blob: cbd8b375e73095ec6582ce2b9a10667f73b4162b [file] [log] [blame]
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**
drh0b9f50d2009-06-23 20:28:53 +000015** $Id: delete.c,v 1.204 2009/06/23 20:28:54 drh 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){
drh7d10d5a2008-08-20 16:35:10 +000046 if( ((pTab->tabFlags & TF_Readonly)!=0
47 && (pParse->db->flags & SQLITE_WriteSchema)==0
drh4cbdda92006-06-14 19:00:20 +000048 && pParse->nested==0)
49#ifndef SQLITE_OMIT_VIRTUALTABLE
danielk1977d1ab1ba2006-06-15 04:28:13 +000050 || (pTab->pMod && pTab->pMod->pModule->xUpdate==0)
drh4cbdda92006-06-14 19:00:20 +000051#endif
52 ){
danielk19774adee202004-05-08 08:23:19 +000053 sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
drh5cf590c2003-04-24 01:45:04 +000054 return 1;
55 }
danielk1977b84f96f2005-01-20 11:32:23 +000056#ifndef SQLITE_OMIT_VIEW
drh5cf590c2003-04-24 01:45:04 +000057 if( !viewOk && pTab->pSelect ){
drhda71ce12004-06-21 18:14:45 +000058 sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
drh812d7a22003-03-27 13:50:00 +000059 return 1;
60 }
danielk1977b84f96f2005-01-20 11:32:23 +000061#endif
drh812d7a22003-03-27 13:50:00 +000062 return 0;
63}
64
danielk1977299b1872004-11-22 10:02:10 +000065
drh0f35a6b2008-02-12 16:52:14 +000066#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
67/*
68** Evaluate a view and store its result in an ephemeral table. The
69** pWhere argument is an optional WHERE clause that restricts the
70** set of rows in the view that are to be added to the ephemeral table.
71*/
72void sqlite3MaterializeView(
73 Parse *pParse, /* Parsing context */
drh2a5d8252008-08-22 12:30:52 +000074 Table *pView, /* View definition */
drh0f35a6b2008-02-12 16:52:14 +000075 Expr *pWhere, /* Optional WHERE clause to be added */
drh0f35a6b2008-02-12 16:52:14 +000076 int iCur /* Cursor number for ephemerial table */
77){
78 SelectDest dest;
79 Select *pDup;
80 sqlite3 *db = pParse->db;
81
danielk19776ab3a2e2009-02-19 14:39:25 +000082 pDup = sqlite3SelectDup(db, pView->pSelect, 0);
drh0f35a6b2008-02-12 16:52:14 +000083 if( pWhere ){
84 SrcList *pFrom;
85
danielk19776ab3a2e2009-02-19 14:39:25 +000086 pWhere = sqlite3ExprDup(db, pWhere, 0);
drhb7916a72009-05-27 10:31:29 +000087 pFrom = sqlite3SrcListAppend(db, 0, 0, 0);
88 if( pFrom ){
89 assert( pFrom->nSrc==1 );
90 pFrom->a[0].zAlias = sqlite3DbStrDup(db, pView->zName);
91 pFrom->a[0].pSelect = pDup;
92 assert( pFrom->a[0].pOn==0 );
93 assert( pFrom->a[0].pUsing==0 );
94 }else{
95 sqlite3SelectDelete(db, pDup);
96 }
drh0f35a6b2008-02-12 16:52:14 +000097 pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
98 }
drh0f35a6b2008-02-12 16:52:14 +000099 sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
drh7d10d5a2008-08-20 16:35:10 +0000100 sqlite3Select(pParse, pDup, &dest);
drh633e6d52008-07-28 19:34:53 +0000101 sqlite3SelectDelete(db, pDup);
drh0f35a6b2008-02-12 16:52:14 +0000102}
103#endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
104
shane273f6192008-10-10 04:34:16 +0000105#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
shane4281bd42008-10-07 05:27:11 +0000106/*
107** Generate an expression tree to implement the WHERE, ORDER BY,
108** and LIMIT/OFFSET portion of DELETE and UPDATE statements.
109**
110** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1;
111** \__________________________/
112** pLimitWhere (pInClause)
113*/
114Expr *sqlite3LimitWhere(
shane49ffdbf2008-10-10 18:25:45 +0000115 Parse *pParse, /* The parser context */
116 SrcList *pSrc, /* the FROM clause -- which tables to scan */
117 Expr *pWhere, /* The WHERE clause. May be null */
118 ExprList *pOrderBy, /* The ORDER BY clause. May be null */
119 Expr *pLimit, /* The LIMIT clause. May be null */
120 Expr *pOffset, /* The OFFSET clause. May be null */
121 char *zStmtType /* Either DELETE or UPDATE. For error messages. */
shane4281bd42008-10-07 05:27:11 +0000122){
shane49ffdbf2008-10-10 18:25:45 +0000123 Expr *pWhereRowid = NULL; /* WHERE rowid .. */
124 Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */
125 Expr *pSelectRowid = NULL; /* SELECT rowid ... */
126 ExprList *pEList = NULL; /* Expression list contaning only pSelectRowid */
127 SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */
128 Select *pSelect = NULL; /* Complete SELECT tree */
129
130 /* Check that there isn't an ORDER BY without a LIMIT clause.
