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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
drhb19a2bc2001-09-16 00:13:26 +000013** to handle SELECT statements in SQLite.
drhcce7d172000-05-31 15:34:51 +000014*/
15#include "sqliteInt.h"
16
drh079a3072014-03-19 14:10:55 +000017/*
drhabd4c722014-09-20 18:18:33 +000018** Trace output macros
19*/
20#if SELECTTRACE_ENABLED
21/***/ int sqlite3SelectTrace = 0;
drheb9b8842014-09-21 00:27:26 +000022# define SELECTTRACE(K,P,S,X) \
23 if(sqlite3SelectTrace&(K)) \
drhe2ca99c2018-05-02 00:33:43 +000024 sqlite3DebugPrintf("%s/%d/%p: ",(S)->zSelName,(P)->addrExplain,(S)),\
drheb9b8842014-09-21 00:27:26 +000025 sqlite3DebugPrintf X
drhabd4c722014-09-20 18:18:33 +000026#else
drheb9b8842014-09-21 00:27:26 +000027# define SELECTTRACE(K,P,S,X)
drhabd4c722014-09-20 18:18:33 +000028#endif
29
drh315555c2002-10-20 15:53:03 +000030
drhcce7d172000-05-31 15:34:51 +000031/*
drh079a3072014-03-19 14:10:55 +000032** An instance of the following object is used to record information about
33** how to process the DISTINCT keyword, to simplify passing that information
34** into the selectInnerLoop() routine.
drheda639e2006-01-22 00:42:09 +000035*/
drh079a3072014-03-19 14:10:55 +000036typedef struct DistinctCtx DistinctCtx;
37struct DistinctCtx {
38 u8 isTnct; /* True if the DISTINCT keyword is present */
39 u8 eTnctType; /* One of the WHERE_DISTINCT_* operators */
40 int tabTnct; /* Ephemeral table used for DISTINCT processing */
41 int addrTnct; /* Address of OP_OpenEphemeral opcode for tabTnct */
42};
43
44/*
45** An instance of the following object is used to record information about
46** the ORDER BY (or GROUP BY) clause of query is being coded.
dan24e25d32018-04-14 18:46:20 +000047**
48** The aDefer[] array is used by the sorter-references optimization. For
49** example, assuming there is no index that can be used for the ORDER BY,
50** for the query:
51**
52** SELECT a, bigblob FROM t1 ORDER BY a LIMIT 10;
53**
54** it may be more efficient to add just the "a" values to the sorter, and
55** retrieve the associated "bigblob" values directly from table t1 as the
56** 10 smallest "a" values are extracted from the sorter.
57**
58** When the sorter-reference optimization is used, there is one entry in the
59** aDefer[] array for each database table that may be read as values are
60** extracted from the sorter.
drh079a3072014-03-19 14:10:55 +000061*/
62typedef struct SortCtx SortCtx;
63struct SortCtx {
64 ExprList *pOrderBy; /* The ORDER BY (or GROUP BY clause) */
65 int nOBSat; /* Number of ORDER BY terms satisfied by indices */
66 int iECursor; /* Cursor number for the sorter */
67 int regReturn; /* Register holding block-output return address */
68 int labelBkOut; /* Start label for the block-output subroutine */
69 int addrSortIndex; /* Address of the OP_SorterOpen or OP_OpenEphemeral */
drha04a8be2016-01-13 17:50:10 +000070 int labelDone; /* Jump here when done, ex: LIMIT reached */
drh079a3072014-03-19 14:10:55 +000071 u8 sortFlags; /* Zero or more SORTFLAG_* bits */
drha536df42016-05-19 22:13:37 +000072 u8 bOrderedInnerLoop; /* ORDER BY correctly sorts the inner loop */
dan24e25d32018-04-14 18:46:20 +000073#ifdef SQLITE_ENABLE_SORTER_REFERENCES
74 u8 nDefer; /* Number of valid entries in aDefer[] */
75 struct DeferredCsr {
76 Table *pTab; /* Table definition */
77 int iCsr; /* Cursor number for table */
78 int nKey; /* Number of PK columns for table pTab (>=1) */
79 } aDefer[4];
80#endif
drhbbd4ae52018-04-30 19:32:49 +000081 struct RowLoadInfo *pDeferredRowLoad; /* Deferred row loading info or NULL */
drh079a3072014-03-19 14:10:55 +000082};
83#define SORTFLAG_UseSorter 0x01 /* Use SorterOpen instead of OpenEphemeral */
drhcce7d172000-05-31 15:34:51 +000084
85/*
drhb87fbed2015-01-05 15:48:45 +000086** Delete all the content of a Select structure. Deallocate the structure
87** itself only if bFree is true.
drheda639e2006-01-22 00:42:09 +000088*/
drhb87fbed2015-01-05 15:48:45 +000089static void clearSelect(sqlite3 *db, Select *p, int bFree){
90 while( p ){
91 Select *pPrior = p->pPrior;
92 sqlite3ExprListDelete(db, p->pEList);
93 sqlite3SrcListDelete(db, p->pSrc);
94 sqlite3ExprDelete(db, p->pWhere);
95 sqlite3ExprListDelete(db, p->pGroupBy);
96 sqlite3ExprDelete(db, p->pHaving);
97 sqlite3ExprListDelete(db, p->pOrderBy);
98 sqlite3ExprDelete(db, p->pLimit);
dan67a9b8e2018-06-22 20:51:35 +000099#ifndef SQLITE_OMIT_WINDOWFUNC
dane3bf6322018-06-08 20:58:27 +0000100 if( OK_IF_ALWAYS_TRUE(p->pWinDefn) ){
101 sqlite3WindowListDelete(db, p->pWinDefn);
102 }
dan67a9b8e2018-06-22 20:51:35 +0000103#endif
drh8906a4b2017-10-03 17:29:40 +0000104 if( OK_IF_ALWAYS_TRUE(p->pWith) ) sqlite3WithDelete(db, p->pWith);
drhdbd6a7d2017-04-05 12:39:49 +0000105 if( bFree ) sqlite3DbFreeNN(db, p);
drhb87fbed2015-01-05 15:48:45 +0000106 p = pPrior;
107 bFree = 1;
108 }
drheda639e2006-01-22 00:42:09 +0000109}
110
drh1013c932008-01-06 00:25:21 +0000111/*
112** Initialize a SelectDest structure.
113*/
114void sqlite3SelectDestInit(SelectDest *pDest, int eDest, int iParm){
drhea678832008-12-10 19:26:22 +0000115 pDest->eDest = (u8)eDest;
drh2b596da2012-07-23 21:43:19 +0000116 pDest->iSDParm = iParm;
dan71c57db2016-07-09 20:23:55 +0000117 pDest->zAffSdst = 0;
drh2b596da2012-07-23 21:43:19 +0000118 pDest->iSdst = 0;
119 pDest->nSdst = 0;
drh1013c932008-01-06 00:25:21 +0000120}
121
drheda639e2006-01-22 00:42:09 +0000122
123/*
drh9bb61fe2000-06-05 16:01:39 +0000124** Allocate a new Select structure and return a pointer to that
125** structure.
drhcce7d172000-05-31 15:34:51 +0000126*/
danielk19774adee202004-05-08 08:23:19 +0000127Select *sqlite3SelectNew(
drh17435752007-08-16 04:30:38 +0000128 Parse *pParse, /* Parsing context */
drhdaffd0e2001-04-11 14:28:42 +0000129 ExprList *pEList, /* which columns to include in the result */
drhad3cab52002-05-24 02:04:32 +0000130 SrcList *pSrc, /* the FROM clause -- which tables to scan */
drhdaffd0e2001-04-11 14:28:42 +0000131 Expr *pWhere, /* the WHERE clause */
132 ExprList *pGroupBy, /* the GROUP BY clause */
133 Expr *pHaving, /* the HAVING clause */
134 ExprList *pOrderBy, /* the ORDER BY clause */
drhc3489bb2016-02-25 16:04:59 +0000135 u32 selFlags, /* Flag parameters, such as SF_Distinct */
drh8c0833f2017-11-14 23:48:23 +0000136 Expr *pLimit /* LIMIT value. NULL means not used */
drh9bb61fe2000-06-05 16:01:39 +0000137){
138 Select *pNew;
drheda639e2006-01-22 00:42:09 +0000139 Select standin;
drhef90a6b2017-04-11 16:44:39 +0000140 pNew = sqlite3DbMallocRawNN(pParse->db, sizeof(*pNew) );
drhdaffd0e2001-04-11 14:28:42 +0000141 if( pNew==0 ){
drhef90a6b2017-04-11 16:44:39 +0000142 assert( pParse->db->mallocFailed );
drheda639e2006-01-22 00:42:09 +0000143 pNew = &standin;
drheda639e2006-01-22 00:42:09 +0000144 }
145 if( pEList==0 ){
drh3d240d22017-09-28 16:56:55 +0000146 pEList = sqlite3ExprListAppend(pParse, 0,
147 sqlite3Expr(pParse->db,TK_ASTERISK,0));
drheda639e2006-01-22 00:42:09 +0000148 }
149 pNew->pEList = pEList;
drhca3862d2016-01-08 12:46:39 +0000150 pNew->op = TK_SELECT;
151 pNew->selFlags = selFlags;
152 pNew->iLimit = 0;
153 pNew->iOffset = 0;
drh9ca33fa2016-01-12 02:00:24 +0000154#if SELECTTRACE_ENABLED
155 pNew->zSelName[0] = 0;
156#endif
drhca3862d2016-01-08 12:46:39 +0000157 pNew->addrOpenEphm[0] = -1;
158 pNew->addrOpenEphm[1] = -1;
159 pNew->nSelectRow = 0;
drhef90a6b2017-04-11 16:44:39 +0000160 if( pSrc==0 ) pSrc = sqlite3DbMallocZero(pParse->db, sizeof(*pSrc));
drheda639e2006-01-22 00:42:09 +0000161 pNew->pSrc = pSrc;
162 pNew->pWhere = pWhere;
163 pNew->pGroupBy = pGroupBy;
164 pNew->pHaving = pHaving;
165 pNew->pOrderBy = pOrderBy;
drhca3862d2016-01-08 12:46:39 +0000166 pNew->pPrior = 0;
167 pNew->pNext = 0;
drheda639e2006-01-22 00:42:09 +0000168 pNew->pLimit = pLimit;
drhca3862d2016-01-08 12:46:39 +0000169 pNew->pWith = 0;
dan67a9b8e2018-06-22 20:51:35 +0000170#ifndef SQLITE_OMIT_WINDOWFUNC
dan86fb6e12018-05-16 20:58:07 +0000171 pNew->pWin = 0;
dane3bf6322018-06-08 20:58:27 +0000172 pNew->pWinDefn = 0;
dan67a9b8e2018-06-22 20:51:35 +0000173#endif
drhef90a6b2017-04-11 16:44:39 +0000174 if( pParse->db->mallocFailed ) {
175 clearSelect(pParse->db, pNew, pNew!=&standin);
drheda639e2006-01-22 00:42:09 +0000176 pNew = 0;
drha464c232011-09-16 19:04:03 +0000177 }else{
178 assert( pNew->pSrc!=0 || pParse->nErr>0 );
drhdaffd0e2001-04-11 14:28:42 +0000179 }
drh338ec3e2011-10-11 20:14:41 +0000180 assert( pNew!=&standin );
drh9bb61fe2000-06-05 16:01:39 +0000181 return pNew;
182}
183
drheb9b8842014-09-21 00:27:26 +0000184#if SELECTTRACE_ENABLED
185/*
186** Set the name of a Select object
187*/
188void sqlite3SelectSetName(Select *p, const char *zName){
189 if( p && zName ){
190 sqlite3_snprintf(sizeof(p->zSelName), p->zSelName, "%s", zName);
191 }
192}
193#endif
194
195
drh9bb61fe2000-06-05 16:01:39 +0000196/*
drheda639e2006-01-22 00:42:09 +0000197** Delete the given Select structure and all of its substructures.
198*/
drh633e6d52008-07-28 19:34:53 +0000199void sqlite3SelectDelete(sqlite3 *db, Select *p){
drh8906a4b2017-10-03 17:29:40 +0000200 if( OK_IF_ALWAYS_TRUE(p) ) clearSelect(db, p, 1);
drheda639e2006-01-22 00:42:09 +0000201}
202
203/*
drhd227a292014-02-09 18:02:09 +0000204** Return a pointer to the right-most SELECT statement in a compound.
205*/
206static Select *findRightmost(Select *p){
207 while( p->pNext ) p = p->pNext;
208 return p;
drh9bb61fe2000-06-05 16:01:39 +0000209}
210
211/*
drhf7b54962013-05-28 12:11:54 +0000212** Given 1 to 3 identifiers preceding the JOIN keyword, determine the
drh01f3f252002-05-24 16:14:15 +0000213** type of join. Return an integer constant that expresses that type
214** in terms of the following bit values:
215**
216** JT_INNER
drh3dec2232005-09-10 15:28:09 +0000217** JT_CROSS
drh01f3f252002-05-24 16:14:15 +0000218** JT_OUTER
219** JT_NATURAL
220** JT_LEFT
221** JT_RIGHT
222**
223** A full outer join is the combination of JT_LEFT and JT_RIGHT.
224**
225** If an illegal or unsupported join type is seen, then still return
226** a join type, but put an error in the pParse structure.
227*/
danielk19774adee202004-05-08 08:23:19 +0000228int sqlite3JoinType(Parse *pParse, Token *pA, Token *pB, Token *pC){
drh01f3f252002-05-24 16:14:15 +0000229 int jointype = 0;
230 Token *apAll[3];
231 Token *p;
drh373cc2d2009-05-17 02:06:14 +0000232 /* 0123456789 123456789 123456789 123 */
233 static const char zKeyText[] = "naturaleftouterightfullinnercross";
drh57196282004-10-06 15:41:16 +0000234 static const struct {
drh373cc2d2009-05-17 02:06:14 +0000235 u8 i; /* Beginning of keyword text in zKeyText[] */
236 u8 nChar; /* Length of the keyword in characters */
237 u8 code; /* Join type mask */
238 } aKeyword[] = {
239 /* natural */ { 0, 7, JT_NATURAL },
240 /* left */ { 6, 4, JT_LEFT|JT_OUTER },
241 /* outer */ { 10, 5, JT_OUTER },
242 /* right */ { 14, 5, JT_RIGHT|JT_OUTER },
243 /* full */ { 19, 4, JT_LEFT|JT_RIGHT|JT_OUTER },
244 /* inner */ { 23, 5, JT_INNER },
245 /* cross */ { 28, 5, JT_INNER|JT_CROSS },
drh01f3f252002-05-24 16:14:15 +0000246 };
247 int i, j;
248 apAll[0] = pA;
249 apAll[1] = pB;
250 apAll[2] = pC;
drh195e6962002-05-25 00:18:20 +0000251 for(i=0; i<3 && apAll[i]; i++){
drh01f3f252002-05-24 16:14:15 +0000252 p = apAll[i];
drh373cc2d2009-05-17 02:06:14 +0000253 for(j=0; j<ArraySize(aKeyword); j++){
254 if( p->n==aKeyword[j].nChar
255 && sqlite3StrNICmp((char*)p->z, &zKeyText[aKeyword[j].i], p->n)==0 ){
256 jointype |= aKeyword[j].code;
drh01f3f252002-05-24 16:14:15 +0000257 break;
258 }
259 }
drh373cc2d2009-05-17 02:06:14 +0000260 testcase( j==0 || j==1 || j==2 || j==3 || j==4 || j==5 || j==6 );
261 if( j>=ArraySize(aKeyword) ){
drh01f3f252002-05-24 16:14:15 +0000262 jointype |= JT_ERROR;
263 break;
264 }
265 }
drhad2d8302002-05-24 20:31:36 +0000266 if(
267 (jointype & (JT_INNER|JT_OUTER))==(JT_INNER|JT_OUTER) ||
drh195e6962002-05-25 00:18:20 +0000268 (jointype & JT_ERROR)!=0
drhad2d8302002-05-24 20:31:36 +0000269 ){
drha9671a22008-07-08 23:40:20 +0000270 const char *zSp = " ";
271 assert( pB!=0 );
272 if( pC==0 ){ zSp++; }
drhae29ffb2004-09-25 14:39:18 +0000273 sqlite3ErrorMsg(pParse, "unknown or unsupported join type: "
drha9671a22008-07-08 23:40:20 +0000274 "%T %T%s%T", pA, pB, zSp, pC);
drh01f3f252002-05-24 16:14:15 +0000275 jointype = JT_INNER;
drh373cc2d2009-05-17 02:06:14 +0000276 }else if( (jointype & JT_OUTER)!=0
277 && (jointype & (JT_LEFT|JT_RIGHT))!=JT_LEFT ){
danielk19774adee202004-05-08 08:23:19 +0000278 sqlite3ErrorMsg(pParse,
drhda93d232003-03-31 02:12:46 +0000279 "RIGHT and FULL OUTER JOINs are not currently supported");
drh195e6962002-05-25 00:18:20 +0000280 jointype = JT_INNER;
drh01f3f252002-05-24 16:14:15 +0000281 }
282 return jointype;
283}
284
285/*
drhad2d8302002-05-24 20:31:36 +0000286** Return the index of a column in a table. Return -1 if the column
287** is not contained in the table.
288*/
289static int columnIndex(Table *pTab, const char *zCol){
290 int i;
291 for(i=0; i<pTab->nCol; i++){
danielk19774adee202004-05-08 08:23:19 +0000292 if( sqlite3StrICmp(pTab->aCol[i].zName, zCol)==0 ) return i;
drhad2d8302002-05-24 20:31:36 +0000293 }
294 return -1;
295}
296
297/*
drh2179b432009-12-09 17:36:39 +0000298** Search the first N tables in pSrc, from left to right, looking for a
299** table that has a column named zCol.
300**
301** When found, set *piTab and *piCol to the table index and column index
302** of the matching column and return TRUE.
303**
304** If not found, return FALSE.
305*/
306static int tableAndColumnIndex(
307 SrcList *pSrc, /* Array of tables to search */
308 int N, /* Number of tables in pSrc->a[] to search */
309 const char *zCol, /* Name of the column we are looking for */
310 int *piTab, /* Write index of pSrc->a[] here */
311 int *piCol /* Write index of pSrc->a[*piTab].pTab->aCol[] here */
312){
313 int i; /* For looping over tables in pSrc */
314 int iCol; /* Index of column matching zCol */
315
316 assert( (piTab==0)==(piCol==0) ); /* Both or neither are NULL */
317 for(i=0; i<N; i++){
318 iCol = columnIndex(pSrc->a[i].pTab, zCol);
319 if( iCol>=0 ){
320 if( piTab ){
321 *piTab = i;
322 *piCol = iCol;
323 }
324 return 1;
325 }
326 }
327 return 0;
328}
329
330/*
danf7b0b0a2009-10-19 15:52:32 +0000331** This function is used to add terms implied by JOIN syntax to the
332** WHERE clause expression of a SELECT statement. The new term, which
333** is ANDed with the existing WHERE clause, is of the form:
334**
335** (tab1.col1 = tab2.col2)
336**
337** where tab1 is the iSrc'th table in SrcList pSrc and tab2 is the
338** (iSrc+1)'th. Column col1 is column iColLeft of tab1, and col2 is
339** column iColRight of tab2.
drhad2d8302002-05-24 20:31:36 +0000340*/
341static void addWhereTerm(
danf7b0b0a2009-10-19 15:52:32 +0000342 Parse *pParse, /* Parsing context */
343 SrcList *pSrc, /* List of tables in FROM clause */
drh2179b432009-12-09 17:36:39 +0000344 int iLeft, /* Index of first table to join in pSrc */
danf7b0b0a2009-10-19 15:52:32 +0000345 int iColLeft, /* Index of column in first table */
drh2179b432009-12-09 17:36:39 +0000346 int iRight, /* Index of second table in pSrc */
danf7b0b0a2009-10-19 15:52:32 +0000347 int iColRight, /* Index of column in second table */
348 int isOuterJoin, /* True if this is an OUTER join */
349 Expr **ppWhere /* IN/OUT: The WHERE clause to add to */
drhad2d8302002-05-24 20:31:36 +0000350){
danf7b0b0a2009-10-19 15:52:32 +0000351 sqlite3 *db = pParse->db;
352 Expr *pE1;
353 Expr *pE2;
354 Expr *pEq;
drhad2d8302002-05-24 20:31:36 +0000355
drh2179b432009-12-09 17:36:39 +0000356 assert( iLeft<iRight );
357 assert( pSrc->nSrc>iRight );
358 assert( pSrc->a[iLeft].pTab );
359 assert( pSrc->a[iRight].pTab );
danf7b0b0a2009-10-19 15:52:32 +0000360
drh2179b432009-12-09 17:36:39 +0000361 pE1 = sqlite3CreateColumnExpr(db, pSrc, iLeft, iColLeft);
362 pE2 = sqlite3CreateColumnExpr(db, pSrc, iRight, iColRight);
danf7b0b0a2009-10-19 15:52:32 +0000363
drhabfd35e2016-12-06 22:47:23 +0000364 pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2);
danf7b0b0a2009-10-19 15:52:32 +0000365 if( pEq && isOuterJoin ){
366 ExprSetProperty(pEq, EP_FromJoin);
drhc5cd1242013-09-12 16:50:49 +0000367 assert( !ExprHasProperty(pEq, EP_TokenOnly|EP_Reduced) );
drhebb6a652013-09-12 23:42:22 +0000368 ExprSetVVAProperty(pEq, EP_NoReduce);
danf7b0b0a2009-10-19 15:52:32 +0000369 pEq->iRightJoinTable = (i16)pE2->iTable;
drh030530d2005-01-18 17:40:04 +0000370 }
danf7b0b0a2009-10-19 15:52:32 +0000371 *ppWhere = sqlite3ExprAnd(db, *ppWhere, pEq);
drhad2d8302002-05-24 20:31:36 +0000372}
373
374/*
drh1f162302002-10-27 19:35:33 +0000375** Set the EP_FromJoin property on all terms of the given expression.
drh22d6a532005-09-19 21:05:48 +0000376** And set the Expr.iRightJoinTable to iTable for every term in the
377** expression.
drh1cc093c2002-06-24 22:01:57 +0000378**
drhe78e8282003-01-19 03:59:45 +0000379** The EP_FromJoin property is used on terms of an expression to tell
drh1cc093c2002-06-24 22:01:57 +0000380** the LEFT OUTER JOIN processing logic that this term is part of the
drh1f162302002-10-27 19:35:33 +0000381** join restriction specified in the ON or USING clause and not a part
382** of the more general WHERE clause. These terms are moved over to the
383** WHERE clause during join processing but we need to remember that they
384** originated in the ON or USING clause.
drh22d6a532005-09-19 21:05:48 +0000385**
386** The Expr.iRightJoinTable tells the WHERE clause processing that the
387** expression depends on table iRightJoinTable even if that table is not
388** explicitly mentioned in the expression. That information is needed
389** for cases like this:
390**
391** SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.b AND t1.x=5
392**
393** The where clause needs to defer the handling of the t1.x=5
394** term until after the t2 loop of the join. In that way, a
395** NULL t2 row will be inserted whenever t1.x!=5. If we do not
396** defer the handling of t1.x=5, it will be processed immediately
397** after the t1 loop and rows with t1.x!=5 will never appear in
398** the output, which is incorrect.
drh1cc093c2002-06-24 22:01:57 +0000399*/
drh22d6a532005-09-19 21:05:48 +0000400static void setJoinExpr(Expr *p, int iTable){
drh1cc093c2002-06-24 22:01:57 +0000401 while( p ){
drh1f162302002-10-27 19:35:33 +0000402 ExprSetProperty(p, EP_FromJoin);
drhc5cd1242013-09-12 16:50:49 +0000403 assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
drhebb6a652013-09-12 23:42:22 +0000404 ExprSetVVAProperty(p, EP_NoReduce);
shanecf697392009-06-01 16:53:09 +0000405 p->iRightJoinTable = (i16)iTable;
drh606f2342015-06-18 14:32:51 +0000406 if( p->op==TK_FUNCTION && p->x.pList ){
407 int i;
408 for(i=0; i<p->x.pList->nExpr; i++){
409 setJoinExpr(p->x.pList->a[i].pExpr, iTable);
410 }
411 }
drh22d6a532005-09-19 21:05:48 +0000412 setJoinExpr(p->pLeft, iTable);
drh1cc093c2002-06-24 22:01:57 +0000413 p = p->pRight;
414 }
415}
416
drh25897872018-03-20 21:16:15 +0000417/* Undo the work of setJoinExpr(). In the expression tree p, convert every
418** term that is marked with EP_FromJoin and iRightJoinTable==iTable into
419** an ordinary term that omits the EP_FromJoin mark.
420**
421** This happens when a LEFT JOIN is simplified into an ordinary JOIN.
422*/
423static void unsetJoinExpr(Expr *p, int iTable){
424 while( p ){
drh7fbb1012018-03-21 01:59:46 +0000425 if( ExprHasProperty(p, EP_FromJoin)
426 && (iTable<0 || p->iRightJoinTable==iTable) ){
drh25897872018-03-20 21:16:15 +0000427 ExprClearProperty(p, EP_FromJoin);
428 }
429 if( p->op==TK_FUNCTION && p->x.pList ){
430 int i;
431 for(i=0; i<p->x.pList->nExpr; i++){
432 unsetJoinExpr(p->x.pList->a[i].pExpr, iTable);
433 }
434 }
435 unsetJoinExpr(p->pLeft, iTable);
436 p = p->pRight;
437 }
438}
439
drh1cc093c2002-06-24 22:01:57 +0000440/*
drhad2d8302002-05-24 20:31:36 +0000441** This routine processes the join information for a SELECT statement.
442** ON and USING clauses are converted into extra terms of the WHERE clause.
443** NATURAL joins also create extra WHERE clause terms.
444**
drh91bb0ee2004-09-01 03:06:34 +0000445** The terms of a FROM clause are contained in the Select.pSrc structure.
446** The left most table is the first entry in Select.pSrc. The right-most
447** table is the last entry. The join operator is held in the entry to
448** the left. Thus entry 0 contains the join operator for the join between
449** entries 0 and 1. Any ON or USING clauses associated with the join are
450** also attached to the left entry.
451**
drhad2d8302002-05-24 20:31:36 +0000452** This routine returns the number of errors encountered.
