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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**
drh1bd10f82008-12-10 21:19:56 +000015** $Id: delete.c,v 1.190 2008/12/10 21:19:57 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
65/*
drhad6d9462004-09-19 02:15:24 +000066** Generate code that will open a table for reading.
67*/
danielk1977c00da102006-01-07 13:21:04 +000068void sqlite3OpenTable(
69 Parse *p, /* Generate code into this VDBE */
drhad6d9462004-09-19 02:15:24 +000070 int iCur, /* The cursor number of the table */
danielk1977da184232006-01-05 11:34:32 +000071 int iDb, /* The database index in sqlite3.aDb[] */
danielk1977c00da102006-01-07 13:21:04 +000072 Table *pTab, /* The table to be opened */
73 int opcode /* OP_OpenRead or OP_OpenWrite */
drhad6d9462004-09-19 02:15:24 +000074){
drh4cbdda92006-06-14 19:00:20 +000075 Vdbe *v;
76 if( IsVirtual(pTab) ) return;
77 v = sqlite3GetVdbe(p);
danielk1977c00da102006-01-07 13:21:04 +000078 assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
drh1bd10f82008-12-10 21:19:56 +000079 sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite)?1:0, pTab->zName);
danielk1977cd3e8f72008-03-25 09:47:35 +000080 sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
danielk1977207872a2008-01-03 07:54:23 +000081 sqlite3VdbeAddOp3(v, opcode, iCur, pTab->tnum, iDb);
drhd4e70eb2008-01-02 00:34:36 +000082 VdbeComment((v, "%s", pTab->zName));
drhad6d9462004-09-19 02:15:24 +000083}
84
danielk1977299b1872004-11-22 10:02:10 +000085
drh0f35a6b2008-02-12 16:52:14 +000086#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
87/*
88** Evaluate a view and store its result in an ephemeral table. The
89** pWhere argument is an optional WHERE clause that restricts the
90** set of rows in the view that are to be added to the ephemeral table.
91*/
92void sqlite3MaterializeView(
93 Parse *pParse, /* Parsing context */
drh2a5d8252008-08-22 12:30:52 +000094 Table *pView, /* View definition */
drh0f35a6b2008-02-12 16:52:14 +000095 Expr *pWhere, /* Optional WHERE clause to be added */
drh0f35a6b2008-02-12 16:52:14 +000096 int iCur /* Cursor number for ephemerial table */
97){
98 SelectDest dest;
99 Select *pDup;
100 sqlite3 *db = pParse->db;
101
drh2a5d8252008-08-22 12:30:52 +0000102 pDup = sqlite3SelectDup(db, pView->pSelect);
drh0f35a6b2008-02-12 16:52:14 +0000103 if( pWhere ){
104 SrcList *pFrom;
drh2a5d8252008-08-22 12:30:52 +0000105 Token viewName;
drh0f35a6b2008-02-12 16:52:14 +0000106
107 pWhere = sqlite3ExprDup(db, pWhere);
drh8b213892008-08-29 02:14:02 +0000108 viewName.z = (u8*)pView->zName;
drhea678832008-12-10 19:26:22 +0000109 viewName.n = (unsigned int)sqlite3Strlen30((const char*)viewName.z);
danielk1977b1c685b2008-10-06 16:18:39 +0000110 pFrom = sqlite3SrcListAppendFromTerm(pParse, 0, 0, 0, &viewName, pDup, 0,0);
drh0f35a6b2008-02-12 16:52:14 +0000111 pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
112 }
drh0f35a6b2008-02-12 16:52:14 +0000113 sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
drh7d10d5a2008-08-20 16:35:10 +0000114 sqlite3Select(pParse, pDup, &dest);
drh633e6d52008-07-28 19:34:53 +0000115 sqlite3SelectDelete(db, pDup);
drh0f35a6b2008-02-12 16:52:14 +0000116}
117#endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
118
shane273f6192008-10-10 04:34:16 +0000119#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
shane4281bd42008-10-07 05:27:11 +0000120/*
121** Generate an expression tree to implement the WHERE, ORDER BY,
122** and LIMIT/OFFSET portion of DELETE and UPDATE statements.
123**
124** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1;
125** \__________________________/
126** pLimitWhere (pInClause)
127*/
128Expr *sqlite3LimitWhere(
shane49ffdbf2008-10-10 18:25:45 +0000129 Parse *pParse, /* The parser context */
130 SrcList *pSrc, /* the FROM clause -- which tables to scan */
131 Expr *pWhere, /* The WHERE clause. May be null */
132 ExprList *pOrderBy, /* The ORDER BY clause. May be null */
133 Expr *pLimit, /* The LIMIT clause. May be null */
134 Expr *pOffset, /* The OFFSET clause. May be null */
135 char *zStmtType /* Either DELETE or UPDATE. For error messages. */
shane4281bd42008-10-07 05:27:11 +0000136){
shane49ffdbf2008-10-10 18:25:45 +0000137 Expr *pWhereRowid = NULL; /* WHERE rowid .. */
138 Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */
139 Expr *pSelectRowid = NULL; /* SELECT rowid ... */
140 ExprList *pEList = NULL; /* Expression list contaning only pSelectRowid */
141 SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */
142 Select *pSelect = NULL; /* Complete SELECT tree */
143
144 /* Check that there isn't an ORDER BY without a LIMIT clause.