131 */
132 if( pOrderBy && (pLimit == 0) ) {
133 sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
134 pParse->parseError = 1;
135 goto limit_where_cleanup_2;
136 }
shane273f6192008-10-10 04:34:16 +0000137
138 /* We only need to generate a select expression if there
139 ** is a limit/offset term to enforce.
140 */
shane49ffdbf2008-10-10 18:25:45 +0000141 if( pLimit == 0 ) {
142 /* if pLimit is null, pOffset will always be null as well. */
143 assert( pOffset == 0 );
144 return pWhere;
145 }
shane273f6192008-10-10 04:34:16 +0000146
147 /* Generate a select expression tree to enforce the limit/offset
148 ** term for the DELETE or UPDATE statement. For example:
149 ** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
150 ** becomes:
151 ** DELETE FROM table_a WHERE rowid IN (
shaneb235db92008-10-10 13:35:57 +0000152 ** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
shane273f6192008-10-10 04:34:16 +0000153 ** );
154 */
shaneb235db92008-10-10 13:35:57 +0000155
drhb7916a72009-05-27 10:31:29 +0000156 pSelectRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
shane49ffdbf2008-10-10 18:25:45 +0000157 if( pSelectRowid == 0 ) goto limit_where_cleanup_2;
drhb7916a72009-05-27 10:31:29 +0000158 pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid);
shane49ffdbf2008-10-10 18:25:45 +0000159 if( pEList == 0 ) goto limit_where_cleanup_2;
shaneb235db92008-10-10 13:35:57 +0000160
shane273f6192008-10-10 04:34:16 +0000161 /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
shaneb235db92008-10-10 13:35:57 +0000162 ** and the SELECT subtree. */
danielk19776ab3a2e2009-02-19 14:39:25 +0000163 pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0);
shaneb235db92008-10-10 13:35:57 +0000164 if( pSelectSrc == 0 ) {
165 sqlite3ExprListDelete(pParse->db, pEList);
shane49ffdbf2008-10-10 18:25:45 +0000166 goto limit_where_cleanup_2;
shaneb235db92008-10-10 13:35:57 +0000167 }
168
169 /* generate the SELECT expression tree. */
drh18209cd2009-03-02 14:24:21 +0000170 pSelect = sqlite3SelectNew(pParse,pEList,pSelectSrc,pWhere,0,0,
171 pOrderBy,0,pLimit,pOffset);
shaneb235db92008-10-10 13:35:57 +0000172 if( pSelect == 0 ) return 0;
173
shane49ffdbf2008-10-10 18:25:45 +0000174 /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
drhb7916a72009-05-27 10:31:29 +0000175 pWhereRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
shane49ffdbf2008-10-10 18:25:45 +0000176 if( pWhereRowid == 0 ) goto limit_where_cleanup_1;
shane273f6192008-10-10 04:34:16 +0000177 pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0);
shane49ffdbf2008-10-10 18:25:45 +0000178 if( pInClause == 0 ) goto limit_where_cleanup_1;
shaneb235db92008-10-10 13:35:57 +0000179
drh18209cd2009-03-02 14:24:21 +0000180 pInClause->x.pSelect = pSelect;
181 pInClause->flags |= EP_xIsSelect;
shane273f6192008-10-10 04:34:16 +0000182 sqlite3ExprSetHeight(pParse, pInClause);
183 return pInClause;
184
shane273f6192008-10-10 04:34:16 +0000185 /* something went wrong. clean up anything allocated. */
shane49ffdbf2008-10-10 18:25:45 +0000186limit_where_cleanup_1:
shaneb235db92008-10-10 13:35:57 +0000187 sqlite3SelectDelete(pParse->db, pSelect);
shane4281bd42008-10-07 05:27:11 +0000188 return 0;
shane49ffdbf2008-10-10 18:25:45 +0000189
190limit_where_cleanup_2:
191 sqlite3ExprDelete(pParse->db, pWhere);
192 sqlite3ExprListDelete(pParse->db, pOrderBy);
193 sqlite3ExprDelete(pParse->db, pLimit);
194 sqlite3ExprDelete(pParse->db, pOffset);
195 return 0;
shane4281bd42008-10-07 05:27:11 +0000196}
shane273f6192008-10-10 04:34:16 +0000197#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
drh0f35a6b2008-02-12 16:52:14 +0000198
drhad6d9462004-09-19 02:15:24 +0000199/*
drh23bf66d2004-12-14 03:34:34 +0000200** Generate code for a DELETE FROM statement.
