && nColumn!=pColumn->nId ){
sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
goto insert_cleanup;
}
/* If the INSERT statement included an IDLIST term, then make sure
** all elements of the IDLIST really are columns of the table and
** remember the column indices.
**
** If the table has an INTEGER PRIMARY KEY column and that column
** is named in the IDLIST, then record in the keyColumn variable
** the index into IDLIST of the primary key column. keyColumn is
** the index of the primary key as it appears in IDLIST, not as
** is appears in the original table. (The index of the primary
** key in the original table is pTab->iPKey.)
*/
if( pColumn ){
for(i=0; i<pColumn->nId; i++){
pColumn->a[i].idx = -1;
}
for(i=0; i<pColumn->nId; i++){
for(j=0; j<pTab->nCol; j++){
if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
pColumn->a[i].idx = j;
if( j==pTab->iPKey ){
keyColumn = i;
}
break;
}
}
if( j>=pTab->nCol ){
if( sqlite3IsRowid(pColumn->a[i].zName) ){
keyColumn = i;
}else{
sqlite3ErrorMsg(pParse, "table %S has no column named %s",
pTabList, 0, pColumn->a[i].zName);
pParse->nErr++;
goto insert_cleanup;
}
}
}
}
/* If there is no IDLIST term but the table has an integer primary
** key, the set the keyColumn variable to the primary key column index
** in the original table definition.
*/
if( pColumn==0 ){
keyColumn = pTab->iPKey;
}
/* Open the temp table for FOR EACH ROW triggers
*/
if( triggers_exist ){
sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
sqlite3VdbeAddOp(v, OP_SetNumColumns, newIdx, pTab->nCol);
}
/* Initialize the count of rows to be inserted
*/
if( db->flags & SQLITE_CountRows ){
iCntMem = pParse->nMem++;
sqlite3VdbeAddOp(v, OP_MemInt, 0, iCntMem);
}
/* Open tables and indices if there are no row triggers */
if( !triggers_exist ){
base = pParse->nTab;
sqlite3OpenTableAndIndices(pParse, pTab, base, OP_OpenWrite);
}
/* If the data source is a temporary table, then we have to create
** a loop because there might be multiple rows of data. If the data
** source is a subroutine call from the SELECT statement, then we need
** to launch the SELECT statement processing.
*/
if( useTempTable ){
iBreak = sqlite3VdbeMakeLabel(v);
sqlite3VdbeAddOp(v, OP_Rewind, srcTab, iBreak);
iCont = sqlite3VdbeCurrentAddr(v);
}else if( pSelect ){
sqlite3VdbeAddOp(v, OP_Goto, 0, iSelectLoop);
sqlite3VdbeResolveLabel(v, iInsertBlock);
}
/* Run the BEFORE and INSTEAD OF triggers, if there are any
*/
endOfLoop = sqlite3VdbeMakeLabel(v);
if( triggers_exist & TRIGGER_BEFORE ){
/* build the NEW.* reference row. Note that if there is an INTEGER
** PRIMARY KEY into which a NULL is being inserted, that NULL will be
** translated into a unique ID for the row. But on a BEFORE trigger,
** we do not know what the unique ID will be (because the insert has
** not happened yet) so we substitute a rowid of -1
*/
if( keyColumn<0 ){
sqlite3VdbeAddOp(v, OP_Integer, -1, 0);
}else if( useTempTable ){
sqlite3VdbeAddOp(v, OP_Column, srcTab, keyColumn);
}else{
assert( pSelect==0 ); /* Otherwise useTempTable is true */
sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr);
sqlite3VdbeAddOp(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
sqlite3VdbeAddOp(v, OP_Integer, -1, 0);
sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
}
/* Create the new column data
*/
for(i=0; i<pTab->nCol; i++){
if( pColumn==0 ){
j = i;
}else{
for(j=0; j<pColumn->nId; j++){
if( pColumn->a[j].idx==i ) break;
}
}
if( pColumn && j>=pColumn->nId ){
sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
}else if( useTempTable ){
sqlite3VdbeAddOp(v, OP_Column, srcTab, j);
}else{
assert( pSelect==0 ); /* Otherwise useTempTable is true */
sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr);
}
}
sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
/* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
** do not attempt any conversions before assembling the record.
** If this is a real table, attempt conversions as required by the
** table column affinities.
*/
if( !isView ){
sqlite3TableAffinityStr(v, pTab);
}
sqlite3VdbeAddOp(v, OP_Insert, newIdx, 0);
/* Fire BEFORE or INSTEAD OF triggers */
if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_BEFORE, pTab,
newIdx, -1, onError, endOfLoop) ){
goto insert_cleanup;
}
}
/* If any triggers exists, the opening of tables and indices is deferred
** until now.
*/
if( triggers_exist && !isView ){
base = pParse->nTab;
sqlite3OpenTableAndIndices(pParse, pTab, base, OP_OpenWrite);
}
/* Push the record number for the new entry onto the stack. The
** record number is a randomly generate integer created by NewRowid
** except when the table has an INTEGER PRIMARY KEY column, in which
** case the record number is the same as that column.
*/
if( !isView ){
if( keyColumn>=0 ){
if( useTempTable ){
sqlite3VdbeAddOp(v, OP_Column, srcTab, keyColumn);
}else if( pSelect ){
sqlite3VdbeAddOp(v, OP_Dup, nColumn - keyColumn - 1, 1);
}else{
sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr);
}
/* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
** to generate a unique primary key value.
*/
sqlite3VdbeAddOp(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
sqlite3VdbeAddOp(v, OP_NewRowid, base, counterMem);
sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
}else{
sqlite3VdbeAddOp(v, OP_NewRowid, base, counterMem);
}
#ifndef SQLITE_OMIT_AUTOINCREMENT
if( pTab->autoInc ){
sqlite3VdbeAddOp(v, OP_MemMax, counterMem, 0);
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */
/* Push onto the stack, data for all columns of the new entry, beginning
** with the first column.
*/
for(i=0; i<pTab->nCol; i++){
if( i==pTab->iPKey ){
/* The value of the INTEGER PRIMARY KEY column is always a NULL.
