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drhcce7d172000-05-31 15:34:51 +00001/*
drhb19a2bc2001-09-16 00:13:26 +00002** 2001 September 15
drhcce7d172000-05-31 15:34:51 +00003**
drhb19a2bc2001-09-16 00:13:26 +00004** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
drhcce7d172000-05-31 15:34:51 +00006**
drhb19a2bc2001-09-16 00:13:26 +00007** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
drhcce7d172000-05-31 15:34:51 +000010**
11*************************************************************************
12** This file contains C code routines that are called by the parser
drh23bf66d2004-12-14 03:34:34 +000013** in order to generate code for DELETE FROM statements.
drhcce7d172000-05-31 15:34:51 +000014**
danielk1977595a5232009-07-24 17:58:53 +000015** $Id: delete.c,v 1.205 2009/07/24 17:58:53 danielk1977 Exp $
drhcce7d172000-05-31 15:34:51 +000016*/
17#include "sqliteInt.h"
18
drha76b5df2002-02-23 02:32:10 +000019/*
drh812d7a22003-03-27 13:50:00 +000020** Look up every table that is named in pSrc. If any table is not found,
21** add an error message to pParse->zErrMsg and return NULL. If all tables
22** are found, return a pointer to the last table.
drha76b5df2002-02-23 02:32:10 +000023*/
danielk19774adee202004-05-08 08:23:19 +000024Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
danielk1977b1c685b2008-10-06 16:18:39 +000025 struct SrcList_item *pItem = pSrc->a;
26 Table *pTab;
27 assert( pItem && pSrc->nSrc==1 );
28 pTab = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase);
29 sqlite3DeleteTable(pItem->pTab);
30 pItem->pTab = pTab;
31 if( pTab ){
32 pTab->nRef++;
33 }
34 if( sqlite3IndexedByLookup(pParse, pItem) ){
35 pTab = 0;
drha76b5df2002-02-23 02:32:10 +000036 }
37 return pTab;
38}
39
40/*
drh812d7a22003-03-27 13:50:00 +000041** Check to make sure the given table is writable. If it is not
42** writable, generate an error message and return 1. If it is
43** writable return 0;
44*/
danielk19774adee202004-05-08 08:23:19 +000045int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){
danielk1977595a5232009-07-24 17:58:53 +000046 /* A table is not writable under the following circumstances:
47 **
48 ** 1) It is a virtual table and no implementation of the xUpdate method
49 ** has been provided, or
50 ** 2) It is a system table (i.e. sqlite_master), this call is not
51 ** part of a nested parse and writable_schema pragma has not
52 ** been specified.
53 **
54 ** In either case leave an error message in pParse and return non-zero.
55 */
56 if( ( IsVirtual(pTab)
57 && sqlite3GetVTable(pParse->db, pTab)->pMod->pModule->xUpdate==0 )
58 || ( (pTab->tabFlags & TF_Readonly)!=0
59 && (pParse->db->flags & SQLITE_WriteSchema)==0
60 && pParse->nested==0 )
drh4cbdda92006-06-14 19:00:20 +000061 ){
danielk19774adee202004-05-08 08:23:19 +000062 sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
drh5cf590c2003-04-24 01:45:04 +000063 return 1;
64 }
danielk1977595a5232009-07-24 17:58:53 +000065
danielk1977b84f96f2005-01-20 11:32:23 +000066#ifndef SQLITE_OMIT_VIEW
drh5cf590c2003-04-24 01:45:04 +000067 if( !viewOk && pTab->pSelect ){
drhda71ce12004-06-21 18:14:45 +000068 sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
drh812d7a22003-03-27 13:50:00 +000069 return 1;
70 }
danielk1977b84f96f2005-01-20 11:32:23 +000071#endif
drh812d7a22003-03-27 13:50:00 +000072 return 0;
73}
74
danielk1977299b1872004-11-22 10:02:10 +000075
drh0f35a6b2008-02-12 16:52:14 +000076#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
77/*
78** Evaluate a view and store its result in an ephemeral table. The
79** pWhere argument is an optional WHERE clause that restricts the
80** set of rows in the view that are to be added to the ephemeral table.
81*/
82void sqlite3MaterializeView(
83 Parse *pParse, /* Parsing context */
drh2a5d8252008-08-22 12:30:52 +000084 Table *pView, /* View definition */
drh0f35a6b2008-02-12 16:52:14 +000085 Expr *pWhere, /* Optional WHERE clause to be added */
drh0f35a6b2008-02-12 16:52:14 +000086 int iCur /* Cursor number for ephemerial table */
87){
88 SelectDest dest;
89 Select *pDup;
90 sqlite3 *db = pParse->db;
91
danielk19776ab3a2e2009-02-19 14:39:25 +000092 pDup = sqlite3SelectDup(db, pView->pSelect, 0);
drh0f35a6b2008-02-12 16:52:14 +000093 if( pWhere ){
94 SrcList *pFrom;
95
danielk19776ab3a2e2009-02-19 14:39:25 +000096 pWhere = sqlite3ExprDup(db, pWhere, 0);
drhb7916a72009-05-27 10:31:29 +000097 pFrom = sqlite3SrcListAppend(db, 0, 0, 0);
98 if( pFrom ){
99 assert( pFrom->nSrc==1 );
100 pFrom->a[0].zAlias = sqlite3DbStrDup(db, pView->zName);
101 pFrom->a[0].pSelect = pDup;
102 assert( pFrom->a[0].pOn==0 );
103 assert( pFrom->a[0].pUsing==0 );
104 }else{
105 sqlite3SelectDelete(db, pDup);
106 }
drh0f35a6b2008-02-12 16:52:14 +0000107 pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
108 }
drh0f35a6b2008-02-12 16:52:14 +0000109 sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
drh7d10d5a2008-08-20 16:35:10 +0000110 sqlite3Select(pParse, pDup, &dest);
drh633e6d52008-07-28 19:34:53 +0000111 sqlite3SelectDelete(db, pDup);
drh0f35a6b2008-02-12 16:52:14 +0000112}
113#endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
114
shane273f6192008-10-10 04:34:16 +0000115#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
shane4281bd42008-10-07 05:27:11 +0000116/*
117** Generate an expression tree to implement the WHERE, ORDER BY,
118** and LIMIT/OFFSET portion of DELETE and UPDATE statements.