201**
202** DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
203** \________/ \________________/
204** pTabList pWhere
drhcce7d172000-05-31 15:34:51 +0000205*/
danielk19774adee202004-05-08 08:23:19 +0000206void sqlite3DeleteFrom(
drhcce7d172000-05-31 15:34:51 +0000207 Parse *pParse, /* The parser context */
drh113088e2003-03-20 01:16:58 +0000208 SrcList *pTabList, /* The table from which we should delete things */
drhcce7d172000-05-31 15:34:51 +0000209 Expr *pWhere /* The WHERE clause. May be null */
210){
211 Vdbe *v; /* The virtual database engine */
212 Table *pTab; /* The table from which records will be deleted */
drhe22a3342003-04-22 20:30:37 +0000213 const char *zDb; /* Name of database holding pTab */
danielk1977299b1872004-11-22 10:02:10 +0000214 int end, addr = 0; /* A couple addresses of generated code */
drhcce7d172000-05-31 15:34:51 +0000215 int i; /* Loop counter */
216 WhereInfo *pWInfo; /* Information about the WHERE clause */
217 Index *pIdx; /* For looping over indices of the table */
drh6a3ea0e2003-05-02 14:32:12 +0000218 int iCur; /* VDBE Cursor number for pTab */
drh9bb575f2004-09-06 17:24:11 +0000219 sqlite3 *db; /* Main database structure */
drh85e20962003-04-25 17:52:11 +0000220 AuthContext sContext; /* Authorization context */
drh798da522004-11-04 04:42:28 +0000221 int oldIdx = -1; /* Cursor for the OLD table of AFTER triggers */
danielk1977b3bce662005-01-29 08:32:43 +0000222 NameContext sNC; /* Name context to resolve expressions in */
drh53a67772007-02-07 01:06:52 +0000223 int iDb; /* Database number */
danielk1977c7af4842008-10-27 13:59:33 +0000224 int memCnt = -1; /* Memory cell used for change counting */
danielk197752bd7912008-10-27 15:34:32 +0000225 int rcauth; /* Value returned by authorization callback */
drh1bee3d72001-10-15 00:44:35 +0000226
drh798da522004-11-04 04:42:28 +0000227#ifndef SQLITE_OMIT_TRIGGER
228 int isView; /* True if attempting to delete from a view */
danielk19772f886d12009-02-28 10:47:41 +0000229 Trigger *pTrigger; /* List of table triggers, if required */
drh798da522004-11-04 04:42:28 +0000230#endif
drh1bd10f82008-12-10 21:19:56 +0000231 int iBeginAfterTrigger = 0; /* Address of after trigger program */
232 int iEndAfterTrigger = 0; /* Exit of after trigger program */
233 int iBeginBeforeTrigger = 0; /* Address of before trigger program */
234 int iEndBeforeTrigger = 0; /* Exit of before trigger program */
danielk19778f2c54e2008-01-01 19:02:09 +0000235 u32 old_col_mask = 0; /* Mask of OLD.* columns in use */
drhcce7d172000-05-31 15:34:51 +0000236
drh85e20962003-04-25 17:52:11 +0000237 sContext.pParse = 0;
drh17435752007-08-16 04:30:38 +0000238 db = pParse->db;
239 if( pParse->nErr || db->mallocFailed ){
drhdaffd0e2001-04-11 14:28:42 +0000240 goto delete_from_cleanup;
241 }
drh113088e2003-03-20 01:16:58 +0000242 assert( pTabList->nSrc==1 );
drhdaffd0e2001-04-11 14:28:42 +0000243
drh1ccde152000-06-17 13:12:39 +0000244 /* Locate the table which we want to delete. This table has to be
drhad3cab52002-05-24 02:04:32 +0000245 ** put in an SrcList structure because some of the subroutines we
drhcce7d172000-05-31 15:34:51 +0000246 ** will be calling are designed to work with multiple tables and expect
drhad3cab52002-05-24 02:04:32 +0000247 ** an SrcList* parameter instead of just a Table* parameter.
drhcce7d172000-05-31 15:34:51 +0000248 */
danielk19774adee202004-05-08 08:23:19 +0000249 pTab = sqlite3SrcListLookup(pParse, pTabList);
drha69d9162003-04-17 22:57:53 +0000250 if( pTab==0 ) goto delete_from_cleanup;
drhb7f91642004-10-31 02:22:47 +0000251
252 /* Figure out if we have any triggers and if the table being
253 ** deleted from is a view
254 */
255#ifndef SQLITE_OMIT_TRIGGER
danielk19772f886d12009-02-28 10:47:41 +0000256 pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
drh5cf590c2003-04-24 01:45:04 +0000257 isView = pTab->pSelect!=0;
drhb7f91642004-10-31 02:22:47 +0000258#else
danielk19772f886d12009-02-28 10:47:41 +0000259# define pTrigger 0
drhb7f91642004-10-31 02:22:47 +0000260# define isView 0
261#endif
262#ifdef SQLITE_OMIT_VIEW
263# undef isView
264# define isView 0
265#endif
266
danielk19772f886d12009-02-28 10:47:41 +0000267 if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){
drh5cf590c2003-04-24 01:45:04 +0000268 goto delete_from_cleanup;
drh113088e2003-03-20 01:16:58 +0000269 }
danielk1977da184232006-01-05 11:34:32 +0000270 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
271 assert( iDb<db->nDb );
272 zDb = db->aDb[iDb].zName;
danielk197752bd7912008-10-27 15:34:32 +0000273 rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb);
274 assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
275 if( rcauth==SQLITE_DENY ){
drhe5f9c642003-01-13 23:27:31 +0000276 goto delete_from_cleanup;
277 }
danielk19772f886d12009-02-28 10:47:41 +0000278 assert(!isView || pTrigger);
drhcce7d172000-05-31 15:34:51 +0000279
drh5cf590c2003-04-24 01:45:04 +0000280 /* If pTab is really a view, make sure it has been initialized.