145 */
146 if( pOrderBy && (pLimit == 0) ) {
147 sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
148 pParse->parseError = 1;
149 goto limit_where_cleanup_2;
150 }
shane273f6192008-10-10 04:34:16 +0000151
152 /* We only need to generate a select expression if there
153 ** is a limit/offset term to enforce.
154 */
shane49ffdbf2008-10-10 18:25:45 +0000155 if( pLimit == 0 ) {
156 /* if pLimit is null, pOffset will always be null as well. */
157 assert( pOffset == 0 );
158 return pWhere;
159 }
shane273f6192008-10-10 04:34:16 +0000160
161 /* Generate a select expression tree to enforce the limit/offset
162 ** term for the DELETE or UPDATE statement. For example:
163 ** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
164 ** becomes:
165 ** DELETE FROM table_a WHERE rowid IN (
shaneb235db92008-10-10 13:35:57 +0000166 ** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
shane273f6192008-10-10 04:34:16 +0000167 ** );
168 */
shaneb235db92008-10-10 13:35:57 +0000169
shane273f6192008-10-10 04:34:16 +0000170 pSelectRowid = sqlite3Expr(pParse->db, TK_ROW, 0, 0, 0);
shane49ffdbf2008-10-10 18:25:45 +0000171 if( pSelectRowid == 0 ) goto limit_where_cleanup_2;
shane273f6192008-10-10 04:34:16 +0000172 pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid, 0);
shane49ffdbf2008-10-10 18:25:45 +0000173 if( pEList == 0 ) goto limit_where_cleanup_2;
shaneb235db92008-10-10 13:35:57 +0000174
shane273f6192008-10-10 04:34:16 +0000175 /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
shaneb235db92008-10-10 13:35:57 +0000176 ** and the SELECT subtree. */
shane273f6192008-10-10 04:34:16 +0000177 pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc);
shaneb235db92008-10-10 13:35:57 +0000178 if( pSelectSrc == 0 ) {
179 sqlite3ExprListDelete(pParse->db, pEList);
shane49ffdbf2008-10-10 18:25:45 +0000180 goto limit_where_cleanup_2;
shaneb235db92008-10-10 13:35:57 +0000181 }
182
183 /* generate the SELECT expression tree. */
shane273f6192008-10-10 04:34:16 +0000184 pSelect = sqlite3SelectNew(pParse,pEList,pSelectSrc,pWhere,0,0,pOrderBy,0,pLimit,pOffset);
shaneb235db92008-10-10 13:35:57 +0000185 if( pSelect == 0 ) return 0;
186
shane49ffdbf2008-10-10 18:25:45 +0000187 /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
shane273f6192008-10-10 04:34:16 +0000188 pWhereRowid = sqlite3Expr(pParse->db, TK_ROW, 0, 0, 0);
shane49ffdbf2008-10-10 18:25:45 +0000189 if( pWhereRowid == 0 ) goto limit_where_cleanup_1;
shane273f6192008-10-10 04:34:16 +0000190 pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0);
shane49ffdbf2008-10-10 18:25:45 +0000191 if( pInClause == 0 ) goto limit_where_cleanup_1;
shaneb235db92008-10-10 13:35:57 +0000192
shane273f6192008-10-10 04:34:16 +0000193 pInClause->pSelect = pSelect;
194 sqlite3ExprSetHeight(pParse, pInClause);
195 return pInClause;
196
shane273f6192008-10-10 04:34:16 +0000197 /* something went wrong. clean up anything allocated. */
shane49ffdbf2008-10-10 18:25:45 +0000198limit_where_cleanup_1:
shaneb235db92008-10-10 13:35:57 +0000199 sqlite3SelectDelete(pParse->db, pSelect);
shane4281bd42008-10-07 05:27:11 +0000200 return 0;
shane49ffdbf2008-10-10 18:25:45 +0000201
202limit_where_cleanup_2:
203 sqlite3ExprDelete(pParse->db, pWhere);
204 sqlite3ExprListDelete(pParse->db, pOrderBy);
205 sqlite3ExprDelete(pParse->db, pLimit);
206 sqlite3ExprDelete(pParse->db, pOffset);
207 return 0;
shane4281bd42008-10-07 05:27:11 +0000208}
shane273f6192008-10-10 04:34:16 +0000209#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
drh0f35a6b2008-02-12 16:52:14 +0000210
drhad6d9462004-09-19 02:15:24 +0000211/*
drh23bf66d2004-12-14 03:34:34 +0000212** Generate code for a DELETE FROM statement.