453*/
454static int sqliteProcessJoin(Parse *pParse, Select *p){
drh91bb0ee2004-09-01 03:06:34 +0000455 SrcList *pSrc; /* All tables in the FROM clause */
456 int i, j; /* Loop counters */
457 struct SrcList_item *pLeft; /* Left table being joined */
458 struct SrcList_item *pRight; /* Right table being joined */
drhad2d8302002-05-24 20:31:36 +0000459
drh91bb0ee2004-09-01 03:06:34 +0000460 pSrc = p->pSrc;
461 pLeft = &pSrc->a[0];
462 pRight = &pLeft[1];
463 for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){
drh91bb0ee2004-09-01 03:06:34 +0000464 Table *pRightTab = pRight->pTab;
drhad27e762008-03-26 12:46:23 +0000465 int isOuter;
drh91bb0ee2004-09-01 03:06:34 +0000466
drhce2c4822017-10-03 17:17:34 +0000467 if( NEVER(pLeft->pTab==0 || pRightTab==0) ) continue;
drh8a48b9c2015-08-19 15:20:00 +0000468 isOuter = (pRight->fg.jointype & JT_OUTER)!=0;
drhad2d8302002-05-24 20:31:36 +0000469
470 /* When the NATURAL keyword is present, add WHERE clause terms for
471 ** every column that the two tables have in common.
472 */
drh8a48b9c2015-08-19 15:20:00 +0000473 if( pRight->fg.jointype & JT_NATURAL ){
drh61dfc312006-12-16 16:25:15 +0000474 if( pRight->pOn || pRight->pUsing ){
danielk19774adee202004-05-08 08:23:19 +0000475 sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
drhad2d8302002-05-24 20:31:36 +0000476 "an ON or USING clause", 0);
drhad2d8302002-05-24 20:31:36 +0000477 return 1;
478 }
drh2179b432009-12-09 17:36:39 +0000479 for(j=0; j<pRightTab->nCol; j++){
480 char *zName; /* Name of column in the right table */
481 int iLeft; /* Matching left table */
482 int iLeftCol; /* Matching column in the left table */
483
484 zName = pRightTab->aCol[j].zName;
485 if( tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol) ){
486 addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, j,
487 isOuter, &p->pWhere);
drhad2d8302002-05-24 20:31:36 +0000488 }
489 }
490 }
491
492 /* Disallow both ON and USING clauses in the same join
493 */
drh61dfc312006-12-16 16:25:15 +0000494 if( pRight->pOn && pRight->pUsing ){
danielk19774adee202004-05-08 08:23:19 +0000495 sqlite3ErrorMsg(pParse, "cannot have both ON and USING "
drhda93d232003-03-31 02:12:46 +0000496 "clauses in the same join");
drhad2d8302002-05-24 20:31:36 +0000497 return 1;
498 }
499
500 /* Add the ON clause to the end of the WHERE clause, connected by
drh91bb0ee2004-09-01 03:06:34 +0000501 ** an AND operator.
drhad2d8302002-05-24 20:31:36 +0000502 */
drh61dfc312006-12-16 16:25:15 +0000503 if( pRight->pOn ){
drhad27e762008-03-26 12:46:23 +0000504 if( isOuter ) setJoinExpr(pRight->pOn, pRight->iCursor);
drh17435752007-08-16 04:30:38 +0000505 p->pWhere = sqlite3ExprAnd(pParse->db, p->pWhere, pRight->pOn);
drh61dfc312006-12-16 16:25:15 +0000506 pRight->pOn = 0;
drhad2d8302002-05-24 20:31:36 +0000507 }
508
509 /* Create extra terms on the WHERE clause for each column named
510 ** in the USING clause. Example: If the two tables to be joined are
511 ** A and B and the USING clause names X, Y, and Z, then add this
512 ** to the WHERE clause: A.X=B.X AND A.Y=B.Y AND A.Z=B.Z
513 ** Report an error if any column mentioned in the USING clause is
514 ** not contained in both tables to be joined.
515 */
drh61dfc312006-12-16 16:25:15 +0000516 if( pRight->pUsing ){
517 IdList *pList = pRight->pUsing;
drhad2d8302002-05-24 20:31:36 +0000518 for(j=0; j<pList->nId; j++){
drh2179b432009-12-09 17:36:39 +0000519 char *zName; /* Name of the term in the USING clause */
520 int iLeft; /* Table on the left with matching column name */
521 int iLeftCol; /* Column number of matching column on the left */
522 int iRightCol; /* Column number of matching column on the right */
523
524 zName = pList->a[j].zName;
525 iRightCol = columnIndex(pRightTab, zName);
526 if( iRightCol<0
527 || !tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol)
528 ){
danielk19774adee202004-05-08 08:23:19 +0000529 sqlite3ErrorMsg(pParse, "cannot join using column %s - column "
drh91bb0ee2004-09-01 03:06:34 +0000530 "not present in both tables", zName);
drhad2d8302002-05-24 20:31:36 +0000531 return 1;
532 }
drh2179b432009-12-09 17:36:39 +0000533 addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, iRightCol,
534 isOuter, &p->pWhere);
drhad2d8302002-05-24 20:31:36 +0000535 }
536 }
537 }
538 return 0;
539}
540
541/*
drhbbd4ae52018-04-30 19:32:49 +0000542** An instance of this object holds information (beyond pParse and pSelect)
543** needed to load the next result row that is to be added to the sorter.
544*/
545typedef struct RowLoadInfo RowLoadInfo;
546struct RowLoadInfo {
547 int regResult; /* Store results in array of registers here */
548 u8 ecelFlags; /* Flag argument to ExprCodeExprList() */
549#ifdef SQLITE_ENABLE_SORTER_REFERENCES
550 ExprList *pExtra; /* Extra columns needed by sorter refs */
551 int regExtraResult; /* Where to load the extra columns */
552#endif
553};
554
555/*
556** This routine does the work of loading query data into an array of
557** registers so that it can be added to the sorter.
558*/
559static void innerLoopLoadRow(
560 Parse *pParse, /* Statement under construction */
561 Select *pSelect, /* The query being coded */
562 RowLoadInfo *pInfo /* Info needed to complete the row load */
563){
564 sqlite3ExprCodeExprList(pParse, pSelect->pEList, pInfo->regResult,
565 0, pInfo->ecelFlags);
566#ifdef SQLITE_ENABLE_SORTER_REFERENCES
567 if( pInfo->pExtra ){
568 sqlite3ExprCodeExprList(pParse, pInfo->pExtra, pInfo->regExtraResult, 0, 0);
569 sqlite3ExprListDelete(pParse->db, pInfo->pExtra);
570 }
571#endif
572}
573
574/*
575** Code the OP_MakeRecord instruction that generates the entry to be
576** added into the sorter.
577**
578** Return the register in which the result is stored.
579*/
580static int makeSorterRecord(
581 Parse *pParse,
582 SortCtx *pSort,
583 Select *pSelect,
584 int regBase,
585 int nBase
586){
587 int nOBSat = pSort->nOBSat;
588 Vdbe *v = pParse->pVdbe;
589 int regOut = ++pParse->nMem;
590 if( pSort->pDeferredRowLoad ){
591 innerLoopLoadRow(pParse, pSelect, pSort->pDeferredRowLoad);
592 }
593 sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regOut);
594 return regOut;
595}
596
597/*
drhf45f2322014-03-23 17:45:03 +0000598** Generate code that will push the record in registers regData
599** through regData+nData-1 onto the sorter.
drhc926afb2002-06-20 03:38:26 +0000600*/
drhd59ba6c2006-01-08 05:02:54 +0000601static void pushOntoSorter(
602 Parse *pParse, /* Parser context */
drh079a3072014-03-19 14:10:55 +0000603 SortCtx *pSort, /* Information about the ORDER BY clause */
drhb7654112008-01-12 12:48:07 +0000604 Select *pSelect, /* The whole SELECT statement */
drhf45f2322014-03-23 17:45:03 +0000605 int regData, /* First register holding data to be sorted */
drh5579d592015-08-26 14:01:41 +0000606 int regOrigData, /* First register holding data before packing */
drhbbd4ae52018-04-30 19:32:49 +0000607 int nData, /* Number of elements in the regData data array */
drhfd0a2f92014-03-24 18:08:15 +0000608 int nPrefixReg /* No. of reg prior to regData available for use */
drhd59ba6c2006-01-08 05:02:54 +0000609){
drhf45f2322014-03-23 17:45:03 +0000610 Vdbe *v = pParse->pVdbe; /* Stmt under construction */
dan78d58432014-03-25 15:04:07 +0000611 int bSeq = ((pSort->sortFlags & SORTFLAG_UseSorter)==0);
drhf45f2322014-03-23 17:45:03 +0000612 int nExpr = pSort->pOrderBy->nExpr; /* No. of ORDER BY terms */
dan78d58432014-03-25 15:04:07 +0000613 int nBase = nExpr + bSeq + nData; /* Fields in sorter record */
drhfd0a2f92014-03-24 18:08:15 +0000614 int regBase; /* Regs for sorter record */
drhbbd4ae52018-04-30 19:32:49 +0000615 int regRecord = 0; /* Assembled sorter record */
dan78d58432014-03-25 15:04:07 +0000616 int nOBSat = pSort->nOBSat; /* ORDER BY terms to skip */
617 int op; /* Opcode to add sorter record to sorter */
drha04a8be2016-01-13 17:50:10 +0000618 int iLimit; /* LIMIT counter */
drhbbd4ae52018-04-30 19:32:49 +0000619 int iSkip = 0; /* End of the sorter insert loop */
drhf45f2322014-03-23 17:45:03 +0000620
dan78d58432014-03-25 15:04:07 +0000621 assert( bSeq==0 || bSeq==1 );
drhbbd4ae52018-04-30 19:32:49 +0000622
623 /* Three cases:
624 ** (1) The data to be sorted has already been packed into a Record
625 ** by a prior OP_MakeRecord. In this case nData==1 and regData
626 ** will be completely unrelated to regOrigData.
627 ** (2) All output columns are included in the sort record. In that
628 ** case regData==regOrigData.
629 ** (3) Some output columns are omitted from the sort record due to
630 ** the SQLITE_ENABLE_SORTER_REFERENCE optimization, or due to the
drhc6f36fa2018-05-05 16:50:35 +0000631 ** SQLITE_ECEL_OMITREF optimization, or due to the
632 ** SortCtx.pDeferredRowLoad optimiation. In any of these cases
633 ** regOrigData is 0 to prevent this routine from trying to copy
634 ** values that might not yet exist.
drhbbd4ae52018-04-30 19:32:49 +0000635 */
dan9af90b72016-11-11 18:08:59 +0000636 assert( nData==1 || regData==regOrigData || regOrigData==0 );
drhbbd4ae52018-04-30 19:32:49 +0000637
drhfd0a2f92014-03-24 18:08:15 +0000638 if( nPrefixReg ){
dan78d58432014-03-25 15:04:07 +0000639 assert( nPrefixReg==nExpr+bSeq );
drhbbd4ae52018-04-30 19:32:49 +0000640 regBase = regData - nPrefixReg;
drhfd0a2f92014-03-24 18:08:15 +0000641 }else{
drhfb0d6e52014-05-02 13:09:06 +0000642 regBase = pParse->nMem + 1;
643 pParse->nMem += nBase;
drhfd0a2f92014-03-24 18:08:15 +0000644 }
drha04a8be2016-01-13 17:50:10 +0000645 assert( pSelect->iOffset==0 || pSelect->iLimit!=0 );
646 iLimit = pSelect->iOffset ? pSelect->iOffset+1 : pSelect->iLimit;
647 pSort->labelDone = sqlite3VdbeMakeLabel(v);
drh5579d592015-08-26 14:01:41 +0000648 sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, regOrigData,
dan9af90b72016-11-11 18:08:59 +0000649 SQLITE_ECEL_DUP | (regOrigData? SQLITE_ECEL_REF : 0));
dan78d58432014-03-25 15:04:07 +0000650 if( bSeq ){
651 sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr);
drhfd0a2f92014-03-24 18:08:15 +0000652 }
dan257c13f2016-11-10 20:14:06 +0000653 if( nPrefixReg==0 && nData>0 ){
drh236241a2014-09-12 17:41:30 +0000654 sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+bSeq, nData);
dan78d58432014-03-25 15:04:07 +0000655 }
drh079a3072014-03-19 14:10:55 +0000656 if( nOBSat>0 ){
657 int regPrevKey; /* The first nOBSat columns of the previous row */
658 int addrFirst; /* Address of the OP_IfNot opcode */
659 int addrJmp; /* Address of the OP_Jump opcode */
660 VdbeOp *pOp; /* Opcode that opens the sorter */
661 int nKey; /* Number of sorting key columns, including OP_Sequence */
drhdbfca2b2014-03-22 02:19:53 +0000662 KeyInfo *pKI; /* Original KeyInfo on the sorter table */
drh079a3072014-03-19 14:10:55 +0000663
drhbbd4ae52018-04-30 19:32:49 +0000664 regRecord = makeSorterRecord(pParse, pSort, pSelect, regBase, nBase);
drh26d7e7c2014-03-19 16:56:58 +0000665 regPrevKey = pParse->nMem+1;
666 pParse->nMem += pSort->nOBSat;
dan78d58432014-03-25 15:04:07 +0000667 nKey = nExpr - pSort->nOBSat + bSeq;
668 if( bSeq ){
669 addrFirst = sqlite3VdbeAddOp1(v, OP_IfNot, regBase+nExpr);
670 }else{
671 addrFirst = sqlite3VdbeAddOp1(v, OP_SequenceTest, pSort->iECursor);
672 }
673 VdbeCoverage(v);
drh26d7e7c2014-03-19 16:56:58 +0000674 sqlite3VdbeAddOp3(v, OP_Compare, regPrevKey, regBase, pSort->nOBSat);
drh079a3072014-03-19 14:10:55 +0000675 pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex);
drh59b8f2e2014-03-22 00:27:14 +0000676 if( pParse->db->mallocFailed ) return;
drhfb0d6e52014-05-02 13:09:06 +0000677 pOp->p2 = nKey + nData;
drhdbfca2b2014-03-22 02:19:53 +0000678 pKI = pOp->p4.pKeyInfo;
drha485ad12017-08-02 22:43:14 +0000679 memset(pKI->aSortOrder, 0, pKI->nKeyField); /* Makes OP_Jump testable */
drhdbfca2b2014-03-22 02:19:53 +0000680 sqlite3VdbeChangeP4(v, -1, (char*)pKI, P4_KEYINFO);
drha485ad12017-08-02 22:43:14 +0000681 testcase( pKI->nAllField > pKI->nKeyField+2 );
danf9eae182018-05-21 19:45:11 +0000682 pOp->p4.pKeyInfo = sqlite3KeyInfoFromExprList(pParse,pSort->pOrderBy,nOBSat,
drha485ad12017-08-02 22:43:14 +0000683 pKI->nAllField-pKI->nKeyField-1);
drh079a3072014-03-19 14:10:55 +0000684 addrJmp = sqlite3VdbeCurrentAddr(v);
685 sqlite3VdbeAddOp3(v, OP_Jump, addrJmp+1, 0, addrJmp+1); VdbeCoverage(v);
686 pSort->labelBkOut = sqlite3VdbeMakeLabel(v);
687 pSort->regReturn = ++pParse->nMem;
688 sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
drh65ea12c2014-03-19 17:41:36 +0000689 sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor);
drha04a8be2016-01-13 17:50:10 +0000690 if( iLimit ){
691 sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, pSort->labelDone);
692 VdbeCoverage(v);
693 }
drh079a3072014-03-19 14:10:55 +0000694 sqlite3VdbeJumpHere(v, addrFirst);
drh236241a2014-09-12 17:41:30 +0000695 sqlite3ExprCodeMove(pParse, regBase, regPrevKey, pSort->nOBSat);
drh079a3072014-03-19 14:10:55 +0000696 sqlite3VdbeJumpHere(v, addrJmp);
697 }
danf226f032018-04-26 16:13:47 +0000698 if( iLimit ){
699 /* At this point the values for the new sorter entry are stored
700 ** in an array of registers. They need to be composed into a record
701 ** and inserted into the sorter if either (a) there are currently
702 ** less than LIMIT+OFFSET items or (b) the new record is smaller than
703 ** the largest record currently in the sorter. If (b) is true and there
704 ** are already LIMIT+OFFSET items in the sorter, delete the largest
705 ** entry before inserting the new one. This way there are never more
706 ** than LIMIT+OFFSET items in the sorter.
707 **
708 ** If the new record does not need to be inserted into the sorter,
709 ** jump to the next iteration of the loop. Or, if the
710 ** pSort->bOrderedInnerLoop flag is set to indicate that the inner
711 ** loop delivers items in sorted order, jump to the next iteration
712 ** of the outer loop.
713 */
714 int iCsr = pSort->iECursor;
danf226f032018-04-26 16:13:47 +0000715 sqlite3VdbeAddOp2(v, OP_IfNotZero, iLimit, sqlite3VdbeCurrentAddr(v)+4);
716 VdbeCoverage(v);
717 sqlite3VdbeAddOp2(v, OP_Last, iCsr, 0);
drhbbd4ae52018-04-30 19:32:49 +0000718 iSkip = sqlite3VdbeAddOp4Int(v, OP_IdxLE,
719 iCsr, 0, regBase+nOBSat, nExpr-nOBSat);
danf226f032018-04-26 16:13:47 +0000720 VdbeCoverage(v);
721 sqlite3VdbeAddOp1(v, OP_Delete, iCsr);
722 }
drhbbd4ae52018-04-30 19:32:49 +0000723 if( regRecord==0 ){
724 regRecord = makeSorterRecord(pParse, pSort, pSelect, regBase, nBase);
danf226f032018-04-26 16:13:47 +0000725 }
drh079a3072014-03-19 14:10:55 +0000726 if( pSort->sortFlags & SORTFLAG_UseSorter ){
drhc6aff302011-09-01 15:32:47 +0000727 op = OP_SorterInsert;
728 }else{
729 op = OP_IdxInsert;
730 }
drh4a8b0132016-11-09 01:38:56 +0000731 sqlite3VdbeAddOp4Int(v, op, pSort->iECursor, regRecord,
732 regBase+nOBSat, nBase-nOBSat);
drhbbd4ae52018-04-30 19:32:49 +0000733 if( iSkip ){
734 assert( pSort->bOrderedInnerLoop==0 || pSort->bOrderedInnerLoop==1 );
735 sqlite3VdbeChangeP2(v, iSkip,
736 sqlite3VdbeCurrentAddr(v) + pSort->bOrderedInnerLoop);
737 }
drhc926afb2002-06-20 03:38:26 +0000738}
739
740/*
drhec7429a2005-10-06 16:53:14 +0000741** Add code to implement the OFFSET
drhea48eb22004-07-19 23:16:38 +0000742*/
drhec7429a2005-10-06 16:53:14 +0000743static void codeOffset(
drhbab39e12004-07-19 23:38:11 +0000744 Vdbe *v, /* Generate code into this VM */
drhaa9ce702014-01-22 18:07:04 +0000745 int iOffset, /* Register holding the offset counter */
drhb7654112008-01-12 12:48:07 +0000746 int iContinue /* Jump here to skip the current record */
drhea48eb22004-07-19 23:16:38 +0000747){
drha22a75e2014-03-21 18:16:23 +0000748 if( iOffset>0 ){
drh8b0cf382015-10-06 21:07:06 +0000749 sqlite3VdbeAddOp3(v, OP_IfPos, iOffset, iContinue, 1); VdbeCoverage(v);
750 VdbeComment((v, "OFFSET"));
drhea48eb22004-07-19 23:16:38 +0000751 }
drhea48eb22004-07-19 23:16:38 +0000752}
753
754/*
drh98757152008-01-09 23:04:12 +0000755** Add code that will check to make sure the N registers starting at iMem
756** form a distinct entry. iTab is a sorting index that holds previously
drha2a49dc2008-01-02 14:28:13 +0000757** seen combinations of the N values. A new entry is made in iTab
758** if the current N values are new.
759**
760** A jump to addrRepeat is made and the N+1 values are popped from the
761** stack if the top N elements are not distinct.
762*/
763static void codeDistinct(
drh2dcef112008-01-12 19:03:48 +0000764 Parse *pParse, /* Parsing and code generating context */
drha2a49dc2008-01-02 14:28:13 +0000765 int iTab, /* A sorting index used to test for distinctness */
766 int addrRepeat, /* Jump to here if not distinct */
drh477df4b2008-01-05 18:48:24 +0000767 int N, /* Number of elements */
drha2a49dc2008-01-02 14:28:13 +0000768 int iMem /* First element */
769){
drh2dcef112008-01-12 19:03:48 +0000770 Vdbe *v;
771 int r1;
772
773 v = pParse->pVdbe;
774 r1 = sqlite3GetTempReg(pParse);
drh688852a2014-02-17 22:40:43 +0000775 sqlite3VdbeAddOp4Int(v, OP_Found, iTab, addrRepeat, iMem, N); VdbeCoverage(v);
drh1db639c2008-01-17 02:36:28 +0000776 sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, N, r1);
drh9b4eaeb2016-11-09 00:10:33 +0000777 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r1, iMem, N);
drha67b5cb2017-01-07 00:56:01 +0000778 sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
drh2dcef112008-01-12 19:03:48 +0000779 sqlite3ReleaseTempReg(pParse, r1);
drha2a49dc2008-01-02 14:28:13 +0000780}
781
dan24e25d32018-04-14 18:46:20 +0000782#ifdef SQLITE_ENABLE_SORTER_REFERENCES
783/*
784** This function is called as part of inner-loop generation for a SELECT
785** statement with an ORDER BY that is not optimized by an index. It
786** determines the expressions, if any, that the sorter-reference
787** optimization should be used for. The sorter-reference optimization
788** is used for SELECT queries like:
789**
790** SELECT a, bigblob FROM t1 ORDER BY a LIMIT 10
791**
792** If the optimization is used for expression "bigblob", then instead of
793** storing values read from that column in the sorter records, the PK of
794** the row from table t1 is stored instead. Then, as records are extracted from
795** the sorter to return to the user, the required value of bigblob is
796** retrieved directly from table t1. If the values are very large, this
797** can be more efficient than storing them directly in the sorter records.
798**
799** The ExprList_item.bSorterRef flag is set for each expression in pEList
800** for which the sorter-reference optimization should be enabled.
801** Additionally, the pSort->aDefer[] array is populated with entries
802** for all cursors required to evaluate all selected expressions. Finally.
803** output variable (*ppExtra) is set to an expression list containing
804** expressions for all extra PK values that should be stored in the
805** sorter records.
806*/
807static void selectExprDefer(
808 Parse *pParse, /* Leave any error here */
809 SortCtx *pSort, /* Sorter context */
810 ExprList *pEList, /* Expressions destined for sorter */
811 ExprList **ppExtra /* Expressions to append to sorter record */
812){
813 int i;
814 int nDefer = 0;
815 ExprList *pExtra = 0;
816 for(i=0; i<pEList->nExpr; i++){
817 struct ExprList_item *pItem = &pEList->a[i];
818 if( pItem->u.x.iOrderByCol==0 ){
819 Expr *pExpr = pItem->pExpr;
820 Table *pTab = pExpr->pTab;
dan0f86c9d2018-06-01 13:30:45 +0000821 if( pExpr->op==TK_COLUMN && pExpr->iColumn>=0 && pTab && !IsVirtual(pTab)
dan2e3a5a82018-04-16 21:12:42 +0000822 && (pTab->aCol[pExpr->iColumn].colFlags & COLFLAG_SORTERREF)
dan24e25d32018-04-14 18:46:20 +0000823 ){
824 int j;
825 for(j=0; j<nDefer; j++){
826 if( pSort->aDefer[j].iCsr==pExpr->iTable ) break;
827 }
828 if( j==nDefer ){
829 if( nDefer==ArraySize(pSort->aDefer) ){
830 continue;
831 }else{
832 int nKey = 1;
833 int k;
834 Index *pPk = 0;
835 if( !HasRowid(pTab) ){
836 pPk = sqlite3PrimaryKeyIndex(pTab);
837 nKey = pPk->nKeyCol;
838 }
839 for(k=0; k<nKey; k++){
840 Expr *pNew = sqlite3PExpr(pParse, TK_COLUMN, 0, 0);
841 if( pNew ){
842 pNew->iTable = pExpr->iTable;
843 pNew->pTab = pExpr->pTab;
844 pNew->iColumn = pPk ? pPk->aiColumn[k] : -1;
845 pExtra = sqlite3ExprListAppend(pParse, pExtra, pNew);
846 }
847 }
848 pSort->aDefer[nDefer].pTab = pExpr->pTab;
849 pSort->aDefer[nDefer].iCsr = pExpr->iTable;
850 pSort->aDefer[nDefer].nKey = nKey;
851 nDefer++;
852 }
853 }
854 pItem->bSorterRef = 1;
855 }
856 }
857 }
858 pSort->nDefer = (u8)nDefer;
859 *ppExtra = pExtra;
860}
861#endif
862
drhc99130f2005-09-11 11:56:27 +0000863/*
drh22827922000-06-06 17:27:05 +0000864** This routine generates the code for the inside of the inner loop
865** of a SELECT.
drh82c3d632000-06-06 21:56:07 +0000866**
drh2def2f72017-09-15 17:40:34 +0000867** If srcTab is negative, then the p->pEList expressions
drh340309f2014-01-22 00:23:49 +0000868** are evaluated in order to get the data for this row. If srcTab is
drh2def2f72017-09-15 17:40:34 +0000869** zero or more, then data is pulled from srcTab and p->pEList is used only
dan257c13f2016-11-10 20:14:06 +0000870** to get the number of columns and the collation sequence for each column.