281 */
danielk1977b3d24bf2006-06-19 03:05:10 +0000282 if( sqlite3ViewGetColumnNames(pParse, pTab) ){
drh5cf590c2003-04-24 01:45:04 +0000283 goto delete_from_cleanup;
284 }
285
drhc977f7f2002-05-21 11:38:11 +0000286 /* Allocate a cursor used to store the old.* data for a trigger.
287 */
danielk19772f886d12009-02-28 10:47:41 +0000288 if( pTrigger ){
danielk1977c3f9bad2002-05-15 08:30:12 +0000289 oldIdx = pParse->nTab++;
danielk1977f29ce552002-05-19 23:43:12 +0000290 }
danielk1977c3f9bad2002-05-15 08:30:12 +0000291
drh0f35a6b2008-02-12 16:52:14 +0000292 /* Assign cursor number to the table and all its indices.
drhcce7d172000-05-31 15:34:51 +0000293 */
drh6a3ea0e2003-05-02 14:32:12 +0000294 assert( pTabList->nSrc==1 );
295 iCur = pTabList->a[0].iCursor = pParse->nTab++;
danielk1977e448dc42008-01-02 11:50:51 +0000296 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
297 pParse->nTab++;
298 }
drhcce7d172000-05-31 15:34:51 +0000299
drh85e20962003-04-25 17:52:11 +0000300 /* Start the view context
301 */
302 if( isView ){
danielk19774adee202004-05-08 08:23:19 +0000303 sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
drh85e20962003-04-25 17:52:11 +0000304 }
305
drhcce7d172000-05-31 15:34:51 +0000306 /* Begin generating code.
307 */
danielk19774adee202004-05-08 08:23:19 +0000308 v = sqlite3GetVdbe(pParse);
danielk1977f29ce552002-05-19 23:43:12 +0000309 if( v==0 ){
310 goto delete_from_cleanup;
311 }
drh4794f732004-11-05 17:17:50 +0000312 if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
danielk19772f886d12009-02-28 10:47:41 +0000313 sqlite3BeginWriteOperation(pParse, (pTrigger?1:0), iDb);
drh5e00f6c2001-09-13 13:46:56 +0000314
danielk19772f886d12009-02-28 10:47:41 +0000315 if( pTrigger ){
danielk1977dd2fb292008-01-04 13:57:26 +0000316 int orconf = ((pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
drh66a51672008-01-03 00:01:23 +0000317 int iGoto = sqlite3VdbeAddOp0(v, OP_Goto);
danielk19778f2c54e2008-01-01 19:02:09 +0000318 addr = sqlite3VdbeMakeLabel(v);
danielk1977dd2fb292008-01-04 13:57:26 +0000319
danielk19778f2c54e2008-01-01 19:02:09 +0000320 iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
danielk19772f886d12009-02-28 10:47:41 +0000321 (void)sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0,
322 TRIGGER_BEFORE, pTab, -1, oldIdx, orconf, addr, &old_col_mask, 0);
drh66a51672008-01-03 00:01:23 +0000323 iEndBeforeTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
danielk1977dd2fb292008-01-04 13:57:26 +0000324
danielk19778f2c54e2008-01-01 19:02:09 +0000325 iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
danielk19772f886d12009-02-28 10:47:41 +0000326 (void)sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0,
327 TRIGGER_AFTER, pTab, -1, oldIdx, orconf, addr, &old_col_mask, 0);
drh66a51672008-01-03 00:01:23 +0000328 iEndAfterTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
danielk1977dd2fb292008-01-04 13:57:26 +0000329
danielk19778f2c54e2008-01-01 19:02:09 +0000330 sqlite3VdbeJumpHere(v, iGoto);
331 }
332
drh9d2985c2005-09-08 01:58:42 +0000333 /* If we are trying to delete from a view, realize that view into
334 ** a ephemeral table.
drh5cf590c2003-04-24 01:45:04 +0000335 */
shanefa4e62f2008-09-01 21:59:42 +0000336#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
drh5cf590c2003-04-24 01:45:04 +0000337 if( isView ){
drh2a5d8252008-08-22 12:30:52 +0000338 sqlite3MaterializeView(pParse, pTab, pWhere, iCur);
drh0f35a6b2008-02-12 16:52:14 +0000339 }
shanefa4e62f2008-09-01 21:59:42 +0000340#endif
drh1013c932008-01-06 00:25:21 +0000341
drh0f35a6b2008-02-12 16:52:14 +0000342 /* Resolve the column names in the WHERE clause.