213**
214** DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
215** \________/ \________________/
216** pTabList pWhere
drhcce7d172000-05-31 15:34:51 +0000217*/
danielk19774adee202004-05-08 08:23:19 +0000218void sqlite3DeleteFrom(
drhcce7d172000-05-31 15:34:51 +0000219 Parse *pParse, /* The parser context */
drh113088e2003-03-20 01:16:58 +0000220 SrcList *pTabList, /* The table from which we should delete things */
drhcce7d172000-05-31 15:34:51 +0000221 Expr *pWhere /* The WHERE clause. May be null */
222){
223 Vdbe *v; /* The virtual database engine */
224 Table *pTab; /* The table from which records will be deleted */
drhe22a3342003-04-22 20:30:37 +0000225 const char *zDb; /* Name of database holding pTab */
danielk1977299b1872004-11-22 10:02:10 +0000226 int end, addr = 0; /* A couple addresses of generated code */
drhcce7d172000-05-31 15:34:51 +0000227 int i; /* Loop counter */
228 WhereInfo *pWInfo; /* Information about the WHERE clause */
229 Index *pIdx; /* For looping over indices of the table */
drh6a3ea0e2003-05-02 14:32:12 +0000230 int iCur; /* VDBE Cursor number for pTab */
drh9bb575f2004-09-06 17:24:11 +0000231 sqlite3 *db; /* Main database structure */
drh85e20962003-04-25 17:52:11 +0000232 AuthContext sContext; /* Authorization context */
drh798da522004-11-04 04:42:28 +0000233 int oldIdx = -1; /* Cursor for the OLD table of AFTER triggers */
danielk1977b3bce662005-01-29 08:32:43 +0000234 NameContext sNC; /* Name context to resolve expressions in */
drh53a67772007-02-07 01:06:52 +0000235 int iDb; /* Database number */
danielk1977c7af4842008-10-27 13:59:33 +0000236 int memCnt = -1; /* Memory cell used for change counting */
danielk197752bd7912008-10-27 15:34:32 +0000237 int rcauth; /* Value returned by authorization callback */
drh1bee3d72001-10-15 00:44:35 +0000238
drh798da522004-11-04 04:42:28 +0000239#ifndef SQLITE_OMIT_TRIGGER
240 int isView; /* True if attempting to delete from a view */
drhdca76842004-12-07 14:06:13 +0000241 int triggers_exist = 0; /* True if any triggers exist */
drh798da522004-11-04 04:42:28 +0000242#endif
drh1bd10f82008-12-10 21:19:56 +0000243 int iBeginAfterTrigger = 0; /* Address of after trigger program */
244 int iEndAfterTrigger = 0; /* Exit of after trigger program */
245 int iBeginBeforeTrigger = 0; /* Address of before trigger program */
246 int iEndBeforeTrigger = 0; /* Exit of before trigger program */
danielk19778f2c54e2008-01-01 19:02:09 +0000247 u32 old_col_mask = 0; /* Mask of OLD.* columns in use */
drhcce7d172000-05-31 15:34:51 +0000248
drh85e20962003-04-25 17:52:11 +0000249 sContext.pParse = 0;
drh17435752007-08-16 04:30:38 +0000250 db = pParse->db;
251 if( pParse->nErr || db->mallocFailed ){
drhdaffd0e2001-04-11 14:28:42 +0000252 goto delete_from_cleanup;
253 }
drh113088e2003-03-20 01:16:58 +0000254 assert( pTabList->nSrc==1 );
drhdaffd0e2001-04-11 14:28:42 +0000255
drh1ccde152000-06-17 13:12:39 +0000256 /* Locate the table which we want to delete. This table has to be
drhad3cab52002-05-24 02:04:32 +0000257 ** put in an SrcList structure because some of the subroutines we
drhcce7d172000-05-31 15:34:51 +0000258 ** will be calling are designed to work with multiple tables and expect
drhad3cab52002-05-24 02:04:32 +0000259 ** an SrcList* parameter instead of just a Table* parameter.
drhcce7d172000-05-31 15:34:51 +0000260 */
danielk19774adee202004-05-08 08:23:19 +0000261 pTab = sqlite3SrcListLookup(pParse, pTabList);
drha69d9162003-04-17 22:57:53 +0000262 if( pTab==0 ) goto delete_from_cleanup;
drhb7f91642004-10-31 02:22:47 +0000263
264 /* Figure out if we have any triggers and if the table being
265 ** deleted from is a view
266 */
267#ifndef SQLITE_OMIT_TRIGGER
danielk197762c14b32008-11-19 09:05:26 +0000268 triggers_exist = sqlite3TriggersExist(pTab, TK_DELETE, 0);
drh5cf590c2003-04-24 01:45:04 +0000269 isView = pTab->pSelect!=0;
drhb7f91642004-10-31 02:22:47 +0000270#else
drhdca76842004-12-07 14:06:13 +0000271# define triggers_exist 0
drhb7f91642004-10-31 02:22:47 +0000272# define isView 0
273#endif
274#ifdef SQLITE_OMIT_VIEW
275# undef isView
276# define isView 0
277#endif
278
drhdca76842004-12-07 14:06:13 +0000279 if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){
drh5cf590c2003-04-24 01:45:04 +0000280 goto delete_from_cleanup;
drh113088e2003-03-20 01:16:58 +0000281 }
danielk1977da184232006-01-05 11:34:32 +0000282 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
283 assert( iDb<db->nDb );
284 zDb = db->aDb[iDb].zName;
danielk197752bd7912008-10-27 15:34:32 +0000285 rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb);
286 assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
287 if( rcauth==SQLITE_DENY ){
drhe5f9c642003-01-13 23:27:31 +0000288 goto delete_from_cleanup;
289 }
danielk19779a02fb42008-10-27 08:24:38 +0000290 assert(!isView || triggers_exist);
drhcce7d172000-05-31 15:34:51 +0000291
drh5cf590c2003-04-24 01:45:04 +0000292 /* If pTab is really a view, make sure it has been initialized.