drh22827922000-06-06 17:27:05 +0000871*/
drhd2b3e232008-01-23 14:51:49 +0000872static void selectInnerLoop(
drh22827922000-06-06 17:27:05 +0000873 Parse *pParse, /* The parser context */
drhdf199a22002-06-14 22:38:41 +0000874 Select *p, /* The complete select statement being coded */
drh2def2f72017-09-15 17:40:34 +0000875 int srcTab, /* Pull data from this table if non-negative */
drh079a3072014-03-19 14:10:55 +0000876 SortCtx *pSort, /* If not NULL, info on how to process ORDER BY */
drhe8e4af72012-09-21 00:04:28 +0000877 DistinctCtx *pDistinct, /* If not NULL, info on how to process DISTINCT */
danielk19776c8c8ce2008-01-02 16:27:09 +0000878 SelectDest *pDest, /* How to dispose of the results */
drh22827922000-06-06 17:27:05 +0000879 int iContinue, /* Jump here to continue with next row */
drha9671a22008-07-08 23:40:20 +0000880 int iBreak /* Jump here to break out of the inner loop */
drh22827922000-06-06 17:27:05 +0000881){
882 Vdbe *v = pParse->pVdbe;
drhd847eaa2008-01-17 17:15:56 +0000883 int i;
dan9af90b72016-11-11 18:08:59 +0000884 int hasDistinct; /* True if the DISTINCT keyword is present */
drhd847eaa2008-01-17 17:15:56 +0000885 int eDest = pDest->eDest; /* How to dispose of results */
drh2b596da2012-07-23 21:43:19 +0000886 int iParm = pDest->iSDParm; /* First argument to disposal method */
drhd847eaa2008-01-17 17:15:56 +0000887 int nResultCol; /* Number of result columns */
drhfd0a2f92014-03-24 18:08:15 +0000888 int nPrefixReg = 0; /* Number of extra registers before regResult */
drhbbd4ae52018-04-30 19:32:49 +0000889 RowLoadInfo sRowLoadInfo; /* Info for deferred row loading */
drh38640e12002-07-05 21:42:36 +0000890
dan9af90b72016-11-11 18:08:59 +0000891 /* Usually, regResult is the first cell in an array of memory cells
892 ** containing the current result row. In this case regOrig is set to the
893 ** same value. However, if the results are being sent to the sorter, the
894 ** values for any expressions that are also part of the sort-key are omitted
895 ** from this array. In this case regOrig is set to zero. */
896 int regResult; /* Start of memory holding current results */
897 int regOrig; /* Start of memory holding full result (or 0) */
898
drh1c767f02009-01-09 02:49:31 +0000899 assert( v );
drh2def2f72017-09-15 17:40:34 +0000900 assert( p->pEList!=0 );
drhe8e4af72012-09-21 00:04:28 +0000901 hasDistinct = pDistinct ? pDistinct->eTnctType : WHERE_DISTINCT_NOOP;
drh079a3072014-03-19 14:10:55 +0000902 if( pSort && pSort->pOrderBy==0 ) pSort = 0;
903 if( pSort==0 && !hasDistinct ){
drha22a75e2014-03-21 18:16:23 +0000904 assert( iContinue!=0 );
drhaa9ce702014-01-22 18:07:04 +0000905 codeOffset(v, p->iOffset, iContinue);
drhdf199a22002-06-14 22:38:41 +0000906 }
907
drh967e8b72000-06-21 13:59:10 +0000908 /* Pull the requested columns.
drh22827922000-06-06 17:27:05 +0000909 */
drh2def2f72017-09-15 17:40:34 +0000910 nResultCol = p->pEList->nExpr;
drh05a86c52014-02-16 01:55:49 +0000911
drh2b596da2012-07-23 21:43:19 +0000912 if( pDest->iSdst==0 ){
drhfd0a2f92014-03-24 18:08:15 +0000913 if( pSort ){
dan78d58432014-03-25 15:04:07 +0000914 nPrefixReg = pSort->pOrderBy->nExpr;
915 if( !(pSort->sortFlags & SORTFLAG_UseSorter) ) nPrefixReg++;
drhfd0a2f92014-03-24 18:08:15 +0000916 pParse->nMem += nPrefixReg;
917 }
drh2b596da2012-07-23 21:43:19 +0000918 pDest->iSdst = pParse->nMem+1;
drh0acb7e42008-06-25 00:12:41 +0000919 pParse->nMem += nResultCol;
drh05a86c52014-02-16 01:55:49 +0000920 }else if( pDest->iSdst+nResultCol > pParse->nMem ){
921 /* This is an error condition that can result, for example, when a SELECT
922 ** on the right-hand side of an INSERT contains more result columns than
923 ** there are columns in the table on the left. The error will be caught
924 ** and reported later. But we need to make sure enough memory is allocated
925 ** to avoid other spurious errors in the meantime. */
926 pParse->nMem += nResultCol;
drh1013c932008-01-06 00:25:21 +0000927 }
drh05a86c52014-02-16 01:55:49 +0000928 pDest->nSdst = nResultCol;
dan9af90b72016-11-11 18:08:59 +0000929 regOrig = regResult = pDest->iSdst;
drh340309f2014-01-22 00:23:49 +0000930 if( srcTab>=0 ){
931 for(i=0; i<nResultCol; i++){
drhd847eaa2008-01-17 17:15:56 +0000932 sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i);
drh2def2f72017-09-15 17:40:34 +0000933 VdbeComment((v, "%s", p->pEList->a[i].zName));
drh82c3d632000-06-06 21:56:07 +0000934 }
danielk19779ed1dfa2008-01-02 17:11:14 +0000935 }else if( eDest!=SRT_Exists ){
dan24e25d32018-04-14 18:46:20 +0000936#ifdef SQLITE_ENABLE_SORTER_REFERENCES
937 ExprList *pExtra = 0;
938#endif
danielk19779ed1dfa2008-01-02 17:11:14 +0000939 /* If the destination is an EXISTS(...) expression, the actual
940 ** values returned by the SELECT are not required.
941 */
drhbbd4ae52018-04-30 19:32:49 +0000942 u8 ecelFlags; /* "ecel" is an abbreviation of "ExprCodeExprList" */
943 ExprList *pEList;
drhdf553652015-05-18 04:24:27 +0000944 if( eDest==SRT_Mem || eDest==SRT_Output || eDest==SRT_Coroutine ){
945 ecelFlags = SQLITE_ECEL_DUP;
946 }else{
947 ecelFlags = 0;
948 }
danac56ab72017-01-05 17:23:11 +0000949 if( pSort && hasDistinct==0 && eDest!=SRT_EphemTab && eDest!=SRT_Table ){
drh2def2f72017-09-15 17:40:34 +0000950 /* For each expression in p->pEList that is a copy of an expression in
dan257c13f2016-11-10 20:14:06 +0000951 ** the ORDER BY clause (pSort->pOrderBy), set the associated
952 ** iOrderByCol value to one more than the index of the ORDER BY
953 ** expression within the sort-key that pushOntoSorter() will generate.
drh2def2f72017-09-15 17:40:34 +0000954 ** This allows the p->pEList field to be omitted from the sorted record,
dan257c13f2016-11-10 20:14:06 +0000955 ** saving space and CPU cycles. */
956 ecelFlags |= (SQLITE_ECEL_OMITREF|SQLITE_ECEL_REF);
drhbbd4ae52018-04-30 19:32:49 +0000957
dan257c13f2016-11-10 20:14:06 +0000958 for(i=pSort->nOBSat; i<pSort->pOrderBy->nExpr; i++){
959 int j;
960 if( (j = pSort->pOrderBy->a[i].u.x.iOrderByCol)>0 ){
drh2def2f72017-09-15 17:40:34 +0000961 p->pEList->a[j-1].u.x.iOrderByCol = i+1-pSort->nOBSat;
dan257c13f2016-11-10 20:14:06 +0000962 }
963 }
dan24e25d32018-04-14 18:46:20 +0000964#ifdef SQLITE_ENABLE_SORTER_REFERENCES
965 selectExprDefer(pParse, pSort, p->pEList, &pExtra);
drh5a2e65e2018-04-18 19:08:44 +0000966 if( pExtra && pParse->db->mallocFailed==0 ){
dan24e25d32018-04-14 18:46:20 +0000967 /* If there are any extra PK columns to add to the sorter records,
968 ** allocate extra memory cells and adjust the OpenEphemeral
969 ** instruction to account for the larger records. This is only
970 ** required if there are one or more WITHOUT ROWID tables with
971 ** composite primary keys in the SortCtx.aDefer[] array. */
972 VdbeOp *pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex);
973 pOp->p2 += (pExtra->nExpr - pSort->nDefer);
974 pOp->p4.pKeyInfo->nAllField += (pExtra->nExpr - pSort->nDefer);
975 pParse->nMem += pExtra->nExpr;
976 }
977#endif
drhbbd4ae52018-04-30 19:32:49 +0000978
979 /* Adjust nResultCol to account for columns that are omitted
980 ** from the sorter by the optimizations in this branch */
981 pEList = p->pEList;
982 for(i=0; i<pEList->nExpr; i++){
983 if( pEList->a[i].u.x.iOrderByCol>0
984#ifdef SQLITE_ENABLE_SORTER_REFERENCES
985 || pEList->a[i].bSorterRef
986#endif
987 ){
988 nResultCol--;
989 regOrig = 0;
990 }
991 }
992
993 testcase( regOrig );
994 testcase( eDest==SRT_Set );
995 testcase( eDest==SRT_Mem );
996 testcase( eDest==SRT_Coroutine );
997 testcase( eDest==SRT_Output );
dan257c13f2016-11-10 20:14:06 +0000998 assert( eDest==SRT_Set || eDest==SRT_Mem
999 || eDest==SRT_Coroutine || eDest==SRT_Output );
1000 }
drhbbd4ae52018-04-30 19:32:49 +00001001 sRowLoadInfo.regResult = regResult;
1002 sRowLoadInfo.ecelFlags = ecelFlags;
dan24e25d32018-04-14 18:46:20 +00001003#ifdef SQLITE_ENABLE_SORTER_REFERENCES
drhbbd4ae52018-04-30 19:32:49 +00001004 sRowLoadInfo.pExtra = pExtra;
1005 sRowLoadInfo.regExtraResult = regResult + nResultCol;
1006 if( pExtra ) nResultCol += pExtra->nExpr;
dan24e25d32018-04-14 18:46:20 +00001007#endif
drhbbd4ae52018-04-30 19:32:49 +00001008 if( p->iLimit
1009 && (ecelFlags & SQLITE_ECEL_OMITREF)!=0
1010 && nPrefixReg>0
1011 ){
1012 assert( pSort!=0 );
1013 assert( hasDistinct==0 );
1014 pSort->pDeferredRowLoad = &sRowLoadInfo;
drhc6f36fa2018-05-05 16:50:35 +00001015 regOrig = 0;
drhbbd4ae52018-04-30 19:32:49 +00001016 }else{
1017 innerLoopLoadRow(pParse, p, &sRowLoadInfo);
1018 }
drh22827922000-06-06 17:27:05 +00001019 }
1020
drhdaffd0e2001-04-11 14:28:42 +00001021 /* If the DISTINCT keyword was present on the SELECT statement
1022 ** and this row has been seen before, then do not make this row
1023 ** part of the result.
drh22827922000-06-06 17:27:05 +00001024 */
drhea48eb22004-07-19 23:16:38 +00001025 if( hasDistinct ){
drhe8e4af72012-09-21 00:04:28 +00001026 switch( pDistinct->eTnctType ){
1027 case WHERE_DISTINCT_ORDERED: {
1028 VdbeOp *pOp; /* No longer required OpenEphemeral instr. */
1029 int iJump; /* Jump destination */
1030 int regPrev; /* Previous row content */
1031
1032 /* Allocate space for the previous row */
1033 regPrev = pParse->nMem+1;
drh340309f2014-01-22 00:23:49 +00001034 pParse->nMem += nResultCol;
drhe8e4af72012-09-21 00:04:28 +00001035
1036 /* Change the OP_OpenEphemeral coded earlier to an OP_Null
1037 ** sets the MEM_Cleared bit on the first register of the
1038 ** previous value. This will cause the OP_Ne below to always
1039 ** fail on the first iteration of the loop even if the first
1040 ** row is all NULLs.
1041 */
1042 sqlite3VdbeChangeToNoop(v, pDistinct->addrTnct);
1043 pOp = sqlite3VdbeGetOp(v, pDistinct->addrTnct);
1044 pOp->opcode = OP_Null;
1045 pOp->p1 = 1;
1046 pOp->p2 = regPrev;
1047
drh340309f2014-01-22 00:23:49 +00001048 iJump = sqlite3VdbeCurrentAddr(v) + nResultCol;
1049 for(i=0; i<nResultCol; i++){
drh2def2f72017-09-15 17:40:34 +00001050 CollSeq *pColl = sqlite3ExprCollSeq(pParse, p->pEList->a[i].pExpr);
drh340309f2014-01-22 00:23:49 +00001051 if( i<nResultCol-1 ){
drhe8e4af72012-09-21 00:04:28 +00001052 sqlite3VdbeAddOp3(v, OP_Ne, regResult+i, iJump, regPrev+i);
drh688852a2014-02-17 22:40:43 +00001053 VdbeCoverage(v);
drhe8e4af72012-09-21 00:04:28 +00001054 }else{
1055 sqlite3VdbeAddOp3(v, OP_Eq, regResult+i, iContinue, regPrev+i);
drh688852a2014-02-17 22:40:43 +00001056 VdbeCoverage(v);
1057 }
drhe8e4af72012-09-21 00:04:28 +00001058 sqlite3VdbeChangeP4(v, -1, (const char *)pColl, P4_COLLSEQ);
1059 sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
1060 }
drhfcf2a772014-08-12 01:23:07 +00001061 assert( sqlite3VdbeCurrentAddr(v)==iJump || pParse->db->mallocFailed );
drh340309f2014-01-22 00:23:49 +00001062 sqlite3VdbeAddOp3(v, OP_Copy, regResult, regPrev, nResultCol-1);
drhe8e4af72012-09-21 00:04:28 +00001063 break;
1064 }
1065
1066 case WHERE_DISTINCT_UNIQUE: {
1067 sqlite3VdbeChangeToNoop(v, pDistinct->addrTnct);
1068 break;
1069 }
1070
1071 default: {
1072 assert( pDistinct->eTnctType==WHERE_DISTINCT_UNORDERED );
drh38b41492015-06-08 15:08:15 +00001073 codeDistinct(pParse, pDistinct->tabTnct, iContinue, nResultCol,
1074 regResult);
drhe8e4af72012-09-21 00:04:28 +00001075 break;
1076 }
1077 }
drh079a3072014-03-19 14:10:55 +00001078 if( pSort==0 ){
drhaa9ce702014-01-22 18:07:04 +00001079 codeOffset(v, p->iOffset, iContinue);
drhea48eb22004-07-19 23:16:38 +00001080 }
drh22827922000-06-06 17:27:05 +00001081 }
drh82c3d632000-06-06 21:56:07 +00001082
drhc926afb2002-06-20 03:38:26 +00001083 switch( eDest ){
1084 /* In this mode, write each query result to the key of the temporary
1085 ** table iParm.
1086 */
drh13449892005-09-07 21:22:45 +00001087#ifndef SQLITE_OMIT_COMPOUND_SELECT
drhc926afb2002-06-20 03:38:26 +00001088 case SRT_Union: {
drh9cbf3422008-01-17 16:22:13 +00001089 int r1;
1090 r1 = sqlite3GetTempReg(pParse);
drh340309f2014-01-22 00:23:49 +00001091 sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1);
drh9b4eaeb2016-11-09 00:10:33 +00001092 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, regResult, nResultCol);
drh9cbf3422008-01-17 16:22:13 +00001093 sqlite3ReleaseTempReg(pParse, r1);
drhc926afb2002-06-20 03:38:26 +00001094 break;
drh22827922000-06-06 17:27:05 +00001095 }
drh22827922000-06-06 17:27:05 +00001096
drhc926afb2002-06-20 03:38:26 +00001097 /* Construct a record from the query result, but instead of
1098 ** saving that record, use it as a key to delete elements from
1099 ** the temporary table iParm.
1100 */
1101 case SRT_Except: {
drh340309f2014-01-22 00:23:49 +00001102 sqlite3VdbeAddOp3(v, OP_IdxDelete, iParm, regResult, nResultCol);
drhc926afb2002-06-20 03:38:26 +00001103 break;
1104 }
drh781def22014-01-22 13:35:53 +00001105#endif /* SQLITE_OMIT_COMPOUND_SELECT */
danielk19775338a5f2005-01-20 13:03:10 +00001106
1107 /* Store the result as data using a unique key.
1108 */
drh8e1ee882014-03-21 19:56:09 +00001109 case SRT_Fifo:
1110 case SRT_DistFifo:
danielk19775338a5f2005-01-20 13:03:10 +00001111 case SRT_Table:
drhb9bb7c12006-06-11 23:41:55 +00001112 case SRT_EphemTab: {
drhfd0a2f92014-03-24 18:08:15 +00001113 int r1 = sqlite3GetTempRange(pParse, nPrefixReg+1);
drh373cc2d2009-05-17 02:06:14 +00001114 testcase( eDest==SRT_Table );
1115 testcase( eDest==SRT_EphemTab );
drhe2248cf2015-05-22 17:29:27 +00001116 testcase( eDest==SRT_Fifo );
1117 testcase( eDest==SRT_DistFifo );
drhfd0a2f92014-03-24 18:08:15 +00001118 sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1+nPrefixReg);
dan8ce71842014-01-14 20:14:09 +00001119#ifndef SQLITE_OMIT_CTE
drh8e1ee882014-03-21 19:56:09 +00001120 if( eDest==SRT_DistFifo ){
1121 /* If the destination is DistFifo, then cursor (iParm+1) is open
dan8ce71842014-01-14 20:14:09 +00001122 ** on an ephemeral index. If the current row is already present
1123 ** in the index, do not write it to the output. If not, add the
1124 ** current row to the index and proceed with writing it to the
1125 ** output table as well. */
1126 int addr = sqlite3VdbeCurrentAddr(v) + 4;
drh38b41492015-06-08 15:08:15 +00001127 sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0);
1128 VdbeCoverage(v);
drh9b4eaeb2016-11-09 00:10:33 +00001129 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm+1, r1,regResult,nResultCol);
drh079a3072014-03-19 14:10:55 +00001130 assert( pSort==0 );
dan8ce71842014-01-14 20:14:09 +00001131 }
1132#endif
drh079a3072014-03-19 14:10:55 +00001133 if( pSort ){
drhbbd4ae52018-04-30 19:32:49 +00001134 assert( regResult==regOrig );
1135 pushOntoSorter(pParse, pSort, p, r1+nPrefixReg, regOrig, 1, nPrefixReg);
danielk19775338a5f2005-01-20 13:03:10 +00001136 }else{
drhb7654112008-01-12 12:48:07 +00001137 int r2 = sqlite3GetTempReg(pParse);
1138 sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);
1139 sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, r2);
1140 sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
1141 sqlite3ReleaseTempReg(pParse, r2);
danielk19775338a5f2005-01-20 13:03:10 +00001142 }
drhfd0a2f92014-03-24 18:08:15 +00001143 sqlite3ReleaseTempRange(pParse, r1, nPrefixReg+1);
danielk19775338a5f2005-01-20 13:03:10 +00001144 break;
1145 }
drh5974a302000-06-07 14:42:26 +00001146
danielk197793758c82005-01-21 08:13:14 +00001147#ifndef SQLITE_OMIT_SUBQUERY
drhc926afb2002-06-20 03:38:26 +00001148 /* If we are creating a set for an "expr IN (SELECT ...)" construct,
1149 ** then there should be a single item on the stack. Write this
1150 ** item into the set table with bogus data.
1151 */
1152 case SRT_Set: {
drh079a3072014-03-19 14:10:55 +00001153 if( pSort ){
drhde941c62005-08-28 01:34:21 +00001154 /* At first glance you would think we could optimize out the
1155 ** ORDER BY in this case since the order of entries in the set
1156 ** does not matter. But there might be a LIMIT clause, in which
1157 ** case the order does matter */
dan51d82d12016-08-02 18:50:15 +00001158 pushOntoSorter(
dan9af90b72016-11-11 18:08:59 +00001159 pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg);
drhc926afb2002-06-20 03:38:26 +00001160 }else{
drhb7654112008-01-12 12:48:07 +00001161 int r1 = sqlite3GetTempReg(pParse);
dan71c57db2016-07-09 20:23:55 +00001162 assert( sqlite3Strlen30(pDest->zAffSdst)==nResultCol );
1163 sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult, nResultCol,
dan553168c2016-08-01 20:14:31 +00001164 r1, pDest->zAffSdst, nResultCol);
dan71c57db2016-07-09 20:23:55 +00001165 sqlite3ExprCacheAffinityChange(pParse, regResult, nResultCol);
drh9b4eaeb2016-11-09 00:10:33 +00001166 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, regResult, nResultCol);
drhb7654112008-01-12 12:48:07 +00001167 sqlite3ReleaseTempReg(pParse, r1);
drhc926afb2002-06-20 03:38:26 +00001168 }
1169 break;
1170 }
drh22827922000-06-06 17:27:05 +00001171
drh504b6982006-01-22 21:52:56 +00001172 /* If any row exist in the result set, record that fact and abort.
drhec7429a2005-10-06 16:53:14 +00001173 */
1174 case SRT_Exists: {
drh4c583122008-01-04 22:01:03 +00001175 sqlite3VdbeAddOp2(v, OP_Integer, 1, iParm);
drhec7429a2005-10-06 16:53:14 +00001176 /* The LIMIT clause will terminate the loop for us */
1177 break;
1178 }
1179
drhc926afb2002-06-20 03:38:26 +00001180 /* If this is a scalar select that is part of an expression, then
dan870a0702016-08-01 16:37:43 +00001181 ** store the results in the appropriate memory cell or array of
1182 ** memory cells and break out of the scan loop.
drhc926afb2002-06-20 03:38:26 +00001183 */
1184 case SRT_Mem: {
drh079a3072014-03-19 14:10:55 +00001185 if( pSort ){
dan257c13f2016-11-10 20:14:06 +00001186 assert( nResultCol<=pDest->nSdst );
dan870a0702016-08-01 16:37:43 +00001187 pushOntoSorter(
dan9af90b72016-11-11 18:08:59 +00001188 pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg);
drhc926afb2002-06-20 03:38:26 +00001189 }else{
dan257c13f2016-11-10 20:14:06 +00001190 assert( nResultCol==pDest->nSdst );
drh53932ce2014-08-29 12:29:39 +00001191 assert( regResult==iParm );
drhec7429a2005-10-06 16:53:14 +00001192 /* The LIMIT clause will jump out of the loop for us */
drhc926afb2002-06-20 03:38:26 +00001193 }
1194 break;
1195 }
danielk197793758c82005-01-21 08:13:14 +00001196#endif /* #ifndef SQLITE_OMIT_SUBQUERY */
drh22827922000-06-06 17:27:05 +00001197
drh81cf13e2014-02-07 18:27:53 +00001198 case SRT_Coroutine: /* Send data to a co-routine */
1199 case SRT_Output: { /* Return the results */
drh373cc2d2009-05-17 02:06:14 +00001200 testcase( eDest==SRT_Coroutine );
1201 testcase( eDest==SRT_Output );
drh079a3072014-03-19 14:10:55 +00001202 if( pSort ){
dan9af90b72016-11-11 18:08:59 +00001203 pushOntoSorter(pParse, pSort, p, regResult, regOrig, nResultCol,
drh5579d592015-08-26 14:01:41 +00001204 nPrefixReg);
drhe00ee6e2008-06-20 15:24:01 +00001205 }else if( eDest==SRT_Coroutine ){
drh2b596da2012-07-23 21:43:19 +00001206 sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
drhc182d162005-08-14 20:47:16 +00001207 }else{
drh340309f2014-01-22 00:23:49 +00001208 sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nResultCol);
1209 sqlite3ExprCacheAffinityChange(pParse, regResult, nResultCol);
drhac82fcf2002-09-08 17:23:41 +00001210 }
drh142e30d2002-08-28 03:00:58 +00001211 break;
1212 }
1213
drhfe1c6bb2014-01-22 17:28:35 +00001214#ifndef SQLITE_OMIT_CTE
1215 /* Write the results into a priority queue that is order according to
1216 ** pDest->pOrderBy (in pSO). pDest->iSDParm (in iParm) is the cursor for an
1217 ** index with pSO->nExpr+2 columns. Build a key using pSO for the first
1218 ** pSO->nExpr columns, then make sure all keys are unique by adding a
1219 ** final OP_Sequence column. The last column is the record as a blob.
1220 */
1221 case SRT_DistQueue:
1222 case SRT_Queue: {
1223 int nKey;
1224 int r1, r2, r3;
1225 int addrTest = 0;
1226 ExprList *pSO;
1227 pSO = pDest->pOrderBy;
1228 assert( pSO );
1229 nKey = pSO->nExpr;
1230 r1 = sqlite3GetTempReg(pParse);
1231 r2 = sqlite3GetTempRange(pParse, nKey+2);
1232 r3 = r2+nKey+1;
drhfe1c6bb2014-01-22 17:28:35 +00001233 if( eDest==SRT_DistQueue ){
1234 /* If the destination is DistQueue, then cursor (iParm+1) is open
1235 ** on a second ephemeral index that holds all values every previously
drh7e4efae2014-02-26 21:35:31 +00001236 ** added to the queue. */
1237 addrTest = sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, 0,
1238 regResult, nResultCol);
drh688852a2014-02-17 22:40:43 +00001239 VdbeCoverage(v);
drh7e4efae2014-02-26 21:35:31 +00001240 }
1241 sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r3);
1242 if( eDest==SRT_DistQueue ){
drhfe1c6bb2014-01-22 17:28:35 +00001243 sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r3);
dancfe24582014-01-22 19:23:30 +00001244 sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
drhfe1c6bb2014-01-22 17:28:35 +00001245 }
1246 for(i=0; i<nKey; i++){
1247 sqlite3VdbeAddOp2(v, OP_SCopy,
1248 regResult + pSO->a[i].u.x.iOrderByCol - 1,
1249 r2+i);
1250 }
1251 sqlite3VdbeAddOp2(v, OP_Sequence, iParm, r2+nKey);
1252 sqlite3VdbeAddOp3(v, OP_MakeRecord, r2, nKey+2, r1);
drh9b4eaeb2016-11-09 00:10:33 +00001253 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, r2, nKey+2);
drhfe1c6bb2014-01-22 17:28:35 +00001254 if( addrTest ) sqlite3VdbeJumpHere(v, addrTest);
1255 sqlite3ReleaseTempReg(pParse, r1);
1256 sqlite3ReleaseTempRange(pParse, r2, nKey+2);
1257 break;
1258 }
1259#endif /* SQLITE_OMIT_CTE */
1260
1261
1262
danielk19776a67fe82005-02-04 04:07:16 +00001263#if !defined(SQLITE_OMIT_TRIGGER)
drhc926afb2002-06-20 03:38:26 +00001264 /* Discard the results. This is used for SELECT statements inside
1265 ** the body of a TRIGGER. The purpose of such selects is to call
1266 ** user-defined functions that have side effects. We do not care
1267 ** about the actual results of the select.
