1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/persistentdata/persistentstorage/sql/SQLite364/delete.c Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,644 @@
1.4 +/*
1.5 +** 2001 September 15
1.6 +**
1.7 +** The author disclaims copyright to this source code. In place of
1.8 +** a legal notice, here is a blessing:
1.9 +**
1.10 +** May you do good and not evil.
1.11 +** May you find forgiveness for yourself and forgive others.
1.12 +** May you share freely, never taking more than you give.
1.13 +**
1.14 +*************************************************************************
1.15 +** This file contains C code routines that are called by the parser
1.16 +** in order to generate code for DELETE FROM statements.
1.17 +**
1.18 +** $Id: delete.c,v 1.182 2008/10/10 23:48:26 drh Exp $
1.19 +*/
1.20 +#include "sqliteInt.h"
1.21 +
1.22 +/*
1.23 +** Look up every table that is named in pSrc. If any table is not found,
1.24 +** add an error message to pParse->zErrMsg and return NULL. If all tables
1.25 +** are found, return a pointer to the last table.
1.26 +*/
1.27 +Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
1.28 + struct SrcList_item *pItem = pSrc->a;
1.29 + Table *pTab;
1.30 + assert( pItem && pSrc->nSrc==1 );
1.31 + pTab = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase);
1.32 + sqlite3DeleteTable(pItem->pTab);
1.33 + pItem->pTab = pTab;
1.34 + if( pTab ){
1.35 + pTab->nRef++;
1.36 + }
1.37 + if( sqlite3IndexedByLookup(pParse, pItem) ){
1.38 + pTab = 0;
1.39 + }
1.40 + return pTab;
1.41 +}
1.42 +
1.43 +/*
1.44 +** Check to make sure the given table is writable. If it is not
1.45 +** writable, generate an error message and return 1. If it is
1.46 +** writable return 0;
1.47 +*/
1.48 +int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){
1.49 + if( ((pTab->tabFlags & TF_Readonly)!=0
1.50 + && (pParse->db->flags & SQLITE_WriteSchema)==0
1.51 + && pParse->nested==0)
1.52 +#ifndef SQLITE_OMIT_VIRTUALTABLE
1.53 + || (pTab->pMod && pTab->pMod->pModule->xUpdate==0)
1.54 +#endif
1.55 + ){
1.56 + sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
1.57 + return 1;
1.58 + }
1.59 +#ifndef SQLITE_OMIT_VIEW
1.60 + if( !viewOk && pTab->pSelect ){
1.61 + sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
1.62 + return 1;
1.63 + }
1.64 +#endif
1.65 + return 0;
1.66 +}
1.67 +
1.68 +/*
1.69 +** Generate code that will open a table for reading.
1.70 +*/
1.71 +void sqlite3OpenTable(
1.72 + Parse *p, /* Generate code into this VDBE */
1.73 + int iCur, /* The cursor number of the table */
1.74 + int iDb, /* The database index in sqlite3.aDb[] */
1.75 + Table *pTab, /* The table to be opened */
1.76 + int opcode /* OP_OpenRead or OP_OpenWrite */
1.77 +){
1.78 + Vdbe *v;
1.79 + if( IsVirtual(pTab) ) return;
1.80 + v = sqlite3GetVdbe(p);
1.81 + assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
1.82 + sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite), pTab->zName);
1.83 + sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
1.84 + sqlite3VdbeAddOp3(v, opcode, iCur, pTab->tnum, iDb);
1.85 + VdbeComment((v, "%s", pTab->zName));
1.86 +}
1.87 +
1.88 +
1.89 +#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
1.90 +/*
1.91 +** Evaluate a view and store its result in an ephemeral table. The
1.92 +** pWhere argument is an optional WHERE clause that restricts the
1.93 +** set of rows in the view that are to be added to the ephemeral table.