119**
120** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1;
121** \__________________________/
122** pLimitWhere (pInClause)
123*/
124Expr *sqlite3LimitWhere(
shane49ffdbf2008-10-10 18:25:45 +0000125 Parse *pParse, /* The parser context */
126 SrcList *pSrc, /* the FROM clause -- which tables to scan */
127 Expr *pWhere, /* The WHERE clause. May be null */
128 ExprList *pOrderBy, /* The ORDER BY clause. May be null */
129 Expr *pLimit, /* The LIMIT clause. May be null */
130 Expr *pOffset, /* The OFFSET clause. May be null */
131 char *zStmtType /* Either DELETE or UPDATE. For error messages. */
shane4281bd42008-10-07 05:27:11 +0000132){
shane49ffdbf2008-10-10 18:25:45 +0000133 Expr *pWhereRowid = NULL; /* WHERE rowid .. */
134 Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */
135 Expr *pSelectRowid = NULL; /* SELECT rowid ... */
136 ExprList *pEList = NULL; /* Expression list contaning only pSelectRowid */
137 SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */
138 Select *pSelect = NULL; /* Complete SELECT tree */
139
140 /* Check that there isn't an ORDER BY without a LIMIT clause.
141 */
142 if( pOrderBy && (pLimit == 0) ) {
143 sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
144 pParse->parseError = 1;
145 goto limit_where_cleanup_2;
146 }
shane273f6192008-10-10 04:34:16 +0000147
148 /* We only need to generate a select expression if there
149 ** is a limit/offset term to enforce.
150 */
shane49ffdbf2008-10-10 18:25:45 +0000151 if( pLimit == 0 ) {
152 /* if pLimit is null, pOffset will always be null as well. */
153 assert( pOffset == 0 );
154 return pWhere;
155 }
shane273f6192008-10-10 04:34:16 +0000156
157 /* Generate a select expression tree to enforce the limit/offset
158 ** term for the DELETE or UPDATE statement. For example:
159 ** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
160 ** becomes:
161 ** DELETE FROM table_a WHERE rowid IN (
shaneb235db92008-10-10 13:35:57 +0000162 ** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
shane273f6192008-10-10 04:34:16 +0000163 ** );
164 */
shaneb235db92008-10-10 13:35:57 +0000165
drhb7916a72009-05-27 10:31:29 +0000166 pSelectRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
shane49ffdbf2008-10-10 18:25:45 +0000167 if( pSelectRowid == 0 ) goto limit_where_cleanup_2;
drhb7916a72009-05-27 10:31:29 +0000168 pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid);
shane49ffdbf2008-10-10 18:25:45 +0000169 if( pEList == 0 ) goto limit_where_cleanup_2;
shaneb235db92008-10-10 13:35:57 +0000170
shane273f6192008-10-10 04:34:16 +0000171 /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
shaneb235db92008-10-10 13:35:57 +0000172 ** and the SELECT subtree. */
danielk19776ab3a2e2009-02-19 14:39:25 +0000173 pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0);
shaneb235db92008-10-10 13:35:57 +0000174 if( pSelectSrc == 0 ) {
175 sqlite3ExprListDelete(pParse->db, pEList);
shane49ffdbf2008-10-10 18:25:45 +0000176 goto limit_where_cleanup_2;
shaneb235db92008-10-10 13:35:57 +0000177 }
178
179 /* generate the SELECT expression tree. */
drh18209cd2009-03-02 14:24:21 +0000180 pSelect = sqlite3SelectNew(pParse,pEList,pSelectSrc,pWhere,0,0,
181 pOrderBy,0,pLimit,pOffset);
shaneb235db92008-10-10 13:35:57 +0000182 if( pSelect == 0 ) return 0;
183
shane49ffdbf2008-10-10 18:25:45 +0000184 /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
drhb7916a72009-05-27 10:31:29 +0000185 pWhereRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
shane49ffdbf2008-10-10 18:25:45 +0000186 if( pWhereRowid == 0 ) goto limit_where_cleanup_1;
shane273f6192008-10-10 04:34:16 +0000187 pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0);
shane49ffdbf2008-10-10 18:25:45 +0000188 if( pInClause == 0 ) goto limit_where_cleanup_1;
shaneb235db92008-10-10 13:35:57 +0000189
drh18209cd2009-03-02 14:24:21 +0000190 pInClause->x.pSelect = pSelect;
191 pInClause->flags |= EP_xIsSelect;
shane273f6192008-10-10 04:34:16 +0000192 sqlite3ExprSetHeight(pParse, pInClause);
193 return pInClause;
194
shane273f6192008-10-10 04:34:16 +0000195 /* something went wrong. clean up anything allocated. */
shane49ffdbf2008-10-10 18:25:45 +0000196limit_where_cleanup_1:
shaneb235db92008-10-10 13:35:57 +0000197 sqlite3SelectDelete(pParse->db, pSelect);
shane4281bd42008-10-07 05:27:11 +0000198 return 0;
shane49ffdbf2008-10-10 18:25:45 +0000199
200limit_where_cleanup_2:
201 sqlite3ExprDelete(pParse->db, pWhere);
202 sqlite3ExprListDelete(pParse->db, pOrderBy);
203 sqlite3ExprDelete(pParse->db, pLimit);
204 sqlite3ExprDelete(pParse->db, pOffset);
205 return 0;
shane4281bd42008-10-07 05:27:11 +0000206}
shane273f6192008-10-10 04:34:16 +0000207#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
drh0f35a6b2008-02-12 16:52:14 +0000208
drhad6d9462004-09-19 02:15:24 +0000209/*
drh23bf66d2004-12-14 03:34:34 +0000210** Generate code for a DELETE FROM statement.
