| Index: third_party/sqlite/src/src/delete.c
|
| diff --git a/third_party/sqlite/src/src/delete.c b/third_party/sqlite/src/src/delete.c
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..e5389e2b6a743fada5ffecdb04dd080603be31a5
|
| --- /dev/null
|
| +++ b/third_party/sqlite/src/src/delete.c
|
| @@ -0,0 +1,643 @@
|
| +/*
|
| +** 2001 September 15
|
| +**
|
| +** The author disclaims copyright to this source code. In place of
|
| +** a legal notice, here is a blessing:
|
| +**
|
| +** May you do good and not evil.
|
| +** May you find forgiveness for yourself and forgive others.
|
| +** May you share freely, never taking more than you give.
|
| +**
|
| +*************************************************************************
|
| +** This file contains C code routines that are called by the parser
|
| +** in order to generate code for DELETE FROM statements.
|
| +*/
|
| +#include "sqliteInt.h"
|
| +
|
| +/*
|
| +** While a SrcList can in general represent multiple tables and subqueries
|
| +** (as in the FROM clause of a SELECT statement) in this case it contains
|
| +** the name of a single table, as one might find in an INSERT, DELETE,
|
| +** or UPDATE statement. Look up that table in the symbol table and
|
| +** return a pointer. Set an error message and return NULL if the table
|
| +** name is not found or if any other error occurs.
|
| +**
|
| +** The following fields are initialized appropriate in pSrc:
|
| +**
|
| +** pSrc->a[0].pTab Pointer to the Table object
|
| +** pSrc->a[0].pIndex Pointer to the INDEXED BY index, if there is one
|
| +**
|
| +*/
|
| +Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
|
| + struct SrcList_item *pItem = pSrc->a;
|
| + Table *pTab;
|
| + assert( pItem && pSrc->nSrc==1 );
|
| + pTab = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase);
|
| + sqlite3DeleteTable(pParse->db, pItem->pTab);
|
| + pItem->pTab = pTab;
|
| + if( pTab ){
|
| + pTab->nRef++;
|
| + }
|
| + if( sqlite3IndexedByLookup(pParse, pItem) ){
|
| + pTab = 0;
|
| + }
|
| + return pTab;
|
| +}
|
| +
|
| +/*
|
| +** Check to make sure the given table is writable. If it is not
|
| +** writable, generate an error message and return 1. If it is
|
| +** writable return 0;
|
| +*/
|
| +int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){
|
| + /* A table is not writable under the following circumstances:
|
| + **
|
| + ** 1) It is a virtual table and no implementation of the xUpdate method
|
| + ** has been provided, or
|
| + ** 2) It is a system table (i.e. sqlite_master), this call is not
|
| + ** part of a nested parse and writable_schema pragma has not
|
| + ** been specified.
|
| + **
|
| + ** In either case leave an error message in pParse and return non-zero.
|
| + */
|
| + if( ( IsVirtual(pTab)
|
| + && sqlite3GetVTable(pParse->db, pTab)->pMod->pModule->xUpdate==0 )
|
| + || ( (pTab->tabFlags & TF_Readonly)!=0
|
| + && (pParse->db->flags & SQLITE_WriteSchema)==0
|
| + && pParse->nested==0 )
|
| + ){
|
| + 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;
|
| +}
|
| +
|
| +
|
| +#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
|
| +/*
|
| +** 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);
|
| + }
|
| + sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
|
| + sqlite3Select(pParse, pDup, &dest);
|
| + sqlite3SelectDelete(db, pDup);
|
| +}
|
| +#endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
|
| +
|
| +#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
|
| +/*
|
| +** 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);
|
| + pParse->parseError = 1;
|
| + 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;
|
| +}
|
| +#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
|
| +
|
| +/*
|
| +** 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 */
|
| + NameContext sNC; /* Name context to resolve expressions in */
|
| + int iDb; /* Database number */
|
| + int memCnt = -1; /* Memory cell used for change counting */
|
| + int rcauth; /* Value returned by authorization callback */
|
| +
|
| +#ifndef SQLITE_OMIT_TRIGGER
|
| + int isView; /* True if attempting to delete from a view */
|
| + Trigger *pTrigger; /* List of table triggers, if required */
|
| +#endif
|
| +
|
| + memset(&sContext, 0, sizeof(sContext));
|
| + db = pParse->db;
|
| + if( pParse->nErr || db->mallocFailed ){
|
| + goto delete_from_cleanup;
|
| + }
|
| + 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
|
| + pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
|
| + isView = pTab->pSelect!=0;
|
| +#else
|
| +# define pTrigger 0
|
| +# define isView 0
|
| +#endif
|
| +#ifdef SQLITE_OMIT_VIEW
|
| +# undef isView
|
| +# define isView 0
|
| +#endif
|
| +
|
| + /* If pTab is really a view, make sure it has been initialized.