1268 */
drhc926afb2002-06-20 03:38:26 +00001269 default: {
drhf46f9052002-06-22 02:33:38 +00001270 assert( eDest==SRT_Discard );
drhc926afb2002-06-20 03:38:26 +00001271 break;
1272 }
danielk197793758c82005-01-21 08:13:14 +00001273#endif
drh82c3d632000-06-06 21:56:07 +00001274 }
drhec7429a2005-10-06 16:53:14 +00001275
drh5e87be82010-10-06 18:55:37 +00001276 /* Jump to the end of the loop if the LIMIT is reached. Except, if
1277 ** there is a sorter, in which case the sorter has already limited
1278 ** the output for us.
drhec7429a2005-10-06 16:53:14 +00001279 */
drh079a3072014-03-19 14:10:55 +00001280 if( pSort==0 && p->iLimit ){
drh16897072015-03-07 00:57:37 +00001281 sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
drhec7429a2005-10-06 16:53:14 +00001282 }
drh82c3d632000-06-06 21:56:07 +00001283}
1284
1285/*
drhad124322013-10-23 13:30:58 +00001286** Allocate a KeyInfo object sufficient for an index of N key columns and
1287** X extra columns.
drh323df792013-08-05 19:11:29 +00001288*/
drhad124322013-10-23 13:30:58 +00001289KeyInfo *sqlite3KeyInfoAlloc(sqlite3 *db, int N, int X){
drhd4ab0032017-05-31 13:45:59 +00001290 int nExtra = (N+X)*(sizeof(CollSeq*)+1) - sizeof(CollSeq*);
drhd8e4b132016-10-01 19:21:56 +00001291 KeyInfo *p = sqlite3DbMallocRawNN(db, sizeof(KeyInfo) + nExtra);
drh323df792013-08-05 19:11:29 +00001292 if( p ){
drhad124322013-10-23 13:30:58 +00001293 p->aSortOrder = (u8*)&p->aColl[N+X];
drha485ad12017-08-02 22:43:14 +00001294 p->nKeyField = (u16)N;
1295 p->nAllField = (u16)(N+X);
drh323df792013-08-05 19:11:29 +00001296 p->enc = ENC(db);
1297 p->db = db;
drh2ec2fb22013-11-06 19:59:23 +00001298 p->nRef = 1;
drhc263f7c2016-01-18 13:18:54 +00001299 memset(&p[1], 0, nExtra);
drh2ec2fb22013-11-06 19:59:23 +00001300 }else{
drh4a642b62016-02-05 01:55:27 +00001301 sqlite3OomFault(db);
drh323df792013-08-05 19:11:29 +00001302 }
1303 return p;
1304}
1305
1306/*
drh2ec2fb22013-11-06 19:59:23 +00001307** Deallocate a KeyInfo object
1308*/
1309void sqlite3KeyInfoUnref(KeyInfo *p){
1310 if( p ){
1311 assert( p->nRef>0 );
drh2ec2fb22013-11-06 19:59:23 +00001312 p->nRef--;
drhdbd6a7d2017-04-05 12:39:49 +00001313 if( p->nRef==0 ) sqlite3DbFreeNN(p->db, p);
drh2ec2fb22013-11-06 19:59:23 +00001314 }
1315}
1316
1317/*
1318** Make a new pointer to a KeyInfo object
1319*/
1320KeyInfo *sqlite3KeyInfoRef(KeyInfo *p){
1321 if( p ){
1322 assert( p->nRef>0 );
1323 p->nRef++;
1324 }
1325 return p;
1326}
1327
1328#ifdef SQLITE_DEBUG
1329/*
1330** Return TRUE if a KeyInfo object can be change. The KeyInfo object
1331** can only be changed if this is just a single reference to the object.
1332**
1333** This routine is used only inside of assert() statements.
1334*/
1335int sqlite3KeyInfoIsWriteable(KeyInfo *p){ return p->nRef==1; }
1336#endif /* SQLITE_DEBUG */
1337
1338/*
drhdece1a82005-08-31 18:20:00 +00001339** Given an expression list, generate a KeyInfo structure that records
1340** the collating sequence for each expression in that expression list.
1341**
drh0342b1f2005-09-01 03:07:44 +00001342** If the ExprList is an ORDER BY or GROUP BY clause then the resulting
1343** KeyInfo structure is appropriate for initializing a virtual index to
1344** implement that clause. If the ExprList is the result set of a SELECT
1345** then the KeyInfo structure is appropriate for initializing a virtual
1346** index to implement a DISTINCT test.
1347**
peter.d.reid60ec9142014-09-06 16:39:46 +00001348** Space to hold the KeyInfo structure is obtained from malloc. The calling
drhdece1a82005-08-31 18:20:00 +00001349** function is responsible for seeing that this structure is eventually
drh2ec2fb22013-11-06 19:59:23 +00001350** freed.
drhdece1a82005-08-31 18:20:00 +00001351*/
danf9eae182018-05-21 19:45:11 +00001352KeyInfo *sqlite3KeyInfoFromExprList(
drh079a3072014-03-19 14:10:55 +00001353 Parse *pParse, /* Parsing context */
1354 ExprList *pList, /* Form the KeyInfo object from this ExprList */
1355 int iStart, /* Begin with this column of pList */
1356 int nExtra /* Add this many extra columns to the end */
1357){
drhdece1a82005-08-31 18:20:00 +00001358 int nExpr;
1359 KeyInfo *pInfo;
1360 struct ExprList_item *pItem;
drh323df792013-08-05 19:11:29 +00001361 sqlite3 *db = pParse->db;
drhdece1a82005-08-31 18:20:00 +00001362 int i;
1363
1364 nExpr = pList->nExpr;
drh3f39bcf2015-01-19 20:59:34 +00001365 pInfo = sqlite3KeyInfoAlloc(db, nExpr-iStart, nExtra+1);
drhdece1a82005-08-31 18:20:00 +00001366 if( pInfo ){
drh2ec2fb22013-11-06 19:59:23 +00001367 assert( sqlite3KeyInfoIsWriteable(pInfo) );
drh6284db92014-03-19 23:24:49 +00001368 for(i=iStart, pItem=pList->a+iStart; i<nExpr; i++, pItem++){
drh70efa842017-09-28 01:58:23 +00001369 pInfo->aColl[i-iStart] = sqlite3ExprNNCollSeq(pParse, pItem->pExpr);
drh6284db92014-03-19 23:24:49 +00001370 pInfo->aSortOrder[i-iStart] = pItem->sortOrder;
drhdece1a82005-08-31 18:20:00 +00001371 }
1372 }
1373 return pInfo;
1374}
1375
dan7f61e922010-11-11 16:46:40 +00001376/*
1377** Name of the connection operator, used for error messages.
1378*/
1379static const char *selectOpName(int id){
1380 char *z;
1381 switch( id ){
1382 case TK_ALL: z = "UNION ALL"; break;
1383 case TK_INTERSECT: z = "INTERSECT"; break;
1384 case TK_EXCEPT: z = "EXCEPT"; break;
1385 default: z = "UNION"; break;
1386 }
1387 return z;
1388}
dan7f61e922010-11-11 16:46:40 +00001389
dan2ce22452010-11-08 19:01:16 +00001390#ifndef SQLITE_OMIT_EXPLAIN
dan17c0bc02010-11-09 17:35:19 +00001391/*
1392** Unless an "EXPLAIN QUERY PLAN" command is being processed, this function
1393** is a no-op. Otherwise, it adds a single row of output to the EQP result,
1394** where the caption is of the form:
1395**
1396** "USE TEMP B-TREE FOR xxx"
1397**
1398** where xxx is one of "DISTINCT", "ORDER BY" or "GROUP BY". Exactly which
1399** is determined by the zUsage argument.
1400*/
dan2ce22452010-11-08 19:01:16 +00001401static void explainTempTable(Parse *pParse, const char *zUsage){
drhe2ca99c2018-05-02 00:33:43 +00001402 ExplainQueryPlan((pParse, 0, "USE TEMP B-TREE FOR %s", zUsage));
dan2ce22452010-11-08 19:01:16 +00001403}
dan17c0bc02010-11-09 17:35:19 +00001404
1405/*
danbb2b4412011-04-06 17:54:31 +00001406** Assign expression b to lvalue a. A second, no-op, version of this macro
1407** is provided when SQLITE_OMIT_EXPLAIN is defined. This allows the code
1408** in sqlite3Select() to assign values to structure member variables that
1409** only exist if SQLITE_OMIT_EXPLAIN is not defined without polluting the
1410** code with #ifndef directives.
1411*/
1412# define explainSetInteger(a, b) a = b
1413
1414#else
1415/* No-op versions of the explainXXX() functions and macros. */
1416# define explainTempTable(y,z)
1417# define explainSetInteger(y,z)
1418#endif
1419
drhdece1a82005-08-31 18:20:00 +00001420
1421/*
drhd8bc7082000-06-07 23:51:50 +00001422** If the inner loop was generated using a non-null pOrderBy argument,
1423** then the results were placed in a sorter. After the loop is terminated
1424** we need to run the sorter and output the results. The following
1425** routine generates the code needed to do that.
1426*/
drhc926afb2002-06-20 03:38:26 +00001427static void generateSortTail(
danielk19776c8c8ce2008-01-02 16:27:09 +00001428 Parse *pParse, /* Parsing context */
1429 Select *p, /* The SELECT statement */
drh079a3072014-03-19 14:10:55 +00001430 SortCtx *pSort, /* Information on the ORDER BY clause */
danielk19776c8c8ce2008-01-02 16:27:09 +00001431 int nColumn, /* Number of columns of data */
1432 SelectDest *pDest /* Write the sorted results here */
drhc926afb2002-06-20 03:38:26 +00001433){
drhddba0c22014-03-18 20:33:42 +00001434 Vdbe *v = pParse->pVdbe; /* The prepared statement */
drha04a8be2016-01-13 17:50:10 +00001435 int addrBreak = pSort->labelDone; /* Jump here to exit loop */
drhdc5ea5c2008-12-10 17:19:59 +00001436 int addrContinue = sqlite3VdbeMakeLabel(v); /* Jump here for next cycle */
dan24e25d32018-04-14 18:46:20 +00001437 int addr; /* Top of output loop. Jump for Next. */
drh079a3072014-03-19 14:10:55 +00001438 int addrOnce = 0;
drh0342b1f2005-09-01 03:07:44 +00001439 int iTab;
drh079a3072014-03-19 14:10:55 +00001440 ExprList *pOrderBy = pSort->pOrderBy;
danielk19776c8c8ce2008-01-02 16:27:09 +00001441 int eDest = pDest->eDest;
drh2b596da2012-07-23 21:43:19 +00001442 int iParm = pDest->iSDParm;
drh2d401ab2008-01-10 23:50:11 +00001443 int regRow;
1444 int regRowid;
dan257c13f2016-11-10 20:14:06 +00001445 int iCol;
dan24e25d32018-04-14 18:46:20 +00001446 int nKey; /* Number of key columns in sorter record */
drhf45f2322014-03-23 17:45:03 +00001447 int iSortTab; /* Sorter cursor to read from */
drhf45f2322014-03-23 17:45:03 +00001448 int i;
dan78d58432014-03-25 15:04:07 +00001449 int bSeq; /* True if sorter record includes seq. no. */
dan24e25d32018-04-14 18:46:20 +00001450 int nRefKey = 0;
drh70f624c2014-03-24 01:43:50 +00001451 struct ExprList_item *aOutEx = p->pEList->a;
drh2d401ab2008-01-10 23:50:11 +00001452
drha04a8be2016-01-13 17:50:10 +00001453 assert( addrBreak<0 );
drh079a3072014-03-19 14:10:55 +00001454 if( pSort->labelBkOut ){
1455 sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
drh076e85f2015-09-03 13:46:12 +00001456 sqlite3VdbeGoto(v, addrBreak);
drh079a3072014-03-19 14:10:55 +00001457 sqlite3VdbeResolveLabel(v, pSort->labelBkOut);
drh079a3072014-03-19 14:10:55 +00001458 }
dan24e25d32018-04-14 18:46:20 +00001459
1460#ifdef SQLITE_ENABLE_SORTER_REFERENCES
1461 /* Open any cursors needed for sorter-reference expressions */
1462 for(i=0; i<pSort->nDefer; i++){
1463 Table *pTab = pSort->aDefer[i].pTab;
1464 int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
1465 sqlite3OpenTable(pParse, pSort->aDefer[i].iCsr, iDb, pTab, OP_OpenRead);
1466 nRefKey = MAX(nRefKey, pSort->aDefer[i].nKey);
1467 }
1468#endif
1469
drh079a3072014-03-19 14:10:55 +00001470 iTab = pSort->iECursor;
dan71c57db2016-07-09 20:23:55 +00001471 if( eDest==SRT_Output || eDest==SRT_Coroutine || eDest==SRT_Mem ){
drh3e9ca092009-09-08 01:14:48 +00001472 regRowid = 0;
drhf45f2322014-03-23 17:45:03 +00001473 regRow = pDest->iSdst;
drhed24da42016-09-06 14:37:05 +00001474 }else{
dan51d82d12016-08-02 18:50:15 +00001475 regRowid = sqlite3GetTempReg(pParse);
1476 regRow = sqlite3GetTempRange(pParse, nColumn);
drhcdd536f2006-03-17 00:04:03 +00001477 }
drh079a3072014-03-19 14:10:55 +00001478 nKey = pOrderBy->nExpr - pSort->nOBSat;
1479 if( pSort->sortFlags & SORTFLAG_UseSorter ){
drhc2bb3282011-09-04 01:11:46 +00001480 int regSortOut = ++pParse->nMem;
drhf45f2322014-03-23 17:45:03 +00001481 iSortTab = pParse->nTab++;
drh83553ee2014-03-24 02:20:53 +00001482 if( pSort->labelBkOut ){
drh511f9e82016-09-22 18:53:13 +00001483 addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
drh83553ee2014-03-24 02:20:53 +00001484 }
dan24e25d32018-04-14 18:46:20 +00001485 sqlite3VdbeAddOp3(v, OP_OpenPseudo, iSortTab, regSortOut,
1486 nKey+1+nColumn+nRefKey);
drh079a3072014-03-19 14:10:55 +00001487 if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);
drhc6aff302011-09-01 15:32:47 +00001488 addr = 1 + sqlite3VdbeAddOp2(v, OP_SorterSort, iTab, addrBreak);
drh688852a2014-02-17 22:40:43 +00001489 VdbeCoverage(v);
drhaa9ce702014-01-22 18:07:04 +00001490 codeOffset(v, p->iOffset, addrContinue);
drh6cf4a7d2014-10-13 13:00:58 +00001491 sqlite3VdbeAddOp3(v, OP_SorterData, iTab, regSortOut, iSortTab);
dan78d58432014-03-25 15:04:07 +00001492 bSeq = 0;
drhc6aff302011-09-01 15:32:47 +00001493 }else{
drh688852a2014-02-17 22:40:43 +00001494 addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak); VdbeCoverage(v);
drhaa9ce702014-01-22 18:07:04 +00001495 codeOffset(v, p->iOffset, addrContinue);
drhf45f2322014-03-23 17:45:03 +00001496 iSortTab = iTab;
dan78d58432014-03-25 15:04:07 +00001497 bSeq = 1;
drhf45f2322014-03-23 17:45:03 +00001498 }
dand6189ea2018-04-11 14:11:53 +00001499 for(i=0, iCol=nKey+bSeq-1; i<nColumn; i++){
dan24e25d32018-04-14 18:46:20 +00001500#ifdef SQLITE_ENABLE_SORTER_REFERENCES
1501 if( aOutEx[i].bSorterRef ) continue;
1502#endif
drh9f895232018-01-24 20:42:42 +00001503 if( aOutEx[i].u.x.iOrderByCol==0 ) iCol++;
1504 }
dan24e25d32018-04-14 18:46:20 +00001505#ifdef SQLITE_ENABLE_SORTER_REFERENCES
1506 if( pSort->nDefer ){
1507 int iKey = iCol+1;
1508 int regKey = sqlite3GetTempRange(pParse, nRefKey);
1509
1510 for(i=0; i<pSort->nDefer; i++){
1511 int iCsr = pSort->aDefer[i].iCsr;
1512 Table *pTab = pSort->aDefer[i].pTab;
1513 int nKey = pSort->aDefer[i].nKey;
1514
1515 sqlite3VdbeAddOp1(v, OP_NullRow, iCsr);
1516 if( HasRowid(pTab) ){
1517 sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iKey++, regKey);
1518 sqlite3VdbeAddOp3(v, OP_SeekRowid, iCsr,
1519 sqlite3VdbeCurrentAddr(v)+1, regKey);
1520 }else{
dan24e25d32018-04-14 18:46:20 +00001521 int k;
1522 int iJmp;
drh7590d092018-04-18 14:04:19 +00001523 assert( sqlite3PrimaryKeyIndex(pTab)->nKeyCol==nKey );
dan24e25d32018-04-14 18:46:20 +00001524 for(k=0; k<nKey; k++){
1525 sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iKey++, regKey+k);
1526 }
1527 iJmp = sqlite3VdbeCurrentAddr(v);
1528 sqlite3VdbeAddOp4Int(v, OP_SeekGE, iCsr, iJmp+2, regKey, nKey);
1529 sqlite3VdbeAddOp4Int(v, OP_IdxLE, iCsr, iJmp+3, regKey, nKey);
1530 sqlite3VdbeAddOp1(v, OP_NullRow, iCsr);
1531 }
dan257c13f2016-11-10 20:14:06 +00001532 }
dan24e25d32018-04-14 18:46:20 +00001533 sqlite3ReleaseTempRange(pParse, regKey, nRefKey);
1534 }
1535#endif
1536 for(i=nColumn-1; i>=0; i--){
1537#ifdef SQLITE_ENABLE_SORTER_REFERENCES
1538 if( aOutEx[i].bSorterRef ){
1539 sqlite3ExprCode(pParse, aOutEx[i].pExpr, regRow+i);
1540 }else
1541#endif
1542 {
1543 int iRead;
1544 if( aOutEx[i].u.x.iOrderByCol ){
1545 iRead = aOutEx[i].u.x.iOrderByCol-1;
1546 }else{
1547 iRead = iCol--;
1548 }
1549 sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iRead, regRow+i);
1550 VdbeComment((v, "%s", aOutEx[i].zName?aOutEx[i].zName : aOutEx[i].zSpan));
1551 }
drhc6aff302011-09-01 15:32:47 +00001552 }
drhc926afb2002-06-20 03:38:26 +00001553 switch( eDest ){
danac56ab72017-01-05 17:23:11 +00001554 case SRT_Table:
drhb9bb7c12006-06-11 23:41:55 +00001555 case SRT_EphemTab: {
drh2d401ab2008-01-10 23:50:11 +00001556 sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);
1557 sqlite3VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid);
1558 sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
drhc926afb2002-06-20 03:38:26 +00001559 break;
1560 }
danielk197793758c82005-01-21 08:13:14 +00001561#ifndef SQLITE_OMIT_SUBQUERY
drhc926afb2002-06-20 03:38:26 +00001562 case SRT_Set: {
dan71c57db2016-07-09 20:23:55 +00001563 assert( nColumn==sqlite3Strlen30(pDest->zAffSdst) );
1564 sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, nColumn, regRowid,
dan553168c2016-08-01 20:14:31 +00001565 pDest->zAffSdst, nColumn);
dan71c57db2016-07-09 20:23:55 +00001566 sqlite3ExprCacheAffinityChange(pParse, regRow, nColumn);
drh9b4eaeb2016-11-09 00:10:33 +00001567 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, regRowid, regRow, nColumn);
drhc926afb2002-06-20 03:38:26 +00001568 break;
1569 }
1570 case SRT_Mem: {
drhec7429a2005-10-06 16:53:14 +00001571 /* The LIMIT clause will terminate the loop for us */
drhc926afb2002-06-20 03:38:26 +00001572 break;
1573 }
danielk197793758c82005-01-21 08:13:14 +00001574#endif
drh373cc2d2009-05-17 02:06:14 +00001575 default: {
drh373cc2d2009-05-17 02:06:14 +00001576 assert( eDest==SRT_Output || eDest==SRT_Coroutine );
drh1c767f02009-01-09 02:49:31 +00001577 testcase( eDest==SRT_Output );
1578 testcase( eDest==SRT_Coroutine );
drh7d10d5a2008-08-20 16:35:10 +00001579 if( eDest==SRT_Output ){
drh2b596da2012-07-23 21:43:19 +00001580 sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iSdst, nColumn);
1581 sqlite3ExprCacheAffinityChange(pParse, pDest->iSdst, nColumn);
drha9671a22008-07-08 23:40:20 +00001582 }else{
drh2b596da2012-07-23 21:43:19 +00001583 sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
drhce665cf2004-05-21 03:01:58 +00001584 }
drhac82fcf2002-09-08 17:23:41 +00001585 break;
1586 }
drhc926afb2002-06-20 03:38:26 +00001587 }
drhf45f2322014-03-23 17:45:03 +00001588 if( regRowid ){
dan51d82d12016-08-02 18:50:15 +00001589 if( eDest==SRT_Set ){
1590 sqlite3ReleaseTempRange(pParse, regRow, nColumn);
1591 }else{
1592 sqlite3ReleaseTempReg(pParse, regRow);
1593 }
drhf45f2322014-03-23 17:45:03 +00001594 sqlite3ReleaseTempReg(pParse, regRowid);
1595 }
drhec7429a2005-10-06 16:53:14 +00001596 /* The bottom of the loop
1597 */
drhdc5ea5c2008-12-10 17:19:59 +00001598 sqlite3VdbeResolveLabel(v, addrContinue);
drh079a3072014-03-19 14:10:55 +00001599 if( pSort->sortFlags & SORTFLAG_UseSorter ){
drh688852a2014-02-17 22:40:43 +00001600 sqlite3VdbeAddOp2(v, OP_SorterNext, iTab, addr); VdbeCoverage(v);
drhc6aff302011-09-01 15:32:47 +00001601 }else{
drh688852a2014-02-17 22:40:43 +00001602 sqlite3VdbeAddOp2(v, OP_Next, iTab, addr); VdbeCoverage(v);
drhc6aff302011-09-01 15:32:47 +00001603 }
drh079a3072014-03-19 14:10:55 +00001604 if( pSort->regReturn ) sqlite3VdbeAddOp1(v, OP_Return, pSort->regReturn);
drhdc5ea5c2008-12-10 17:19:59 +00001605 sqlite3VdbeResolveLabel(v, addrBreak);
drhd8bc7082000-06-07 23:51:50 +00001606}
1607
1608/*
danielk1977517eb642004-06-07 10:00:31 +00001609** Return a pointer to a string containing the 'declaration type' of the
1610** expression pExpr. The string may be treated as static by the caller.
drhe78e8282003-01-19 03:59:45 +00001611**
drh5f3e5e72013-10-08 20:01:35 +00001612** Also try to estimate the size of the returned value and return that
1613** result in *pEstWidth.
1614**
danielk1977955de522006-02-10 02:27:42 +00001615** The declaration type is the exact datatype definition extracted from the
1616** original CREATE TABLE statement if the expression is a column. The
1617** declaration type for a ROWID field is INTEGER. Exactly when an expression
1618** is considered a column can be complex in the presence of subqueries. The
1619** result-set expression in all of the following SELECT statements is
1620** considered a column by this function.
1621**
1622** SELECT col FROM tbl;
1623** SELECT (SELECT col FROM tbl;
1624** SELECT (SELECT col FROM tbl);
1625** SELECT abc FROM (SELECT col AS abc FROM tbl);
danielk1977517eb642004-06-07 10:00:31 +00001626**
danielk1977955de522006-02-10 02:27:42 +00001627** The declaration type for any expression other than a column is NULL.
drh5f3e5e72013-10-08 20:01:35 +00001628**
1629** This routine has either 3 or 6 parameters depending on whether or not
1630** the SQLITE_ENABLE_COLUMN_METADATA compile-time option is used.
danielk1977517eb642004-06-07 10:00:31 +00001631*/
drh5f3e5e72013-10-08 20:01:35 +00001632#ifdef SQLITE_ENABLE_COLUMN_METADATA
drhcafc2f72017-10-03 03:01:09 +00001633# define columnType(A,B,C,D,E) columnTypeImpl(A,B,C,D,E)
drhb121dd12015-06-06 18:30:17 +00001634#else /* if !defined(SQLITE_ENABLE_COLUMN_METADATA) */
drhcafc2f72017-10-03 03:01:09 +00001635# define columnType(A,B,C,D,E) columnTypeImpl(A,B)
drhb121dd12015-06-06 18:30:17 +00001636#endif
drh5f3e5e72013-10-08 20:01:35 +00001637static const char *columnTypeImpl(
danielk1977955de522006-02-10 02:27:42 +00001638 NameContext *pNC,
drhcafc2f72017-10-03 03:01:09 +00001639#ifndef SQLITE_ENABLE_COLUMN_METADATA
1640 Expr *pExpr
1641#else
danielk1977955de522006-02-10 02:27:42 +00001642 Expr *pExpr,
drh5f3e5e72013-10-08 20:01:35 +00001643 const char **pzOrigDb,
1644 const char **pzOrigTab,
drhcafc2f72017-10-03 03:01:09 +00001645 const char **pzOrigCol
drhb121dd12015-06-06 18:30:17 +00001646#endif
danielk1977955de522006-02-10 02:27:42 +00001647){
1648 char const *zType = 0;
danielk1977517eb642004-06-07 10:00:31 +00001649 int j;
drhb121dd12015-06-06 18:30:17 +00001650#ifdef SQLITE_ENABLE_COLUMN_METADATA
1651 char const *zOrigDb = 0;
1652 char const *zOrigTab = 0;
1653 char const *zOrigCol = 0;
1654#endif
danielk19775338a5f2005-01-20 13:03:10 +00001655
drhf7ce4292015-12-02 19:46:12 +00001656 assert( pExpr!=0 );
1657 assert( pNC->pSrcList!=0 );
drh755b0fd2017-12-23 12:33:40 +00001658 assert( pExpr->op!=TK_AGG_COLUMN ); /* This routine runes before aggregates
1659 ** are processed */
danielk197700e279d2004-06-21 07:36:32 +00001660 switch( pExpr->op ){
1661 case TK_COLUMN: {
danielk1977955de522006-02-10 02:27:42 +00001662 /* The expression is a column. Locate the table the column is being
1663 ** extracted from in NameContext.pSrcList. This table may be real
1664 ** database table or a subquery.