211**
212** DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
213** \________/ \________________/
214** pTabList pWhere
drhcce7d172000-05-31 15:34:51 +0000215*/
danielk19774adee202004-05-08 08:23:19 +0000216void sqlite3DeleteFrom(
drhcce7d172000-05-31 15:34:51 +0000217 Parse *pParse, /* The parser context */
drh113088e2003-03-20 01:16:58 +0000218 SrcList *pTabList, /* The table from which we should delete things */
drhcce7d172000-05-31 15:34:51 +0000219 Expr *pWhere /* The WHERE clause. May be null */
220){
221 Vdbe *v; /* The virtual database engine */
222 Table *pTab; /* The table from which records will be deleted */
drhe22a3342003-04-22 20:30:37 +0000223 const char *zDb; /* Name of database holding pTab */
danielk1977299b1872004-11-22 10:02:10 +0000224 int end, addr = 0; /* A couple addresses of generated code */
drhcce7d172000-05-31 15:34:51 +0000225 int i; /* Loop counter */
226 WhereInfo *pWInfo; /* Information about the WHERE clause */
227 Index *pIdx; /* For looping over indices of the table */
drh6a3ea0e2003-05-02 14:32:12 +0000228 int iCur; /* VDBE Cursor number for pTab */
drh9bb575f2004-09-06 17:24:11 +0000229 sqlite3 *db; /* Main database structure */
drh85e20962003-04-25 17:52:11 +0000230 AuthContext sContext; /* Authorization context */
drh798da522004-11-04 04:42:28 +0000231 int oldIdx = -1; /* Cursor for the OLD table of AFTER triggers */
danielk1977b3bce662005-01-29 08:32:43 +0000232 NameContext sNC; /* Name context to resolve expressions in */
drh53a67772007-02-07 01:06:52 +0000233 int iDb; /* Database number */
danielk1977c7af4842008-10-27 13:59:33 +0000234 int memCnt = -1; /* Memory cell used for change counting */
danielk197752bd7912008-10-27 15:34:32 +0000235 int rcauth; /* Value returned by authorization callback */
drh1bee3d72001-10-15 00:44:35 +0000236
drh798da522004-11-04 04:42:28 +0000237#ifndef SQLITE_OMIT_TRIGGER
238 int isView; /* True if attempting to delete from a view */
danielk19772f886d12009-02-28 10:47:41 +0000239 Trigger *pTrigger; /* List of table triggers, if required */
drh798da522004-11-04 04:42:28 +0000240#endif
drh1bd10f82008-12-10 21:19:56 +0000241 int iBeginAfterTrigger = 0; /* Address of after trigger program */
242 int iEndAfterTrigger = 0; /* Exit of after trigger program */
243 int iBeginBeforeTrigger = 0; /* Address of before trigger program */
244 int iEndBeforeTrigger = 0; /* Exit of before trigger program */
danielk19778f2c54e2008-01-01 19:02:09 +0000245 u32 old_col_mask = 0; /* Mask of OLD.* columns in use */
drhcce7d172000-05-31 15:34:51 +0000246
drh85e20962003-04-25 17:52:11 +0000247 sContext.pParse = 0;
drh17435752007-08-16 04:30:38 +0000248 db = pParse->db;
249 if( pParse->nErr || db->mallocFailed ){
drhdaffd0e2001-04-11 14:28:42 +0000250 goto delete_from_cleanup;
251 }
drh113088e2003-03-20 01:16:58 +0000252 assert( pTabList->nSrc==1 );
drhdaffd0e2001-04-11 14:28:42 +0000253
drh1ccde152000-06-17 13:12:39 +0000254 /* Locate the table which we want to delete. This table has to be
drhad3cab52002-05-24 02:04:32 +0000255 ** put in an SrcList structure because some of the subroutines we
drhcce7d172000-05-31 15:34:51 +0000256 ** will be calling are designed to work with multiple tables and expect
drhad3cab52002-05-24 02:04:32 +0000257 ** an SrcList* parameter instead of just a Table* parameter.