|
| + */
|
| + if( sqlite3ViewGetColumnNames(pParse, pTab) ){
|
| + goto delete_from_cleanup;
|
| + }
|
| +
|
| + if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){
|
| + goto delete_from_cleanup;
|
| + }
|
| + iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
|
| + assert( iDb<db->nDb );
|
| + zDb = db->aDb[iDb].zName;
|
| + rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb);
|
| + assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
|
| + if( rcauth==SQLITE_DENY ){
|
| + goto delete_from_cleanup;
|
| + }
|
| + assert(!isView || pTrigger);
|
| +
|
| + /* Assign cursor number to the table and all its indices.
|
| + */
|
| + assert( pTabList->nSrc==1 );
|
| + iCur = pTabList->a[0].iCursor = pParse->nTab++;
|
| + for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
|
| + pParse->nTab++;
|
| + }
|
| +
|
| + /* 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, 1, iDb);
|
| +
|
| + /* If we are trying to delete from a view, realize that view into
|
| + ** a ephemeral table.
|
| + */
|
| +#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
|
| + if( isView ){
|
| + sqlite3MaterializeView(pParse, pTab, pWhere, iCur);
|
| + }
|
| +#endif
|
| +
|
| + /* Resolve the column names in the WHERE clause.
|
| + */
|
| + memset(&sNC, 0, sizeof(sNC));
|
| + sNC.pParse = pParse;
|
| + sNC.pSrcList = pTabList;
|
| + if( sqlite3ResolveExprNames(&sNC, pWhere) ){
|
| + goto delete_from_cleanup;
|
| + }
|
| +
|
| + /* Initialize the counter of the number of rows deleted, if
|
| + ** we are counting rows.
|
| + */
|
| + if( db->flags & SQLITE_CountRows ){
|
| + memCnt = ++pParse->nMem;
|
| + sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt);
|
| + }
|
| +
|
| +#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
|
| + /* Special case: A DELETE without a WHERE clause deletes everything.
|
| + ** It is easier just to erase the whole table. Prior to version 3.6.5,
|
| + ** this optimization caused the row change count (the value returned by
|
| + ** API function sqlite3_count_changes) to be set incorrectly. */
|
| + if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab)
|
| + && 0==sqlite3FkRequired(pParse, pTab, 0, 0)
|
| + ){
|
| + assert( !isView );
|
| + sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt,
|
| + pTab->zName, P4_STATIC);
|
| + for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
|
| + assert( pIdx->pSchema==pTab->pSchema );
|
| + sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
|
| + }
|
| + }else
|
| +#endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
|
| + /* The usual case: There is a WHERE clause so we have to scan through
|
| + ** the table and pick which records to delete.
|
| + */
|
| + {
|
| + int iRowSet = ++pParse->nMem; /* Register for rowset of rows to delete */
|
| + int iRowid = ++pParse->nMem; /* Used for storing rowid values. */
|
| + int regRowid; /* Actual register containing rowids */
|
| +
|
| + /* Collect rowids of every row to be deleted.