1665 */
1666 Table *pTab = 0; /* Table structure column is extracted from */
1667 Select *pS = 0; /* Select the column is extracted from */
1668 int iCol = pExpr->iColumn; /* Index of column in pTab */
dan43bc88b2009-09-10 10:15:59 +00001669 while( pNC && !pTab ){
danielk1977b3bce662005-01-29 08:32:43 +00001670 SrcList *pTabList = pNC->pSrcList;
1671 for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
1672 if( j<pTabList->nSrc ){
1673 pTab = pTabList->a[j].pTab;
danielk1977955de522006-02-10 02:27:42 +00001674 pS = pTabList->a[j].pSelect;
danielk1977b3bce662005-01-29 08:32:43 +00001675 }else{
1676 pNC = pNC->pNext;
1677 }
1678 }
danielk1977955de522006-02-10 02:27:42 +00001679
dan43bc88b2009-09-10 10:15:59 +00001680 if( pTab==0 ){
drh417168a2009-09-07 18:14:02 +00001681 /* At one time, code such as "SELECT new.x" within a trigger would
1682 ** cause this condition to run. Since then, we have restructured how
1683 ** trigger code is generated and so this condition is no longer
dan43bc88b2009-09-10 10:15:59 +00001684 ** possible. However, it can still be true for statements like
1685 ** the following:
1686 **
1687 ** CREATE TABLE t1(col INTEGER);
1688 ** SELECT (SELECT t1.col) FROM FROM t1;
1689 **
1690 ** when columnType() is called on the expression "t1.col" in the
1691 ** sub-select. In this case, set the column type to NULL, even
1692 ** though it should really be "INTEGER".
1693 **
1694 ** This is not a problem, as the column type of "t1.col" is never
1695 ** used. When columnType() is called on the expression
1696 ** "(SELECT t1.col)", the correct type is returned (see the TK_SELECT
1697 ** branch below. */
drh7e627792005-04-29 02:10:00 +00001698 break;
1699 }
danielk1977955de522006-02-10 02:27:42 +00001700
dan43bc88b2009-09-10 10:15:59 +00001701 assert( pTab && pExpr->pTab==pTab );
danielk1977955de522006-02-10 02:27:42 +00001702 if( pS ){
1703 /* The "table" is actually a sub-select or a view in the FROM clause
1704 ** of the SELECT statement. Return the declaration type and origin
1705 ** data for the result-set column of the sub-select.
1706 */
drhf35f2f92017-07-29 16:01:55 +00001707 if( iCol>=0 && iCol<pS->pEList->nExpr ){
danielk1977955de522006-02-10 02:27:42 +00001708 /* If iCol is less than zero, then the expression requests the
1709 ** rowid of the sub-select or view. This expression is legal (see
1710 ** test case misc2.2.2) - it always evaluates to NULL.
1711 */
1712 NameContext sNC;
1713 Expr *p = pS->pEList->a[iCol].pExpr;
1714 sNC.pSrcList = pS->pSrc;
dan43bc88b2009-09-10 10:15:59 +00001715 sNC.pNext = pNC;
danielk1977955de522006-02-10 02:27:42 +00001716 sNC.pParse = pNC->pParse;
drhcafc2f72017-10-03 03:01:09 +00001717 zType = columnType(&sNC, p,&zOrigDb,&zOrigTab,&zOrigCol);
danielk1977955de522006-02-10 02:27:42 +00001718 }
drha78d7572017-10-03 16:57:33 +00001719 }else{
1720 /* A real table or a CTE table */
danielk1977955de522006-02-10 02:27:42 +00001721 assert( !pS );
drh5f3e5e72013-10-08 20:01:35 +00001722#ifdef SQLITE_ENABLE_COLUMN_METADATA
drha78d7572017-10-03 16:57:33 +00001723 if( iCol<0 ) iCol = pTab->iPKey;
1724 assert( iCol==XN_ROWID || (iCol>=0 && iCol<pTab->nCol) );
danielk1977955de522006-02-10 02:27:42 +00001725 if( iCol<0 ){
1726 zType = "INTEGER";
drh5f3e5e72013-10-08 20:01:35 +00001727 zOrigCol = "rowid";
danielk1977955de522006-02-10 02:27:42 +00001728 }else{
drh5f3e5e72013-10-08 20:01:35 +00001729 zOrigCol = pTab->aCol[iCol].zName;
drhd7564862016-03-22 20:05:09 +00001730 zType = sqlite3ColumnType(&pTab->aCol[iCol],0);
danielk1977955de522006-02-10 02:27:42 +00001731 }
drh5f3e5e72013-10-08 20:01:35 +00001732 zOrigTab = pTab->zName;
drha78d7572017-10-03 16:57:33 +00001733 if( pNC->pParse && pTab->pSchema ){
danielk1977955de522006-02-10 02:27:42 +00001734 int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);
drhe59be012016-08-18 20:56:39 +00001735 zOrigDb = pNC->pParse->db->aDb[iDb].zDbSName;
danielk1977955de522006-02-10 02:27:42 +00001736 }
drh5f3e5e72013-10-08 20:01:35 +00001737#else
drha78d7572017-10-03 16:57:33 +00001738 assert( iCol==XN_ROWID || (iCol>=0 && iCol<pTab->nCol) );
drh5f3e5e72013-10-08 20:01:35 +00001739 if( iCol<0 ){
1740 zType = "INTEGER";
1741 }else{
drhd7564862016-03-22 20:05:09 +00001742 zType = sqlite3ColumnType(&pTab->aCol[iCol],0);
drh5f3e5e72013-10-08 20:01:35 +00001743 }
1744#endif
danielk197700e279d2004-06-21 07:36:32 +00001745 }
1746 break;
danielk1977517eb642004-06-07 10:00:31 +00001747 }
danielk197793758c82005-01-21 08:13:14 +00001748#ifndef SQLITE_OMIT_SUBQUERY
danielk197700e279d2004-06-21 07:36:32 +00001749 case TK_SELECT: {
danielk1977955de522006-02-10 02:27:42 +00001750 /* The expression is a sub-select. Return the declaration type and
1751 ** origin info for the single column in the result set of the SELECT
1752 ** statement.
1753 */
danielk1977b3bce662005-01-29 08:32:43 +00001754 NameContext sNC;
danielk19776ab3a2e2009-02-19 14:39:25 +00001755 Select *pS = pExpr->x.pSelect;
danielk1977955de522006-02-10 02:27:42 +00001756 Expr *p = pS->pEList->a[0].pExpr;
danielk19776ab3a2e2009-02-19 14:39:25 +00001757 assert( ExprHasProperty(pExpr, EP_xIsSelect) );
danielk1977955de522006-02-10 02:27:42 +00001758 sNC.pSrcList = pS->pSrc;
danielk1977b3bce662005-01-29 08:32:43 +00001759 sNC.pNext = pNC;
danielk1977955de522006-02-10 02:27:42 +00001760 sNC.pParse = pNC->pParse;
drhcafc2f72017-10-03 03:01:09 +00001761 zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);
danielk197700e279d2004-06-21 07:36:32 +00001762 break;
danielk1977517eb642004-06-07 10:00:31 +00001763 }
danielk197793758c82005-01-21 08:13:14 +00001764#endif
danielk1977517eb642004-06-07 10:00:31 +00001765 }
drh5f3e5e72013-10-08 20:01:35 +00001766
1767#ifdef SQLITE_ENABLE_COLUMN_METADATA
1768 if( pzOrigDb ){
1769 assert( pzOrigTab && pzOrigCol );
1770 *pzOrigDb = zOrigDb;
1771 *pzOrigTab = zOrigTab;
1772 *pzOrigCol = zOrigCol;
danielk1977955de522006-02-10 02:27:42 +00001773 }
drh5f3e5e72013-10-08 20:01:35 +00001774#endif
danielk1977517eb642004-06-07 10:00:31 +00001775 return zType;
1776}
1777
1778/*
1779** Generate code that will tell the VDBE the declaration types of columns
1780** in the result set.
drhfcb78a42003-01-18 20:11:05 +00001781*/
1782static void generateColumnTypes(
1783 Parse *pParse, /* Parser context */
drhfcb78a42003-01-18 20:11:05 +00001784 SrcList *pTabList, /* List of tables */
1785 ExprList *pEList /* Expressions defining the result set */
1786){
drh3f913572008-03-22 01:07:17 +00001787#ifndef SQLITE_OMIT_DECLTYPE
drhfcb78a42003-01-18 20:11:05 +00001788 Vdbe *v = pParse->pVdbe;
danielk1977517eb642004-06-07 10:00:31 +00001789 int i;
danielk1977b3bce662005-01-29 08:32:43 +00001790 NameContext sNC;
1791 sNC.pSrcList = pTabList;
danielk1977955de522006-02-10 02:27:42 +00001792 sNC.pParse = pParse;
drheac5fc02017-04-11 01:01:27 +00001793 sNC.pNext = 0;
drhfcb78a42003-01-18 20:11:05 +00001794 for(i=0; i<pEList->nExpr; i++){
1795 Expr *p = pEList->a[i].pExpr;
drh3f913572008-03-22 01:07:17 +00001796 const char *zType;
1797#ifdef SQLITE_ENABLE_COLUMN_METADATA
danielk1977955de522006-02-10 02:27:42 +00001798 const char *zOrigDb = 0;
1799 const char *zOrigTab = 0;
1800 const char *zOrigCol = 0;
drhcafc2f72017-10-03 03:01:09 +00001801 zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);
danielk1977955de522006-02-10 02:27:42 +00001802
drh85b623f2007-12-13 21:54:09 +00001803 /* The vdbe must make its own copy of the column-type and other
danielk19774b1ae992006-02-10 03:06:10 +00001804 ** column specific strings, in case the schema is reset before this
1805 ** virtual machine is deleted.
danielk1977fbcd5852004-06-15 02:44:18 +00001806 */
danielk197710fb7492008-10-31 10:53:22 +00001807 sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, SQLITE_TRANSIENT);
1808 sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, SQLITE_TRANSIENT);
1809 sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, SQLITE_TRANSIENT);
drh3f913572008-03-22 01:07:17 +00001810#else
drhcafc2f72017-10-03 03:01:09 +00001811 zType = columnType(&sNC, p, 0, 0, 0);
drh3f913572008-03-22 01:07:17 +00001812#endif
danielk197710fb7492008-10-31 10:53:22 +00001813 sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT);
drhfcb78a42003-01-18 20:11:05 +00001814 }
drh5f3e5e72013-10-08 20:01:35 +00001815#endif /* !defined(SQLITE_OMIT_DECLTYPE) */
drhfcb78a42003-01-18 20:11:05 +00001816}
1817
drheac5fc02017-04-11 01:01:27 +00001818
1819/*
drhec360a82017-07-12 14:10:19 +00001820** Compute the column names for a SELECT statement.
1821**
1822** The only guarantee that SQLite makes about column names is that if the
1823** column has an AS clause assigning it a name, that will be the name used.
1824** That is the only documented guarantee. However, countless applications
1825** developed over the years have made baseless assumptions about column names
1826** and will break if those assumptions changes. Hence, use extreme caution
1827** when modifying this routine to avoid breaking legacy.
1828**
1829** See Also: sqlite3ColumnsFromExprList()
1830**
1831** The PRAGMA short_column_names and PRAGMA full_column_names settings are
1832** deprecated. The default setting is short=ON, full=OFF. 99.9% of all
1833** applications should operate this way. Nevertheless, we need to support the
1834** other modes for legacy:
1835**
1836** short=OFF, full=OFF: Column name is the text of the expression has it
1837** originally appears in the SELECT statement. In
1838** other words, the zSpan of the result expression.
1839**
1840** short=ON, full=OFF: (This is the default setting). If the result
drh3d240d22017-09-28 16:56:55 +00001841** refers directly to a table column, then the
1842** result column name is just the table column
1843** name: COLUMN. Otherwise use zSpan.
drhec360a82017-07-12 14:10:19 +00001844**
1845** full=ON, short=ANY: If the result refers directly to a table column,
1846** then the result column name with the table name
1847** prefix, ex: TABLE.COLUMN. Otherwise use zSpan.
drh82c3d632000-06-06 21:56:07 +00001848*/
drh832508b2002-03-02 17:04:07 +00001849static void generateColumnNames(
1850 Parse *pParse, /* Parser context */
drhf35f2f92017-07-29 16:01:55 +00001851 Select *pSelect /* Generate column names for this SELECT statement */
drh832508b2002-03-02 17:04:07 +00001852){
drhd8bc7082000-06-07 23:51:50 +00001853 Vdbe *v = pParse->pVdbe;
drheac5fc02017-04-11 01:01:27 +00001854 int i;
1855 Table *pTab;
drhf35f2f92017-07-29 16:01:55 +00001856 SrcList *pTabList;
1857 ExprList *pEList;
drh9bb575f2004-09-06 17:24:11 +00001858 sqlite3 *db = pParse->db;
drhf35f2f92017-07-29 16:01:55 +00001859 int fullName; /* TABLE.COLUMN if no AS clause and is a direct table ref */
1860 int srcName; /* COLUMN or TABLE.COLUMN if no AS clause and is direct */
drhfcabd462004-02-20 14:50:58 +00001861
drhfe2093d2005-01-20 22:48:47 +00001862#ifndef SQLITE_OMIT_EXPLAIN
danielk19773cf86062004-05-26 10:11:05 +00001863 /* If this is an EXPLAIN, skip this step */
1864 if( pParse->explain ){
danielk197761de0d12004-05-27 23:56:16 +00001865 return;
danielk19773cf86062004-05-26 10:11:05 +00001866 }
danielk19775338a5f2005-01-20 13:03:10 +00001867#endif
danielk19773cf86062004-05-26 10:11:05 +00001868
drh5e8b9852018-05-03 22:52:56 +00001869 if( pParse->colNamesSet ) return;
drhf35f2f92017-07-29 16:01:55 +00001870 /* Column names are determined by the left-most term of a compound select */
1871 while( pSelect->pPrior ) pSelect = pSelect->pPrior;
drh07859482017-12-23 11:51:40 +00001872 SELECTTRACE(1,pParse,pSelect,("generating column names\n"));
drhf35f2f92017-07-29 16:01:55 +00001873 pTabList = pSelect->pSrc;
1874 pEList = pSelect->pEList;
drh98029472015-12-03 21:47:30 +00001875 assert( v!=0 );
drhf7ce4292015-12-02 19:46:12 +00001876 assert( pTabList!=0 );
drhd8bc7082000-06-07 23:51:50 +00001877 pParse->colNamesSet = 1;
drhec360a82017-07-12 14:10:19 +00001878 fullName = (db->flags & SQLITE_FullColNames)!=0;
1879 srcName = (db->flags & SQLITE_ShortColNames)!=0 || fullName;
danielk197722322fd2004-05-25 23:35:17 +00001880 sqlite3VdbeSetNumCols(v, pEList->nExpr);
drh82c3d632000-06-06 21:56:07 +00001881 for(i=0; i<pEList->nExpr; i++){
drhec360a82017-07-12 14:10:19 +00001882 Expr *p = pEList->a[i].pExpr;
1883
1884 assert( p!=0 );
drh4dd89d52017-08-14 14:53:24 +00001885 assert( p->op!=TK_AGG_COLUMN ); /* Agg processing has not run yet */
drh3d240d22017-09-28 16:56:55 +00001886 assert( p->op!=TK_COLUMN || p->pTab!=0 ); /* Covering idx not yet coded */
drh82c3d632000-06-06 21:56:07 +00001887 if( pEList->a[i].zName ){
drhec360a82017-07-12 14:10:19 +00001888 /* An AS clause always takes first priority */
drh82c3d632000-06-06 21:56:07 +00001889 char *zName = pEList->a[i].zName;
danielk197710fb7492008-10-31 10:53:22 +00001890 sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
drhf35f2f92017-07-29 16:01:55 +00001891 }else if( srcName && p->op==TK_COLUMN ){
drh97665872002-02-13 23:22:53 +00001892 char *zCol;
drh8aff1012001-12-22 14:49:24 +00001893 int iCol = p->iColumn;
drhf35f2f92017-07-29 16:01:55 +00001894 pTab = p->pTab;
1895 assert( pTab!=0 );
drh8aff1012001-12-22 14:49:24 +00001896 if( iCol<0 ) iCol = pTab->iPKey;
drh97665872002-02-13 23:22:53 +00001897 assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
drhb1363202002-06-26 02:45:03 +00001898 if( iCol<0 ){
drh47a6db22005-01-18 16:02:40 +00001899 zCol = "rowid";
drhb1363202002-06-26 02:45:03 +00001900 }else{
1901 zCol = pTab->aCol[iCol].zName;
drhb1363202002-06-26 02:45:03 +00001902 }
drhec360a82017-07-12 14:10:19 +00001903 if( fullName ){
drh82c3d632000-06-06 21:56:07 +00001904 char *zName = 0;
drh1c767f02009-01-09 02:49:31 +00001905 zName = sqlite3MPrintf(db, "%s.%s", pTab->zName, zCol);
danielk197710fb7492008-10-31 10:53:22 +00001906 sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_DYNAMIC);
drh82c3d632000-06-06 21:56:07 +00001907 }else{
danielk197710fb7492008-10-31 10:53:22 +00001908 sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT);
drh82c3d632000-06-06 21:56:07 +00001909 }
drh1bee3d72001-10-15 00:44:35 +00001910 }else{
drh859bc542014-01-13 20:32:18 +00001911 const char *z = pEList->a[i].zSpan;
1912 z = z==0 ? sqlite3MPrintf(db, "column%d", i+1) : sqlite3DbStrDup(db, z);
1913 sqlite3VdbeSetColName(v, i, COLNAME_NAME, z, SQLITE_DYNAMIC);
drh82c3d632000-06-06 21:56:07 +00001914 }
1915 }
danielk197776d505b2004-05-28 13:13:02 +00001916 generateColumnTypes(pParse, pTabList, pEList);
drh82c3d632000-06-06 21:56:07 +00001917}
1918
drhd8bc7082000-06-07 23:51:50 +00001919/*
peter.d.reid60ec9142014-09-06 16:39:46 +00001920** Given an expression list (which is really the list of expressions
drh7d10d5a2008-08-20 16:35:10 +00001921** that form the result set of a SELECT statement) compute appropriate
1922** column names for a table that would hold the expression list.
1923**
1924** All column names will be unique.
1925**
1926** Only the column names are computed. Column.zType, Column.zColl,
1927** and other fields of Column are zeroed.
1928**
1929** Return SQLITE_OK on success. If a memory allocation error occurs,
1930** store NULL in *paCol and 0 in *pnCol and return SQLITE_NOMEM.
drhec360a82017-07-12 14:10:19 +00001931**
1932** The only guarantee that SQLite makes about column names is that if the
1933** column has an AS clause assigning it a name, that will be the name used.
1934** That is the only documented guarantee. However, countless applications
1935** developed over the years have made baseless assumptions about column names
1936** and will break if those assumptions changes. Hence, use extreme caution
1937** when modifying this routine to avoid breaking legacy.
1938**
1939** See Also: generateColumnNames()
drh315555c2002-10-20 15:53:03 +00001940*/
drh8981b902015-08-24 17:42:49 +00001941int sqlite3ColumnsFromExprList(
drh7d10d5a2008-08-20 16:35:10 +00001942 Parse *pParse, /* Parsing context */
1943 ExprList *pEList, /* Expr list from which to derive column names */
drhd815f172012-09-13 14:42:43 +00001944 i16 *pnCol, /* Write the number of columns here */
drh7d10d5a2008-08-20 16:35:10 +00001945 Column **paCol /* Write the new column list here */
1946){
drhdc5ea5c2008-12-10 17:19:59 +00001947 sqlite3 *db = pParse->db; /* Database connection */
1948 int i, j; /* Loop counters */
drhebed3fa2015-11-14 16:47:23 +00001949 u32 cnt; /* Index added to make the name unique */
drhdc5ea5c2008-12-10 17:19:59 +00001950 Column *aCol, *pCol; /* For looping over result columns */
1951 int nCol; /* Number of columns in the result set */
drhdc5ea5c2008-12-10 17:19:59 +00001952 char *zName; /* Column name */
1953 int nName; /* Size of name in zName[] */
drh0315e3c2015-11-14 20:52:43 +00001954 Hash ht; /* Hash table of column names */
drh22f70c32002-02-18 01:17:00 +00001955
drh0315e3c2015-11-14 20:52:43 +00001956 sqlite3HashInit(&ht);
dan8c2e0f02012-03-31 15:08:56 +00001957 if( pEList ){
1958 nCol = pEList->nExpr;
1959 aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
1960 testcase( aCol==0 );
drh6fe37332017-10-21 14:17:31 +00001961 if( nCol>32767 ) nCol = 32767;
dan8c2e0f02012-03-31 15:08:56 +00001962 }else{
1963 nCol = 0;
1964 aCol = 0;
1965 }
dan8836cbb2015-11-21 19:43:29 +00001966 assert( nCol==(i16)nCol );
dan8c2e0f02012-03-31 15:08:56 +00001967 *pnCol = nCol;
1968 *paCol = aCol;
1969
drh0315e3c2015-11-14 20:52:43 +00001970 for(i=0, pCol=aCol; i<nCol && !db->mallocFailed; i++, pCol++){
drh79d5f632005-01-18 17:20:10 +00001971 /* Get an appropriate name for the column
1972 */
drh91bb0ee2004-09-01 03:06:34 +00001973 if( (zName = pEList->a[i].zName)!=0 ){
drh79d5f632005-01-18 17:20:10 +00001974 /* If the column contains an "AS <name>" phrase, use <name> as the name */
drh93a960a2008-07-10 00:32:42 +00001975 }else{
drhec360a82017-07-12 14:10:19 +00001976 Expr *pColExpr = sqlite3ExprSkipCollate(pEList->a[i].pExpr);
drhb07028f2011-10-14 21:49:18 +00001977 while( pColExpr->op==TK_DOT ){
1978 pColExpr = pColExpr->pRight;
1979 assert( pColExpr!=0 );
1980 }
drh755b0fd2017-12-23 12:33:40 +00001981 assert( pColExpr->op!=TK_AGG_COLUMN );
1982 if( pColExpr->op==TK_COLUMN ){
drh7d10d5a2008-08-20 16:35:10 +00001983 /* For columns use the column name name */
drhdc5ea5c2008-12-10 17:19:59 +00001984 int iCol = pColExpr->iColumn;
drhec360a82017-07-12 14:10:19 +00001985 Table *pTab = pColExpr->pTab;
drh755b0fd2017-12-23 12:33:40 +00001986 assert( pTab!=0 );
drhf0209f72008-08-21 14:54:28 +00001987 if( iCol<0 ) iCol = pTab->iPKey;
drh96ceaf82015-11-14 22:04:22 +00001988 zName = iCol>=0 ? pTab->aCol[iCol].zName : "rowid";
drhb7916a72009-05-27 10:31:29 +00001989 }else if( pColExpr->op==TK_ID ){
drh33e619f2009-05-28 01:00:55 +00001990 assert( !ExprHasProperty(pColExpr, EP_IntValue) );
drh96ceaf82015-11-14 22:04:22 +00001991 zName = pColExpr->u.zToken;
drh7d10d5a2008-08-20 16:35:10 +00001992 }else{
1993 /* Use the original text of the column expression as its name */
drh96ceaf82015-11-14 22:04:22 +00001994 zName = pEList->a[i].zSpan;
drh7d10d5a2008-08-20 16:35:10 +00001995 }
drh22f70c32002-02-18 01:17:00 +00001996 }
drhd7ca6002017-07-09 00:30:58 +00001997 if( zName ){
1998 zName = sqlite3DbStrDup(db, zName);
1999 }else{
drh155507b2017-07-09 18:55:29 +00002000 zName = sqlite3MPrintf(db,"column%d",i+1);
drhd7ca6002017-07-09 00:30:58 +00002001 }
drh79d5f632005-01-18 17:20:10 +00002002
2003 /* Make sure the column name is unique. If the name is not unique,
peter.d.reid60ec9142014-09-06 16:39:46 +00002004 ** append an integer to the name so that it becomes unique.
drh79d5f632005-01-18 17:20:10 +00002005 */
drh0315e3c2015-11-14 20:52:43 +00002006 cnt = 0;
2007 while( zName && sqlite3HashFind(&ht, zName)!=0 ){
drh0315e3c2015-11-14 20:52:43 +00002008 nName = sqlite3Strlen30(zName);
drhf7ee8962015-11-15 11:13:49 +00002009 if( nName>0 ){
2010 for(j=nName-1; j>0 && sqlite3Isdigit(zName[j]); j--){}
2011 if( zName[j]==':' ) nName = j;
2012 }
drh96ceaf82015-11-14 22:04:22 +00002013 zName = sqlite3MPrintf(db, "%.*z:%u", nName, zName, ++cnt);
drh0315e3c2015-11-14 20:52:43 +00002014 if( cnt>3 ) sqlite3_randomness(sizeof(cnt), &cnt);
drh79d5f632005-01-18 17:20:10 +00002015 }
drh91bb0ee2004-09-01 03:06:34 +00002016 pCol->zName = zName;
danba68f8f2015-11-19 16:46:46 +00002017 sqlite3ColumnPropertiesFromName(0, pCol);
drh03d69a62015-11-19 13:53:57 +00002018 if( zName && sqlite3HashInsert(&ht, zName, pCol)==pCol ){
drh4a642b62016-02-05 01:55:27 +00002019 sqlite3OomFault(db);
drh0315e3c2015-11-14 20:52:43 +00002020 }
drh7d10d5a2008-08-20 16:35:10 +00002021 }
drh0315e3c2015-11-14 20:52:43 +00002022 sqlite3HashClear(&ht);
drh7d10d5a2008-08-20 16:35:10 +00002023 if( db->mallocFailed ){
drh7d10d5a2008-08-20 16:35:10 +00002024 for(j=0; j<i; j++){
2025 sqlite3DbFree(db, aCol[j].zName);
2026 }
2027 sqlite3DbFree(db, aCol);
2028 *paCol = 0;
2029 *pnCol = 0;
mistachkinfad30392016-02-13 23:43:46 +00002030 return SQLITE_NOMEM_BKPT;
drh7d10d5a2008-08-20 16:35:10 +00002031 }
2032 return SQLITE_OK;
2033}
danielk1977517eb642004-06-07 10:00:31 +00002034
drh7d10d5a2008-08-20 16:35:10 +00002035/*
2036** Add type and collation information to a column list based on
2037** a SELECT statement.
2038**
2039** The column list presumably came from selectColumnNamesFromExprList().
2040** The column list has only names, not types or collations. This
2041** routine goes through and adds the types and collations.
2042**
shaneb08a67a2009-03-31 03:41:56 +00002043** This routine requires that all identifiers in the SELECT
drh7d10d5a2008-08-20 16:35:10 +00002044** statement be resolved.