** Whenever this column is read, the record number will be substituted
** in its place. So will fill this column with a NULL to avoid
** taking up data space with information that will never be used. */
sqlite3VdbeAddOp(v, OP_Null, 0, 0);
continue;
}
if( pColumn==0 ){
j = i;
}else{
for(j=0; j<pColumn->nId; j++){
if( pColumn->a[j].idx==i ) break;
}
}
if( pColumn && j>=pColumn->nId ){
sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
}else if( useTempTable ){
sqlite3VdbeAddOp(v, OP_Column, srcTab, j);
}else if( pSelect ){
sqlite3VdbeAddOp(v, OP_Dup, i+nColumn-j, 1);
}else{
sqlite3ExprCode(pParse, pList->a[j].pExpr);
}
}
/* Generate code to check constraints and generate index keys and
** do the insertion.
*/
sqlite3GenerateConstraintChecks(pParse, pTab, base, 0, keyColumn>=0,
0, onError, endOfLoop);
sqlite3CompleteInsertion(pParse, pTab, base, 0,0,0,
(triggers_exist & TRIGGER_AFTER)!=0 ? newIdx : -1);
}
/* Update the count of rows that are inserted
*/
if( (db->flags & SQLITE_CountRows)!=0 ){
sqlite3VdbeAddOp(v, OP_MemIncr, 1, iCntMem);
}
if( triggers_exist ){
/* Close all tables opened */
if( !isView ){
sqlite3VdbeAddOp(v, OP_Close, base, 0);
for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
sqlite3VdbeAddOp(v, OP_Close, idx+base, 0);
}
}
/* Code AFTER triggers */
if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_AFTER, pTab,
newIdx, -1, onError, endOfLoop) ){
goto insert_cleanup;
}
}
/* The bottom of the loop, if the data source is a SELECT statement
*/
sqlite3VdbeResolveLabel(v, endOfLoop);
if( useTempTable ){
sqlite3VdbeAddOp(v, OP_Next, srcTab, iCont);
sqlite3VdbeResolveLabel(v, iBreak);
sqlite3VdbeAddOp(v, OP_Close, srcTab, 0);
}else if( pSelect ){
sqlite3VdbeAddOp(v, OP_Pop, nColumn, 0);
sqlite3VdbeAddOp(v, OP_Return, 0, 0);
sqlite3VdbeResolveLabel(v, iCleanup);
}
if( !triggers_exist ){
/* Close all tables opened */
sqlite3VdbeAddOp(v, OP_Close, base, 0);
for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
sqlite3VdbeAddOp(v, OP_Close, idx+base, 0);
}
}
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* Update the sqlite_sequence table by storing the content of the
** counter value in memory counterMem back into the sqlite_sequence
** table.
*/
if( pTab->autoInc ){
int iCur = pParse->nTab;
int addr = sqlite3VdbeCurrentAddr(v);
sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
sqlite3VdbeAddOp(v, OP_MemLoad, counterRowid, 0);
sqlite3VdbeAddOp(v, OP_NotNull, -1, addr+7);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
sqlite3VdbeAddOp(v, OP_NewRowid, iCur, 0);
sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0);
sqlite3VdbeAddOp(v, OP_MemLoad, counterMem, 0);
sqlite3VdbeAddOp(v, OP_MakeRecord, 2, 0);
sqlite3VdbeAddOp(v, OP_Insert, iCur, 0);
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
#endif
/*
** Return the number of rows inserted. If this routine is
** generating code because of a call to sqlite3NestedParse(), do not
** invoke the callback function.
*/
if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
sqlite3VdbeAddOp(v, OP_MemLoad, iCntMem, 0);
sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows inserted", P3_STATIC);
}
insert_cleanup:
sqlite3SrcListDelete(pTabList);
sqlite3ExprListDelete(pList);
sqlite3SelectDelete(pSelect);
sqlite3IdListDelete(pColumn);
}
/*
** 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 sqlite3Update(
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 = 0; /* 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 */
sqlite3 *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 = 0; /* Expression defining the new record number */
int openAll = 0; /* True if all indices need to be opened */
AuthContext sContext; /* The authorization context */
NameContext sNC; /* The name-context to resolve expressions in */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* Trying to update a view */
int triggers_exist = 0; /* True if any row triggers exist */
#endif
int newIdx = -1; /* index of trigger "new" temp table */
int oldIdx = -1; /* index of trigger "old" temp table */
sContext.pParse = 0;
if( pParse->nErr || sqlite3_malloc_failed ) goto update_cleanup;
db = pParse->db;
assert( pTabList->nSrc==1 );
/* Locate the table which we want to update.