|
| + */
|
| + sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
|
| + pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0,WHERE_DUPLICATES_OK);
|
| + if( pWInfo==0 ) goto delete_from_cleanup;
|
| + regRowid = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, iRowid);
|
| + sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, regRowid);
|
| + if( db->flags & SQLITE_CountRows ){
|
| + sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
|
| + }
|
| + sqlite3WhereEnd(pWInfo);
|
| +
|
| + /* 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. */
|
| + end = sqlite3VdbeMakeLabel(v);
|
| +
|
| + /* Unless this is a view, open cursors for the table we are
|
| + ** deleting from and all its indices. If this is a view, then the
|
| + ** only effect this statement has is to fire the INSTEAD OF
|
| + ** triggers. */
|
| + if( !isView ){
|
| + sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);
|
| + }
|
| +
|
| + addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, iRowid);
|
| +
|
| + /* Delete the row */
|
| +#ifndef SQLITE_OMIT_VIRTUALTABLE
|
| + if( IsVirtual(pTab) ){
|
| + const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
|
| + sqlite3VtabMakeWritable(pParse, pTab);
|
| + sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVTab, P4_VTAB);
|
| + sqlite3MayAbort(pParse);
|
| + }else
|
| +#endif
|
| + {
|
| + int count = (pParse->nested==0); /* True to count changes */
|
| + sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, count, pTrigger, OE_Default);
|
| + }
|
| +
|
| + /* End of the delete loop */
|
| + sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
|
| + sqlite3VdbeResolveLabel(v, end);
|
| +
|
| + /* Close the cursors open on the table and its indexes. */
|
| + if( !isView && !IsVirtual(pTab) ){
|
| + for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
|
| + sqlite3VdbeAddOp2(v, OP_Close, iCur + i, pIdx->tnum);
|
| + }
|
| + sqlite3VdbeAddOp1(v, OP_Close, iCur);
|
| + }
|
| + }
|
| +
|
| + /* Update the sqlite_sequence table by storing the content of the
|
| + ** maximum rowid counter values recorded while inserting into
|
| + ** autoincrement tables.
|
| + */
|
| + if( pParse->nested==0 && pParse->pTriggerTab==0 ){
|
| + sqlite3AutoincrementEnd(pParse);
|
| + }
|
| +
|
| + /* 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 && !pParse->pTriggerTab ){
|
| + sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1);
|
| + sqlite3VdbeSetNumCols(v, 1);
|
| + sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC);
|
| + }
|
| +
|
| +delete_from_cleanup:
|
| + sqlite3AuthContextPop(&sContext);
|
| + sqlite3SrcListDelete(db, pTabList);
|
| + sqlite3ExprDelete(db, pWhere);
|
| + return;
|
| +}
|
| +/* Make sure "isView" and other macros defined above are undefined. Otherwise
|
| +** thely may interfere with compilation of other functions in this file
|
| +** (or in another file, if this file becomes part of the amalgamation). */
|
| +#ifdef isView
|
| + #undef isView
|
| +#endif
|
| +#ifdef pTrigger
|
| + #undef pTrigger
|
| +#endif
|
| +
|
| +/*
|
| +** This routine generates VDBE code that causes a single row of a
|
| +** single table to be deleted.
|
| +**
|
| +** The VDBE must be in a particular state when this routine is called.
|
| +** These are the requirements:
|
| +**
|
| +** 1. A read/write cursor pointing to pTab, the table containing the row
|
| +** to be deleted, must be opened as cursor number $iCur.
|
| +**
|
| +** 2. Read/write cursors for all indices of pTab must be open as
|
| +** cursor number base+i for the i-th index.
|
| +**
|
| +** 3. The record number of the row to be deleted must be stored in
|
| +** memory cell iRowid.
|
| +**
|
| +** This routine generates code to remove both the table record and all
|
| +** index entries that point to that record.