343 */
344 memset(&sNC, 0, sizeof(sNC));
345 sNC.pParse = pParse;
346 sNC.pSrcList = pTabList;
drh7d10d5a2008-08-20 16:35:10 +0000347 if( sqlite3ResolveExprNames(&sNC, pWhere) ){
drh0f35a6b2008-02-12 16:52:14 +0000348 goto delete_from_cleanup;
drh5cf590c2003-04-24 01:45:04 +0000349 }
350
drh1bee3d72001-10-15 00:44:35 +0000351 /* Initialize the counter of the number of rows deleted, if
352 ** we are counting rows.
353 */
354 if( db->flags & SQLITE_CountRows ){
drh0a07c102008-01-03 18:03:08 +0000355 memCnt = ++pParse->nMem;
drh4c583122008-01-04 22:01:03 +0000356 sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt);
drh1bee3d72001-10-15 00:44:35 +0000357 }
drhcce7d172000-05-31 15:34:51 +0000358
drhf8cecda2008-10-10 23:48:25 +0000359#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
drh0353ced2001-03-20 22:05:00 +0000360 /* Special case: A DELETE without a WHERE clause deletes everything.
drhc977f7f2002-05-21 11:38:11 +0000361 ** It is easier just to erase the whole table. Note, however, that
362 ** this means that the row change count will be incorrect.
drhcce7d172000-05-31 15:34:51 +0000363 */
danielk19772f886d12009-02-28 10:47:41 +0000364 if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab) ){
danielk19779a02fb42008-10-27 08:24:38 +0000365 assert( !isView );
drhbbb5e4e2009-04-30 00:11:09 +0000366 sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt,
367 pTab->zName, P4_STATIC);
danielk19779a02fb42008-10-27 08:24:38 +0000368 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
369 assert( pIdx->pSchema==pTab->pSchema );
370 sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
drhcce7d172000-05-31 15:34:51 +0000371 }
drhf8cecda2008-10-10 23:48:25 +0000372 }else
373#endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
drh0353ced2001-03-20 22:05:00 +0000374 /* The usual case: There is a WHERE clause so we have to scan through
jplyon8bc03a72004-01-19 04:54:28 +0000375 ** the table and pick which records to delete.
drh0353ced2001-03-20 22:05:00 +0000376 */
drhf8cecda2008-10-10 23:48:25 +0000377 {
danielk1977dd2fb292008-01-04 13:57:26 +0000378 int iRowid = ++pParse->nMem; /* Used for storing rowid values. */
drh3d4501e2008-12-04 20:40:10 +0000379 int iRowSet = ++pParse->nMem; /* Register for rowset of rows to delete */
drh336a5302009-04-24 15:46:21 +0000380 int regRowid; /* Actual register containing rowids */
danielk197796cb76f2008-01-04 13:24:28 +0000381
drh23d04d52008-12-23 23:56:22 +0000382 /* Collect rowids of every row to be deleted.
danielk1977299b1872004-11-22 10:02:10 +0000383 */
drh23d04d52008-12-23 23:56:22 +0000384 sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
drh336a5302009-04-24 15:46:21 +0000385 pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0,WHERE_DUPLICATES_OK);
danielk1977299b1872004-11-22 10:02:10 +0000386 if( pWInfo==0 ) goto delete_from_cleanup;
drh336a5302009-04-24 15:46:21 +0000387 regRowid = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, iRowid, 0);
388 sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, regRowid);
danielk1977299b1872004-11-22 10:02:10 +0000389 if( db->flags & SQLITE_CountRows ){
drh8558cde2008-01-05 05:20:10 +0000390 sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
danielk1977299b1872004-11-22 10:02:10 +0000391 }
danielk1977299b1872004-11-22 10:02:10 +0000392 sqlite3WhereEnd(pWInfo);
393
drh70ce3f02003-04-15 19:22:22 +0000394 /* Open the pseudo-table used to store OLD if there are triggers.
395 */
danielk19772f886d12009-02-28 10:47:41 +0000396 if( pTrigger ){
danielk1977d336e222009-02-20 10:58:41 +0000397 sqlite3VdbeAddOp3(v, OP_OpenPseudo, oldIdx, 0, pTab->nCol);
drh70ce3f02003-04-15 19:22:22 +0000398 }
399
danielk1977299b1872004-11-22 10:02:10 +0000400 /* Delete every item whose key was written to the list during the
401 ** database scan. We have to delete items after the scan is complete
402 ** because deleting an item can change the scan order.
danielk1977ed326d72004-11-16 15:50:19 +0000403 */
danielk1977299b1872004-11-22 10:02:10 +0000404 end = sqlite3VdbeMakeLabel(v);
danielk1977ed326d72004-11-16 15:50:19 +0000405
danielk1977e448dc42008-01-02 11:50:51 +0000406 if( !isView ){
407 /* Open cursors for the table we are deleting from and
408 ** all its indices.