drhcce7d172000-05-31 15:34:51 +0000258 */
danielk19774adee202004-05-08 08:23:19 +0000259 pTab = sqlite3SrcListLookup(pParse, pTabList);
drha69d9162003-04-17 22:57:53 +0000260 if( pTab==0 ) goto delete_from_cleanup;
drhb7f91642004-10-31 02:22:47 +0000261
262 /* Figure out if we have any triggers and if the table being
263 ** deleted from is a view
264 */
265#ifndef SQLITE_OMIT_TRIGGER
danielk19772f886d12009-02-28 10:47:41 +0000266 pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
drh5cf590c2003-04-24 01:45:04 +0000267 isView = pTab->pSelect!=0;
drhb7f91642004-10-31 02:22:47 +0000268#else
danielk19772f886d12009-02-28 10:47:41 +0000269# define pTrigger 0
drhb7f91642004-10-31 02:22:47 +0000270# define isView 0
271#endif
272#ifdef SQLITE_OMIT_VIEW
273# undef isView
274# define isView 0
275#endif
276
danielk1977595a5232009-07-24 17:58:53 +0000277 /* If pTab is really a view, make sure it has been initialized.
278 */
279 if( sqlite3ViewGetColumnNames(pParse, pTab) ){
280 goto delete_from_cleanup;
281 }
282
danielk19772f886d12009-02-28 10:47:41 +0000283 if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){
drh5cf590c2003-04-24 01:45:04 +0000284 goto delete_from_cleanup;
drh113088e2003-03-20 01:16:58 +0000285 }
danielk1977da184232006-01-05 11:34:32 +0000286 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
287 assert( iDb<db->nDb );
288 zDb = db->aDb[iDb].zName;
danielk197752bd7912008-10-27 15:34:32 +0000289 rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb);
290 assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
291 if( rcauth==SQLITE_DENY ){
drhe5f9c642003-01-13 23:27:31 +0000292 goto delete_from_cleanup;
293 }
danielk19772f886d12009-02-28 10:47:41 +0000294 assert(!isView || pTrigger);
drhcce7d172000-05-31 15:34:51 +0000295
drhc977f7f2002-05-21 11:38:11 +0000296 /* Allocate a cursor used to store the old.* data for a trigger.
297 */
danielk19772f886d12009-02-28 10:47:41 +0000298 if( pTrigger ){
danielk1977c3f9bad2002-05-15 08:30:12 +0000299 oldIdx = pParse->nTab++;
danielk1977f29ce552002-05-19 23:43:12 +0000300 }
danielk1977c3f9bad2002-05-15 08:30:12 +0000301
drh0f35a6b2008-02-12 16:52:14 +0000302 /* Assign cursor number to the table and all its indices.
drhcce7d172000-05-31 15:34:51 +0000303 */
drh6a3ea0e2003-05-02 14:32:12 +0000304 assert( pTabList->nSrc==1 );
305 iCur = pTabList->a[0].iCursor = pParse->nTab++;
danielk1977e448dc42008-01-02 11:50:51 +0000306 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
307 pParse->nTab++;
308 }
drhcce7d172000-05-31 15:34:51 +0000309
drh85e20962003-04-25 17:52:11 +0000310 /* Start the view context
311 */
312 if( isView ){
danielk19774adee202004-05-08 08:23:19 +0000313 sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
drh85e20962003-04-25 17:52:11 +0000314 }
315
drhcce7d172000-05-31 15:34:51 +0000316 /* Begin generating code.
317 */
danielk19774adee202004-05-08 08:23:19 +0000318 v = sqlite3GetVdbe(pParse);
danielk1977f29ce552002-05-19 23:43:12 +0000319 if( v==0 ){
320 goto delete_from_cleanup;
321 }
drh4794f732004-11-05 17:17:50 +0000322 if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
danielk19772f886d12009-02-28 10:47:41 +0000323 sqlite3BeginWriteOperation(pParse, (pTrigger?1:0), iDb);
drh5e00f6c2001-09-13 13:46:56 +0000324
danielk19772f886d12009-02-28 10:47:41 +0000325 if( pTrigger ){
danielk1977dd2fb292008-01-04 13:57:26 +0000326 int orconf = ((pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
drh66a51672008-01-03 00:01:23 +0000327 int iGoto = sqlite3VdbeAddOp0(v, OP_Goto);
danielk19778f2c54e2008-01-01 19:02:09 +0000328 addr = sqlite3VdbeMakeLabel(v);
danielk1977dd2fb292008-01-04 13:57:26 +0000329
danielk19778f2c54e2008-01-01 19:02:09 +0000330 iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
danielk19772f886d12009-02-28 10:47:41 +0000331 (void)sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0,
332 TRIGGER_BEFORE, pTab, -1, oldIdx, orconf, addr, &old_col_mask, 0);
drh66a51672008-01-03 00:01:23 +0000333 iEndBeforeTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
danielk1977dd2fb292008-01-04 13:57:26 +0000334
danielk19778f2c54e2008-01-01 19:02:09 +0000335 iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
danielk19772f886d12009-02-28 10:47:41 +0000336 (void)sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0,
337 TRIGGER_AFTER, pTab, -1, oldIdx, orconf, addr, &old_col_mask, 0);
drh66a51672008-01-03 00:01:23 +0000338 iEndAfterTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
danielk1977dd2fb292008-01-04 13:57:26 +0000339
danielk19778f2c54e2008-01-01 19:02:09 +0000340 sqlite3VdbeJumpHere(v, iGoto);
341 }
342
drh9d2985c2005-09-08 01:58:42 +0000343 /* If we are trying to delete from a view, realize that view into
344 ** a ephemeral table.