293 */
danielk1977b3d24bf2006-06-19 03:05:10 +0000294 if( sqlite3ViewGetColumnNames(pParse, pTab) ){
drh5cf590c2003-04-24 01:45:04 +0000295 goto delete_from_cleanup;
296 }
297
drhc977f7f2002-05-21 11:38:11 +0000298 /* Allocate a cursor used to store the old.* data for a trigger.
299 */
drhdca76842004-12-07 14:06:13 +0000300 if( triggers_exist ){
danielk1977c3f9bad2002-05-15 08:30:12 +0000301 oldIdx = pParse->nTab++;
danielk1977f29ce552002-05-19 23:43:12 +0000302 }
danielk1977c3f9bad2002-05-15 08:30:12 +0000303
drh0f35a6b2008-02-12 16:52:14 +0000304 /* Assign cursor number to the table and all its indices.
drhcce7d172000-05-31 15:34:51 +0000305 */
drh6a3ea0e2003-05-02 14:32:12 +0000306 assert( pTabList->nSrc==1 );
307 iCur = pTabList->a[0].iCursor = pParse->nTab++;
danielk1977e448dc42008-01-02 11:50:51 +0000308 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
309 pParse->nTab++;
310 }
drhcce7d172000-05-31 15:34:51 +0000311
drh85e20962003-04-25 17:52:11 +0000312 /* Start the view context
313 */
314 if( isView ){
danielk19774adee202004-05-08 08:23:19 +0000315 sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
drh85e20962003-04-25 17:52:11 +0000316 }
317
drhcce7d172000-05-31 15:34:51 +0000318 /* Begin generating code.
319 */
danielk19774adee202004-05-08 08:23:19 +0000320 v = sqlite3GetVdbe(pParse);
danielk1977f29ce552002-05-19 23:43:12 +0000321 if( v==0 ){
322 goto delete_from_cleanup;
323 }
drh4794f732004-11-05 17:17:50 +0000324 if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
danielk1977da184232006-01-05 11:34:32 +0000325 sqlite3BeginWriteOperation(pParse, triggers_exist, iDb);
drh5e00f6c2001-09-13 13:46:56 +0000326
danielk19778f2c54e2008-01-01 19:02:09 +0000327 if( triggers_exist ){
danielk1977dd2fb292008-01-04 13:57:26 +0000328 int orconf = ((pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
drh66a51672008-01-03 00:01:23 +0000329 int iGoto = sqlite3VdbeAddOp0(v, OP_Goto);
danielk19778f2c54e2008-01-01 19:02:09 +0000330 addr = sqlite3VdbeMakeLabel(v);
danielk1977dd2fb292008-01-04 13:57:26 +0000331
danielk19778f2c54e2008-01-01 19:02:09 +0000332 iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
333 (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_BEFORE, pTab,
danielk1977dd2fb292008-01-04 13:57:26 +0000334 -1, oldIdx, orconf, addr, &old_col_mask, 0);
drh66a51672008-01-03 00:01:23 +0000335 iEndBeforeTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
danielk1977dd2fb292008-01-04 13:57:26 +0000336
danielk19778f2c54e2008-01-01 19:02:09 +0000337 iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
338 (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_AFTER, pTab, -1,
danielk1977dd2fb292008-01-04 13:57:26 +0000339 oldIdx, orconf, addr, &old_col_mask, 0);
drh66a51672008-01-03 00:01:23 +0000340 iEndAfterTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
danielk1977dd2fb292008-01-04 13:57:26 +0000341
danielk19778f2c54e2008-01-01 19:02:09 +0000342 sqlite3VdbeJumpHere(v, iGoto);
343 }
344
drh9d2985c2005-09-08 01:58:42 +0000345 /* If we are trying to delete from a view, realize that view into
346 ** a ephemeral table.
drh5cf590c2003-04-24 01:45:04 +0000347 */
shanefa4e62f2008-09-01 21:59:42 +0000348#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
drh5cf590c2003-04-24 01:45:04 +0000349 if( isView ){
drh2a5d8252008-08-22 12:30:52 +0000350 sqlite3MaterializeView(pParse, pTab, pWhere, iCur);
drh0f35a6b2008-02-12 16:52:14 +0000351 }
shanefa4e62f2008-09-01 21:59:42 +0000352#endif
drh1013c932008-01-06 00:25:21 +0000353
drh0f35a6b2008-02-12 16:52:14 +0000354 /* Resolve the column names in the WHERE clause.