|
| +*/
|
| +void sqlite3GenerateRowDelete(
|
| + Parse *pParse, /* Parsing context */
|
| + Table *pTab, /* Table containing the row to be deleted */
|
| + int iCur, /* Cursor number for the table */
|
| + int iRowid, /* Memory cell that contains the rowid to delete */
|
| + int count, /* If non-zero, increment the row change counter */
|
| + Trigger *pTrigger, /* List of triggers to (potentially) fire */
|
| + int onconf /* Default ON CONFLICT policy for triggers */
|
| +){
|
| + Vdbe *v = pParse->pVdbe; /* Vdbe */
|
| + int iOld = 0; /* First register in OLD.* array */
|
| + int iLabel; /* Label resolved to end of generated code */
|
| +
|
| + /* Vdbe is guaranteed to have been allocated by this stage. */
|
| + assert( v );
|
| +
|
| + /* Seek cursor iCur to the row to delete. If this row no longer exists
|
| + ** (this can happen if a trigger program has already deleted it), do
|
| + ** not attempt to delete it or fire any DELETE triggers. */
|
| + iLabel = sqlite3VdbeMakeLabel(v);
|
| + sqlite3VdbeAddOp3(v, OP_NotExists, iCur, iLabel, iRowid);
|
| +
|
| + /* If there are any triggers to fire, allocate a range of registers to
|
| + ** use for the old.* references in the triggers. */
|
| + if( sqlite3FkRequired(pParse, pTab, 0, 0) || pTrigger ){
|
| + u32 mask; /* Mask of OLD.* columns in use */
|
| + int iCol; /* Iterator used while populating OLD.* */
|
| +
|
| + /* TODO: Could use temporary registers here. Also could attempt to
|
| + ** avoid copying the contents of the rowid register. */
|
| + mask = sqlite3TriggerColmask(
|
| + pParse, pTrigger, 0, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onconf
|
| + );
|
| + mask |= sqlite3FkOldmask(pParse, pTab);
|
| + iOld = pParse->nMem+1;
|
| + pParse->nMem += (1 + pTab->nCol);
|
| +
|
| + /* Populate the OLD.* pseudo-table register array. These values will be
|
| + ** used by any BEFORE and AFTER triggers that exist. */
|
| + sqlite3VdbeAddOp2(v, OP_Copy, iRowid, iOld);
|
| + for(iCol=0; iCol<pTab->nCol; iCol++){
|
| + if( mask==0xffffffff || mask&(1<<iCol) ){
|
| + sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, iCol, iOld+iCol+1);
|
| + }
|
| + }
|
| +
|
| + /* Invoke BEFORE DELETE trigger programs. */
|
| + sqlite3CodeRowTrigger(pParse, pTrigger,
|
| + TK_DELETE, 0, TRIGGER_BEFORE, pTab, iOld, onconf, iLabel
|
| + );
|
| +
|
| + /* Seek the cursor to the row to be deleted again. It may be that
|
| + ** the BEFORE triggers coded above have already removed the row
|
| + ** being deleted. Do not attempt to delete the row a second time, and
|
| + ** do not fire AFTER triggers. */
|
| + sqlite3VdbeAddOp3(v, OP_NotExists, iCur, iLabel, iRowid);
|
| +
|
| + /* Do FK processing. This call checks that any FK constraints that
|
| + ** refer to this table (i.e. constraints attached to other tables)
|
| + ** are not violated by deleting this row. */
|
| + sqlite3FkCheck(pParse, pTab, iOld, 0);
|
| + }
|
| +
|
| + /* Delete the index and table entries. Skip this step if pTab is really
|
| + ** a view (in which case the only effect of the DELETE statement is to
|
| + ** fire the INSTEAD OF triggers). */
|
| + if( pTab->pSelect==0 ){
|
| + sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, 0);
|
| + sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
|
| + if( count ){
|
| + sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
|
| + }
|
| + }
|
| +
|
| + /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
|
| + ** handle rows (possibly in other tables) that refer via a foreign key
|
| + ** to the row just deleted. */
|
| + sqlite3FkActions(pParse, pTab, 0, iOld);
|
| +
|
| + /* Invoke AFTER DELETE trigger programs. */
|
| + sqlite3CodeRowTrigger(pParse, pTrigger,
|
| + TK_DELETE, 0, TRIGGER_AFTER, pTab, iOld, onconf, iLabel
|
| + );
|
| +
|
| + /* Jump here if the row had already been deleted before any BEFORE
|
| + ** trigger programs were invoked. Or if a trigger program throws a
|
| + ** RAISE(IGNORE) exception. */
|
| + sqlite3VdbeResolveLabel(v, iLabel);
|
| +}
|
| +
|
| +/*
|
| +** This routine generates VDBE code that causes the deletion of all
|
| +** index entries associated with a single row of a single table.