409 */
410 sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);
411 }
412
413 /* This is the beginning of the delete loop. If a trigger encounters
414 ** an IGNORE constraint, it jumps back to here.
drhc977f7f2002-05-21 11:38:11 +0000415 */
danielk19772f886d12009-02-28 10:47:41 +0000416 if( pTrigger ){
danielk19778f2c54e2008-01-01 19:02:09 +0000417 sqlite3VdbeResolveLabel(v, addr);
danielk1977e448dc42008-01-02 11:50:51 +0000418 }
drh3d4501e2008-12-04 20:40:10 +0000419 addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, iRowid);
danielk1977e448dc42008-01-02 11:50:51 +0000420
danielk19772f886d12009-02-28 10:47:41 +0000421 if( pTrigger ){
danielk197796cb76f2008-01-04 13:24:28 +0000422 int iData = ++pParse->nMem; /* For storing row data of OLD table */
423
424 /* If the record is no longer present in the table, jump to the
425 ** next iteration of the loop through the contents of the fifo.
426 */
427 sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, iRowid);
428
429 /* Populate the OLD.* pseudo-table */
danielk19778f2c54e2008-01-01 19:02:09 +0000430 if( old_col_mask ){
drh98757152008-01-09 23:04:12 +0000431 sqlite3VdbeAddOp2(v, OP_RowData, iCur, iData);
danielk19778f2c54e2008-01-01 19:02:09 +0000432 }else{
drh4c583122008-01-04 22:01:03 +0000433 sqlite3VdbeAddOp2(v, OP_Null, 0, iData);
danielk19778f2c54e2008-01-01 19:02:09 +0000434 }
danielk197796cb76f2008-01-04 13:24:28 +0000435 sqlite3VdbeAddOp3(v, OP_Insert, oldIdx, iData, iRowid);
danielk1977299b1872004-11-22 10:02:10 +0000436
danielk19778f2c54e2008-01-01 19:02:09 +0000437 /* Jump back and run the BEFORE triggers */
drh66a51672008-01-03 00:01:23 +0000438 sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger);
danielk19778f2c54e2008-01-01 19:02:09 +0000439 sqlite3VdbeJumpHere(v, iEndBeforeTrigger);
danielk1977c3f9bad2002-05-15 08:30:12 +0000440 }
441
danielk1977299b1872004-11-22 10:02:10 +0000442 if( !isView ){
danielk1977299b1872004-11-22 10:02:10 +0000443 /* Delete the row */
drh4cbdda92006-06-14 19:00:20 +0000444#ifndef SQLITE_OMIT_VIRTUALTABLE
445 if( IsVirtual(pTab) ){
danielk197796cb76f2008-01-04 13:24:28 +0000446 const char *pVtab = (const char *)pTab->pVtab;
drh4f3dd152008-04-28 18:46:43 +0000447 sqlite3VtabMakeWritable(pParse, pTab);
danielk197796cb76f2008-01-04 13:24:28 +0000448 sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVtab, P4_VTAB);
drh4cbdda92006-06-14 19:00:20 +0000449 }else
450#endif
451 {
drh2d401ab2008-01-10 23:50:11 +0000452 sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, pParse->nested==0);
drh4cbdda92006-06-14 19:00:20 +0000453 }
danielk1977299b1872004-11-22 10:02:10 +0000454 }
455
456 /* If there are row triggers, close all cursors then invoke
457 ** the AFTER triggers
458 */
danielk19772f886d12009-02-28 10:47:41 +0000459 if( pTrigger ){
danielk19778f2c54e2008-01-01 19:02:09 +0000460 /* Jump back and run the AFTER triggers */
drh66a51672008-01-03 00:01:23 +0000461 sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger);
danielk19778f2c54e2008-01-01 19:02:09 +0000462 sqlite3VdbeJumpHere(v, iEndAfterTrigger);
danielk1977c3f9bad2002-05-15 08:30:12 +0000463 }
464
danielk1977299b1872004-11-22 10:02:10 +0000465 /* End of the delete loop */
drh66a51672008-01-03 00:01:23 +0000466 sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
danielk1977299b1872004-11-22 10:02:10 +0000467 sqlite3VdbeResolveLabel(v, end);
danielk1977299b1872004-11-22 10:02:10 +0000468
469 /* Close the cursors after the loop if there are no row triggers */
danielk1977e448dc42008-01-02 11:50:51 +0000470 if( !isView && !IsVirtual(pTab) ){
danielk1977299b1872004-11-22 10:02:10 +0000471 for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
drh66a51672008-01-03 00:01:23 +0000472 sqlite3VdbeAddOp2(v, OP_Close, iCur + i, pIdx->tnum);
danielk1977299b1872004-11-22 10:02:10 +0000473 }
drh66a51672008-01-03 00:01:23 +0000474 sqlite3VdbeAddOp1(v, OP_Close, iCur);
danielk1977c3f9bad2002-05-15 08:30:12 +0000475 }
drh0353ced2001-03-20 22:05:00 +0000476 }
drh5e00f6c2001-09-13 13:46:56 +0000477
drh0b9f50d2009-06-23 20:28:53 +0000478 /* Update the sqlite_sequence table by storing the content of the
479 ** maximum rowid counter values recorded while inserting into
480 ** autoincrement tables.