*/
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ) goto update_cleanup;
/* Figure out if we have any triggers and if the table being
** updated is a view
*/
#ifndef SQLITE_OMIT_TRIGGER
triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges);
isView = pTab->pSelect!=0;
#else
# define triggers_exist 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
goto update_cleanup;
}
if( isView ){
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto update_cleanup;
}
}
aXRef = sqliteMallocRaw( 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( 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++;
}
/* Initialize the name-context */
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
/* 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( sqlite3ExprResolveNames(&sNC, pChanges->a[i].pExpr) ){
goto update_cleanup;
}
for(j=0; j<pTab->nCol; j++){
if( sqlite3StrICmp(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( sqlite3IsRowid(pChanges->a[i].zName) ){
chngRecno = 1;
pRecnoExpr = pChanges->a[i].pExpr;
}else{
sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName);
goto update_cleanup;
}
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int rc;
rc = sqlite3AuthCheck(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 = sqliteMallocRaw( 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 ){
if( sqlite3CheckIndexCollSeq(pParse, pIdx) ) goto update_cleanup;
apIdx[nIdx++] = pIdx;
aIdxUsed[j] = 1;
}else{
aIdxUsed[j] = 0;
}
}
/* Resolve the column names in all the expressions in the
** WHERE clause.
*/
if( sqlite3ExprResolveNames(&sNC, pWhere) ){
goto update_cleanup;
}
/* Start the view context
*/
if( isView ){
sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
}
/* Begin generating code.
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto update_cleanup;
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, 1, pTab->iDb);
/* If we are trying to update a view, construct that view into
** a temporary table.
*/
if( isView ){
Select *pView;
pView = sqlite3SelectDup(pTab->pSelect);
sqlite3Select(pParse, pView, SRT_TempTable, iCur, 0, 0, 0, 0);
sqlite3SelectDelete(pView);
}
/* Begin the database scan
*/
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0);
if( pWInfo==0 ) goto update_cleanup;
/* Remember the index of every item to be updated.
*/
sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
sqlite3VdbeAddOp(v, OP_ListWrite, 0, 0);
/* End the database scan loop.
*/
sqlite3WhereEnd(pWInfo);
/* Initialize the count of updated rows
*/
if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
}
if( triggers_exist ){
/* Create pseudo-tables for NEW and OLD
*/
sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol);
sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
sqlite3VdbeAddOp(v, OP_SetNumColumns, newIdx, pTab->nCol);
/* The top of the update loop for when there are triggers.
*/
sqlite3VdbeAddOp(v, OP_ListRewind, 0, 0);
addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, 0);
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
/* Open a cursor and make it point to the record that is
** being updated.
*/
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
if( !isView ){
sqlite3OpenTableForReading(v, iCur, pTab);
}
sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
/* Generate the OLD table
*/
sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
sqlite3VdbeAddOp(v, OP_PutIntKey, oldIdx, 0);
/* Generate the NEW table
*/
if( chngRecno ){
sqlite3ExprCodeAndCache(pParse, pRecnoExpr);
}else{
sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
}
for(i=0; i<pTab->nCol; i++){
if( i==pTab->iPKey ){
sqlite3VdbeAddOp(v, OP_String8, 0, 0);
continue;
}
j = aXRef[i];
if( j<0 ){
sqlite3VdbeAddOp(v, OP_Column, iCur, i);
sqlite3ColumnDefault(v, pTab, i);
}else{
sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr);
}
}
sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
if( !isView ){
sqlite3TableAffinityStr(v, pTab);
}
if( pParse->nErr ) goto update_cleanup;
sqlite3VdbeAddOp(v, OP_PutIntKey, newIdx, 0);
if( !isView ){
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
/* Fire the BEFORE and INSTEAD OF triggers
*/
if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_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.
*/
sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0);
sqlite3VdbeAddOp(v, OP_OpenWrite, iCur, pTab->tnum);
sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, pTab->nCol);
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] ){
sqlite3VdbeAddOp(v, OP_Integer, pIdx->iDb, 0);
sqlite3VdbeOp3(v, OP_OpenWrite, iCur+i+1, pIdx->tnum,
(char*)&pIdx->keyInfo, P3_KEYINFO);
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( !triggers_exist ){
sqlite3VdbeAddOp(v, OP_ListRewind, 0, 0);
addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, 0);
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
}
sqlite3VdbeAddOp(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 ){
sqlite3ExprCode(pParse, pRecnoExpr);
sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
}
/* Compute new data for this record.
*/
for(i=0; i<pTab->nCol; i++){
if( i==pTab->iPKey ){
sqlite3VdbeAddOp(v, OP_String8, 0, 0);
continue;
}
j = aXRef[i];
if( j<0 ){
sqlite3VdbeAddOp(v, OP_Column, iCur, i);
sqlite3ColumnDefault(v, pTab, i);
}else{
sqlite3ExprCode(pParse, pChanges->a[j].pExpr);
}
}
/* Do constraint checks
*/
sqlite3GenerateConstraintChecks(pParse, pTab, iCur, aIdxUsed, chngRecno, 1,
onError, addr);
/* Delete the old indices for the current record.
*/
sqlite3GenerateRowIndexDelete(db, v, pTab, iCur, aIdxUsed);
/* If changing the record number, delete the old record.
*/
if( chngRecno ){
sqlite3VdbeAddOp(v, OP_Delete, iCur, 0);
}
/* Create the new index entries and the new record.
*/
sqlite3CompleteInsertion(pParse, pTab, iCur, aIdxUsed, chngRecno, 1, -1);
}
/* Increment the row counter
*/
if( db->flags & SQLITE_CountRows && !pParse->trigStack){
sqlite3VdbeAddOp(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( triggers_exist ){
if( !isView ){
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
if( openAll || aIdxUsed[i] )
sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0);
}
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_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.