355 */
356 memset(&sNC, 0, sizeof(sNC));
357 sNC.pParse = pParse;
358 sNC.pSrcList = pTabList;
drh7d10d5a2008-08-20 16:35:10 +0000359 if( sqlite3ResolveExprNames(&sNC, pWhere) ){
drh0f35a6b2008-02-12 16:52:14 +0000360 goto delete_from_cleanup;
drh5cf590c2003-04-24 01:45:04 +0000361 }
362
drh1bee3d72001-10-15 00:44:35 +0000363 /* Initialize the counter of the number of rows deleted, if
364 ** we are counting rows.
365 */
366 if( db->flags & SQLITE_CountRows ){
drh0a07c102008-01-03 18:03:08 +0000367 memCnt = ++pParse->nMem;
drh4c583122008-01-04 22:01:03 +0000368 sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt);
drh1bee3d72001-10-15 00:44:35 +0000369 }
drhcce7d172000-05-31 15:34:51 +0000370
drhf8cecda2008-10-10 23:48:25 +0000371#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
drh0353ced2001-03-20 22:05:00 +0000372 /* Special case: A DELETE without a WHERE clause deletes everything.
drhc977f7f2002-05-21 11:38:11 +0000373 ** It is easier just to erase the whole table. Note, however, that
374 ** this means that the row change count will be incorrect.
drhcce7d172000-05-31 15:34:51 +0000375 */
danielk197752bd7912008-10-27 15:34:32 +0000376 if( rcauth==SQLITE_OK && pWhere==0 && !triggers_exist && !IsVirtual(pTab) ){
danielk19779a02fb42008-10-27 08:24:38 +0000377 assert( !isView );
danielk1977c7af4842008-10-27 13:59:33 +0000378 sqlite3VdbeAddOp3(v, OP_Clear, pTab->tnum, iDb, memCnt);
danielk19779a02fb42008-10-27 08:24:38 +0000379 if( !pParse->nested ){
380 sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
381 }
382 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
383 assert( pIdx->pSchema==pTab->pSchema );
384 sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
drhcce7d172000-05-31 15:34:51 +0000385 }
drhf8cecda2008-10-10 23:48:25 +0000386 }else
387#endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
drh0353ced2001-03-20 22:05:00 +0000388 /* The usual case: There is a WHERE clause so we have to scan through
jplyon8bc03a72004-01-19 04:54:28 +0000389 ** the table and pick which records to delete.
drh0353ced2001-03-20 22:05:00 +0000390 */
drhf8cecda2008-10-10 23:48:25 +0000391 {
danielk1977dd2fb292008-01-04 13:57:26 +0000392 int iRowid = ++pParse->nMem; /* Used for storing rowid values. */
drh3d4501e2008-12-04 20:40:10 +0000393 int iRowSet = ++pParse->nMem; /* Register for rowset of rows to delete */
danielk197796cb76f2008-01-04 13:24:28 +0000394
danielk1977299b1872004-11-22 10:02:10 +0000395 /* Begin the database scan
396 */
danielk1977a9d1ccb2008-01-05 17:39:29 +0000397 pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0);
danielk1977299b1872004-11-22 10:02:10 +0000398 if( pWInfo==0 ) goto delete_from_cleanup;
399
drhe6f85e72004-12-25 01:03:13 +0000400 /* Remember the rowid of every item to be deleted.
danielk1977299b1872004-11-22 10:02:10 +0000401 */
danielk1977dd2fb292008-01-04 13:57:26 +0000402 sqlite3VdbeAddOp2(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur, iRowid);
drh3d4501e2008-12-04 20:40:10 +0000403 sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iRowid);
danielk1977299b1872004-11-22 10:02:10 +0000404 if( db->flags & SQLITE_CountRows ){
drh8558cde2008-01-05 05:20:10 +0000405 sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
danielk1977299b1872004-11-22 10:02:10 +0000406 }
407
408 /* End the database scan loop.
409 */
410 sqlite3WhereEnd(pWInfo);
411
drh70ce3f02003-04-15 19:22:22 +0000412 /* Open the pseudo-table used to store OLD if there are triggers.