drh5cf590c2003-04-24 01:45:04 +0000345 */
shanefa4e62f2008-09-01 21:59:42 +0000346#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
drh5cf590c2003-04-24 01:45:04 +0000347 if( isView ){
drh2a5d8252008-08-22 12:30:52 +0000348 sqlite3MaterializeView(pParse, pTab, pWhere, iCur);
drh0f35a6b2008-02-12 16:52:14 +0000349 }
shanefa4e62f2008-09-01 21:59:42 +0000350#endif
drh1013c932008-01-06 00:25:21 +0000351
drh0f35a6b2008-02-12 16:52:14 +0000352 /* Resolve the column names in the WHERE clause.
353 */
354 memset(&sNC, 0, sizeof(sNC));
355 sNC.pParse = pParse;
356 sNC.pSrcList = pTabList;
drh7d10d5a2008-08-20 16:35:10 +0000357 if( sqlite3ResolveExprNames(&sNC, pWhere) ){
drh0f35a6b2008-02-12 16:52:14 +0000358 goto delete_from_cleanup;
drh5cf590c2003-04-24 01:45:04 +0000359 }
360
drh1bee3d72001-10-15 00:44:35 +0000361 /* Initialize the counter of the number of rows deleted, if
362 ** we are counting rows.
363 */
364 if( db->flags & SQLITE_CountRows ){
drh0a07c102008-01-03 18:03:08 +0000365 memCnt = ++pParse->nMem;
drh4c583122008-01-04 22:01:03 +0000366 sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt);
drh1bee3d72001-10-15 00:44:35 +0000367 }
drhcce7d172000-05-31 15:34:51 +0000368
drhf8cecda2008-10-10 23:48:25 +0000369#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
drh0353ced2001-03-20 22:05:00 +0000370 /* Special case: A DELETE without a WHERE clause deletes everything.
drhc977f7f2002-05-21 11:38:11 +0000371 ** It is easier just to erase the whole table. Note, however, that
372 ** this means that the row change count will be incorrect.
drhcce7d172000-05-31 15:34:51 +0000373 */
danielk19772f886d12009-02-28 10:47:41 +0000374 if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab) ){
danielk19779a02fb42008-10-27 08:24:38 +0000375 assert( !isView );
drhbbb5e4e2009-04-30 00:11:09 +0000376 sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt,
377 pTab->zName, P4_STATIC);
danielk19779a02fb42008-10-27 08:24:38 +0000378 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
379 assert( pIdx->pSchema==pTab->pSchema );
380 sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
drhcce7d172000-05-31 15:34:51 +0000381 }
drhf8cecda2008-10-10 23:48:25 +0000382 }else
383#endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
drh0353ced2001-03-20 22:05:00 +0000384 /* The usual case: There is a WHERE clause so we have to scan through
jplyon8bc03a72004-01-19 04:54:28 +0000385 ** the table and pick which records to delete.
drh0353ced2001-03-20 22:05:00 +0000386 */
drhf8cecda2008-10-10 23:48:25 +0000387 {
danielk1977dd2fb292008-01-04 13:57:26 +0000388 int iRowid = ++pParse->nMem; /* Used for storing rowid values. */
drh3d4501e2008-12-04 20:40:10 +0000389 int iRowSet = ++pParse->nMem; /* Register for rowset of rows to delete */
drh336a5302009-04-24 15:46:21 +0000390 int regRowid; /* Actual register containing rowids */
danielk197796cb76f2008-01-04 13:24:28 +0000391
drh23d04d52008-12-23 23:56:22 +0000392 /* Collect rowids of every row to be deleted.
danielk1977299b1872004-11-22 10:02:10 +0000393 */
drh23d04d52008-12-23 23:56:22 +0000394 sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
drh336a5302009-04-24 15:46:21 +0000395 pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0,WHERE_DUPLICATES_OK);
danielk1977299b1872004-11-22 10:02:10 +0000396 if( pWInfo==0 ) goto delete_from_cleanup;
drh336a5302009-04-24 15:46:21 +0000397 regRowid = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, iRowid, 0);
398 sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, regRowid);
danielk1977299b1872004-11-22 10:02:10 +0000399 if( db->flags & SQLITE_CountRows ){
drh8558cde2008-01-05 05:20:10 +0000400 sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
danielk1977299b1872004-11-22 10:02:10 +0000401 }
danielk1977299b1872004-11-22 10:02:10 +0000402 sqlite3WhereEnd(pWInfo);
403
drh70ce3f02003-04-15 19:22:22 +0000404 /* Open the pseudo-table used to store OLD if there are triggers.