2045*/
drhed06a132016-04-05 20:59:12 +00002046void sqlite3SelectAddColumnTypeAndCollation(
drh7d10d5a2008-08-20 16:35:10 +00002047 Parse *pParse, /* Parsing contexts */
drh186ad8c2013-10-08 18:40:37 +00002048 Table *pTab, /* Add column type information to this table */
drh7d10d5a2008-08-20 16:35:10 +00002049 Select *pSelect /* SELECT used to determine types and collations */
2050){
2051 sqlite3 *db = pParse->db;
2052 NameContext sNC;
2053 Column *pCol;
2054 CollSeq *pColl;
2055 int i;
2056 Expr *p;
2057 struct ExprList_item *a;
2058
2059 assert( pSelect!=0 );
2060 assert( (pSelect->selFlags & SF_Resolved)!=0 );
drh186ad8c2013-10-08 18:40:37 +00002061 assert( pTab->nCol==pSelect->pEList->nExpr || db->mallocFailed );
drh7d10d5a2008-08-20 16:35:10 +00002062 if( db->mallocFailed ) return;
2063 memset(&sNC, 0, sizeof(sNC));
2064 sNC.pSrcList = pSelect->pSrc;
2065 a = pSelect->pEList->a;
drh186ad8c2013-10-08 18:40:37 +00002066 for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
drhed06a132016-04-05 20:59:12 +00002067 const char *zType;
2068 int n, m;
drh7d10d5a2008-08-20 16:35:10 +00002069 p = a[i].pExpr;
drhcafc2f72017-10-03 03:01:09 +00002070 zType = columnType(&sNC, p, 0, 0, 0);
2071 /* pCol->szEst = ... // Column size est for SELECT tables never used */
danielk1977c60e9b82005-01-31 12:42:29 +00002072 pCol->affinity = sqlite3ExprAffinity(p);
drh0c4db032017-10-03 19:53:12 +00002073 if( zType ){
2074 m = sqlite3Strlen30(zType);
drhed06a132016-04-05 20:59:12 +00002075 n = sqlite3Strlen30(pCol->zName);
2076 pCol->zName = sqlite3DbReallocOrFree(db, pCol->zName, n+m+2);
2077 if( pCol->zName ){
2078 memcpy(&pCol->zName[n+1], zType, m+1);
2079 pCol->colFlags |= COLFLAG_HASTYPE;
2080 }
2081 }
drh05883a32015-06-02 15:32:08 +00002082 if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_BLOB;
danielk1977b3bf5562006-01-10 17:58:23 +00002083 pColl = sqlite3ExprCollSeq(pParse, p);
drh1cb50c82015-04-21 17:17:47 +00002084 if( pColl && pCol->zColl==0 ){
drh17435752007-08-16 04:30:38 +00002085 pCol->zColl = sqlite3DbStrDup(db, pColl->zName);
danielk19770202b292004-06-09 09:55:16 +00002086 }
drh22f70c32002-02-18 01:17:00 +00002087 }
drhcafc2f72017-10-03 03:01:09 +00002088 pTab->szTabRow = 1; /* Any non-zero value works */
drh7d10d5a2008-08-20 16:35:10 +00002089}
2090
2091/*
2092** Given a SELECT statement, generate a Table structure that describes
2093** the result set of that SELECT.
2094*/
2095Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect){
2096 Table *pTab;
2097 sqlite3 *db = pParse->db;
2098 int savedFlags;
2099
2100 savedFlags = db->flags;
2101 db->flags &= ~SQLITE_FullColNames;
2102 db->flags |= SQLITE_ShortColNames;
2103 sqlite3SelectPrep(pParse, pSelect, 0);
2104 if( pParse->nErr ) return 0;
2105 while( pSelect->pPrior ) pSelect = pSelect->pPrior;
2106 db->flags = savedFlags;
2107 pTab = sqlite3DbMallocZero(db, sizeof(Table) );
2108 if( pTab==0 ){
2109 return 0;
2110 }
drh373cc2d2009-05-17 02:06:14 +00002111 /* The sqlite3ResultSetOfSelect() is only used n contexts where lookaside
drhb2468952010-07-23 17:06:32 +00002112 ** is disabled */
drh4a642b62016-02-05 01:55:27 +00002113 assert( db->lookaside.bDisable );
drh79df7782016-12-14 14:07:35 +00002114 pTab->nTabRef = 1;
drh7d10d5a2008-08-20 16:35:10 +00002115 pTab->zName = 0;
dancfc9df72014-04-25 15:01:01 +00002116 pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
drh8981b902015-08-24 17:42:49 +00002117 sqlite3ColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
drhed06a132016-04-05 20:59:12 +00002118 sqlite3SelectAddColumnTypeAndCollation(pParse, pTab, pSelect);
drh22f70c32002-02-18 01:17:00 +00002119 pTab->iPKey = -1;
drh7ce72f62008-07-24 15:50:41 +00002120 if( db->mallocFailed ){
dan1feeaed2010-07-23 15:41:47 +00002121 sqlite3DeleteTable(db, pTab);
drh7ce72f62008-07-24 15:50:41 +00002122 return 0;
2123 }
drh22f70c32002-02-18 01:17:00 +00002124 return pTab;
2125}
2126
2127/*
drhd8bc7082000-06-07 23:51:50 +00002128** Get a VDBE for the given parser context. Create a new one if necessary.
2129** If an error occurs, return NULL and leave a message in pParse.
2130*/
drh55965612017-09-16 20:58:41 +00002131Vdbe *sqlite3GetVdbe(Parse *pParse){
2132 if( pParse->pVdbe ){
2133 return pParse->pVdbe;
2134 }
drh6f077342016-04-12 00:26:59 +00002135 if( pParse->pToplevel==0
2136 && OptimizationEnabled(pParse->db,SQLITE_FactorOutConst)
2137 ){
2138 pParse->okConstFactor = 1;
drhd8bc7082000-06-07 23:51:50 +00002139 }
drh55965612017-09-16 20:58:41 +00002140 return sqlite3VdbeCreate(pParse);
drh6f077342016-04-12 00:26:59 +00002141}
drhfcb78a42003-01-18 20:11:05 +00002142
drh15007a92006-01-08 18:10:17 +00002143
drhd8bc7082000-06-07 23:51:50 +00002144/*
drh7b58dae2003-07-20 01:16:46 +00002145** Compute the iLimit and iOffset fields of the SELECT based on the
drh8c0833f2017-11-14 23:48:23 +00002146** pLimit expressions. pLimit->pLeft and pLimit->pRight hold the expressions
drh7b58dae2003-07-20 01:16:46 +00002147** that appear in the original SQL statement after the LIMIT and OFFSET
danielk1977a2dc3b12005-02-05 12:48:48 +00002148** keywords. Or NULL if those keywords are omitted. iLimit and iOffset
2149** are the integer memory register numbers for counters used to compute
2150** the limit and offset. If there is no limit and/or offset, then
2151** iLimit and iOffset are negative.
drh7b58dae2003-07-20 01:16:46 +00002152**
drhd59ba6c2006-01-08 05:02:54 +00002153** This routine changes the values of iLimit and iOffset only if
drh8c0833f2017-11-14 23:48:23 +00002154** a limit or offset is defined by pLimit->pLeft and pLimit->pRight. iLimit
2155** and iOffset should have been preset to appropriate default values (zero)
drhaa9ce702014-01-22 18:07:04 +00002156** prior to calling this routine.
2157**
2158** The iOffset register (if it exists) is initialized to the value
2159** of the OFFSET. The iLimit register is initialized to LIMIT. Register
2160** iOffset+1 is initialized to LIMIT+OFFSET.
2161**
drh8c0833f2017-11-14 23:48:23 +00002162** Only if pLimit->pLeft!=0 do the limit registers get
drh7b58dae2003-07-20 01:16:46 +00002163** redefined. The UNION ALL operator uses this property to force
2164** the reuse of the same limit and offset registers across multiple
2165** SELECT statements.
2166*/
drhec7429a2005-10-06 16:53:14 +00002167static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
drh02afc862006-01-20 18:10:57 +00002168 Vdbe *v = 0;
2169 int iLimit = 0;
drh15007a92006-01-08 18:10:17 +00002170 int iOffset;
drh8b0cf382015-10-06 21:07:06 +00002171 int n;
drh8c0833f2017-11-14 23:48:23 +00002172 Expr *pLimit = p->pLimit;
2173
drh0acb7e42008-06-25 00:12:41 +00002174 if( p->iLimit ) return;
drh15007a92006-01-08 18:10:17 +00002175
drh7b58dae2003-07-20 01:16:46 +00002176 /*
drh7b58dae2003-07-20 01:16:46 +00002177 ** "LIMIT -1" always shows all rows. There is some
drhf7b54962013-05-28 12:11:54 +00002178 ** controversy about what the correct behavior should be.
drh7b58dae2003-07-20 01:16:46 +00002179 ** The current implementation interprets "LIMIT 0" to mean
2180 ** no rows.
2181 */
drhceea3322009-04-23 13:22:42 +00002182 sqlite3ExprCacheClear(pParse);
drh8c0833f2017-11-14 23:48:23 +00002183 if( pLimit ){
2184 assert( pLimit->op==TK_LIMIT );
2185 assert( pLimit->pLeft!=0 );
drh0a07c102008-01-03 18:03:08 +00002186 p->iLimit = iLimit = ++pParse->nMem;
drh15007a92006-01-08 18:10:17 +00002187 v = sqlite3GetVdbe(pParse);
drhaa9ce702014-01-22 18:07:04 +00002188 assert( v!=0 );
drh8c0833f2017-11-14 23:48:23 +00002189 if( sqlite3ExprIsInteger(pLimit->pLeft, &n) ){
drh456e4e42009-11-20 16:13:15 +00002190 sqlite3VdbeAddOp2(v, OP_Integer, n, iLimit);
2191 VdbeComment((v, "LIMIT counter"));
drh9b918ed2009-11-12 03:13:26 +00002192 if( n==0 ){
drh076e85f2015-09-03 13:46:12 +00002193 sqlite3VdbeGoto(v, iBreak);
drhc3489bb2016-02-25 16:04:59 +00002194 }else if( n>=0 && p->nSelectRow>sqlite3LogEst((u64)n) ){
2195 p->nSelectRow = sqlite3LogEst((u64)n);
2196 p->selFlags |= SF_FixedLimit;
drh9b918ed2009-11-12 03:13:26 +00002197 }
2198 }else{
drh8c0833f2017-11-14 23:48:23 +00002199 sqlite3ExprCode(pParse, pLimit->pLeft, iLimit);
drh688852a2014-02-17 22:40:43 +00002200 sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit); VdbeCoverage(v);
drh9b918ed2009-11-12 03:13:26 +00002201 VdbeComment((v, "LIMIT counter"));
drh16897072015-03-07 00:57:37 +00002202 sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, iBreak); VdbeCoverage(v);
drh9b918ed2009-11-12 03:13:26 +00002203 }
drh8c0833f2017-11-14 23:48:23 +00002204 if( pLimit->pRight ){
drh373cc2d2009-05-17 02:06:14 +00002205 p->iOffset = iOffset = ++pParse->nMem;
drhb7654112008-01-12 12:48:07 +00002206 pParse->nMem++; /* Allocate an extra register for limit+offset */
drh8c0833f2017-11-14 23:48:23 +00002207 sqlite3ExprCode(pParse, pLimit->pRight, iOffset);
drh688852a2014-02-17 22:40:43 +00002208 sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);
drh373cc2d2009-05-17 02:06:14 +00002209 VdbeComment((v, "OFFSET counter"));
drhcc2fa4c2016-01-25 15:57:29 +00002210 sqlite3VdbeAddOp3(v, OP_OffsetLimit, iLimit, iOffset+1, iOffset);
drhb7654112008-01-12 12:48:07 +00002211 VdbeComment((v, "LIMIT+OFFSET"));
drhd59ba6c2006-01-08 05:02:54 +00002212 }
drh7b58dae2003-07-20 01:16:46 +00002213 }
2214}
2215
drhb7f91642004-10-31 02:22:47 +00002216#ifndef SQLITE_OMIT_COMPOUND_SELECT
drhfbc4ee72004-08-29 01:31:05 +00002217/*
drhfbc4ee72004-08-29 01:31:05 +00002218** Return the appropriate collating sequence for the iCol-th column of
2219** the result set for the compound-select statement "p". Return NULL if
2220** the column has no default collating sequence.
2221**
2222** The collating sequence for the compound select is taken from the
2223** left-most term of the select that has a collating sequence.
2224*/
danielk1977dc1bdc42004-06-11 10:51:27 +00002225static CollSeq *multiSelectCollSeq(Parse *pParse, Select *p, int iCol){
drhfbc4ee72004-08-29 01:31:05 +00002226 CollSeq *pRet;
danielk1977dc1bdc42004-06-11 10:51:27 +00002227 if( p->pPrior ){
2228 pRet = multiSelectCollSeq(pParse, p->pPrior, iCol);
drhfbc4ee72004-08-29 01:31:05 +00002229 }else{
2230 pRet = 0;
danielk1977dc1bdc42004-06-11 10:51:27 +00002231 }
drh10c081a2009-04-16 00:24:23 +00002232 assert( iCol>=0 );
drh2ec18a32015-06-23 23:31:52 +00002233 /* iCol must be less than p->pEList->nExpr. Otherwise an error would
2234 ** have been thrown during name resolution and we would not have gotten
2235 ** this far */
2236 if( pRet==0 && ALWAYS(iCol<p->pEList->nExpr) ){
danielk1977dc1bdc42004-06-11 10:51:27 +00002237 pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr);
2238 }
2239 return pRet;
drhd3d39e92004-05-20 22:16:29 +00002240}
2241
dan53bed452014-01-24 20:37:18 +00002242/*
2243** The select statement passed as the second parameter is a compound SELECT
2244** with an ORDER BY clause. This function allocates and returns a KeyInfo
2245** structure suitable for implementing the ORDER BY.
2246**
2247** Space to hold the KeyInfo structure is obtained from malloc. The calling
2248** function is responsible for ensuring that this structure is eventually
2249** freed.
2250*/
2251static KeyInfo *multiSelectOrderByKeyInfo(Parse *pParse, Select *p, int nExtra){
2252 ExprList *pOrderBy = p->pOrderBy;
2253 int nOrderBy = p->pOrderBy->nExpr;
2254 sqlite3 *db = pParse->db;
2255 KeyInfo *pRet = sqlite3KeyInfoAlloc(db, nOrderBy+nExtra, 1);
2256 if( pRet ){
2257 int i;
2258 for(i=0; i<nOrderBy; i++){
2259 struct ExprList_item *pItem = &pOrderBy->a[i];
2260 Expr *pTerm = pItem->pExpr;
2261 CollSeq *pColl;
2262
2263 if( pTerm->flags & EP_Collate ){
2264 pColl = sqlite3ExprCollSeq(pParse, pTerm);
2265 }else{
2266 pColl = multiSelectCollSeq(pParse, p, pItem->u.x.iOrderByCol-1);
2267 if( pColl==0 ) pColl = db->pDfltColl;
2268 pOrderBy->a[i].pExpr =
2269 sqlite3ExprAddCollateString(pParse, pTerm, pColl->zName);
2270 }
2271 assert( sqlite3KeyInfoIsWriteable(pRet) );
2272 pRet->aColl[i] = pColl;
2273 pRet->aSortOrder[i] = pOrderBy->a[i].sortOrder;
2274 }
2275 }
2276
2277 return pRet;
2278}
drhd3d39e92004-05-20 22:16:29 +00002279
drh781def22014-01-22 13:35:53 +00002280#ifndef SQLITE_OMIT_CTE
2281/*
2282** This routine generates VDBE code to compute the content of a WITH RECURSIVE
2283** query of the form:
2284**
2285** <recursive-table> AS (<setup-query> UNION [ALL] <recursive-query>)
2286** \___________/ \_______________/
2287** p->pPrior p
2288**
2289**
2290** There is exactly one reference to the recursive-table in the FROM clause
drh8a48b9c2015-08-19 15:20:00 +00002291** of recursive-query, marked with the SrcList->a[].fg.isRecursive flag.
drh781def22014-01-22 13:35:53 +00002292**
2293** The setup-query runs once to generate an initial set of rows that go
2294** into a Queue table. Rows are extracted from the Queue table one by
drhfe1c6bb2014-01-22 17:28:35 +00002295** one. Each row extracted from Queue is output to pDest. Then the single
2296** extracted row (now in the iCurrent table) becomes the content of the
2297** recursive-table for a recursive-query run. The output of the recursive-query
drh781def22014-01-22 13:35:53 +00002298** is added back into the Queue table. Then another row is extracted from Queue
2299** and the iteration continues until the Queue table is empty.
2300**
2301** If the compound query operator is UNION then no duplicate rows are ever
2302** inserted into the Queue table. The iDistinct table keeps a copy of all rows
2303** that have ever been inserted into Queue and causes duplicates to be
2304** discarded. If the operator is UNION ALL, then duplicates are allowed.
2305**
2306** If the query has an ORDER BY, then entries in the Queue table are kept in
2307** ORDER BY order and the first entry is extracted for each cycle. Without
2308** an ORDER BY, the Queue table is just a FIFO.
2309**
2310** If a LIMIT clause is provided, then the iteration stops after LIMIT rows
2311** have been output to pDest. A LIMIT of zero means to output no rows and a
2312** negative LIMIT means to output all rows. If there is also an OFFSET clause
2313** with a positive value, then the first OFFSET outputs are discarded rather
2314** than being sent to pDest. The LIMIT count does not begin until after OFFSET
2315** rows have been skipped.
2316*/
2317static void generateWithRecursiveQuery(
2318 Parse *pParse, /* Parsing context */
2319 Select *p, /* The recursive SELECT to be coded */
2320 SelectDest *pDest /* What to do with query results */
2321){
2322 SrcList *pSrc = p->pSrc; /* The FROM clause of the recursive query */
2323 int nCol = p->pEList->nExpr; /* Number of columns in the recursive table */
2324 Vdbe *v = pParse->pVdbe; /* The prepared statement under construction */
2325 Select *pSetup = p->pPrior; /* The setup query */
2326 int addrTop; /* Top of the loop */
2327 int addrCont, addrBreak; /* CONTINUE and BREAK addresses */
drhedf83d12014-01-22 18:31:27 +00002328 int iCurrent = 0; /* The Current table */
drh781def22014-01-22 13:35:53 +00002329 int regCurrent; /* Register holding Current table */
2330 int iQueue; /* The Queue table */
2331 int iDistinct = 0; /* To ensure unique results if UNION */
drh8e1ee882014-03-21 19:56:09 +00002332 int eDest = SRT_Fifo; /* How to write to Queue */
drh781def22014-01-22 13:35:53 +00002333 SelectDest destQueue; /* SelectDest targetting the Queue table */
2334 int i; /* Loop counter */
2335 int rc; /* Result code */
drhfe1c6bb2014-01-22 17:28:35 +00002336 ExprList *pOrderBy; /* The ORDER BY clause */
drh8c0833f2017-11-14 23:48:23 +00002337 Expr *pLimit; /* Saved LIMIT and OFFSET */
drhaa9ce702014-01-22 18:07:04 +00002338 int regLimit, regOffset; /* Registers used by LIMIT and OFFSET */
drh781def22014-01-22 13:35:53 +00002339
2340 /* Obtain authorization to do a recursive query */
2341 if( sqlite3AuthCheck(pParse, SQLITE_RECURSIVE, 0, 0, 0) ) return;
drh781def22014-01-22 13:35:53 +00002342
drhaa9ce702014-01-22 18:07:04 +00002343 /* Process the LIMIT and OFFSET clauses, if they exist */
2344 addrBreak = sqlite3VdbeMakeLabel(v);
dan69b93832016-12-16 15:05:40 +00002345 p->nSelectRow = 320; /* 4 billion rows */
drhaa9ce702014-01-22 18:07:04 +00002346 computeLimitRegisters(pParse, p, addrBreak);
2347 pLimit = p->pLimit;
drhaa9ce702014-01-22 18:07:04 +00002348 regLimit = p->iLimit;
2349 regOffset = p->iOffset;
drh8c0833f2017-11-14 23:48:23 +00002350 p->pLimit = 0;
drhaa9ce702014-01-22 18:07:04 +00002351 p->iLimit = p->iOffset = 0;
dan53bed452014-01-24 20:37:18 +00002352 pOrderBy = p->pOrderBy;
drh781def22014-01-22 13:35:53 +00002353
2354 /* Locate the cursor number of the Current table */
2355 for(i=0; ALWAYS(i<pSrc->nSrc); i++){
drh8a48b9c2015-08-19 15:20:00 +00002356 if( pSrc->a[i].fg.isRecursive ){
drh781def22014-01-22 13:35:53 +00002357 iCurrent = pSrc->a[i].iCursor;
2358 break;
2359 }
2360 }
2361
drhfe1c6bb2014-01-22 17:28:35 +00002362 /* Allocate cursors numbers for Queue and Distinct. The cursor number for
drh781def22014-01-22 13:35:53 +00002363 ** the Distinct table must be exactly one greater than Queue in order
drh8e1ee882014-03-21 19:56:09 +00002364 ** for the SRT_DistFifo and SRT_DistQueue destinations to work. */
drh781def22014-01-22 13:35:53 +00002365 iQueue = pParse->nTab++;
2366 if( p->op==TK_UNION ){
drh8e1ee882014-03-21 19:56:09 +00002367 eDest = pOrderBy ? SRT_DistQueue : SRT_DistFifo;
drh781def22014-01-22 13:35:53 +00002368 iDistinct = pParse->nTab++;
drhfe1c6bb2014-01-22 17:28:35 +00002369 }else{
drh8e1ee882014-03-21 19:56:09 +00002370 eDest = pOrderBy ? SRT_Queue : SRT_Fifo;
drh781def22014-01-22 13:35:53 +00002371 }
2372 sqlite3SelectDestInit(&destQueue, eDest, iQueue);
2373
2374 /* Allocate cursors for Current, Queue, and Distinct. */
2375 regCurrent = ++pParse->nMem;
2376 sqlite3VdbeAddOp3(v, OP_OpenPseudo, iCurrent, regCurrent, nCol);
drhfe1c6bb2014-01-22 17:28:35 +00002377 if( pOrderBy ){
dan53bed452014-01-24 20:37:18 +00002378 KeyInfo *pKeyInfo = multiSelectOrderByKeyInfo(pParse, p, 1);
drhfe1c6bb2014-01-22 17:28:35 +00002379 sqlite3VdbeAddOp4(v, OP_OpenEphemeral, iQueue, pOrderBy->nExpr+2, 0,
2380 (char*)pKeyInfo, P4_KEYINFO);
2381 destQueue.pOrderBy = pOrderBy;
2382 }else{
2383 sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iQueue, nCol);
2384 }
2385 VdbeComment((v, "Queue table"));
drh781def22014-01-22 13:35:53 +00002386 if( iDistinct ){
2387 p->addrOpenEphm[0] = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iDistinct, 0);
2388 p->selFlags |= SF_UsesEphemeral;
2389 }
2390
dan53bed452014-01-24 20:37:18 +00002391 /* Detach the ORDER BY clause from the compound SELECT */
2392 p->pOrderBy = 0;
2393
drh781def22014-01-22 13:35:53 +00002394 /* Store the results of the setup-query in Queue. */
drhd227a292014-02-09 18:02:09 +00002395 pSetup->pNext = 0;
drh84a01de2018-05-02 16:13:48 +00002396 ExplainQueryPlan((pParse, 1, "SETUP"));
drh781def22014-01-22 13:35:53 +00002397 rc = sqlite3Select(pParse, pSetup, &destQueue);
drhd227a292014-02-09 18:02:09 +00002398 pSetup->pNext = p;
drhfe1c6bb2014-01-22 17:28:35 +00002399 if( rc ) goto end_of_recursive_query;
drh781def22014-01-22 13:35:53 +00002400
2401 /* Find the next row in the Queue and output that row */
drh688852a2014-02-17 22:40:43 +00002402 addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iQueue, addrBreak); VdbeCoverage(v);
drh781def22014-01-22 13:35:53 +00002403
2404 /* Transfer the next row in Queue over to Current */
2405 sqlite3VdbeAddOp1(v, OP_NullRow, iCurrent); /* To reset column cache */
drhfe1c6bb2014-01-22 17:28:35 +00002406 if( pOrderBy ){
2407 sqlite3VdbeAddOp3(v, OP_Column, iQueue, pOrderBy->nExpr+1, regCurrent);
2408 }else{
2409 sqlite3VdbeAddOp2(v, OP_RowData, iQueue, regCurrent);
2410 }
drh781def22014-01-22 13:35:53 +00002411 sqlite3VdbeAddOp1(v, OP_Delete, iQueue);
2412
drhfe1c6bb2014-01-22 17:28:35 +00002413 /* Output the single row in Current */
2414 addrCont = sqlite3VdbeMakeLabel(v);
drhaa9ce702014-01-22 18:07:04 +00002415 codeOffset(v, regOffset, addrCont);
drh2def2f72017-09-15 17:40:34 +00002416 selectInnerLoop(pParse, p, iCurrent,
drh079a3072014-03-19 14:10:55 +00002417 0, 0, pDest, addrCont, addrBreak);
drh688852a2014-02-17 22:40:43 +00002418 if( regLimit ){
drh16897072015-03-07 00:57:37 +00002419 sqlite3VdbeAddOp2(v, OP_DecrJumpZero, regLimit, addrBreak);
drh688852a2014-02-17 22:40:43 +00002420 VdbeCoverage(v);
2421 }
drhfe1c6bb2014-01-22 17:28:35 +00002422 sqlite3VdbeResolveLabel(v, addrCont);
2423
drh781def22014-01-22 13:35:53 +00002424 /* Execute the recursive SELECT taking the single row in Current as
2425 ** the value for the recursive-table. Store the results in the Queue.