413 */
drhdca76842004-12-07 14:06:13 +0000414 if( triggers_exist ){
danielk1977cd3e8f72008-03-25 09:47:35 +0000415 sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol);
drh66a51672008-01-03 00:01:23 +0000416 sqlite3VdbeAddOp1(v, OP_OpenPseudo, oldIdx);
drh70ce3f02003-04-15 19:22:22 +0000417 }
418
danielk1977299b1872004-11-22 10:02:10 +0000419 /* Delete every item whose key was written to the list during the
420 ** database scan. We have to delete items after the scan is complete
421 ** because deleting an item can change the scan order.
danielk1977ed326d72004-11-16 15:50:19 +0000422 */
danielk1977299b1872004-11-22 10:02:10 +0000423 end = sqlite3VdbeMakeLabel(v);
danielk1977ed326d72004-11-16 15:50:19 +0000424
danielk1977e448dc42008-01-02 11:50:51 +0000425 if( !isView ){
426 /* Open cursors for the table we are deleting from and
427 ** all its indices.
428 */
429 sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);
430 }
431
432 /* This is the beginning of the delete loop. If a trigger encounters
433 ** an IGNORE constraint, it jumps back to here.
drhc977f7f2002-05-21 11:38:11 +0000434 */
drhdca76842004-12-07 14:06:13 +0000435 if( triggers_exist ){
danielk19778f2c54e2008-01-01 19:02:09 +0000436 sqlite3VdbeResolveLabel(v, addr);
danielk1977e448dc42008-01-02 11:50:51 +0000437 }
drh3d4501e2008-12-04 20:40:10 +0000438 addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, iRowid);
danielk1977e448dc42008-01-02 11:50:51 +0000439
440 if( triggers_exist ){
danielk197796cb76f2008-01-04 13:24:28 +0000441 int iData = ++pParse->nMem; /* For storing row data of OLD table */
442
443 /* If the record is no longer present in the table, jump to the
444 ** next iteration of the loop through the contents of the fifo.
445 */
446 sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, iRowid);
447
448 /* Populate the OLD.* pseudo-table */
danielk19778f2c54e2008-01-01 19:02:09 +0000449 if( old_col_mask ){
drh98757152008-01-09 23:04:12 +0000450 sqlite3VdbeAddOp2(v, OP_RowData, iCur, iData);
danielk19778f2c54e2008-01-01 19:02:09 +0000451 }else{
drh4c583122008-01-04 22:01:03 +0000452 sqlite3VdbeAddOp2(v, OP_Null, 0, iData);
danielk19778f2c54e2008-01-01 19:02:09 +0000453 }
danielk197796cb76f2008-01-04 13:24:28 +0000454 sqlite3VdbeAddOp3(v, OP_Insert, oldIdx, iData, iRowid);
danielk1977299b1872004-11-22 10:02:10 +0000455
danielk19778f2c54e2008-01-01 19:02:09 +0000456 /* Jump back and run the BEFORE triggers */
drh66a51672008-01-03 00:01:23 +0000457 sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger);
danielk19778f2c54e2008-01-01 19:02:09 +0000458 sqlite3VdbeJumpHere(v, iEndBeforeTrigger);
danielk1977c3f9bad2002-05-15 08:30:12 +0000459 }
460
danielk1977299b1872004-11-22 10:02:10 +0000461 if( !isView ){
danielk1977299b1872004-11-22 10:02:10 +0000462 /* Delete the row */
drh4cbdda92006-06-14 19:00:20 +0000463#ifndef SQLITE_OMIT_VIRTUALTABLE
464 if( IsVirtual(pTab) ){
danielk197796cb76f2008-01-04 13:24:28 +0000465 const char *pVtab = (const char *)pTab->pVtab;
drh4f3dd152008-04-28 18:46:43 +0000466 sqlite3VtabMakeWritable(pParse, pTab);
danielk197796cb76f2008-01-04 13:24:28 +0000467 sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVtab, P4_VTAB);
drh4cbdda92006-06-14 19:00:20 +0000468 }else
469#endif
470 {
drh2d401ab2008-01-10 23:50:11 +0000471 sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, pParse->nested==0);
drh4cbdda92006-06-14 19:00:20 +0000472 }
danielk1977299b1872004-11-22 10:02:10 +0000473 }
474
475 /* If there are row triggers, close all cursors then invoke
476 ** the AFTER triggers
477 */
drhdca76842004-12-07 14:06:13 +0000478 if( triggers_exist ){
danielk19778f2c54e2008-01-01 19:02:09 +0000479 /* Jump back and run the AFTER triggers */
drh66a51672008-01-03 00:01:23 +0000480 sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger);
danielk19778f2c54e2008-01-01 19:02:09 +0000481 sqlite3VdbeJumpHere(v, iEndAfterTrigger);
danielk1977c3f9bad2002-05-15 08:30:12 +0000482 }
483
danielk1977299b1872004-11-22 10:02:10 +0000484 /* End of the delete loop */
drh66a51672008-01-03 00:01:23 +0000485 sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
danielk1977299b1872004-11-22 10:02:10 +0000486 sqlite3VdbeResolveLabel(v, end);
danielk1977299b1872004-11-22 10:02:10 +0000487
488 /* Close the cursors after the loop if there are no row triggers */
danielk1977e448dc42008-01-02 11:50:51 +0000489 if( !isView && !IsVirtual(pTab) ){
danielk1977299b1872004-11-22 10:02:10 +0000490 for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
drh66a51672008-01-03 00:01:23 +0000491 sqlite3VdbeAddOp2(v, OP_Close, iCur + i, pIdx->tnum);
danielk1977299b1872004-11-22 10:02:10 +0000492 }
drh66a51672008-01-03 00:01:23 +0000493 sqlite3VdbeAddOp1(v, OP_Close, iCur);
danielk1977c3f9bad2002-05-15 08:30:12 +0000494 }
drh0353ced2001-03-20 22:05:00 +0000495 }
drh5e00f6c2001-09-13 13:46:56 +0000496
drh1bee3d72001-10-15 00:44:35 +0000497 /*
danielk1977e7de6f22004-11-05 06:02:06 +0000498 ** Return the number of rows that were deleted. If this routine is
499 ** generating code because of a call to sqlite3NestedParse(), do not
500 ** invoke the callback function.