1.94 +*/
1.95 +void sqlite3MaterializeView(
1.96 + Parse *pParse, /* Parsing context */
1.97 + Table *pView, /* View definition */
1.98 + Expr *pWhere, /* Optional WHERE clause to be added */
1.99 + int iCur /* Cursor number for ephemerial table */
1.100 +){
1.101 + SelectDest dest;
1.102 + Select *pDup;
1.103 + sqlite3 *db = pParse->db;
1.104 +
1.105 + pDup = sqlite3SelectDup(db, pView->pSelect);
1.106 + if( pWhere ){
1.107 + SrcList *pFrom;
1.108 + Token viewName;
1.109 +
1.110 + pWhere = sqlite3ExprDup(db, pWhere);
1.111 + viewName.z = (u8*)pView->zName;
1.112 + viewName.n = (unsigned int)strlen((const char*)viewName.z);
1.113 + pFrom = sqlite3SrcListAppendFromTerm(pParse, 0, 0, 0, &viewName, pDup, 0,0);
1.114 + pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
1.115 + }
1.116 + sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
1.117 + sqlite3Select(pParse, pDup, &dest);
1.118 + sqlite3SelectDelete(db, pDup);
1.119 +}
1.120 +#endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
1.121 +
1.122 +#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
1.123 +/*
1.124 +** Generate an expression tree to implement the WHERE, ORDER BY,
1.125 +** and LIMIT/OFFSET portion of DELETE and UPDATE statements.
1.126 +**
1.127 +** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1;
1.128 +** \__________________________/
1.129 +** pLimitWhere (pInClause)
1.130 +*/
1.131 +Expr *sqlite3LimitWhere(
1.132 + Parse *pParse, /* The parser context */
1.133 + SrcList *pSrc, /* the FROM clause -- which tables to scan */
1.134 + Expr *pWhere, /* The WHERE clause. May be null */
1.135 + ExprList *pOrderBy, /* The ORDER BY clause. May be null */
1.136 + Expr *pLimit, /* The LIMIT clause. May be null */
1.137 + Expr *pOffset, /* The OFFSET clause. May be null */
1.138 + char *zStmtType /* Either DELETE or UPDATE. For error messages. */
1.139 +){
1.140 + Expr *pWhereRowid = NULL; /* WHERE rowid .. */
1.141 + Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */
1.142 + Expr *pSelectRowid = NULL; /* SELECT rowid ... */
1.143 + ExprList *pEList = NULL; /* Expression list contaning only pSelectRowid */
1.144 + SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */
1.145 + Select *pSelect = NULL; /* Complete SELECT tree */
1.146 +
1.147 + /* Check that there isn't an ORDER BY without a LIMIT clause.
1.148 + */
1.149 + if( pOrderBy && (pLimit == 0) ) {
1.150 + sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
1.151 + pParse->parseError = 1;
1.152 + goto limit_where_cleanup_2;
1.153 + }
1.154 +
1.155 + /* We only need to generate a select expression if there
1.156 + ** is a limit/offset term to enforce.