|
| +**
|
| +** The VDBE must be in a particular state when this routine is called.
|
| +** These are the requirements:
|
| +**
|
| +** 1. A read/write cursor pointing to pTab, the table containing the row
|
| +** to be deleted, must be opened as cursor number "iCur".
|
| +**
|
| +** 2. Read/write cursors for all indices of pTab must be open as
|
| +** cursor number iCur+i for the i-th index.
|
| +**
|
| +** 3. The "iCur" cursor must be pointing to the row that is to be
|
| +** deleted.
|
| +*/
|
| +void sqlite3GenerateRowIndexDelete(
|
| + Parse *pParse, /* Parsing and code generating context */
|
| + Table *pTab, /* Table containing the row to be deleted */
|
| + int iCur, /* Cursor number for the table */
|
| + int *aRegIdx /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
|
| +){
|
| + int i;
|
| + Index *pIdx;
|
| + int r1;
|
| +
|
| + for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
|
| + if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue;
|
| + r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0);
|
| + sqlite3VdbeAddOp3(pParse->pVdbe, OP_IdxDelete, iCur+i, r1,pIdx->nColumn+1);
|
| + }
|
| +}
|
| +
|
| +/*
|
| +** Generate code that will assemble an index key and put it in register
|
| +** regOut. The key with be for index pIdx which is an index on pTab.
|
| +** iCur is the index of a cursor open on the pTab table and pointing to
|
| +** the entry that needs indexing.
|
| +**
|
| +** Return a register number which is the first in a block of
|
| +** registers that holds the elements of the index key. The
|
| +** block of registers has already been deallocated by the time
|
| +** this routine returns.
|
| +*/
|
| +int sqlite3GenerateIndexKey(
|
| + Parse *pParse, /* Parsing context */
|
| + Index *pIdx, /* The index for which to generate a key */
|
| + int iCur, /* Cursor number for the pIdx->pTable table */
|
| + int regOut, /* Write the new index key to this register */
|
| + int doMakeRec /* Run the OP_MakeRecord instruction if true */
|
| +){
|
| + Vdbe *v = pParse->pVdbe;
|
| + int j;
|
| + Table *pTab = pIdx->pTable;
|
| + int regBase;
|
| + int nCol;
|
| +
|
| + nCol = pIdx->nColumn;
|
| + regBase = sqlite3GetTempRange(pParse, nCol+1);
|
| + sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol);
|
| + for(j=0; j<nCol; j++){
|
| + int idx = pIdx->aiColumn[j];
|
| + if( idx==pTab->iPKey ){
|
| + sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
|
| + }else{
|
| + sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
|
| + sqlite3ColumnDefault(v, pTab, idx, -1);
|
| + }
|
| + }
|
| + if( doMakeRec ){
|
| + sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut);
|
| + sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), P4_TRANSIENT);
|
| + }
|
| + sqlite3ReleaseTempRange(pParse, regBase, nCol+1);
|
| + return regBase;
|
| +}
|
|
|