drh1bee3d72001-10-15 00:44:35 +0000501 */
danielk1977cc6bd382005-01-10 02:48:49 +0000502 if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
drh66a51672008-01-03 00:01:23 +0000503 sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1);
danielk197722322fd2004-05-25 23:35:17 +0000504 sqlite3VdbeSetNumCols(v, 1);
danielk197710fb7492008-10-31 10:53:22 +0000505 sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC);
drh1bee3d72001-10-15 00:44:35 +0000506 }
drhcce7d172000-05-31 15:34:51 +0000507
508delete_from_cleanup:
danielk19774adee202004-05-08 08:23:19 +0000509 sqlite3AuthContextPop(&sContext);
drh633e6d52008-07-28 19:34:53 +0000510 sqlite3SrcListDelete(db, pTabList);
511 sqlite3ExprDelete(db, pWhere);
drhcce7d172000-05-31 15:34:51 +0000512 return;
513}
drh9cfcf5d2002-01-29 18:41:24 +0000514
515/*
516** This routine generates VDBE code that causes a single row of a
517** single table to be deleted.
518**
519** The VDBE must be in a particular state when this routine is called.
520** These are the requirements:
521**
522** 1. A read/write cursor pointing to pTab, the table containing the row
523** to be deleted, must be opened as cursor number "base".
524**
525** 2. Read/write cursors for all indices of pTab must be open as
526** cursor number base+i for the i-th index.
527**
danielk197796cb76f2008-01-04 13:24:28 +0000528** 3. The record number of the row to be deleted must be stored in
529** memory cell iRowid.
drh9cfcf5d2002-01-29 18:41:24 +0000530**
531** This routine pops the top of the stack to remove the record number
532** and then generates code to remove both the table record and all index
533** entries that point to that record.
534*/
danielk19774adee202004-05-08 08:23:19 +0000535void sqlite3GenerateRowDelete(
drh2d401ab2008-01-10 23:50:11 +0000536 Parse *pParse, /* Parsing context */
drh9cfcf5d2002-01-29 18:41:24 +0000537 Table *pTab, /* Table containing the row to be deleted */
drh6a3ea0e2003-05-02 14:32:12 +0000538 int iCur, /* Cursor number for the table */
danielk197796cb76f2008-01-04 13:24:28 +0000539 int iRowid, /* Memory cell that contains the rowid to delete */
drhc8d30ac2002-04-12 10:08:59 +0000540 int count /* Increment the row change counter */
drh9cfcf5d2002-01-29 18:41:24 +0000541){
drh07d6e3a2002-05-23 12:50:18 +0000542 int addr;
drh2d401ab2008-01-10 23:50:11 +0000543 Vdbe *v;
544
545 v = pParse->pVdbe;
danielk197796cb76f2008-01-04 13:24:28 +0000546 addr = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowid);
drh2d401ab2008-01-10 23:50:11 +0000547 sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, 0);
drh66a51672008-01-03 00:01:23 +0000548 sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
danielk197794eb6a12005-12-15 15:22:08 +0000549 if( count ){
drh66a51672008-01-03 00:01:23 +0000550 sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
danielk197794eb6a12005-12-15 15:22:08 +0000551 }
drhd654be82005-09-20 17:42:23 +0000552 sqlite3VdbeJumpHere(v, addr);
drh0ca3e242002-01-29 23:07:02 +0000553}
554
555/*
556** This routine generates VDBE code that causes the deletion of all
557** index entries associated with a single row of a single table.
558**
559** The VDBE must be in a particular state when this routine is called.
560** These are the requirements:
561**
562** 1. A read/write cursor pointing to pTab, the table containing the row
drh6a3ea0e2003-05-02 14:32:12 +0000563** to be deleted, must be opened as cursor number "iCur".
drh0ca3e242002-01-29 23:07:02 +0000564**
565** 2. Read/write cursors for all indices of pTab must be open as
drh6a3ea0e2003-05-02 14:32:12 +0000566** cursor number iCur+i for the i-th index.
drh0ca3e242002-01-29 23:07:02 +0000567**
drh6a3ea0e2003-05-02 14:32:12 +0000568** 3. The "iCur" cursor must be pointing to the row that is to be
drh0ca3e242002-01-29 23:07:02 +0000569** deleted.