*/
sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v));
sqlite3VdbeAddOp(v, OP_ListReset, 0, 0);
/* Close all tables if there were no FOR EACH ROW triggers */
if( !triggers_exist ){
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
if( openAll || aIdxUsed[i] ){
sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0);
}
}
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}else{
sqlite3VdbeAddOp(v, OP_Close, newIdx, 0);
sqlite3VdbeAddOp(v, OP_Close, oldIdx, 0);
}
/*
** Return the number of rows that were changed. If this routine is
** generating code because of a call to sqlite3NestedParse(), do not
** invoke the callback function.
*/
if( db->flags & SQLITE_CountRows && !pParse->trigStack && pParse->nested==0 ){
sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, "rows updated", P3_STATIC);
}
update_cleanup:
sqlite3AuthContextPop(&sContext);
sqliteFree(apIdx);
sqliteFree(aXRef);
sqlite3SrcListDelete(pTabList);
sqlite3ExprListDelete(pChanges);
sqlite3ExprDelete(pWhere);
return;
}
/*
** Generate an expression tree to implement the WHERE, ORDER BY,
** and LIMIT/OFFSET portion of DELETE and UPDATE statements.
**
** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1;
** \__________________________/
** pLimitWhere (pInClause)
*/
Expr *sqlite3LimitWhere(
Parse *pParse, /* The parser context */
SrcList *pSrc, /* the FROM clause -- which tables to scan */
Expr *pWhere, /* The WHERE clause. May be null */
ExprList *pOrderBy, /* The ORDER BY clause. May be null */
Expr *pLimit, /* The LIMIT clause. May be null */
Expr *pOffset, /* The OFFSET clause. May be null */
char *zStmtType /* Either DELETE or UPDATE. For error messages. */
){
Expr *pWhereRowid = NULL; /* WHERE rowid .. */
Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */
Expr *pSelectRowid = NULL; /* SELECT rowid ... */
ExprList *pEList = NULL; /* Expression list contaning only pSelectRowid */
SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */
Select *pSelect = NULL; /* Complete SELECT tree */
/* Check that there isn't an ORDER BY without a LIMIT clause.
*/
if( pOrderBy && (pLimit == 0) ) {
sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
goto limit_where_cleanup_2;
}
/* We only need to generate a select expression if there
** is a limit/offset term to enforce.
*/
if( pLimit == 0 ) {
/* if pLimit is null, pOffset will always be null as well. */
assert( pOffset == 0 );
return pWhere;
}
/* Generate a select expression tree to enforce the limit/offset
** term for the DELETE or UPDATE statement. For example:
** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
** becomes:
** DELETE FROM table_a WHERE rowid IN (
** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
** );
*/
pSelectRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
if( pSelectRowid == 0 ) goto limit_where_cleanup_2;
pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid);
if( pEList == 0 ) goto limit_where_cleanup_2;
/* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
** and the SELECT subtree. */
pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0);
if( pSelectSrc == 0 ) {
sqlite3ExprListDelete(pParse->db, pEList);
goto limit_where_cleanup_2;
}
/* generate the SELECT expression tree. */
pSelect = sqlite3SelectNew(pParse,pEList,pSelectSrc,pWhere,0,0,
pOrderBy,0,pLimit,pOffset);
if( pSelect == 0 ) return 0;
/* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
pWhereRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
if( pWhereRowid == 0 ) goto limit_where_cleanup_1;
pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0);
if( pInClause == 0 ) goto limit_where_cleanup_1;
pInClause->x.pSelect = pSelect;
pInClause->flags |= EP_xIsSelect;
sqlite3ExprSetHeight(pParse, pInClause);
return pInClause;
/* something went wrong. clean up anything allocated. */
limit_where_cleanup_1:
sqlite3SelectDelete(pParse->db, pSelect);
return 0;
limit_where_cleanup_2:
sqlite3ExprDelete(pParse->db, pWhere);
sqlite3ExprListDelete(pParse->db, pOrderBy);
sqlite3ExprDelete(pParse->db, pLimit);
sqlite3ExprDelete(pParse->db, pOffset);
return 0;
}
/*
** Generate VDBE code for the statements inside the body of a single
** trigger.
*/
static int codeTriggerProgram(
Parse *pParse, /* The parser context */
TriggerStep *pStepList, /* List of statements inside the trigger body */
int orconf /* Conflict algorithm. (OE_Abort, etc) */
){
TriggerStep *pStep;
Vdbe *v = pParse->pVdbe;
sqlite3 *db = pParse->db;
assert( pParse->pTriggerTab && pParse->pToplevel );
assert( pStepList );
assert( v!=0 );
for(pStep=pStepList; pStep; pStep=pStep->pNext){
/* Figure out the ON CONFLICT policy that will be used for this step
** of the trigger program. If the statement that caused this trigger
** to fire had an explicit ON CONFLICT, then use it. Otherwise, use
** the ON CONFLICT policy that was specified as part of the trigger
** step statement. Example:
**
** CREATE TRIGGER AFTER INSERT ON t1 BEGIN;
** INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);
** END;
**
** INSERT INTO t1 ... ; -- insert into t2 uses REPLACE policy
** INSERT OR IGNORE INTO t1 ... ; -- insert into t2 uses IGNORE policy
*/
pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf;
/* Clear the cookieGoto flag. When coding triggers, the cookieGoto
** variable is used as a flag to indicate to sqlite3ExprCodeConstants()
** that it is not safe to refactor constants (this happens after the
** start of the first loop in the SQL statement is coded - at that
** point code may be conditionally executed, so it is no longer safe to
** initialize constant register values). */
assert( pParse->cookieGoto==0 || pParse->cookieGoto==-1 );
pParse->cookieGoto = 0;
switch( pStep->op ){
case TK_UPDATE: {
sqlite3Update(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprListDup(db, pStep->pExprList, 0),
sqlite3ExprDup(db, pStep->pWhere, 0),
pParse->eOrconf
);
break;
}
case TK_INSERT: {
sqlite3Insert(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprListDup(db, pStep->pExprList, 0),
sqlite3SelectDup(db, pStep->pSelect, 0),
sqlite3IdListDup(db, pStep->pIdList),
pParse->eOrconf
);
break;
}
case TK_DELETE: {
sqlite3DeleteFrom(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprDup(db, pStep->pWhere, 0)
);
break;
}
default: assert( pStep->op==TK_SELECT ); {
SelectDest sDest;
Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
sqlite3SelectDestInit(&sDest, SRT_Discard, 0);
sqlite3Select(pParse, pSelect, &sDest);
sqlite3SelectDelete(db, pSelect);
break;
}
}
if( pStep->op!=TK_SELECT ){
sqlite3VdbeAddOp0(v, OP_ResetCount);
}
}
return 0;