1.157 + */
1.158 + if( pLimit == 0 ) {
1.159 + /* if pLimit is null, pOffset will always be null as well. */
1.160 + assert( pOffset == 0 );
1.161 + return pWhere;
1.162 + }
1.163 +
1.164 + /* Generate a select expression tree to enforce the limit/offset
1.165 + ** term for the DELETE or UPDATE statement. For example:
1.166 + ** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
1.167 + ** becomes:
1.168 + ** DELETE FROM table_a WHERE rowid IN (
1.169 + ** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
1.170 + ** );
1.171 + */
1.172 +
1.173 + pSelectRowid = sqlite3Expr(pParse->db, TK_ROW, 0, 0, 0);
1.174 + if( pSelectRowid == 0 ) goto limit_where_cleanup_2;
1.175 + pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid, 0);
1.176 + if( pEList == 0 ) goto limit_where_cleanup_2;
1.177 +
1.178 + /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
1.179 + ** and the SELECT subtree. */
1.180 + pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc);
1.181 + if( pSelectSrc == 0 ) {
1.182 + sqlite3ExprListDelete(pParse->db, pEList);
1.183 + goto limit_where_cleanup_2;
1.184 + }
1.185 +
1.186 + /* generate the SELECT expression tree. */
1.187 + pSelect = sqlite3SelectNew(pParse,pEList,pSelectSrc,pWhere,0,0,pOrderBy,0,pLimit,pOffset);
1.188 + if( pSelect == 0 ) return 0;
1.189 +
1.190 + /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
1.191 + pWhereRowid = sqlite3Expr(pParse->db, TK_ROW, 0, 0, 0);
1.192 + if( pWhereRowid == 0 ) goto limit_where_cleanup_1;
1.193 + pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0);
1.194 + if( pInClause == 0 ) goto limit_where_cleanup_1;
1.195 +
1.196 + pInClause->pSelect = pSelect;
1.197 + sqlite3ExprSetHeight(pParse, pInClause);
1.198 + return pInClause;
1.199 +
1.200 + /* something went wrong. clean up anything allocated. */
1.201 +limit_where_cleanup_1:
1.202 + sqlite3SelectDelete(pParse->db, pSelect);
1.203 + return 0;
1.204 +
1.205 +limit_where_cleanup_2:
1.206 + sqlite3ExprDelete(pParse->db, pWhere);
1.207 + sqlite3ExprListDelete(pParse->db, pOrderBy);
1.208 + sqlite3ExprDelete(pParse->db, pLimit);
1.209 + sqlite3ExprDelete(pParse->db, pOffset);
1.210 + return 0;
1.211 +}
1.212 +#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
1.213 +
1.214 +/*
1.215 +** Generate code for a DELETE FROM statement.
1.216 +**
1.217 +** DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
1.218 +** \________/ \________________/
1.219 +** pTabList pWhere
1.220 +*/
1.221 +void sqlite3DeleteFrom(
1.222 + Parse *pParse, /* The parser context */
1.223 + SrcList *pTabList, /* The table from which we should delete things */
1.224 + Expr *pWhere /* The WHERE clause. May be null */
1.225 +){
1.226 + Vdbe *v; /* The virtual database engine */
1.227 + Table *pTab; /* The table from which records will be deleted */
1.228 + const char *zDb; /* Name of database holding pTab */
1.229 + int end, addr = 0; /* A couple addresses of generated code */
1.230 + int i; /* Loop counter */
1.231 + WhereInfo *pWInfo; /* Information about the WHERE clause */
1.232 + Index *pIdx; /* For looping over indices of the table */
1.233 + int iCur; /* VDBE Cursor number for pTab */
1.234 + sqlite3 *db; /* Main database structure */
1.235 + AuthContext sContext; /* Authorization context */
1.236 + int oldIdx = -1; /* Cursor for the OLD table of AFTER triggers */
1.237 + NameContext sNC; /* Name context to resolve expressions in */
1.238 + int iDb; /* Database number */
1.239 + int memCnt = 0; /* Memory cell used for change counting */
1.240 +
1.241 +#ifndef SQLITE_OMIT_TRIGGER
1.242 + int isView; /* True if attempting to delete from a view */
1.243 + int triggers_exist = 0; /* True if any triggers exist */
1.244 +#endif
1.245 + int iBeginAfterTrigger; /* Address of after trigger program */
1.246 + int iEndAfterTrigger; /* Exit of after trigger program */
1.247 + int iBeginBeforeTrigger; /* Address of before trigger program */
1.248 + int iEndBeforeTrigger; /* Exit of before trigger program */
1.249 + u32 old_col_mask = 0; /* Mask of OLD.* columns in use */
1.250 +
1.251 + sContext.pParse = 0;
1.252 + db = pParse->db;
1.253 + if( pParse->nErr || db->mallocFailed ){
1.254 + goto delete_from_cleanup;
1.255 + }
1.256 + assert( pTabList->nSrc==1 );
1.257 +
1.258 + /* Locate the table which we want to delete. This table has to be
1.259 + ** put in an SrcList structure because some of the subroutines we
1.260 + ** will be calling are designed to work with multiple tables and expect
1.261 + ** an SrcList* parameter instead of just a Table* parameter.