570*/
danielk19774adee202004-05-08 08:23:19 +0000571void sqlite3GenerateRowIndexDelete(
drh2d401ab2008-01-10 23:50:11 +0000572 Parse *pParse, /* Parsing and code generating context */
drh0ca3e242002-01-29 23:07:02 +0000573 Table *pTab, /* Table containing the row to be deleted */
drh6a3ea0e2003-05-02 14:32:12 +0000574 int iCur, /* Cursor number for the table */
drhaa9b8962008-01-08 02:57:55 +0000575 int *aRegIdx /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
drh0ca3e242002-01-29 23:07:02 +0000576){
drh9cfcf5d2002-01-29 18:41:24 +0000577 int i;
578 Index *pIdx;
drh9cbf3422008-01-17 16:22:13 +0000579 int r1;
drh9cfcf5d2002-01-29 18:41:24 +0000580
drh0ca3e242002-01-29 23:07:02 +0000581 for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
drhaa9b8962008-01-08 02:57:55 +0000582 if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue;
drh3a200e02008-04-11 19:18:24 +0000583 r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0);
drhe14006d2008-03-25 17:23:32 +0000584 sqlite3VdbeAddOp3(pParse->pVdbe, OP_IdxDelete, iCur+i, r1,pIdx->nColumn+1);
drh9cfcf5d2002-01-29 18:41:24 +0000585 }
drh9cfcf5d2002-01-29 18:41:24 +0000586}
drh51846b52004-05-28 16:00:21 +0000587
588/*
drhe14006d2008-03-25 17:23:32 +0000589** Generate code that will assemble an index key and put it in register
590** regOut. The key with be for index pIdx which is an index on pTab.
drh51846b52004-05-28 16:00:21 +0000591** iCur is the index of a cursor open on the pTab table and pointing to
592** the entry that needs indexing.
drh2d401ab2008-01-10 23:50:11 +0000593**
594** Return a register number which is the first in a block of
595** registers that holds the elements of the index key. The
596** block of registers has already been deallocated by the time
597** this routine returns.
drh51846b52004-05-28 16:00:21 +0000598*/
drh2d401ab2008-01-10 23:50:11 +0000599int sqlite3GenerateIndexKey(
600 Parse *pParse, /* Parsing context */
drh51846b52004-05-28 16:00:21 +0000601 Index *pIdx, /* The index for which to generate a key */
drh2d401ab2008-01-10 23:50:11 +0000602 int iCur, /* Cursor number for the pIdx->pTable table */
drhe14006d2008-03-25 17:23:32 +0000603 int regOut, /* Write the new index key to this register */
604 int doMakeRec /* Run the OP_MakeRecord instruction if true */
drh51846b52004-05-28 16:00:21 +0000605){
drh2d401ab2008-01-10 23:50:11 +0000606 Vdbe *v = pParse->pVdbe;
drh51846b52004-05-28 16:00:21 +0000607 int j;
608 Table *pTab = pIdx->pTable;
drh2d401ab2008-01-10 23:50:11 +0000609 int regBase;
610 int nCol;
drh51846b52004-05-28 16:00:21 +0000611
drh2d401ab2008-01-10 23:50:11 +0000612 nCol = pIdx->nColumn;
613 regBase = sqlite3GetTempRange(pParse, nCol+1);
614 sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol);
615 for(j=0; j<nCol; j++){
drh51846b52004-05-28 16:00:21 +0000616 int idx = pIdx->aiColumn[j];
617 if( idx==pTab->iPKey ){
drh2d401ab2008-01-10 23:50:11 +0000618 sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
drh51846b52004-05-28 16:00:21 +0000619 }else{
drh2d401ab2008-01-10 23:50:11 +0000620 sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
danielk1977aee18ef2005-03-09 12:26:50 +0000621 sqlite3ColumnDefault(v, pTab, idx);
drh51846b52004-05-28 16:00:21 +0000622 }
623 }
drhe14006d2008-03-25 17:23:32 +0000624 if( doMakeRec ){
625 sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut);
626 sqlite3IndexAffinityStr(v, pIdx);
drhda250ea2008-04-01 05:07:14 +0000627 sqlite3ExprCacheAffinityChange(pParse, regBase, nCol+1);
drhe14006d2008-03-25 17:23:32 +0000628 }
drh2d401ab2008-01-10 23:50:11 +0000629 sqlite3ReleaseTempRange(pParse, regBase, nCol+1);
630 return regBase;
drh51846b52004-05-28 16:00:21 +0000631}
drhf39d9582008-03-19 20:42:13 +0000632
633/* Make sure "isView" gets undefined in case this file becomes part of
634** the amalgamation - so that subsequent files do not see isView as a
635** macro. */
636#undef isView