405 */
danielk19772f886d12009-02-28 10:47:41 +0000406 if( pTrigger ){
danielk1977d336e222009-02-20 10:58:41 +0000407 sqlite3VdbeAddOp3(v, OP_OpenPseudo, oldIdx, 0, pTab->nCol);
drh70ce3f02003-04-15 19:22:22 +0000408 }
409
danielk1977299b1872004-11-22 10:02:10 +0000410 /* Delete every item whose key was written to the list during the
411 ** database scan. We have to delete items after the scan is complete
412 ** because deleting an item can change the scan order.
danielk1977ed326d72004-11-16 15:50:19 +0000413 */
danielk1977299b1872004-11-22 10:02:10 +0000414 end = sqlite3VdbeMakeLabel(v);
danielk1977ed326d72004-11-16 15:50:19 +0000415
danielk1977e448dc42008-01-02 11:50:51 +0000416 if( !isView ){
417 /* Open cursors for the table we are deleting from and
418 ** all its indices.
419 */
420 sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);
421 }
422
423 /* This is the beginning of the delete loop. If a trigger encounters
424 ** an IGNORE constraint, it jumps back to here.
drhc977f7f2002-05-21 11:38:11 +0000425 */
danielk19772f886d12009-02-28 10:47:41 +0000426 if( pTrigger ){
danielk19778f2c54e2008-01-01 19:02:09 +0000427 sqlite3VdbeResolveLabel(v, addr);
danielk1977e448dc42008-01-02 11:50:51 +0000428 }
drh3d4501e2008-12-04 20:40:10 +0000429 addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, iRowid);
danielk1977e448dc42008-01-02 11:50:51 +0000430
danielk19772f886d12009-02-28 10:47:41 +0000431 if( pTrigger ){
danielk197796cb76f2008-01-04 13:24:28 +0000432 int iData = ++pParse->nMem; /* For storing row data of OLD table */
433
434 /* If the record is no longer present in the table, jump to the
435 ** next iteration of the loop through the contents of the fifo.
436 */
437 sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, iRowid);
438
439 /* Populate the OLD.* pseudo-table */
danielk19778f2c54e2008-01-01 19:02:09 +0000440 if( old_col_mask ){
drh98757152008-01-09 23:04:12 +0000441 sqlite3VdbeAddOp2(v, OP_RowData, iCur, iData);
danielk19778f2c54e2008-01-01 19:02:09 +0000442 }else{
drh4c583122008-01-04 22:01:03 +0000443 sqlite3VdbeAddOp2(v, OP_Null, 0, iData);
danielk19778f2c54e2008-01-01 19:02:09 +0000444 }
danielk197796cb76f2008-01-04 13:24:28 +0000445 sqlite3VdbeAddOp3(v, OP_Insert, oldIdx, iData, iRowid);
danielk1977299b1872004-11-22 10:02:10 +0000446
danielk19778f2c54e2008-01-01 19:02:09 +0000447 /* Jump back and run the BEFORE triggers */
drh66a51672008-01-03 00:01:23 +0000448 sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger);
danielk19778f2c54e2008-01-01 19:02:09 +0000449 sqlite3VdbeJumpHere(v, iEndBeforeTrigger);
danielk1977c3f9bad2002-05-15 08:30:12 +0000450 }
451
danielk1977299b1872004-11-22 10:02:10 +0000452 if( !isView ){
danielk1977299b1872004-11-22 10:02:10 +0000453 /* Delete the row */
drh4cbdda92006-06-14 19:00:20 +0000454#ifndef SQLITE_OMIT_VIRTUALTABLE
455 if( IsVirtual(pTab) ){
danielk1977595a5232009-07-24 17:58:53 +0000456 const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
drh4f3dd152008-04-28 18:46:43 +0000457 sqlite3VtabMakeWritable(pParse, pTab);
danielk1977595a5232009-07-24 17:58:53 +0000458 sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVTab, P4_VTAB);
drh4cbdda92006-06-14 19:00:20 +0000459 }else
460#endif
461 {
drh2d401ab2008-01-10 23:50:11 +0000462 sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, pParse->nested==0);
drh4cbdda92006-06-14 19:00:20 +0000463 }
danielk1977299b1872004-11-22 10:02:10 +0000464 }
465
466 /* If there are row triggers, close all cursors then invoke
467 ** the AFTER triggers
468 */
danielk19772f886d12009-02-28 10:47:41 +0000469 if( pTrigger ){
danielk19778f2c54e2008-01-01 19:02:09 +0000470 /* Jump back and run the AFTER triggers */
drh66a51672008-01-03 00:01:23 +0000471 sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger);
danielk19778f2c54e2008-01-01 19:02:09 +0000472 sqlite3VdbeJumpHere(v, iEndAfterTrigger);
danielk1977c3f9bad2002-05-15 08:30:12 +0000473 }
474
danielk1977299b1872004-11-22 10:02:10 +0000475 /* End of the delete loop */
drh66a51672008-01-03 00:01:23 +0000476 sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
danielk1977299b1872004-11-22 10:02:10 +0000477 sqlite3VdbeResolveLabel(v, end);
danielk1977299b1872004-11-22 10:02:10 +0000478
479 /* Close the cursors after the loop if there are no row triggers */
danielk1977e448dc42008-01-02 11:50:51 +0000480 if( !isView && !IsVirtual(pTab) ){
danielk1977299b1872004-11-22 10:02:10 +0000481 for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
drh66a51672008-01-03 00:01:23 +0000482 sqlite3VdbeAddOp2(v, OP_Close, iCur + i, pIdx->tnum);
danielk1977299b1872004-11-22 10:02:10 +0000483 }
drh66a51672008-01-03 00:01:23 +0000484 sqlite3VdbeAddOp1(v, OP_Close, iCur);
danielk1977c3f9bad2002-05-15 08:30:12 +0000485 }
drh0353ced2001-03-20 22:05:00 +0000486 }
drh5e00f6c2001-09-13 13:46:56 +0000487
drh0b9f50d2009-06-23 20:28:53 +0000488 /* Update the sqlite_sequence table by storing the content of the
489 ** maximum rowid counter values recorded while inserting into
490 ** autoincrement tables.