2426 */
drhb63ce022015-07-05 22:15:10 +00002427 if( p->selFlags & SF_Aggregate ){
2428 sqlite3ErrorMsg(pParse, "recursive aggregate queries not supported");
2429 }else{
2430 p->pPrior = 0;
drh84a01de2018-05-02 16:13:48 +00002431 ExplainQueryPlan((pParse, 1, "RECURSIVE STEP"));
drhb63ce022015-07-05 22:15:10 +00002432 sqlite3Select(pParse, p, &destQueue);
2433 assert( p->pPrior==0 );
2434 p->pPrior = pSetup;
2435 }
drh781def22014-01-22 13:35:53 +00002436
2437 /* Keep running the loop until the Queue is empty */
drh076e85f2015-09-03 13:46:12 +00002438 sqlite3VdbeGoto(v, addrTop);
drh781def22014-01-22 13:35:53 +00002439 sqlite3VdbeResolveLabel(v, addrBreak);
drhfe1c6bb2014-01-22 17:28:35 +00002440
2441end_of_recursive_query:
dan9afccba2014-03-21 19:27:54 +00002442 sqlite3ExprListDelete(pParse->db, p->pOrderBy);
drhfe1c6bb2014-01-22 17:28:35 +00002443 p->pOrderBy = pOrderBy;
drhaa9ce702014-01-22 18:07:04 +00002444 p->pLimit = pLimit;
drhfe1c6bb2014-01-22 17:28:35 +00002445 return;
drh781def22014-01-22 13:35:53 +00002446}
danb68b9772014-01-25 12:16:53 +00002447#endif /* SQLITE_OMIT_CTE */
drh781def22014-01-22 13:35:53 +00002448
2449/* Forward references */
drhb21e7c72008-06-22 12:37:57 +00002450static int multiSelectOrderBy(
2451 Parse *pParse, /* Parsing context */
2452 Select *p, /* The right-most of SELECTs to be coded */
drha9671a22008-07-08 23:40:20 +00002453 SelectDest *pDest /* What to do with query results */
drhb21e7c72008-06-22 12:37:57 +00002454);
2455
drh45f54a52015-01-05 19:16:42 +00002456/*
drh45f54a52015-01-05 19:16:42 +00002457** Handle the special case of a compound-select that originates from a
2458** VALUES clause. By handling this as a special case, we avoid deep
2459** recursion, and thus do not need to enforce the SQLITE_LIMIT_COMPOUND_SELECT
2460** on a VALUES clause.
2461**
2462** Because the Select object originates from a VALUES clause:
drhb058d052018-01-14 20:12:23 +00002463** (1) There is no LIMIT or OFFSET or else there is a LIMIT of exactly 1
drh45f54a52015-01-05 19:16:42 +00002464** (2) All terms are UNION ALL
2465** (3) There is no ORDER BY clause
drhb058d052018-01-14 20:12:23 +00002466**
2467** The "LIMIT of exactly 1" case of condition (1) comes about when a VALUES
2468** clause occurs within scalar expression (ex: "SELECT (VALUES(1),(2),(3))").
2469** The sqlite3CodeSubselect will have added the LIMIT 1 clause in tht case.
2470** Since the limit is exactly 1, we only need to evalutes the left-most VALUES.
drh45f54a52015-01-05 19:16:42 +00002471*/
2472static int multiSelectValues(
2473 Parse *pParse, /* Parsing context */
2474 Select *p, /* The right-most of SELECTs to be coded */
2475 SelectDest *pDest /* What to do with query results */
2476){
drh45f54a52015-01-05 19:16:42 +00002477 int nRow = 1;
2478 int rc = 0;
drhfa16f5d2018-05-03 01:37:13 +00002479 int bShowAll = p->pLimit==0;
drh772460f2015-04-16 14:13:12 +00002480 assert( p->selFlags & SF_MultiValue );
drh45f54a52015-01-05 19:16:42 +00002481 do{
2482 assert( p->selFlags & SF_Values );
2483 assert( p->op==TK_ALL || (p->op==TK_SELECT && p->pPrior==0) );
dan923cadb2015-06-23 12:19:55 +00002484 assert( p->pNext==0 || p->pEList->nExpr==p->pNext->pEList->nExpr );
drh45f54a52015-01-05 19:16:42 +00002485 if( p->pPrior==0 ) break;
2486 assert( p->pPrior->pNext==p );
2487 p = p->pPrior;
drhfa16f5d2018-05-03 01:37:13 +00002488 nRow += bShowAll;
drh45f54a52015-01-05 19:16:42 +00002489 }while(1);
drhfa16f5d2018-05-03 01:37:13 +00002490 ExplainQueryPlan((pParse, 0, "SCAN %d CONSTANT ROW%s", nRow,
2491 nRow==1 ? "" : "S"));
drh45f54a52015-01-05 19:16:42 +00002492 while( p ){
drhfa16f5d2018-05-03 01:37:13 +00002493 selectInnerLoop(pParse, p, -1, 0, 0, pDest, 1, 1);
2494 if( !bShowAll ) break;
drh45f54a52015-01-05 19:16:42 +00002495 p->nSelectRow = nRow;
2496 p = p->pNext;
2497 }
2498 return rc;
2499}
drhb21e7c72008-06-22 12:37:57 +00002500
drhd3d39e92004-05-20 22:16:29 +00002501/*
drh16ee60f2008-06-20 18:13:25 +00002502** This routine is called to process a compound query form from
2503** two or more separate queries using UNION, UNION ALL, EXCEPT, or
2504** INTERSECT
drhc926afb2002-06-20 03:38:26 +00002505**
drhe78e8282003-01-19 03:59:45 +00002506** "p" points to the right-most of the two queries. the query on the
2507** left is p->pPrior. The left query could also be a compound query
2508** in which case this routine will be called recursively.
2509**
2510** The results of the total query are to be written into a destination
2511** of type eDest with parameter iParm.
2512**
2513** Example 1: Consider a three-way compound SQL statement.
2514**
2515** SELECT a FROM t1 UNION SELECT b FROM t2 UNION SELECT c FROM t3
2516**
2517** This statement is parsed up as follows:
2518**
2519** SELECT c FROM t3
2520** |
2521** `-----> SELECT b FROM t2
2522** |
jplyon4b11c6d2004-01-19 04:57:53 +00002523** `------> SELECT a FROM t1
drhe78e8282003-01-19 03:59:45 +00002524**
2525** The arrows in the diagram above represent the Select.pPrior pointer.
2526** So if this routine is called with p equal to the t3 query, then
2527** pPrior will be the t2 query. p->op will be TK_UNION in this case.
2528**
2529** Notice that because of the way SQLite parses compound SELECTs, the
2530** individual selects always group from left to right.
drh82c3d632000-06-06 21:56:07 +00002531*/
danielk197784ac9d02004-05-18 09:58:06 +00002532static int multiSelect(
drhfbc4ee72004-08-29 01:31:05 +00002533 Parse *pParse, /* Parsing context */
2534 Select *p, /* The right-most of SELECTs to be coded */
drha9671a22008-07-08 23:40:20 +00002535 SelectDest *pDest /* What to do with query results */
danielk197784ac9d02004-05-18 09:58:06 +00002536){
drhfbc4ee72004-08-29 01:31:05 +00002537 int rc = SQLITE_OK; /* Success code from a subroutine */
2538 Select *pPrior; /* Another SELECT immediately to our left */
2539 Vdbe *v; /* Generate code to this VDBE */
drh1013c932008-01-06 00:25:21 +00002540 SelectDest dest; /* Alternative data destination */
danielk1977eca7e012008-07-01 16:05:25 +00002541 Select *pDelete = 0; /* Chain of simple selects to delete */
drh633e6d52008-07-28 19:34:53 +00002542 sqlite3 *db; /* Database connection */
drh82c3d632000-06-06 21:56:07 +00002543
drh7b58dae2003-07-20 01:16:46 +00002544 /* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs. Only
drhfbc4ee72004-08-29 01:31:05 +00002545 ** the last (right-most) SELECT in the series may have an ORDER BY or LIMIT.
drh82c3d632000-06-06 21:56:07 +00002546 */
drh701bb3b2008-08-02 03:50:39 +00002547 assert( p && p->pPrior ); /* Calling function guarantees this much */
daneae73fb2014-01-16 18:34:33 +00002548 assert( (p->selFlags & SF_Recursive)==0 || p->op==TK_ALL || p->op==TK_UNION );
drh633e6d52008-07-28 19:34:53 +00002549 db = pParse->db;
drhd8bc7082000-06-07 23:51:50 +00002550 pPrior = p->pPrior;
drhbc103772008-08-08 18:06:25 +00002551 dest = *pDest;
drh63347e72017-09-18 13:16:10 +00002552 if( pPrior->pOrderBy || pPrior->pLimit ){
2553 sqlite3ErrorMsg(pParse,"%s clause should come after %s not before",
2554 pPrior->pOrderBy!=0 ? "ORDER BY" : "LIMIT", selectOpName(p->op));
danielk197784ac9d02004-05-18 09:58:06 +00002555 rc = 1;
2556 goto multi_select_end;
drh7b58dae2003-07-20 01:16:46 +00002557 }
drh82c3d632000-06-06 21:56:07 +00002558
danielk19774adee202004-05-08 08:23:19 +00002559 v = sqlite3GetVdbe(pParse);
drh701bb3b2008-08-02 03:50:39 +00002560 assert( v!=0 ); /* The VDBE already created by calling function */
drhd8bc7082000-06-07 23:51:50 +00002561
drh1cc3d752002-03-23 00:31:29 +00002562 /* Create the destination temporary table if necessary
2563 */
danielk19776c8c8ce2008-01-02 16:27:09 +00002564 if( dest.eDest==SRT_EphemTab ){
danielk1977b4964b72004-05-18 01:23:38 +00002565 assert( p->pEList );
drh2b596da2012-07-23 21:43:19 +00002566 sqlite3VdbeAddOp2(v, OP_OpenEphemeral, dest.iSDParm, p->pEList->nExpr);
danielk19776c8c8ce2008-01-02 16:27:09 +00002567 dest.eDest = SRT_Table;
drh1cc3d752002-03-23 00:31:29 +00002568 }
2569
drh45f54a52015-01-05 19:16:42 +00002570 /* Special handling for a compound-select that originates as a VALUES clause.
2571 */
drh772460f2015-04-16 14:13:12 +00002572 if( p->selFlags & SF_MultiValue ){
drh45f54a52015-01-05 19:16:42 +00002573 rc = multiSelectValues(pParse, p, &dest);
2574 goto multi_select_end;
2575 }
2576
drhf6e369a2008-06-24 12:46:30 +00002577 /* Make sure all SELECTs in the statement have the same number of elements
2578 ** in their result sets.
2579 */
2580 assert( p->pEList && pPrior->pEList );
dan923cadb2015-06-23 12:19:55 +00002581 assert( p->pEList->nExpr==pPrior->pEList->nExpr );
drhf6e369a2008-06-24 12:46:30 +00002582
daneede6a52014-01-15 19:42:23 +00002583#ifndef SQLITE_OMIT_CTE
daneae73fb2014-01-16 18:34:33 +00002584 if( p->selFlags & SF_Recursive ){
drh781def22014-01-22 13:35:53 +00002585 generateWithRecursiveQuery(pParse, p, &dest);
dan8ce71842014-01-14 20:14:09 +00002586 }else
2587#endif
drhf6e369a2008-06-24 12:46:30 +00002588
drha9671a22008-07-08 23:40:20 +00002589 /* Compound SELECTs that have an ORDER BY clause are handled separately.
2590 */
drhf6e369a2008-06-24 12:46:30 +00002591 if( p->pOrderBy ){
drha9671a22008-07-08 23:40:20 +00002592 return multiSelectOrderBy(pParse, p, pDest);
drh03c39052018-05-02 14:24:34 +00002593 }else{
drhf6e369a2008-06-24 12:46:30 +00002594
drhc631ded2018-05-02 02:22:22 +00002595#ifndef SQLITE_OMIT_EXPLAIN
drh03c39052018-05-02 14:24:34 +00002596 if( pPrior->pPrior==0 ){
drh4d799832018-05-03 19:47:14 +00002597 ExplainQueryPlan((pParse, 1, "COMPOUND QUERY"));
drh03c39052018-05-02 14:24:34 +00002598 ExplainQueryPlan((pParse, 1, "LEFT-MOST SUBQUERY"));
drh03c39052018-05-02 14:24:34 +00002599 }
drhc631ded2018-05-02 02:22:22 +00002600#endif
2601
drh03c39052018-05-02 14:24:34 +00002602 /* Generate code for the left and right SELECT statements.
2603 */
2604 switch( p->op ){
2605 case TK_ALL: {
2606 int addr = 0;
2607 int nLimit;
2608 assert( !pPrior->pLimit );
2609 pPrior->iLimit = p->iLimit;
2610 pPrior->iOffset = p->iOffset;
2611 pPrior->pLimit = p->pLimit;
2612 rc = sqlite3Select(pParse, pPrior, &dest);
2613 p->pLimit = 0;
2614 if( rc ){
2615 goto multi_select_end;
drh9f1ef452015-10-06 17:27:18 +00002616 }
drh03c39052018-05-02 14:24:34 +00002617 p->pPrior = 0;
2618 p->iLimit = pPrior->iLimit;
2619 p->iOffset = pPrior->iOffset;
2620 if( p->iLimit ){
2621 addr = sqlite3VdbeAddOp1(v, OP_IfNot, p->iLimit); VdbeCoverage(v);
2622 VdbeComment((v, "Jump ahead if LIMIT reached"));
2623 if( p->iOffset ){
2624 sqlite3VdbeAddOp3(v, OP_OffsetLimit,
2625 p->iLimit, p->iOffset+1, p->iOffset);
2626 }
2627 }
2628 ExplainQueryPlan((pParse, 1, "UNION ALL"));
drh03c39052018-05-02 14:24:34 +00002629 rc = sqlite3Select(pParse, p, &dest);
2630 testcase( rc!=SQLITE_OK );
2631 pDelete = p->pPrior;
2632 p->pPrior = pPrior;
2633 p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
2634 if( pPrior->pLimit
2635 && sqlite3ExprIsInteger(pPrior->pLimit->pLeft, &nLimit)
2636 && nLimit>0 && p->nSelectRow > sqlite3LogEst((u64)nLimit)
2637 ){
2638 p->nSelectRow = sqlite3LogEst((u64)nLimit);
2639 }
2640 if( addr ){
2641 sqlite3VdbeJumpHere(v, addr);
2642 }
2643 break;
drha9671a22008-07-08 23:40:20 +00002644 }
drh03c39052018-05-02 14:24:34 +00002645 case TK_EXCEPT:
2646 case TK_UNION: {
2647 int unionTab; /* Cursor number of the temp table holding result */
2648 u8 op = 0; /* One of the SRT_ operations to apply to self */
2649 int priorOp; /* The SRT_ operation to apply to prior selects */
2650 Expr *pLimit; /* Saved values of p->nLimit */
2651 int addr;
2652 SelectDest uniondest;
2653
2654 testcase( p->op==TK_EXCEPT );
2655 testcase( p->op==TK_UNION );
2656 priorOp = SRT_Union;
2657 if( dest.eDest==priorOp ){
2658 /* We can reuse a temporary table generated by a SELECT to our
2659 ** right.
2660 */
2661 assert( p->pLimit==0 ); /* Not allowed on leftward elements */
2662 unionTab = dest.iSDParm;
2663 }else{
2664 /* We will need to create our own temporary table to hold the
2665 ** intermediate results.
2666 */
2667 unionTab = pParse->nTab++;
2668 assert( p->pOrderBy==0 );
2669 addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, unionTab, 0);
2670 assert( p->addrOpenEphm[0] == -1 );
2671 p->addrOpenEphm[0] = addr;
2672 findRightmost(p)->selFlags |= SF_UsesEphemeral;
2673 assert( p->pEList );
2674 }
2675
2676 /* Code the SELECT statements to our left
drhd8bc7082000-06-07 23:51:50 +00002677 */
drh03c39052018-05-02 14:24:34 +00002678 assert( !pPrior->pOrderBy );
2679 sqlite3SelectDestInit(&uniondest, priorOp, unionTab);
2680 rc = sqlite3Select(pParse, pPrior, &uniondest);
2681 if( rc ){
2682 goto multi_select_end;
2683 }
2684
2685 /* Code the current SELECT statement
drhd8bc7082000-06-07 23:51:50 +00002686 */
drh03c39052018-05-02 14:24:34 +00002687 if( p->op==TK_EXCEPT ){
2688 op = SRT_Except;
2689 }else{
2690 assert( p->op==TK_UNION );
2691 op = SRT_Union;
2692 }
2693 p->pPrior = 0;
2694 pLimit = p->pLimit;
2695 p->pLimit = 0;
2696 uniondest.eDest = op;
2697 ExplainQueryPlan((pParse, 1, "%s USING TEMP B-TREE",
2698 selectOpName(p->op)));
drh03c39052018-05-02 14:24:34 +00002699 rc = sqlite3Select(pParse, p, &uniondest);
2700 testcase( rc!=SQLITE_OK );
2701 /* Query flattening in sqlite3Select() might refill p->pOrderBy.
2702 ** Be sure to delete p->pOrderBy, therefore, to avoid a memory leak. */
2703 sqlite3ExprListDelete(db, p->pOrderBy);
2704 pDelete = p->pPrior;
2705 p->pPrior = pPrior;
2706 p->pOrderBy = 0;
2707 if( p->op==TK_UNION ){
2708 p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
2709 }
2710 sqlite3ExprDelete(db, p->pLimit);
2711 p->pLimit = pLimit;
2712 p->iLimit = 0;
2713 p->iOffset = 0;
2714
2715 /* Convert the data in the temporary table into whatever form
2716 ** it is that we currently need.
2717 */
2718 assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );
2719 if( dest.eDest!=priorOp ){
2720 int iCont, iBreak, iStart;
2721 assert( p->pEList );
2722 iBreak = sqlite3VdbeMakeLabel(v);
2723 iCont = sqlite3VdbeMakeLabel(v);
2724 computeLimitRegisters(pParse, p, iBreak);
2725 sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); VdbeCoverage(v);
2726 iStart = sqlite3VdbeCurrentAddr(v);
2727 selectInnerLoop(pParse, p, unionTab,
2728 0, 0, &dest, iCont, iBreak);
2729 sqlite3VdbeResolveLabel(v, iCont);
2730 sqlite3VdbeAddOp2(v, OP_Next, unionTab, iStart); VdbeCoverage(v);
2731 sqlite3VdbeResolveLabel(v, iBreak);
2732 sqlite3VdbeAddOp2(v, OP_Close, unionTab, 0);
2733 }
2734 break;
2735 }
2736 default: assert( p->op==TK_INTERSECT ); {
2737 int tab1, tab2;
2738 int iCont, iBreak, iStart;
2739 Expr *pLimit;
2740 int addr;
2741 SelectDest intersectdest;
2742 int r1;
2743
2744 /* INTERSECT is different from the others since it requires
2745 ** two temporary tables. Hence it has its own case. Begin
2746 ** by allocating the tables we will need.
2747 */
2748 tab1 = pParse->nTab++;
2749 tab2 = pParse->nTab++;
drh93a960a2008-07-10 00:32:42 +00002750 assert( p->pOrderBy==0 );
drh03c39052018-05-02 14:24:34 +00002751
2752 addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab1, 0);
drh93a960a2008-07-10 00:32:42 +00002753 assert( p->addrOpenEphm[0] == -1 );
2754 p->addrOpenEphm[0] = addr;
drhd227a292014-02-09 18:02:09 +00002755 findRightmost(p)->selFlags |= SF_UsesEphemeral;
danielk197784ac9d02004-05-18 09:58:06 +00002756 assert( p->pEList );
drh03c39052018-05-02 14:24:34 +00002757
2758 /* Code the SELECTs to our left into temporary table "tab1".
2759 */
2760 sqlite3SelectDestInit(&intersectdest, SRT_Union, tab1);
2761 rc = sqlite3Select(pParse, pPrior, &intersectdest);
2762 if( rc ){
2763 goto multi_select_end;
2764 }
2765
2766 /* Code the current SELECT into temporary table "tab2"
2767 */
2768 addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab2, 0);
2769 assert( p->addrOpenEphm[1] == -1 );
2770 p->addrOpenEphm[1] = addr;
2771 p->pPrior = 0;
2772 pLimit = p->pLimit;
2773 p->pLimit = 0;
2774 intersectdest.iSDParm = tab2;
2775 ExplainQueryPlan((pParse, 1, "%s USING TEMP B-TREE",
2776 selectOpName(p->op)));
drh03c39052018-05-02 14:24:34 +00002777 rc = sqlite3Select(pParse, p, &intersectdest);
2778 testcase( rc!=SQLITE_OK );
2779 pDelete = p->pPrior;
2780 p->pPrior = pPrior;
2781 if( p->nSelectRow>pPrior->nSelectRow ){
2782 p->nSelectRow = pPrior->nSelectRow;
2783 }
2784 sqlite3ExprDelete(db, p->pLimit);
2785 p->pLimit = pLimit;
2786
2787 /* Generate code to take the intersection of the two temporary
2788 ** tables.
2789 */
drh82c3d632000-06-06 21:56:07 +00002790 assert( p->pEList );
danielk19774adee202004-05-08 08:23:19 +00002791 iBreak = sqlite3VdbeMakeLabel(v);
2792 iCont = sqlite3VdbeMakeLabel(v);
drhec7429a2005-10-06 16:53:14 +00002793 computeLimitRegisters(pParse, p, iBreak);
drh03c39052018-05-02 14:24:34 +00002794 sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v);
2795 r1 = sqlite3GetTempReg(pParse);
2796 iStart = sqlite3VdbeAddOp2(v, OP_RowData, tab1, r1);
2797 sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0);
2798 VdbeCoverage(v);
2799 sqlite3ReleaseTempReg(pParse, r1);
2800 selectInnerLoop(pParse, p, tab1,
drhe8e4af72012-09-21 00:04:28 +00002801 0, 0, &dest, iCont, iBreak);
danielk19774adee202004-05-08 08:23:19 +00002802 sqlite3VdbeResolveLabel(v, iCont);
drh03c39052018-05-02 14:24:34 +00002803 sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart); VdbeCoverage(v);
danielk19774adee202004-05-08 08:23:19 +00002804 sqlite3VdbeResolveLabel(v, iBreak);
drh03c39052018-05-02 14:24:34 +00002805 sqlite3VdbeAddOp2(v, OP_Close, tab2, 0);
2806 sqlite3VdbeAddOp2(v, OP_Close, tab1, 0);
2807 break;
drh82c3d632000-06-06 21:56:07 +00002808 }
drh82c3d632000-06-06 21:56:07 +00002809 }
drh03c39052018-05-02 14:24:34 +00002810
2811 #ifndef SQLITE_OMIT_EXPLAIN
2812 if( p->pNext==0 ){
2813 ExplainQueryPlanPop(pParse);
drh82c3d632000-06-06 21:56:07 +00002814 }
drh03c39052018-05-02 14:24:34 +00002815 #endif
drh82c3d632000-06-06 21:56:07 +00002816 }
drh03c39052018-05-02 14:24:34 +00002817
drha9671a22008-07-08 23:40:20 +00002818 /* Compute collating sequences used by
2819 ** temporary tables needed to implement the compound select.
2820 ** Attach the KeyInfo structure to all temporary tables.
drh8cdbf832004-08-29 16:25:03 +00002821 **
2822 ** This section is run by the right-most SELECT statement only.
2823 ** SELECT statements to the left always skip this part. The right-most
2824 ** SELECT might also skip this part if it has no ORDER BY clause and
2825 ** no temp tables are required.
drhfbc4ee72004-08-29 01:31:05 +00002826 */
drh7d10d5a2008-08-20 16:35:10 +00002827 if( p->selFlags & SF_UsesEphemeral ){
drhfbc4ee72004-08-29 01:31:05 +00002828 int i; /* Loop counter */
2829 KeyInfo *pKeyInfo; /* Collating sequence for the result set */
drh0342b1f2005-09-01 03:07:44 +00002830 Select *pLoop; /* For looping through SELECT statements */
drhf68d7d12007-05-03 13:02:26 +00002831 CollSeq **apColl; /* For looping through pKeyInfo->aColl[] */
drh93a960a2008-07-10 00:32:42 +00002832 int nCol; /* Number of columns in result set */
drhfbc4ee72004-08-29 01:31:05 +00002833
drhd227a292014-02-09 18:02:09 +00002834 assert( p->pNext==0 );
drh93a960a2008-07-10 00:32:42 +00002835 nCol = p->pEList->nExpr;
drhad124322013-10-23 13:30:58 +00002836 pKeyInfo = sqlite3KeyInfoAlloc(db, nCol, 1);
danielk1977dc1bdc42004-06-11 10:51:27 +00002837 if( !pKeyInfo ){
mistachkinfad30392016-02-13 23:43:46 +00002838 rc = SQLITE_NOMEM_BKPT;
danielk1977dc1bdc42004-06-11 10:51:27 +00002839 goto multi_select_end;
2840 }
drh0342b1f2005-09-01 03:07:44 +00002841 for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){
2842 *apColl = multiSelectCollSeq(pParse, p, i);
2843 if( 0==*apColl ){
drh633e6d52008-07-28 19:34:53 +00002844 *apColl = db->pDfltColl;
danielk1977dc1bdc42004-06-11 10:51:27 +00002845 }
2846 }
2847
drh0342b1f2005-09-01 03:07:44 +00002848 for(pLoop=p; pLoop; pLoop=pLoop->pPrior){
2849 for(i=0; i<2; i++){
drhb9bb7c12006-06-11 23:41:55 +00002850 int addr = pLoop->addrOpenEphm[i];
drh0342b1f2005-09-01 03:07:44 +00002851 if( addr<0 ){
2852 /* If [0] is unused then [1] is also unused. So we can
2853 ** always safely abort as soon as the first unused slot is found */
drhb9bb7c12006-06-11 23:41:55 +00002854 assert( pLoop->addrOpenEphm[1]<0 );
drh0342b1f2005-09-01 03:07:44 +00002855 break;
2856 }
2857 sqlite3VdbeChangeP2(v, addr, nCol);
drh2ec2fb22013-11-06 19:59:23 +00002858 sqlite3VdbeChangeP4(v, addr, (char*)sqlite3KeyInfoRef(pKeyInfo),
2859 P4_KEYINFO);
drh0ee5a1e2007-01-26 19:04:00 +00002860 pLoop->addrOpenEphm[i] = -1;
drh0342b1f2005-09-01 03:07:44 +00002861 }
danielk1977dc1bdc42004-06-11 10:51:27 +00002862 }
drh2ec2fb22013-11-06 19:59:23 +00002863 sqlite3KeyInfoUnref(pKeyInfo);
danielk197784ac9d02004-05-18 09:58:06 +00002864 }
danielk1977dc1bdc42004-06-11 10:51:27 +00002865
2866multi_select_end:
drh2b596da2012-07-23 21:43:19 +00002867 pDest->iSdst = dest.iSdst;
2868 pDest->nSdst = dest.nSdst;
drh633e6d52008-07-28 19:34:53 +00002869 sqlite3SelectDelete(db, pDelete);
danielk197784ac9d02004-05-18 09:58:06 +00002870 return rc;
drh22827922000-06-06 17:27:05 +00002871}
drhb7f91642004-10-31 02:22:47 +00002872#endif /* SQLITE_OMIT_COMPOUND_SELECT */
drh22827922000-06-06 17:27:05 +00002873
drhb21e7c72008-06-22 12:37:57 +00002874/*
mistachkin89b31d72015-07-16 17:29:27 +00002875** Error message for when two or more terms of a compound select have different
2876** size result sets.