}
/*
** This function is called when an UPDATE or DELETE operation is being
** compiled on table pTab, which is the parent table of foreign-key pFKey.
** If the current operation is an UPDATE, then the pChanges parameter is
** passed a pointer to the list of columns being modified. If it is a
** DELETE, pChanges is passed a NULL pointer.
**
** It returns a pointer to a Trigger structure containing a trigger
** equivalent to the ON UPDATE or ON DELETE action specified by pFKey.
** If the action is "NO ACTION" or "RESTRICT", then a NULL pointer is
** returned (these actions require no special handling by the triggers
** sub-system, code for them is created by fkScanChildren()).
**
** For example, if pFKey is the foreign key and pTab is table "p" in
** the following schema:
**
** CREATE TABLE p(pk PRIMARY KEY);
** CREATE TABLE c(ck REFERENCES p ON DELETE CASCADE);
**
** then the returned trigger structure is equivalent to:
**
** CREATE TRIGGER ... DELETE ON p BEGIN
** DELETE FROM c WHERE ck = old.pk;
** END;
**
** The returned pointer is cached as part of the foreign key object. It
** is eventually freed along with the rest of the foreign key object by
** sqlite3FkDelete().
*/
static Trigger *fkActionTrigger(
Parse *pParse, /* Parse context */
Table *pTab, /* Table being updated or deleted from */
FKey *pFKey, /* Foreign key to get action for */
ExprList *pChanges /* Change-list for UPDATE, NULL for DELETE */
){
sqlite3 *db = pParse->db; /* Database handle */
int action; /* One of OE_None, OE_Cascade etc. */
Trigger *pTrigger; /* Trigger definition to return */
int iAction = (pChanges!=0); /* 1 for UPDATE, 0 for DELETE */
action = pFKey->aAction[iAction];
pTrigger = pFKey->apTrigger[iAction];
if( action!=OE_None && !pTrigger ){
u8 enableLookaside; /* Copy of db->lookaside.bEnabled */
char const *zFrom; /* Name of child table */
int nFrom; /* Length in bytes of zFrom */
Index *pIdx = 0; /* Parent key index for this FK */
int *aiCol = 0; /* child table cols -> parent key cols */
TriggerStep *pStep = 0; /* First (only) step of trigger program */
Expr *pWhere = 0; /* WHERE clause of trigger step */
ExprList *pList = 0; /* Changes list if ON UPDATE CASCADE */
Select *pSelect = 0; /* If RESTRICT, "SELECT RAISE(...)" */
int i; /* Iterator variable */
Expr *pWhen = 0; /* WHEN clause for the trigger */
if( locateFkeyIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0;
assert( aiCol || pFKey->nCol==1 );
for(i=0; i<pFKey->nCol; i++){
Token tOld = { "old", 3 }; /* Literal "old" token */
Token tNew = { "new", 3 }; /* Literal "new" token */
Token tFromCol; /* Name of column in child table */
Token tToCol; /* Name of column in parent table */
int iFromCol; /* Idx of column in child table */
Expr *pEq; /* tFromCol = OLD.tToCol */
iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
assert( iFromCol>=0 );
tToCol.z = pIdx ? pTab->aCol[pIdx->aiColumn[i]].zName : "oid";
tFromCol.z = pFKey->pFrom->aCol[iFromCol].zName;
tToCol.n = sqlite3Strlen30(tToCol.z);
tFromCol.n = sqlite3Strlen30(tFromCol.z);
/* Create the expression "OLD.zToCol = zFromCol". It is important
** that the "OLD.zToCol" term is on the LHS of the = operator, so
** that the affinity and collation sequence associated with the
** parent table are used for the comparison. */
pEq = sqlite3PExpr(pParse, TK_EQ,
sqlite3PExpr(pParse, TK_DOT,
sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld),
sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol)
, 0),
sqlite3PExpr(pParse, TK_ID, 0, 0, &tFromCol)
, 0);
pWhere = sqlite3ExprAnd(db, pWhere, pEq);
/* For ON UPDATE, construct the next term of the WHEN clause.