491 */
492 if( pParse->nested==0 && pParse->trigStack==0 ){
493 sqlite3AutoincrementEnd(pParse);
494 }
495
drh1bee3d72001-10-15 00:44:35 +0000496 /*
danielk1977e7de6f22004-11-05 06:02:06 +0000497 ** Return the number of rows that were deleted. If this routine is
498 ** generating code because of a call to sqlite3NestedParse(), do not
499 ** invoke the callback function.
drh1bee3d72001-10-15 00:44:35 +0000500 */
danielk1977cc6bd382005-01-10 02:48:49 +0000501 if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
drh66a51672008-01-03 00:01:23 +0000502 sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1);
danielk197722322fd2004-05-25 23:35:17 +0000503 sqlite3VdbeSetNumCols(v, 1);
danielk197710fb7492008-10-31 10:53:22 +0000504 sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC);
drh1bee3d72001-10-15 00:44:35 +0000505 }
drhcce7d172000-05-31 15:34:51 +0000506
507delete_from_cleanup:
danielk19774adee202004-05-08 08:23:19 +0000508 sqlite3AuthContextPop(&sContext);
drh633e6d52008-07-28 19:34:53 +0000509 sqlite3SrcListDelete(db, pTabList);
510 sqlite3ExprDelete(db, pWhere);
drhcce7d172000-05-31 15:34:51 +0000511 return;
512}
drh9cfcf5d2002-01-29 18:41:24 +0000513
514/*
515** This routine generates VDBE code that causes a single row of a
516** single table to be deleted.
517**
518** The VDBE must be in a particular state when this routine is called.
519** These are the requirements:
520**
521** 1. A read/write cursor pointing to pTab, the table containing the row
522** to be deleted, must be opened as cursor number "base".
523**
524** 2. Read/write cursors for all indices of pTab must be open as
525** cursor number base+i for the i-th index.
526**
danielk197796cb76f2008-01-04 13:24:28 +0000527** 3. The record number of the row to be deleted must be stored in
528** memory cell iRowid.
drh9cfcf5d2002-01-29 18:41:24 +0000529**
530** This routine pops the top of the stack to remove the record number
531** and then generates code to remove both the table record and all index
532** entries that point to that record.
533*/
danielk19774adee202004-05-08 08:23:19 +0000534void sqlite3GenerateRowDelete(
drh2d401ab2008-01-10 23:50:11 +0000535 Parse *pParse, /* Parsing context */
drh9cfcf5d2002-01-29 18:41:24 +0000536 Table *pTab, /* Table containing the row to be deleted */
drh6a3ea0e2003-05-02 14:32:12 +0000537 int iCur, /* Cursor number for the table */
danielk197796cb76f2008-01-04 13:24:28 +0000538 int iRowid, /* Memory cell that contains the rowid to delete */
drhc8d30ac2002-04-12 10:08:59 +0000539 int count /* Increment the row change counter */
drh9cfcf5d2002-01-29 18:41:24 +0000540){
drh07d6e3a2002-05-23 12:50:18 +0000541 int addr;
drh2d401ab2008-01-10 23:50:11 +0000542 Vdbe *v;
543
544 v = pParse->pVdbe;
danielk197796cb76f2008-01-04 13:24:28 +0000545 addr = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowid);
drh2d401ab2008-01-10 23:50:11 +0000546 sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, 0);
drh66a51672008-01-03 00:01:23 +0000547 sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
danielk197794eb6a12005-12-15 15:22:08 +0000548 if( count ){
drh66a51672008-01-03 00:01:23 +0000549 sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
danielk197794eb6a12005-12-15 15:22:08 +0000550 }
drhd654be82005-09-20 17:42:23 +0000551 sqlite3VdbeJumpHere(v, addr);
drh0ca3e242002-01-29 23:07:02 +0000552}
553
554/*
555** This routine generates VDBE code that causes the deletion of all
556** index entries associated with a single row of a single table.
557**
558** The VDBE must be in a particular state when this routine is called.