481 */
482 if( pParse->nested==0 && pParse->trigStack==0 ){
483 sqlite3AutoincrementEnd(pParse);
484 }
485
drh1bee3d72001-10-15 00:44:35 +0000486 /*
danielk1977e7de6f22004-11-05 06:02:06 +0000487 ** Return the number of rows that were deleted. If this routine is
488 ** generating code because of a call to sqlite3NestedParse(), do not
489 ** invoke the callback function.
drh1bee3d72001-10-15 00:44:35 +0000490 */
danielk1977cc6bd382005-01-10 02:48:49 +0000491 if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
drh66a51672008-01-03 00:01:23 +0000492 sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1);
danielk197722322fd2004-05-25 23:35:17 +0000493 sqlite3VdbeSetNumCols(v, 1);
danielk197710fb7492008-10-31 10:53:22 +0000494 sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC);
drh1bee3d72001-10-15 00:44:35 +0000495 }
drhcce7d172000-05-31 15:34:51 +0000496
497delete_from_cleanup:
danielk19774adee202004-05-08 08:23:19 +0000498 sqlite3AuthContextPop(&sContext);
drh633e6d52008-07-28 19:34:53 +0000499 sqlite3SrcListDelete(db, pTabList);
500 sqlite3ExprDelete(db, pWhere);
drhcce7d172000-05-31 15:34:51 +0000501 return;
502}
drh9cfcf5d2002-01-29 18:41:24 +0000503
504/*
505** This routine generates VDBE code that causes a single row of a
506** single table to be deleted.
507**
508** The VDBE must be in a particular state when this routine is called.
509** These are the requirements:
510**
511** 1. A read/write cursor pointing to pTab, the table containing the row
512** to be deleted, must be opened as cursor number "base".
513**
514** 2. Read/write cursors for all indices of pTab must be open as
515** cursor number base+i for the i-th index.
516**
danielk197796cb76f2008-01-04 13:24:28 +0000517** 3. The record number of the row to be deleted must be stored in
518** memory cell iRowid.
drh9cfcf5d2002-01-29 18:41:24 +0000519**
520** This routine pops the top of the stack to remove the record number
521** and then generates code to remove both the table record and all index
522** entries that point to that record.
523*/
danielk19774adee202004-05-08 08:23:19 +0000524void sqlite3GenerateRowDelete(
drh2d401ab2008-01-10 23:50:11 +0000525 Parse *pParse, /* Parsing context */
drh9cfcf5d2002-01-29 18:41:24 +0000526 Table *pTab, /* Table containing the row to be deleted */
drh6a3ea0e2003-05-02 14:32:12 +0000527 int iCur, /* Cursor number for the table */
danielk197796cb76f2008-01-04 13:24:28 +0000528 int iRowid, /* Memory cell that contains the rowid to delete */
drhc8d30ac2002-04-12 10:08:59 +0000529 int count /* Increment the row change counter */
drh9cfcf5d2002-01-29 18:41:24 +0000530){
drh07d6e3a2002-05-23 12:50:18 +0000531 int addr;
drh2d401ab2008-01-10 23:50:11 +0000532 Vdbe *v;
533
534 v = pParse->pVdbe;
danielk197796cb76f2008-01-04 13:24:28 +0000535 addr = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowid);
drh2d401ab2008-01-10 23:50:11 +0000536 sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, 0);
drh66a51672008-01-03 00:01:23 +0000537 sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
danielk197794eb6a12005-12-15 15:22:08 +0000538 if( count ){
drh66a51672008-01-03 00:01:23 +0000539 sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
danielk197794eb6a12005-12-15 15:22:08 +0000540 }
drhd654be82005-09-20 17:42:23 +0000541 sqlite3VdbeJumpHere(v, addr);
drh0ca3e242002-01-29 23:07:02 +0000542}
543
544/*
545** This routine generates VDBE code that causes the deletion of all
546** index entries associated with a single row of a single table.
547**
548** The VDBE must be in a particular state when this routine is called.
549** These are the requirements:
550**
551** 1. A read/write cursor pointing to pTab, the table containing the row
drh6a3ea0e2003-05-02 14:32:12 +0000552** to be deleted, must be opened as cursor number "iCur".
drh0ca3e242002-01-29 23:07:02 +0000553**
554** 2. Read/write cursors for all indices of pTab must be open as
drh6a3ea0e2003-05-02 14:32:12 +0000555** cursor number iCur+i for the i-th index.
drh0ca3e242002-01-29 23:07:02 +0000556**
drh6a3ea0e2003-05-02 14:32:12 +0000557** 3. The "iCur" cursor must be pointing to the row that is to be
drh0ca3e242002-01-29 23:07:02 +0000558** deleted.