** The final WHEN clause will be like this:
**
** WHEN NOT(old.col1 IS new.col1 AND ... AND old.colN IS new.colN)
*/
if( pChanges ){
pEq = sqlite3PExpr(pParse, TK_IS,
sqlite3PExpr(pParse, TK_DOT,
sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld),
sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol),
0),
sqlite3PExpr(pParse, TK_DOT,
sqlite3PExpr(pParse, TK_ID, 0, 0, &tNew),
sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol),
0),
0);
pWhen = sqlite3ExprAnd(db, pWhen, pEq);
}
if( action!=OE_Restrict && (action!=OE_Cascade || pChanges) ){
Expr *pNew;
if( action==OE_Cascade ){
pNew = sqlite3PExpr(pParse, TK_DOT,
sqlite3PExpr(pParse, TK_ID, 0, 0, &tNew),
sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol)
, 0);
}else if( action==OE_SetDflt ){
Expr *pDflt = pFKey->pFrom->aCol[iFromCol].pDflt;
if( pDflt ){
pNew = sqlite3ExprDup(db, pDflt, 0);
}else{
pNew = sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
}
}else{
pNew = sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
}
pList = sqlite3ExprListAppend(pParse, pList, pNew);
sqlite3ExprListSetName(pParse, pList, &tFromCol, 0);
}
}
sqlite3DbFree(db, aiCol);
zFrom = pFKey->pFrom->zName;
nFrom = sqlite3Strlen30(zFrom);
if( action==OE_Restrict ){
Token tFrom;
Expr *pRaise;
tFrom.z = zFrom;
tFrom.n = nFrom;
pRaise = sqlite3Expr(db, TK_RAISE, "foreign key constraint failed");
if( pRaise ){
pRaise->affinity = OE_Abort;
}
pSelect = sqlite3SelectNew(pParse,
sqlite3ExprListAppend(pParse, 0, pRaise),
sqlite3SrcListAppend(db, 0, &tFrom, 0),
pWhere,
0, 0, 0, 0, 0, 0
);
pWhere = 0;
}
/* Disable lookaside memory allocation */
enableLookaside = db->lookaside.bEnabled;
db->lookaside.bEnabled = 0;
pTrigger = (Trigger *)sqlite3DbMallocZero(db,
sizeof(Trigger) + /* struct Trigger */
sizeof(TriggerStep) + /* Single step in trigger program */
nFrom + 1 /* Space for pStep->target.z */
);
if( pTrigger ){
pStep = pTrigger->step_list = (TriggerStep *)&pTrigger[1];
pStep->target.z = (char *)&pStep[1];
pStep->target.n = nFrom;
memcpy((char *)pStep->target.z, zFrom, nFrom);
pStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
pStep->pExprList = sqlite3ExprListDup(db, pList, EXPRDUP_REDUCE);
pStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
if( pWhen ){
pWhen = sqlite3PExpr(pParse, TK_NOT, pWhen, 0, 0);
pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
}
}
/* Re-enable the lookaside buffer, if it was disabled earlier. */
db->lookaside.bEnabled = enableLookaside;
sqlite3ExprDelete(db, pWhere);
sqlite3ExprDelete(db, pWhen);
sqlite3ExprListDelete(db, pList);
sqlite3SelectDelete(db, pSelect);
if( db->mallocFailed==1 ){
fkTriggerDelete(db, pTrigger);
return 0;
}
assert( pStep!=0 );
switch( action ){
case OE_Restrict:
pStep->op = TK_SELECT;
break;
case OE_Cascade:
if( !pChanges ){
pStep->op = TK_DELETE;
break;
}
default:
pStep->op = TK_UPDATE;
}
pStep->pTrig = pTrigger;
pTrigger->pSchema = pTab->pSchema;
pTrigger->pTabSchema = pTab->pSchema;
pFKey->apTrigger[iAction] = pTrigger;
pTrigger->op = (pChanges ? TK_UPDATE : TK_DELETE);
}
return pTrigger;
}
/*
** Generate VDBE code for the statements inside the body of a single
** trigger.
*/
static int codeTriggerProgram(
Parse *pParse, /* The parser context */
TriggerStep *pStepList, /* List of statements inside the trigger body */
int orconf /* Conflict algorithm. (OE_Abort, etc) */
){
TriggerStep *pStep;
Vdbe *v = pParse->pVdbe;
sqlite3 *db = pParse->db;
assert( pParse->pTriggerTab && pParse->pToplevel );
assert( pStepList );
assert( v!=0 );
for(pStep=pStepList; pStep; pStep=pStep->pNext){
/* Figure out the ON CONFLICT policy that will be used for this step
** of the trigger program. If the statement that caused this trigger
** to fire had an explicit ON CONFLICT, then use it. Otherwise, use
** the ON CONFLICT policy that was specified as part of the trigger
** step statement. Example:
**
** CREATE TRIGGER AFTER INSERT ON t1 BEGIN;
** INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);
** END;
**
** INSERT INTO t1 ... ; -- insert into t2 uses REPLACE policy
** INSERT OR IGNORE INTO t1 ... ; -- insert into t2 uses IGNORE policy
*/
pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf;
assert( pParse->okConstFactor==0 );
switch( pStep->op ){
case TK_UPDATE: {
sqlite3Update(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprListDup(db, pStep->pExprList, 0),
sqlite3ExprDup(db, pStep->pWhere, 0),
pParse->eOrconf
);
break;
}
case TK_INSERT: {
sqlite3Insert(pParse,
targetSrcList(pParse, pStep),
sqlite3SelectDup(db, pStep->pSelect, 0),
sqlite3IdListDup(db, pStep->pIdList),
pParse->eOrconf
);
break;
}
case TK_DELETE: {
sqlite3DeleteFrom(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprDup(db, pStep->pWhere, 0)
);
break;
}
default: assert( pStep->op==TK_SELECT ); {
SelectDest sDest;
Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
sqlite3SelectDestInit(&sDest, SRT_Discard, 0);
sqlite3Select(pParse, pSelect, &sDest);
sqlite3SelectDelete(db, pSelect);
break;
}
}
if( pStep->op!=TK_SELECT ){
sqlite3VdbeAddOp0(v, OP_ResetCount);
}
}
return 0;
}
/*
** 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;
sqlite3 *db = pParse->db;
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(db, 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(db, pTriggerStep->pExprList),
sqlite3ExprDup(db, 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(db, pTriggerStep->pExprList),
sqlite3SelectDup(db, pTriggerStep->pSelect),
sqlite3IdListDup(db, 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(db, 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;