1.262 + */
1.263 + pTab = sqlite3SrcListLookup(pParse, pTabList);
1.264 + if( pTab==0 ) goto delete_from_cleanup;
1.265 +
1.266 + /* Figure out if we have any triggers and if the table being
1.267 + ** deleted from is a view
1.268 + */
1.269 +#ifndef SQLITE_OMIT_TRIGGER
1.270 + triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0);
1.271 + isView = pTab->pSelect!=0;
1.272 +#else
1.273 +# define triggers_exist 0
1.274 +# define isView 0
1.275 +#endif
1.276 +#ifdef SQLITE_OMIT_VIEW
1.277 +# undef isView
1.278 +# define isView 0
1.279 +#endif
1.280 +
1.281 + if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
1.282 + goto delete_from_cleanup;
1.283 + }
1.284 + iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
1.285 + assert( iDb<db->nDb );
1.286 + zDb = db->aDb[iDb].zName;
1.287 + if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){
1.288 + goto delete_from_cleanup;
1.289 + }
1.290 +
1.291 + /* If pTab is really a view, make sure it has been initialized.
1.292 + */
1.293 + if( sqlite3ViewGetColumnNames(pParse, pTab) ){
1.294 + goto delete_from_cleanup;
1.295 + }
1.296 +
1.297 + /* Allocate a cursor used to store the old.* data for a trigger.
1.298 + */
1.299 + if( triggers_exist ){
1.300 + oldIdx = pParse->nTab++;
1.301 + }
1.302 +
1.303 + /* Assign cursor number to the table and all its indices.
1.304 + */
1.305 + assert( pTabList->nSrc==1 );
1.306 + iCur = pTabList->a[0].iCursor = pParse->nTab++;
1.307 + for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
1.308 + pParse->nTab++;
1.309 + }
1.310 +
1.311 + /* Start the view context
1.312 + */
1.313 + if( isView ){
1.314 + sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
1.315 + }
1.316 +
1.317 + /* Begin generating code.
1.318 + */
1.319 + v = sqlite3GetVdbe(pParse);
1.320 + if( v==0 ){
1.321 + goto delete_from_cleanup;
1.322 + }
1.323 + if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
1.324 + sqlite3BeginWriteOperation(pParse, triggers_exist, iDb);
1.325 +
1.326 + if( triggers_exist ){
1.327 + int orconf = ((pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
1.328 + int iGoto = sqlite3VdbeAddOp0(v, OP_Goto);
1.329 + addr = sqlite3VdbeMakeLabel(v);
1.330 +
1.331 + iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
1.332 + (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_BEFORE, pTab,
1.333 + -1, oldIdx, orconf, addr, &old_col_mask, 0);
1.334 + iEndBeforeTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
1.335 +
1.336 + iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
1.337 + (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_AFTER, pTab, -1,
1.338 + oldIdx, orconf, addr, &old_col_mask, 0);
1.339 + iEndAfterTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
1.340 +
1.341 + sqlite3VdbeJumpHere(v, iGoto);
1.342 + }
1.343 +
1.344 + /* If we are trying to delete from a view, realize that view into
1.345 + ** a ephemeral table.
1.346 + */
1.347 +#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
1.348 + if( isView ){
1.349 + sqlite3MaterializeView(pParse, pTab, pWhere, iCur);
1.350 + }
1.351 +#endif
1.352 +
1.353 + /* Resolve the column names in the WHERE clause.
1.354 + */
1.355 + memset(&sNC, 0, sizeof(sNC));
1.356 + sNC.pParse = pParse;
1.357 + sNC.pSrcList = pTabList;
1.358 + if( sqlite3ResolveExprNames(&sNC, pWhere) ){
1.359 + goto delete_from_cleanup;
1.360 + }
1.361 +
1.362 + /* Initialize the counter of the number of rows deleted, if
1.363 + ** we are counting rows.