559** These are the requirements:
560**
561** 1. A read/write cursor pointing to pTab, the table containing the row
drh6a3ea0e2003-05-02 14:32:12 +0000562** to be deleted, must be opened as cursor number "iCur".
drh0ca3e242002-01-29 23:07:02 +0000563**
564** 2. Read/write cursors for all indices of pTab must be open as
drh6a3ea0e2003-05-02 14:32:12 +0000565** cursor number iCur+i for the i-th index.
drh0ca3e242002-01-29 23:07:02 +0000566**
drh6a3ea0e2003-05-02 14:32:12 +0000567** 3. The "iCur" cursor must be pointing to the row that is to be
drh0ca3e242002-01-29 23:07:02 +0000568** deleted.
569*/
danielk19774adee202004-05-08 08:23:19 +0000570void sqlite3GenerateRowIndexDelete(
drh2d401ab2008-01-10 23:50:11 +0000571 Parse *pParse, /* Parsing and code generating context */
drh0ca3e242002-01-29 23:07:02 +0000572 Table *pTab, /* Table containing the row to be deleted */
drh6a3ea0e2003-05-02 14:32:12 +0000573 int iCur, /* Cursor number for the table */
drhaa9b8962008-01-08 02:57:55 +0000574 int *aRegIdx /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
drh0ca3e242002-01-29 23:07:02 +0000575){
drh9cfcf5d2002-01-29 18:41:24 +0000576 int i;
577 Index *pIdx;
drh9cbf3422008-01-17 16:22:13 +0000578 int r1;
drh9cfcf5d2002-01-29 18:41:24 +0000579
drh0ca3e242002-01-29 23:07:02 +0000580 for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
drhaa9b8962008-01-08 02:57:55 +0000581 if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue;
drh3a200e02008-04-11 19:18:24 +0000582 r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0);
drhe14006d2008-03-25 17:23:32 +0000583 sqlite3VdbeAddOp3(pParse->pVdbe, OP_IdxDelete, iCur+i, r1,pIdx->nColumn+1);
drh9cfcf5d2002-01-29 18:41:24 +0000584 }
drh9cfcf5d2002-01-29 18:41:24 +0000585}
drh51846b52004-05-28 16:00:21 +0000586
587/*
drhe14006d2008-03-25 17:23:32 +0000588** Generate code that will assemble an index key and put it in register
589** regOut. The key with be for index pIdx which is an index on pTab.
drh51846b52004-05-28 16:00:21 +0000590** iCur is the index of a cursor open on the pTab table and pointing to
591** the entry that needs indexing.
drh2d401ab2008-01-10 23:50:11 +0000592**
593** Return a register number which is the first in a block of
594** registers that holds the elements of the index key. The
595** block of registers has already been deallocated by the time
596** this routine returns.
drh51846b52004-05-28 16:00:21 +0000597*/
drh2d401ab2008-01-10 23:50:11 +0000598int sqlite3GenerateIndexKey(
599 Parse *pParse, /* Parsing context */
drh51846b52004-05-28 16:00:21 +0000600 Index *pIdx, /* The index for which to generate a key */
drh2d401ab2008-01-10 23:50:11 +0000601 int iCur, /* Cursor number for the pIdx->pTable table */
drhe14006d2008-03-25 17:23:32 +0000602 int regOut, /* Write the new index key to this register */
603 int doMakeRec /* Run the OP_MakeRecord instruction if true */
drh51846b52004-05-28 16:00:21 +0000604){
drh2d401ab2008-01-10 23:50:11 +0000605 Vdbe *v = pParse->pVdbe;
drh51846b52004-05-28 16:00:21 +0000606 int j;
607 Table *pTab = pIdx->pTable;
drh2d401ab2008-01-10 23:50:11 +0000608 int regBase;
609 int nCol;
drh51846b52004-05-28 16:00:21 +0000610
drh2d401ab2008-01-10 23:50:11 +0000611 nCol = pIdx->nColumn;
612 regBase = sqlite3GetTempRange(pParse, nCol+1);
613 sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol);
614 for(j=0; j<nCol; j++){
drh51846b52004-05-28 16:00:21 +0000615 int idx = pIdx->aiColumn[j];
616 if( idx==pTab->iPKey ){
drh2d401ab2008-01-10 23:50:11 +0000617 sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
drh51846b52004-05-28 16:00:21 +0000618 }else{
drh2d401ab2008-01-10 23:50:11 +0000619 sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
danielk1977aee18ef2005-03-09 12:26:50 +0000620 sqlite3ColumnDefault(v, pTab, idx);
drh51846b52004-05-28 16:00:21 +0000621 }
622 }
drhe14006d2008-03-25 17:23:32 +0000623 if( doMakeRec ){
624 sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut);
625 sqlite3IndexAffinityStr(v, pIdx);
drhda250ea2008-04-01 05:07:14 +0000626 sqlite3ExprCacheAffinityChange(pParse, regBase, nCol+1);
drhe14006d2008-03-25 17:23:32 +0000627 }
drh2d401ab2008-01-10 23:50:11 +0000628 sqlite3ReleaseTempRange(pParse, regBase, nCol+1);
629 return regBase;
drh51846b52004-05-28 16:00:21 +0000630}
drhf39d9582008-03-19 20:42:13 +0000631
632/* Make sure "isView" gets undefined in case this file becomes part of
633** the amalgamation - so that subsequent files do not see isView as a
634** macro. */
635#undef isView