}
/*
** Generate code for an UPDATE of a virtual table.
**
** The strategy is that we create an ephemerial table that contains
** for each row to be changed:
**
** (A) The original rowid of that row.
** (B) The revised rowid for the row. (note1)
** (C) The content of every column in the row.
**
** Then we loop over this ephemeral table and for each row in
** the ephermeral table call VUpdate.
**
** When finished, drop the ephemeral table.
**
** (note1) Actually, if we know in advance that (A) is always the same
** as (B) we only store (A), then duplicate (A) when pulling
** it out of the ephemeral table before calling VUpdate.
*/
static void updateVirtualTable(
Parse *pParse, /* The parsing context */
SrcList *pSrc, /* The virtual table to be modified */
Table *pTab, /* The virtual table */
ExprList *pChanges, /* The columns to change in the UPDATE statement */
Expr *pRowid, /* Expression used to recompute the rowid */
int *aXRef, /* Mapping from columns of pTab to entries in pChanges */
Expr *pWhere /* WHERE clause of the UPDATE statement */
){
Vdbe *v = pParse->pVdbe; /* Virtual machine under construction */
ExprList *pEList = 0; /* The result set of the SELECT statement */
Select *pSelect = 0; /* The SELECT statement */
Expr *pExpr; /* Temporary expression */
int ephemTab; /* Table holding the result of the SELECT */
int i; /* Loop counter */
int addr; /* Address of top of loop */
int iReg; /* First register in set passed to OP_VUpdate */
sqlite3 *db = pParse->db; /* Database connection */
const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);
SelectDest dest;
/* Construct the SELECT statement that will find the new values for
** all updated rows.
*/
pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, "_rowid_"));
if( pRowid ){
pEList = sqlite3ExprListAppend(pParse, pEList,
sqlite3ExprDup(db, pRowid, 0));
}
assert( pTab->iPKey<0 );
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]>=0 ){
pExpr = sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr, 0);
}else{
pExpr = sqlite3Expr(db, TK_ID, pTab->aCol[i].zName);
}
pEList = sqlite3ExprListAppend(pParse, pEList, pExpr);
}
pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0);
/* Create the ephemeral table into which the update results will
** be stored.
*/
assert( v );
ephemTab = pParse->nTab++;
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0));
sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
/* fill the ephemeral table
*/
sqlite3SelectDestInit(&dest, SRT_Table, ephemTab);
sqlite3Select(pParse, pSelect, &dest);
/* Generate code to scan the ephemeral table and call VUpdate. */
iReg = ++pParse->nMem;
pParse->nMem += pTab->nCol+1;
addr = sqlite3VdbeAddOp2(v, OP_Rewind, ephemTab, 0);
sqlite3VdbeAddOp3(v, OP_Column, ephemTab, 0, iReg);
sqlite3VdbeAddOp3(v, OP_Column, ephemTab, (pRowid?1:0), iReg+1);
for(i=0; i<pTab->nCol; i++){
sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i+1+(pRowid!=0), iReg+2+i);
}
sqlite3VtabMakeWritable(pParse, pTab);
sqlite3VdbeAddOp4(v, OP_VUpdate, 0, pTab->nCol+2, iReg, pVTab, P4_VTAB);
sqlite3MayAbort(pParse);
sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1);
sqlite3VdbeJumpHere(v, addr);
sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
/* Cleanup */
sqlite3SelectDelete(db, pSelect);
}
/*
** 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 = sqlite3SelectDup(pTriggerStep->pSelect);
assert(ss);
assert(ss->pSrc);
sqlite3Select(pParse, ss, SRT_Discard, 0, 0, 0, 0, 0);
sqlite3SelectDelete(ss);
break;
}
case TK_UPDATE: {
SrcList *pSrc;
pSrc = targetSrcList(pParse, pTriggerStep);
sqlite3VdbeAddOp(pParse->pVdbe, OP_ResetCount, 0, 0);
sqlite3VdbeAddOp(pParse->pVdbe, OP_ListPush, 0, 0);
sqlite3Update(pParse, pSrc,
sqlite3ExprListDup(pTriggerStep->pExprList),
sqlite3ExprDup(pTriggerStep->pWhere), orconf);
sqlite3VdbeAddOp(pParse->pVdbe, OP_ListPop, 0, 0);
sqlite3VdbeAddOp(pParse->pVdbe, OP_ResetCount, 1, 0);
break;
}
case TK_INSERT: {
SrcList *pSrc;
pSrc = targetSrcList(pParse, pTriggerStep);
sqlite3VdbeAddOp(pParse->pVdbe, OP_ResetCount, 0, 0);
sqlite3Insert(pParse, pSrc,
sqlite3ExprListDup(pTriggerStep->pExprList),
sqlite3SelectDup(pTriggerStep->pSelect),
sqlite3IdListDup(pTriggerStep->pIdList), orconf);
sqlite3VdbeAddOp(pParse->pVdbe, OP_ResetCount, 1, 0);
break;
}
case TK_DELETE: {
SrcList *pSrc;
sqlite3VdbeAddOp(pParse->pVdbe, OP_ResetCount, 0, 0);
sqlite3VdbeAddOp(pParse->pVdbe, OP_ListPush, 0, 0);
pSrc = targetSrcList(pParse, pTriggerStep);
sqlite3DeleteFrom(pParse, pSrc, sqlite3ExprDup(pTriggerStep->pWhere));
sqlite3VdbeAddOp(pParse->pVdbe, OP_ListPop, 0, 0);
sqlite3VdbeAddOp(pParse->pVdbe, OP_ResetCount, 1, 0);
break;
}
default:
assert(0);
}
pParse->nTab = saveNTab;
pTriggerStep = pTriggerStep->pNext;
}
return 0;