1.364 + */
1.365 + if( db->flags & SQLITE_CountRows ){
1.366 + memCnt = ++pParse->nMem;
1.367 + sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt);
1.368 + }
1.369 +
1.370 +#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
1.371 + /* Special case: A DELETE without a WHERE clause deletes everything.
1.372 + ** It is easier just to erase the whole table. Note, however, that
1.373 + ** this means that the row change count will be incorrect.
1.374 + */
1.375 + if( pWhere==0 && !triggers_exist && !IsVirtual(pTab) ){
1.376 + if( db->flags & SQLITE_CountRows ){
1.377 + /* If counting rows deleted, just count the total number of
1.378 + ** entries in the table. */
1.379 + int addr2;
1.380 + if( !isView ){
1.381 + sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
1.382 + }
1.383 + sqlite3VdbeAddOp2(v, OP_Rewind, iCur, sqlite3VdbeCurrentAddr(v)+2);
1.384 + addr2 = sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
1.385 + sqlite3VdbeAddOp2(v, OP_Next, iCur, addr2);
1.386 + sqlite3VdbeAddOp1(v, OP_Close, iCur);
1.387 + }
1.388 + if( !isView ){
1.389 + sqlite3VdbeAddOp2(v, OP_Clear, pTab->tnum, iDb);
1.390 + if( !pParse->nested ){
1.391 + sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
1.392 + }
1.393 + for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
1.394 + assert( pIdx->pSchema==pTab->pSchema );
1.395 + sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
1.396 + }
1.397 + }
1.398 + }else
1.399 +#endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
1.400 + /* The usual case: There is a WHERE clause so we have to scan through
1.401 + ** the table and pick which records to delete.
1.402 + */
1.403 + {
1.404 + int iRowid = ++pParse->nMem; /* Used for storing rowid values. */
1.405 +
1.406 + /* Begin the database scan
1.407 + */
1.408 + pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0);
1.409 + if( pWInfo==0 ) goto delete_from_cleanup;
1.410 +
1.411 + /* Remember the rowid of every item to be deleted.
1.412 + */
1.413 + sqlite3VdbeAddOp2(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur, iRowid);
1.414 + sqlite3VdbeAddOp1(v, OP_FifoWrite, iRowid);
1.415 + if( db->flags & SQLITE_CountRows ){
1.416 + sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
1.417 + }
1.418 +
1.419 + /* End the database scan loop.
1.420 + */
1.421 + sqlite3WhereEnd(pWInfo);
1.422 +
1.423 + /* Open the pseudo-table used to store OLD if there are triggers.
1.424 + */
1.425 + if( triggers_exist ){
1.426 + sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
1.427 + sqlite3VdbeAddOp1(v, OP_OpenPseudo, oldIdx);
1.428 + }
1.429 +
1.430 + /* Delete every item whose key was written to the list during the
1.431 + ** database scan. We have to delete items after the scan is complete
1.432 + ** because deleting an item can change the scan order.
1.433 + */
1.434 + end = sqlite3VdbeMakeLabel(v);
1.435 +
1.436 + if( !isView ){
1.437 + /* Open cursors for the table we are deleting from and
1.438 + ** all its indices.
1.439 + */
1.440 + sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);
1.441 + }
1.442 +
1.443 + /* This is the beginning of the delete loop. If a trigger encounters
1.444 + ** an IGNORE constraint, it jumps back to here.
1.445 + */
1.446 + if( triggers_exist ){
1.447 + sqlite3VdbeResolveLabel(v, addr);
1.448 + }
1.449 + addr = sqlite3VdbeAddOp2(v, OP_FifoRead, iRowid, end);
1.450 +
1.451 + if( triggers_exist ){
1.452 + int iData = ++pParse->nMem; /* For storing row data of OLD table */
1.453 +
1.454 + /* If the record is no longer present in the table, jump to the
1.455 + ** next iteration of the loop through the contents of the fifo.