559*/
danielk19774adee202004-05-08 08:23:19 +0000560void sqlite3GenerateRowIndexDelete(
drh2d401ab2008-01-10 23:50:11 +0000561 Parse *pParse, /* Parsing and code generating context */
drh0ca3e242002-01-29 23:07:02 +0000562 Table *pTab, /* Table containing the row to be deleted */
drh6a3ea0e2003-05-02 14:32:12 +0000563 int iCur, /* Cursor number for the table */
drhaa9b8962008-01-08 02:57:55 +0000564 int *aRegIdx /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
drh0ca3e242002-01-29 23:07:02 +0000565){
drh9cfcf5d2002-01-29 18:41:24 +0000566 int i;
567 Index *pIdx;
drh9cbf3422008-01-17 16:22:13 +0000568 int r1;
drh9cfcf5d2002-01-29 18:41:24 +0000569
drh0ca3e242002-01-29 23:07:02 +0000570 for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
drhaa9b8962008-01-08 02:57:55 +0000571 if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue;
drh3a200e02008-04-11 19:18:24 +0000572 r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0);
drhe14006d2008-03-25 17:23:32 +0000573 sqlite3VdbeAddOp3(pParse->pVdbe, OP_IdxDelete, iCur+i, r1,pIdx->nColumn+1);
drh9cfcf5d2002-01-29 18:41:24 +0000574 }
drh9cfcf5d2002-01-29 18:41:24 +0000575}
drh51846b52004-05-28 16:00:21 +0000576
577/*
drhe14006d2008-03-25 17:23:32 +0000578** Generate code that will assemble an index key and put it in register
579** regOut. The key with be for index pIdx which is an index on pTab.
drh51846b52004-05-28 16:00:21 +0000580** iCur is the index of a cursor open on the pTab table and pointing to
581** the entry that needs indexing.
drh2d401ab2008-01-10 23:50:11 +0000582**
583** Return a register number which is the first in a block of
584** registers that holds the elements of the index key. The
585** block of registers has already been deallocated by the time
586** this routine returns.
drh51846b52004-05-28 16:00:21 +0000587*/
drh2d401ab2008-01-10 23:50:11 +0000588int sqlite3GenerateIndexKey(
589 Parse *pParse, /* Parsing context */
drh51846b52004-05-28 16:00:21 +0000590 Index *pIdx, /* The index for which to generate a key */
drh2d401ab2008-01-10 23:50:11 +0000591 int iCur, /* Cursor number for the pIdx->pTable table */
drhe14006d2008-03-25 17:23:32 +0000592 int regOut, /* Write the new index key to this register */
593 int doMakeRec /* Run the OP_MakeRecord instruction if true */
drh51846b52004-05-28 16:00:21 +0000594){
drh2d401ab2008-01-10 23:50:11 +0000595 Vdbe *v = pParse->pVdbe;
drh51846b52004-05-28 16:00:21 +0000596 int j;
597 Table *pTab = pIdx->pTable;
drh2d401ab2008-01-10 23:50:11 +0000598 int regBase;
599 int nCol;
drh51846b52004-05-28 16:00:21 +0000600
drh2d401ab2008-01-10 23:50:11 +0000601 nCol = pIdx->nColumn;
602 regBase = sqlite3GetTempRange(pParse, nCol+1);
603 sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol);
604 for(j=0; j<nCol; j++){
drh51846b52004-05-28 16:00:21 +0000605 int idx = pIdx->aiColumn[j];
606 if( idx==pTab->iPKey ){
drh2d401ab2008-01-10 23:50:11 +0000607 sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
drh51846b52004-05-28 16:00:21 +0000608 }else{
drh2d401ab2008-01-10 23:50:11 +0000609 sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
danielk1977aee18ef2005-03-09 12:26:50 +0000610 sqlite3ColumnDefault(v, pTab, idx);
drh51846b52004-05-28 16:00:21 +0000611 }
612 }
drhe14006d2008-03-25 17:23:32 +0000613 if( doMakeRec ){
614 sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut);
615 sqlite3IndexAffinityStr(v, pIdx);
drhda250ea2008-04-01 05:07:14 +0000616 sqlite3ExprCacheAffinityChange(pParse, regBase, nCol+1);
drhe14006d2008-03-25 17:23:32 +0000617 }
drh2d401ab2008-01-10 23:50:11 +0000618 sqlite3ReleaseTempRange(pParse, regBase, nCol+1);
619 return regBase;
drh51846b52004-05-28 16:00:21 +0000620}
drhf39d9582008-03-19 20:42:13 +0000621
622/* Make sure "isView" gets undefined in case this file becomes part of
623** the amalgamation - so that subsequent files do not see isView as a
624** macro. */
625#undef isView