}
/*
** Generate code for an UPDATE of a virtual table.
**
** The strategy is that we create an ephemerial table that contains
** for each row to be changed:
**
** (A) The original rowid of that row.
** (B) The revised rowid for the row. (note1)
** (C) The content of every column in the row.
**
** Then we loop over this ephemeral table and for each row in
** the ephermeral table call VUpdate.
**
** When finished, drop the ephemeral table.
**
** (note1) Actually, if we know in advance that (A) is always the same
** as (B) we only store (A), then duplicate (A) when pulling
** it out of the ephemeral table before calling VUpdate.
*/
static void updateVirtualTable(
Parse *pParse, /* The parsing context */
SrcList *pSrc, /* The virtual table to be modified */
Table *pTab, /* The virtual table */
ExprList *pChanges, /* The columns to change in the UPDATE statement */
Expr *pRowid, /* Expression used to recompute the rowid */
int *aXRef, /* Mapping from columns of pTab to entries in pChanges */
Expr *pWhere /* WHERE clause of the UPDATE statement */
){
Vdbe *v = pParse->pVdbe; /* Virtual machine under construction */
ExprList *pEList = 0; /* The result set of the SELECT statement */
Select *pSelect = 0; /* The SELECT statement */
Expr *pExpr; /* Temporary expression */
int ephemTab; /* Table holding the result of the SELECT */
int i; /* Loop counter */
int addr; /* Address of top of loop */
/* Construct the SELECT statement that will find the new values for
** all updated rows.
*/
pEList = sqlite3ExprListAppend(0, sqlite3CreateIdExpr("_rowid_"), 0);
if( pRowid ){
pEList = sqlite3ExprListAppend(pEList, sqlite3ExprDup(pRowid), 0);
}
assert( pTab->iPKey<0 );
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]>=0 ){
pExpr = sqlite3ExprDup(pChanges->a[aXRef[i]].pExpr);
}else{
pExpr = sqlite3CreateIdExpr(pTab->aCol[i].zName);
}
pEList = sqlite3ExprListAppend(pEList, pExpr, 0);
}
pSelect = sqlite3SelectNew(pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0);
/* Create the ephemeral table into which the update results will
** be stored.
*/
assert( v );
ephemTab = pParse->nTab++;
sqlite3VdbeAddOp(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0));
/* fill the ephemeral table
*/
sqlite3Select(pParse, pSelect, SRT_Table, ephemTab, 0, 0, 0, 0);
/*
** Generate code to scan the ephemeral table and call VDelete and
** VInsert
*/
sqlite3VdbeAddOp(v, OP_Rewind, ephemTab, 0);
addr = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp(v, OP_Column, ephemTab, 0);
if( pRowid ){
sqlite3VdbeAddOp(v, OP_Column, ephemTab, 1);
}else{
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
}
for(i=0; i<pTab->nCol; i++){
sqlite3VdbeAddOp(v, OP_Column, ephemTab, i+1+(pRowid!=0));
}
pParse->pVirtualLock = pTab;
sqlite3VdbeOp3(v, OP_VUpdate, 0, pTab->nCol+2,
(const char*)pTab->pVtab, P3_VTAB);
sqlite3VdbeAddOp(v, OP_Next, ephemTab, addr);
sqlite3VdbeAddOp(v, OP_Close, ephemTab, 0);
/* Cleanup */
sqlite3SelectDelete(pSelect);
}
static void updateVirtualTable(
Parse *pParse,
SrcList *pSrc,
Table *pTab,
ExprList *pChanges,
Expr *pRowid,
int *aXRef,
Expr *pWhere
){
Vdbe *v = pParse->pVdbe;
ExprList *pEList = 0;
Select *pSelect = 0;
Expr *pExpr;
int ephemTab;
int i;
int addr;
int iReg;
sqlite3 *db = pParse->db;
const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);
SelectDest dest;
pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, "_rowid_"));
if( pRowid ){
pEList = sqlite3ExprListAppend(pParse, pEList,
sqlite3ExprDup(db, pRowid, 0));
}
assert( pTab->iPKey<0 );
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]>=0 ){
pExpr = sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr, 0);
}else{
pExpr = sqlite3Expr(db, TK_ID, pTab->aCol[i].zName);
}
pEList = sqlite3ExprListAppend(pParse, pEList, pExpr);
}
pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0);
assert( v );
ephemTab = pParse->nTab++;
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0));
sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
sqlite3SelectDestInit(&dest, SRT_Table, ephemTab);
sqlite3Select(pParse, pSelect, &dest);
iReg = ++pParse->nMem;
pParse->nMem += pTab->nCol+1;
addr = sqlite3VdbeAddOp2(v, OP_Rewind, ephemTab, 0);
sqlite3VdbeAddOp3(v, OP_Column, ephemTab, 0, iReg);
sqlite3VdbeAddOp3(v, OP_Column, ephemTab, (pRowid?1:0), iReg+1);
for(i=0; i<pTab->nCol; i++){
sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i+1+(pRowid!=0), iReg+2+i);
}
sqlite3VtabMakeWritable(pParse, pTab);
sqlite3VdbeAddOp4(v, OP_VUpdate, 0, pTab->nCol+2, iReg, pVTab, P4_VTAB);
sqlite3MayAbort(pParse);
sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1);
sqlite3VdbeJumpHere(v, addr);
sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
sqlite3SelectDelete(db, pSelect);
}