1.456 + */
1.457 + sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, iRowid);
1.458 +
1.459 + /* Populate the OLD.* pseudo-table */
1.460 + if( old_col_mask ){
1.461 + sqlite3VdbeAddOp2(v, OP_RowData, iCur, iData);
1.462 + }else{
1.463 + sqlite3VdbeAddOp2(v, OP_Null, 0, iData);
1.464 + }
1.465 + sqlite3VdbeAddOp3(v, OP_Insert, oldIdx, iData, iRowid);
1.466 +
1.467 + /* Jump back and run the BEFORE triggers */
1.468 + sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger);
1.469 + sqlite3VdbeJumpHere(v, iEndBeforeTrigger);
1.470 + }
1.471 +
1.472 + if( !isView ){
1.473 + /* Delete the row */
1.474 +#ifndef SQLITE_OMIT_VIRTUALTABLE
1.475 + if( IsVirtual(pTab) ){
1.476 + const char *pVtab = (const char *)pTab->pVtab;
1.477 + sqlite3VtabMakeWritable(pParse, pTab);
1.478 + sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVtab, P4_VTAB);
1.479 + }else
1.480 +#endif
1.481 + {
1.482 + sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, pParse->nested==0);
1.483 + }
1.484 + }
1.485 +
1.486 + /* If there are row triggers, close all cursors then invoke
1.487 + ** the AFTER triggers
1.488 + */
1.489 + if( triggers_exist ){
1.490 + /* Jump back and run the AFTER triggers */
1.491 + sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger);
1.492 + sqlite3VdbeJumpHere(v, iEndAfterTrigger);
1.493 + }
1.494 +
1.495 + /* End of the delete loop */
1.496 + sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
1.497 + sqlite3VdbeResolveLabel(v, end);
1.498 +
1.499 + /* Close the cursors after the loop if there are no row triggers */
1.500 + if( !isView && !IsVirtual(pTab) ){
1.501 + for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
1.502 + sqlite3VdbeAddOp2(v, OP_Close, iCur + i, pIdx->tnum);
1.503 + }
1.504 + sqlite3VdbeAddOp1(v, OP_Close, iCur);
1.505 + }
1.506 + }
1.507 +
1.508 + /*
1.509 + ** Return the number of rows that were deleted. If this routine is
1.510 + ** generating code because of a call to sqlite3NestedParse(), do not
1.511 + ** invoke the callback function.
1.512 + */
1.513 + if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
1.514 + sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1);
1.515 + sqlite3VdbeSetNumCols(v, 1);
1.516 + sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", P4_STATIC);
1.517 + }
1.518 +
1.519 +delete_from_cleanup:
1.520 + sqlite3AuthContextPop(&sContext);
1.521 + sqlite3SrcListDelete(db, pTabList);
1.522 + sqlite3ExprDelete(db, pWhere);
1.523 + return;
1.524 +}
1.525 +
1.526 +/*
1.527 +** This routine generates VDBE code that causes a single row of a
1.528 +** single table to be deleted.
1.529 +**
1.530 +** The VDBE must be in a particular state when this routine is called.
1.531 +** These are the requirements:
1.532 +**
1.533 +** 1. A read/write cursor pointing to pTab, the table containing the row
1.534 +** to be deleted, must be opened as cursor number "base".
1.535 +**
1.536 +** 2. Read/write cursors for all indices of pTab must be open as
1.537 +** cursor number base+i for the i-th index.
1.538 +**
1.539 +** 3. The record number of the row to be deleted must be stored in
1.540 +** memory cell iRowid.
1.541 +**
1.542 +** This routine pops the top of the stack to remove the record number
1.543 +** and then generates code to remove both the table record and all index
1.544 +** entries that point to that record.
