#include "sqliteInt.h"
Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
Table *pTab = 0;
int i;
struct SrcList_item *pItem;
for(i=0, pItem=pSrc->a; i<pSrc->nSrc; i++, pItem++){
pTab = sqlite3LocateTable(pParse, pItem->zName, pItem->zDatabase);
sqlite3DeleteTable(pItem->pTab);
pItem->pTab = pTab;
if( pTab ){
pTab->nRef++;
}
}
return pTab;
}
int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){
if( (pTab->readOnly && (pParse->db->flags & SQLITE_WriteSchema)==0
&& pParse->nested==0)
#ifndef SQLITE_OMIT_VIRTUALTABLE
|| (pTab->pMod && pTab->pMod->pModule->xUpdate==0)
#endif
){
sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
return 1;
}
#ifndef SQLITE_OMIT_VIEW
if( !viewOk && pTab->pSelect ){
sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
return 1;
}
#endif
return 0;
}
void sqlite3OpenTable(
Parse *p,
int iCur,
int iDb,
Table *pTab,
int opcode
){
Vdbe *v;
if( IsVirtual(pTab) ) return;
v = sqlite3GetVdbe(p);
assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite), pTab->zName);
sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
VdbeComment((v, "# %s", pTab->zName));
sqlite3VdbeAddOp(v, opcode, iCur, pTab->tnum);
sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, pTab->nCol);
}
void sqlite3DeleteFrom(
Parse *pParse,
SrcList *pTabList,
Expr *pWhere
){
Vdbe *v;
Table *pTab;
const char *zDb;
int end, addr = 0;
int i;
WhereInfo *pWInfo;
Index *pIdx;
int iCur;
sqlite3 *db;
AuthContext sContext;
int oldIdx = -1;
NameContext sNC;
int iDb;
int memCnt = 0;
#ifndef SQLITE_OMIT_TRIGGER
int isView;
int triggers_exist = 0;
#endif
sContext.pParse = 0;
if( pParse->nErr || sqlite3MallocFailed() ){
goto delete_from_cleanup;
}
db = pParse->db;
assert( pTabList->nSrc==1 );
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ) goto delete_from_cleanup;
#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;
}
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
assert( iDb<db->nDb );
zDb = db->aDb[iDb].zName;
if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){
goto delete_from_cleanup;
}
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto delete_from_cleanup;
}
if( triggers_exist ){
oldIdx = pParse->nTab++;
}
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;
}
if( isView ){
sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
}
v = sqlite3GetVdbe(pParse);
if( v==0 ){
goto delete_from_cleanup;
}
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, triggers_exist, iDb);
if( isView ){
Select *pView = sqlite3SelectDup(pTab->pSelect);
sqlite3Select(pParse, pView, SRT_EphemTab, iCur, 0, 0, 0, 0);
sqlite3SelectDelete(pView);
}
if( db->flags & SQLITE_CountRows ){
memCnt = pParse->nMem++;
sqlite3VdbeAddOp(v, OP_MemInt, 0, memCnt);
}
if( pWhere==0 && !triggers_exist && !IsVirtual(pTab) ){
if( db->flags & SQLITE_CountRows ){
int endOfLoop = sqlite3VdbeMakeLabel(v);
int addr2;
if( !isView ){
sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
}
sqlite3VdbeAddOp(v, OP_Rewind, iCur, sqlite3VdbeCurrentAddr(v)+2);
addr2 = sqlite3VdbeAddOp(v, OP_MemIncr, 1, memCnt);
sqlite3VdbeAddOp(v, OP_Next, iCur, addr2);
sqlite3VdbeResolveLabel(v, endOfLoop);
sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
}
if( !isView ){
sqlite3VdbeAddOp(v, OP_Clear, pTab->tnum, iDb);
if( !pParse->nested ){
sqlite3VdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
}
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
assert( pIdx->pSchema==pTab->pSchema );
sqlite3VdbeAddOp(v, OP_Clear, pIdx->tnum, iDb);
}
}
}
else{
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0);
if( pWInfo==0 ) goto delete_from_cleanup;
sqlite3VdbeAddOp(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur, 0);
sqlite3VdbeAddOp(v, OP_FifoWrite, 0, 0);
if( db->flags & SQLITE_CountRows ){
sqlite3VdbeAddOp(v, OP_MemIncr, 1, memCnt);
}
sqlite3WhereEnd(pWInfo);
if( triggers_exist ){
sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol);
}
end = sqlite3VdbeMakeLabel(v);
if( triggers_exist ){
addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, end);
if( !isView ){
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
}
sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
sqlite3VdbeAddOp(v, OP_Insert, 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 ){
sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);
if( !triggers_exist ){
addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, end);
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTab) ){
pParse->pVirtualLock = pTab;
sqlite3VdbeOp3(v, OP_VUpdate, 0, 1, (const char*)pTab->pVtab, P3_VTAB);
}else
#endif
{
sqlite3GenerateRowDelete(db, v, pTab, iCur, pParse->nested==0);
}
}
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);
}
sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
sqlite3VdbeResolveLabel(v, end);
if( !triggers_exist && !IsVirtual(pTab) ){
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);
}
}
if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
sqlite3VdbeAddOp(v, OP_MemLoad, memCnt, 0);
sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", P3_STATIC);
}
delete_from_cleanup:
sqlite3AuthContextPop(&sContext);
sqlite3SrcListDelete(pTabList);
sqlite3ExprDelete(pWhere);
return;
}
void sqlite3GenerateRowDelete(
sqlite3 *db,
Vdbe *v,
Table *pTab,
int iCur,
int count
){
int addr;
addr = sqlite3VdbeAddOp(v, OP_NotExists, iCur, 0);
sqlite3GenerateRowIndexDelete(v, pTab, iCur, 0);
sqlite3VdbeAddOp(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
if( count ){
sqlite3VdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
}
sqlite3VdbeJumpHere(v, addr);
}
void sqlite3GenerateRowIndexDelete(
Vdbe *v,
Table *pTab,
int iCur,
char *aIdxUsed
){
int i;
Index *pIdx;
for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
if( aIdxUsed!=0 && aIdxUsed[i-1]==0 ) continue;
sqlite3GenerateIndexKey(v, pIdx, iCur);
sqlite3VdbeAddOp(v, OP_IdxDelete, iCur+i, 0);
}
}
void sqlite3GenerateIndexKey(
Vdbe *v,
Index *pIdx,
int iCur
){
int j;
Table *pTab = pIdx->pTable;
sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
for(j=0; j<pIdx->nColumn; j++){
int idx = pIdx->aiColumn[j];
if( idx==pTab->iPKey ){
sqlite3VdbeAddOp(v, OP_Dup, j, 0);
}else{
sqlite3VdbeAddOp(v, OP_Column, iCur, idx);
sqlite3ColumnDefault(v, pTab, idx);
}
}
sqlite3VdbeAddOp(v, OP_MakeIdxRec, pIdx->nColumn, 0);
sqlite3IndexAffinityStr(v, pIdx);
}