1.545 +*/
1.546 +void sqlite3GenerateRowDelete(
1.547 + Parse *pParse, /* Parsing context */
1.548 + Table *pTab, /* Table containing the row to be deleted */
1.549 + int iCur, /* Cursor number for the table */
1.550 + int iRowid, /* Memory cell that contains the rowid to delete */
1.551 + int count /* Increment the row change counter */
1.552 +){
1.553 + int addr;
1.554 + Vdbe *v;
1.555 +
1.556 + v = pParse->pVdbe;
1.557 + addr = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowid);
1.558 + sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, 0);
1.559 + sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
1.560 + if( count ){
1.561 + sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
1.562 + }
1.563 + sqlite3VdbeJumpHere(v, addr);
1.564 +}
1.565 +
1.566 +/*
1.567 +** This routine generates VDBE code that causes the deletion of all
1.568 +** index entries associated with a single row of a single table.
1.569 +**
1.570 +** The VDBE must be in a particular state when this routine is called.
1.571 +** These are the requirements:
1.572 +**
1.573 +** 1. A read/write cursor pointing to pTab, the table containing the row
1.574 +** to be deleted, must be opened as cursor number "iCur".
1.575 +**
1.576 +** 2. Read/write cursors for all indices of pTab must be open as
1.577 +** cursor number iCur+i for the i-th index.
1.578 +**
1.579 +** 3. The "iCur" cursor must be pointing to the row that is to be
1.580 +** deleted.
1.581 +*/
1.582 +void sqlite3GenerateRowIndexDelete(
1.583 + Parse *pParse, /* Parsing and code generating context */
1.584 + Table *pTab, /* Table containing the row to be deleted */
1.585 + int iCur, /* Cursor number for the table */
1.586 + int *aRegIdx /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
1.587 +){
1.588 + int i;
1.589 + Index *pIdx;
1.590 + int r1;
1.591 +
1.592 + for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
1.593 + if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue;
1.594 + r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0);
1.595 + sqlite3VdbeAddOp3(pParse->pVdbe, OP_IdxDelete, iCur+i, r1,pIdx->nColumn+1);
1.596 + }
1.597 +}
1.598 +
1.599 +/*
1.600 +** Generate code that will assemble an index key and put it in register
1.601 +** regOut. The key with be for index pIdx which is an index on pTab.
1.602 +** iCur is the index of a cursor open on the pTab table and pointing to
1.603 +** the entry that needs indexing.
1.604 +**
1.605 +** Return a register number which is the first in a block of
1.606 +** registers that holds the elements of the index key. The
1.607 +** block of registers has already been deallocated by the time
1.608 +** this routine returns.
1.609 +*/
1.610 +int sqlite3GenerateIndexKey(
1.611 + Parse *pParse, /* Parsing context */
1.612 + Index *pIdx, /* The index for which to generate a key */
1.613 + int iCur, /* Cursor number for the pIdx->pTable table */
1.614 + int regOut, /* Write the new index key to this register */
1.615 + int doMakeRec /* Run the OP_MakeRecord instruction if true */
1.616 +){
1.617 + Vdbe *v = pParse->pVdbe;
1.618 + int j;
1.619 + Table *pTab = pIdx->pTable;
1.620 + int regBase;
1.621 + int nCol;
1.622 +
1.623 + nCol = pIdx->nColumn;
1.624 + regBase = sqlite3GetTempRange(pParse, nCol+1);
1.625 + sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol);
1.626 + for(j=0; j<nCol; j++){
1.627 + int idx = pIdx->aiColumn[j];
1.628 + if( idx==pTab->iPKey ){
1.629 + sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
1.630 + }else{
1.631 + sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
1.632 + sqlite3ColumnDefault(v, pTab, idx);
1.633 + }
1.634 + }
1.635 + if( doMakeRec ){
1.636 + sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut);
1.637 + sqlite3IndexAffinityStr(v, pIdx);
1.638 + sqlite3ExprCacheAffinityChange(pParse, regBase, nCol+1);
1.639 + }
1.640 + sqlite3ReleaseTempRange(pParse, regBase, nCol+1);
1.641 + return regBase;
1.642 +}
1.643 +
1.644 +/* Make sure "isView" gets undefined in case this file becomes part of
1.645 +** the amalgamation - so that subsequent files do not see isView as a
1.646 +** macro. */
1.647 +#undef isView