2877*/
2878void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p){
2879 if( p->selFlags & SF_Values ){
2880 sqlite3ErrorMsg(pParse, "all VALUES must have the same number of terms");
2881 }else{
2882 sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
2883 " do not have the same number of result columns", selectOpName(p->op));
2884 }
2885}
2886
2887/*
drhb21e7c72008-06-22 12:37:57 +00002888** Code an output subroutine for a coroutine implementation of a
2889** SELECT statment.
drh0acb7e42008-06-25 00:12:41 +00002890**
drh2b596da2012-07-23 21:43:19 +00002891** The data to be output is contained in pIn->iSdst. There are
2892** pIn->nSdst columns to be output. pDest is where the output should
drh0acb7e42008-06-25 00:12:41 +00002893** be sent.
2894**
2895** regReturn is the number of the register holding the subroutine
2896** return address.
2897**
drhf053d5b2010-08-09 14:26:32 +00002898** If regPrev>0 then it is the first register in a vector that
drh0acb7e42008-06-25 00:12:41 +00002899** records the previous output. mem[regPrev] is a flag that is false
2900** if there has been no previous output. If regPrev>0 then code is
2901** generated to suppress duplicates. pKeyInfo is used for comparing
2902** keys.
2903**
2904** If the LIMIT found in p->iLimit is reached, jump immediately to
2905** iBreak.
drhb21e7c72008-06-22 12:37:57 +00002906*/
drh0acb7e42008-06-25 00:12:41 +00002907static int generateOutputSubroutine(
drh92b01d52008-06-24 00:32:35 +00002908 Parse *pParse, /* Parsing context */
2909 Select *p, /* The SELECT statement */
2910 SelectDest *pIn, /* Coroutine supplying data */
2911 SelectDest *pDest, /* Where to send the data */
2912 int regReturn, /* The return address register */
drh0acb7e42008-06-25 00:12:41 +00002913 int regPrev, /* Previous result register. No uniqueness if 0 */
2914 KeyInfo *pKeyInfo, /* For comparing with previous entry */
drh92b01d52008-06-24 00:32:35 +00002915 int iBreak /* Jump here if we hit the LIMIT */
drhb21e7c72008-06-22 12:37:57 +00002916){
2917 Vdbe *v = pParse->pVdbe;
drh92b01d52008-06-24 00:32:35 +00002918 int iContinue;
2919 int addr;
drhb21e7c72008-06-22 12:37:57 +00002920
drh92b01d52008-06-24 00:32:35 +00002921 addr = sqlite3VdbeCurrentAddr(v);
2922 iContinue = sqlite3VdbeMakeLabel(v);
drh0acb7e42008-06-25 00:12:41 +00002923
2924 /* Suppress duplicates for UNION, EXCEPT, and INTERSECT
2925 */
2926 if( regPrev ){
drh728e0f92015-10-10 14:41:28 +00002927 int addr1, addr2;
2928 addr1 = sqlite3VdbeAddOp1(v, OP_IfNot, regPrev); VdbeCoverage(v);
2929 addr2 = sqlite3VdbeAddOp4(v, OP_Compare, pIn->iSdst, regPrev+1, pIn->nSdst,
drh2ec2fb22013-11-06 19:59:23 +00002930 (char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);
drh728e0f92015-10-10 14:41:28 +00002931 sqlite3VdbeAddOp3(v, OP_Jump, addr2+2, iContinue, addr2+2); VdbeCoverage(v);
2932 sqlite3VdbeJumpHere(v, addr1);
drhe8e4af72012-09-21 00:04:28 +00002933 sqlite3VdbeAddOp3(v, OP_Copy, pIn->iSdst, regPrev+1, pIn->nSdst-1);
drhec86c722011-12-09 17:27:51 +00002934 sqlite3VdbeAddOp2(v, OP_Integer, 1, regPrev);
drh0acb7e42008-06-25 00:12:41 +00002935 }
danielk19771f9caa42008-07-02 16:10:45 +00002936 if( pParse->db->mallocFailed ) return 0;
drh0acb7e42008-06-25 00:12:41 +00002937
mistachkind5578432012-08-25 10:01:29 +00002938 /* Suppress the first OFFSET entries if there is an OFFSET clause
drh0acb7e42008-06-25 00:12:41 +00002939 */
drhaa9ce702014-01-22 18:07:04 +00002940 codeOffset(v, p->iOffset, iContinue);
drhb21e7c72008-06-22 12:37:57 +00002941
drhe2248cf2015-05-22 17:29:27 +00002942 assert( pDest->eDest!=SRT_Exists );
2943 assert( pDest->eDest!=SRT_Table );
drhb21e7c72008-06-22 12:37:57 +00002944 switch( pDest->eDest ){
2945 /* Store the result as data using a unique key.
2946 */
drhb21e7c72008-06-22 12:37:57 +00002947 case SRT_EphemTab: {
2948 int r1 = sqlite3GetTempReg(pParse);
2949 int r2 = sqlite3GetTempReg(pParse);
drh2b596da2012-07-23 21:43:19 +00002950 sqlite3VdbeAddOp3(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst, r1);
2951 sqlite3VdbeAddOp2(v, OP_NewRowid, pDest->iSDParm, r2);
2952 sqlite3VdbeAddOp3(v, OP_Insert, pDest->iSDParm, r1, r2);
drhb21e7c72008-06-22 12:37:57 +00002953 sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
2954 sqlite3ReleaseTempReg(pParse, r2);
2955 sqlite3ReleaseTempReg(pParse, r1);
2956 break;
2957 }
2958
2959#ifndef SQLITE_OMIT_SUBQUERY
drh14318072016-09-06 18:51:25 +00002960 /* If we are creating a set for an "expr IN (SELECT ...)".
drhb21e7c72008-06-22 12:37:57 +00002961 */
2962 case SRT_Set: {
drh6fccc352008-06-27 00:52:45 +00002963 int r1;
drh63cecc42016-09-06 19:08:21 +00002964 testcase( pIn->nSdst>1 );
drhb21e7c72008-06-22 12:37:57 +00002965 r1 = sqlite3GetTempReg(pParse);
dan71c57db2016-07-09 20:23:55 +00002966 sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst,
drh14318072016-09-06 18:51:25 +00002967 r1, pDest->zAffSdst, pIn->nSdst);
2968 sqlite3ExprCacheAffinityChange(pParse, pIn->iSdst, pIn->nSdst);
drh9b4eaeb2016-11-09 00:10:33 +00002969 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, pDest->iSDParm, r1,
2970 pIn->iSdst, pIn->nSdst);
drhb21e7c72008-06-22 12:37:57 +00002971 sqlite3ReleaseTempReg(pParse, r1);
drhb21e7c72008-06-22 12:37:57 +00002972 break;
2973 }
2974
drhb21e7c72008-06-22 12:37:57 +00002975 /* If this is a scalar select that is part of an expression, then
2976 ** store the results in the appropriate memory cell and break out
2977 ** of the scan loop.
2978 */
2979 case SRT_Mem: {
drha276e3f2015-04-16 16:22:27 +00002980 assert( pIn->nSdst==1 || pParse->nErr>0 ); testcase( pIn->nSdst!=1 );
drh2b596da2012-07-23 21:43:19 +00002981 sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSDParm, 1);
drhb21e7c72008-06-22 12:37:57 +00002982 /* The LIMIT clause will jump out of the loop for us */
2983 break;
2984 }
2985#endif /* #ifndef SQLITE_OMIT_SUBQUERY */
2986
drh7d10d5a2008-08-20 16:35:10 +00002987 /* The results are stored in a sequence of registers
drh2b596da2012-07-23 21:43:19 +00002988 ** starting at pDest->iSdst. Then the co-routine yields.
drhb21e7c72008-06-22 12:37:57 +00002989 */
drh92b01d52008-06-24 00:32:35 +00002990 case SRT_Coroutine: {
drh2b596da2012-07-23 21:43:19 +00002991 if( pDest->iSdst==0 ){
2992 pDest->iSdst = sqlite3GetTempRange(pParse, pIn->nSdst);
2993 pDest->nSdst = pIn->nSdst;
drhb21e7c72008-06-22 12:37:57 +00002994 }
dan4b79bde2015-04-21 15:49:04 +00002995 sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSdst, pIn->nSdst);
drh2b596da2012-07-23 21:43:19 +00002996 sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
drh92b01d52008-06-24 00:32:35 +00002997 break;
2998 }
2999
drhccfcbce2009-05-18 15:46:07 +00003000 /* If none of the above, then the result destination must be
3001 ** SRT_Output. This routine is never called with any other
3002 ** destination other than the ones handled above or SRT_Output.
3003 **
3004 ** For SRT_Output, results are stored in a sequence of registers.
3005 ** Then the OP_ResultRow opcode is used to cause sqlite3_step() to
3006 ** return the next row of result.
drh7d10d5a2008-08-20 16:35:10 +00003007 */
drhccfcbce2009-05-18 15:46:07 +00003008 default: {
3009 assert( pDest->eDest==SRT_Output );
drh2b596da2012-07-23 21:43:19 +00003010 sqlite3VdbeAddOp2(v, OP_ResultRow, pIn->iSdst, pIn->nSdst);
3011 sqlite3ExprCacheAffinityChange(pParse, pIn->iSdst, pIn->nSdst);
drhb21e7c72008-06-22 12:37:57 +00003012 break;
3013 }
drhb21e7c72008-06-22 12:37:57 +00003014 }
drh92b01d52008-06-24 00:32:35 +00003015
3016 /* Jump to the end of the loop if the LIMIT is reached.
3017 */
3018 if( p->iLimit ){
drh16897072015-03-07 00:57:37 +00003019 sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
drh92b01d52008-06-24 00:32:35 +00003020 }
3021
drh92b01d52008-06-24 00:32:35 +00003022 /* Generate the subroutine return
3023 */
drh0acb7e42008-06-25 00:12:41 +00003024 sqlite3VdbeResolveLabel(v, iContinue);
drh92b01d52008-06-24 00:32:35 +00003025 sqlite3VdbeAddOp1(v, OP_Return, regReturn);
3026
3027 return addr;
drhb21e7c72008-06-22 12:37:57 +00003028}
3029
3030/*
3031** Alternative compound select code generator for cases when there
3032** is an ORDER BY clause.
3033**
3034** We assume a query of the following form:
3035**
3036** <selectA> <operator> <selectB> ORDER BY <orderbylist>
3037**
3038** <operator> is one of UNION ALL, UNION, EXCEPT, or INTERSECT. The idea
3039** is to code both <selectA> and <selectB> with the ORDER BY clause as
3040** co-routines. Then run the co-routines in parallel and merge the results
3041** into the output. In addition to the two coroutines (called selectA and
3042** selectB) there are 7 subroutines:
3043**
3044** outA: Move the output of the selectA coroutine into the output
3045** of the compound query.
3046**
3047** outB: Move the output of the selectB coroutine into the output
3048** of the compound query. (Only generated for UNION and
3049** UNION ALL. EXCEPT and INSERTSECT never output a row that
3050** appears only in B.)
3051**
3052** AltB: Called when there is data from both coroutines and A<B.
3053**
3054** AeqB: Called when there is data from both coroutines and A==B.
3055**
3056** AgtB: Called when there is data from both coroutines and A>B.
3057**
3058** EofA: Called when data is exhausted from selectA.
3059**
3060** EofB: Called when data is exhausted from selectB.
3061**
3062** The implementation of the latter five subroutines depend on which
3063** <operator> is used:
3064**
3065**
3066** UNION ALL UNION EXCEPT INTERSECT
3067** ------------- ----------------- -------------- -----------------
drh0acb7e42008-06-25 00:12:41 +00003068** AltB: outA, nextA outA, nextA outA, nextA nextA
drhb21e7c72008-06-22 12:37:57 +00003069**
drh0acb7e42008-06-25 00:12:41 +00003070** AeqB: outA, nextA nextA nextA outA, nextA
drhb21e7c72008-06-22 12:37:57 +00003071**
drh0acb7e42008-06-25 00:12:41 +00003072** AgtB: outB, nextB outB, nextB nextB nextB
drhb21e7c72008-06-22 12:37:57 +00003073**
drh0acb7e42008-06-25 00:12:41 +00003074** EofA: outB, nextB outB, nextB halt halt
drhb21e7c72008-06-22 12:37:57 +00003075**
drh0acb7e42008-06-25 00:12:41 +00003076** EofB: outA, nextA outA, nextA outA, nextA halt
3077**
3078** In the AltB, AeqB, and AgtB subroutines, an EOF on A following nextA
3079** causes an immediate jump to EofA and an EOF on B following nextB causes
3080** an immediate jump to EofB. Within EofA and EofB, and EOF on entry or
3081** following nextX causes a jump to the end of the select processing.
3082**
3083** Duplicate removal in the UNION, EXCEPT, and INTERSECT cases is handled
3084** within the output subroutine. The regPrev register set holds the previously
3085** output value. A comparison is made against this value and the output
3086** is skipped if the next results would be the same as the previous.
drhb21e7c72008-06-22 12:37:57 +00003087**
3088** The implementation plan is to implement the two coroutines and seven
3089** subroutines first, then put the control logic at the bottom. Like this:
3090**
3091** goto Init
3092** coA: coroutine for left query (A)
3093** coB: coroutine for right query (B)
3094** outA: output one row of A
3095** outB: output one row of B (UNION and UNION ALL only)
3096** EofA: ...
3097** EofB: ...
3098** AltB: ...
3099** AeqB: ...
3100** AgtB: ...
3101** Init: initialize coroutine registers
3102** yield coA
3103** if eof(A) goto EofA
3104** yield coB
3105** if eof(B) goto EofB
3106** Cmpr: Compare A, B
3107** Jump AltB, AeqB, AgtB
3108** End: ...
3109**
3110** We call AltB, AeqB, AgtB, EofA, and EofB "subroutines" but they are not
3111** actually called using Gosub and they do not Return. EofA and EofB loop
3112** until all data is exhausted then jump to the "end" labe. AltB, AeqB,
3113** and AgtB jump to either L2 or to one of EofA or EofB.
3114*/
danielk1977de3e41e2008-08-04 03:51:24 +00003115#ifndef SQLITE_OMIT_COMPOUND_SELECT
drhb21e7c72008-06-22 12:37:57 +00003116static int multiSelectOrderBy(
3117 Parse *pParse, /* Parsing context */
3118 Select *p, /* The right-most of SELECTs to be coded */
drha9671a22008-07-08 23:40:20 +00003119 SelectDest *pDest /* What to do with query results */
drhb21e7c72008-06-22 12:37:57 +00003120){
drh0acb7e42008-06-25 00:12:41 +00003121 int i, j; /* Loop counters */
drhb21e7c72008-06-22 12:37:57 +00003122 Select *pPrior; /* Another SELECT immediately to our left */
3123 Vdbe *v; /* Generate code to this VDBE */
drhb21e7c72008-06-22 12:37:57 +00003124 SelectDest destA; /* Destination for coroutine A */
3125 SelectDest destB; /* Destination for coroutine B */
drh92b01d52008-06-24 00:32:35 +00003126 int regAddrA; /* Address register for select-A coroutine */
drh92b01d52008-06-24 00:32:35 +00003127 int regAddrB; /* Address register for select-B coroutine */
drh92b01d52008-06-24 00:32:35 +00003128 int addrSelectA; /* Address of the select-A coroutine */
3129 int addrSelectB; /* Address of the select-B coroutine */
3130 int regOutA; /* Address register for the output-A subroutine */
3131 int regOutB; /* Address register for the output-B subroutine */
3132 int addrOutA; /* Address of the output-A subroutine */
drhb27b7f52008-12-10 18:03:45 +00003133 int addrOutB = 0; /* Address of the output-B subroutine */
drh92b01d52008-06-24 00:32:35 +00003134 int addrEofA; /* Address of the select-A-exhausted subroutine */
drh81cf13e2014-02-07 18:27:53 +00003135 int addrEofA_noB; /* Alternate addrEofA if B is uninitialized */
drh92b01d52008-06-24 00:32:35 +00003136 int addrEofB; /* Address of the select-B-exhausted subroutine */
3137 int addrAltB; /* Address of the A<B subroutine */
3138 int addrAeqB; /* Address of the A==B subroutine */
3139 int addrAgtB; /* Address of the A>B subroutine */
3140 int regLimitA; /* Limit register for select-A */
3141 int regLimitB; /* Limit register for select-A */
drh0acb7e42008-06-25 00:12:41 +00003142 int regPrev; /* A range of registers to hold previous output */
drh92b01d52008-06-24 00:32:35 +00003143 int savedLimit; /* Saved value of p->iLimit */
3144 int savedOffset; /* Saved value of p->iOffset */
3145 int labelCmpr; /* Label for the start of the merge algorithm */
3146 int labelEnd; /* Label for the end of the overall SELECT stmt */
drh728e0f92015-10-10 14:41:28 +00003147 int addr1; /* Jump instructions that get retargetted */
drh92b01d52008-06-24 00:32:35 +00003148 int op; /* One of TK_ALL, TK_UNION, TK_EXCEPT, TK_INTERSECT */
drh96067812008-09-23 09:36:10 +00003149 KeyInfo *pKeyDup = 0; /* Comparison information for duplicate removal */
drh0acb7e42008-06-25 00:12:41 +00003150 KeyInfo *pKeyMerge; /* Comparison information for merging rows */
3151 sqlite3 *db; /* Database connection */
3152 ExprList *pOrderBy; /* The ORDER BY clause */
3153 int nOrderBy; /* Number of terms in the ORDER BY clause */
3154 int *aPermute; /* Mapping from ORDER BY terms to result set columns */
drhb21e7c72008-06-22 12:37:57 +00003155
drh92b01d52008-06-24 00:32:35 +00003156 assert( p->pOrderBy!=0 );
drh96067812008-09-23 09:36:10 +00003157 assert( pKeyDup==0 ); /* "Managed" code needs this. Ticket #3382. */
drh0acb7e42008-06-25 00:12:41 +00003158 db = pParse->db;
drh92b01d52008-06-24 00:32:35 +00003159 v = pParse->pVdbe;
drhccfcbce2009-05-18 15:46:07 +00003160 assert( v!=0 ); /* Already thrown the error if VDBE alloc failed */
drh92b01d52008-06-24 00:32:35 +00003161 labelEnd = sqlite3VdbeMakeLabel(v);
3162 labelCmpr = sqlite3VdbeMakeLabel(v);
drh0acb7e42008-06-25 00:12:41 +00003163
drh92b01d52008-06-24 00:32:35 +00003164
3165 /* Patch up the ORDER BY clause
3166 */
3167 op = p->op;
drhb21e7c72008-06-22 12:37:57 +00003168 pPrior = p->pPrior;
drh92b01d52008-06-24 00:32:35 +00003169 assert( pPrior->pOrderBy==0 );
drh0acb7e42008-06-25 00:12:41 +00003170 pOrderBy = p->pOrderBy;
drh93a960a2008-07-10 00:32:42 +00003171 assert( pOrderBy );
drh93a960a2008-07-10 00:32:42 +00003172 nOrderBy = pOrderBy->nExpr;
3173
drh0acb7e42008-06-25 00:12:41 +00003174 /* For operators other than UNION ALL we have to make sure that
3175 ** the ORDER BY clause covers every term of the result set. Add
3176 ** terms to the ORDER BY clause as necessary.
3177 */
3178 if( op!=TK_ALL ){
3179 for(i=1; db->mallocFailed==0 && i<=p->pEList->nExpr; i++){
drh7d10d5a2008-08-20 16:35:10 +00003180 struct ExprList_item *pItem;
3181 for(j=0, pItem=pOrderBy->a; j<nOrderBy; j++, pItem++){
drhc2acc4e2013-11-15 18:15:19 +00003182 assert( pItem->u.x.iOrderByCol>0 );
3183 if( pItem->u.x.iOrderByCol==i ) break;
drh0acb7e42008-06-25 00:12:41 +00003184 }
3185 if( j==nOrderBy ){
drhb7916a72009-05-27 10:31:29 +00003186 Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);
mistachkinfad30392016-02-13 23:43:46 +00003187 if( pNew==0 ) return SQLITE_NOMEM_BKPT;
drh0acb7e42008-06-25 00:12:41 +00003188 pNew->flags |= EP_IntValue;
drh33e619f2009-05-28 01:00:55 +00003189 pNew->u.iValue = i;
drh43606172017-04-05 11:32:13 +00003190 p->pOrderBy = pOrderBy = sqlite3ExprListAppend(pParse, pOrderBy, pNew);
drhc2acc4e2013-11-15 18:15:19 +00003191 if( pOrderBy ) pOrderBy->a[nOrderBy++].u.x.iOrderByCol = (u16)i;
drh0acb7e42008-06-25 00:12:41 +00003192 }
3193 }
3194 }
3195
3196 /* Compute the comparison permutation and keyinfo that is used with
drh10c081a2009-04-16 00:24:23 +00003197 ** the permutation used to determine if the next
drh0acb7e42008-06-25 00:12:41 +00003198 ** row of results comes from selectA or selectB. Also add explicit
3199 ** collations to the ORDER BY clause terms so that when the subqueries
3200 ** to the right and the left are evaluated, they use the correct
3201 ** collation.
3202 */
drh575fad62016-02-05 13:38:36 +00003203 aPermute = sqlite3DbMallocRawNN(db, sizeof(int)*(nOrderBy + 1));
drh0acb7e42008-06-25 00:12:41 +00003204 if( aPermute ){
drh7d10d5a2008-08-20 16:35:10 +00003205 struct ExprList_item *pItem;
drhb1702022016-01-30 00:45:18 +00003206 aPermute[0] = nOrderBy;
3207 for(i=1, pItem=pOrderBy->a; i<=nOrderBy; i++, pItem++){
drh67366182015-04-16 14:33:35 +00003208 assert( pItem->u.x.iOrderByCol>0 );
drh2ec18a32015-06-23 23:31:52 +00003209 assert( pItem->u.x.iOrderByCol<=p->pEList->nExpr );
drhc2acc4e2013-11-15 18:15:19 +00003210 aPermute[i] = pItem->u.x.iOrderByCol - 1;
drh0acb7e42008-06-25 00:12:41 +00003211 }
dan53bed452014-01-24 20:37:18 +00003212 pKeyMerge = multiSelectOrderByKeyInfo(pParse, p, 1);
drh0acb7e42008-06-25 00:12:41 +00003213 }else{
3214 pKeyMerge = 0;
3215 }
3216
3217 /* Reattach the ORDER BY clause to the query.
3218 */
3219 p->pOrderBy = pOrderBy;
danielk19776ab3a2e2009-02-19 14:39:25 +00003220 pPrior->pOrderBy = sqlite3ExprListDup(pParse->db, pOrderBy, 0);
drh0acb7e42008-06-25 00:12:41 +00003221
3222 /* Allocate a range of temporary registers and the KeyInfo needed
3223 ** for the logic that removes duplicate result rows when the
3224 ** operator is UNION, EXCEPT, or INTERSECT (but not UNION ALL).
3225 */
3226 if( op==TK_ALL ){
3227 regPrev = 0;
3228 }else{
3229 int nExpr = p->pEList->nExpr;
drh1c0dc822008-10-30 22:13:23 +00003230 assert( nOrderBy>=nExpr || db->mallocFailed );
drhc8ac0d12013-02-16 02:41:01 +00003231 regPrev = pParse->nMem+1;
3232 pParse->nMem += nExpr+1;
drh0acb7e42008-06-25 00:12:41 +00003233 sqlite3VdbeAddOp2(v, OP_Integer, 0, regPrev);
drhad124322013-10-23 13:30:58 +00003234 pKeyDup = sqlite3KeyInfoAlloc(db, nExpr, 1);
drh0acb7e42008-06-25 00:12:41 +00003235 if( pKeyDup ){
drh2ec2fb22013-11-06 19:59:23 +00003236 assert( sqlite3KeyInfoIsWriteable(pKeyDup) );
drh0acb7e42008-06-25 00:12:41 +00003237 for(i=0; i<nExpr; i++){
3238 pKeyDup->aColl[i] = multiSelectCollSeq(pParse, p, i);
3239 pKeyDup->aSortOrder[i] = 0;
3240 }
3241 }
3242 }
drh92b01d52008-06-24 00:32:35 +00003243
3244 /* Separate the left and the right query from one another
3245 */
3246 p->pPrior = 0;
drhd227a292014-02-09 18:02:09 +00003247 pPrior->pNext = 0;
drh7d10d5a2008-08-20 16:35:10 +00003248 sqlite3ResolveOrderGroupBy(pParse, p, p->pOrderBy, "ORDER");
drh0acb7e42008-06-25 00:12:41 +00003249 if( pPrior->pPrior==0 ){
drh7d10d5a2008-08-20 16:35:10 +00003250 sqlite3ResolveOrderGroupBy(pParse, pPrior, pPrior->pOrderBy, "ORDER");
drh0acb7e42008-06-25 00:12:41 +00003251 }
3252
drh92b01d52008-06-24 00:32:35 +00003253 /* Compute the limit registers */
3254 computeLimitRegisters(pParse, p, labelEnd);
drh0acb7e42008-06-25 00:12:41 +00003255 if( p->iLimit && op==TK_ALL ){
drh92b01d52008-06-24 00:32:35 +00003256 regLimitA = ++pParse->nMem;
3257 regLimitB = ++pParse->nMem;
3258 sqlite3VdbeAddOp2(v, OP_Copy, p->iOffset ? p->iOffset+1 : p->iLimit,
3259 regLimitA);
3260 sqlite3VdbeAddOp2(v, OP_Copy, regLimitA, regLimitB);
3261 }else{
3262 regLimitA = regLimitB = 0;
3263 }
drh633e6d52008-07-28 19:34:53 +00003264 sqlite3ExprDelete(db, p->pLimit);
drh0acb7e42008-06-25 00:12:41 +00003265 p->pLimit = 0;
drh92b01d52008-06-24 00:32:35 +00003266
drhb21e7c72008-06-22 12:37:57 +00003267 regAddrA = ++pParse->nMem;
drhb21e7c72008-06-22 12:37:57 +00003268 regAddrB = ++pParse->nMem;
drhb21e7c72008-06-22 12:37:57 +00003269 regOutA = ++pParse->nMem;
3270 regOutB = ++pParse->nMem;
3271 sqlite3SelectDestInit(&destA, SRT_Coroutine, regAddrA);
3272 sqlite3SelectDestInit(&destB, SRT_Coroutine, regAddrB);
drhe2ca99c2018-05-02 00:33:43 +00003273
drhc631ded2018-05-02 02:22:22 +00003274 ExplainQueryPlan((pParse, 1, "MERGE (%s)", selectOpName(p->op)));
drhb21e7c72008-06-22 12:37:57 +00003275
drh92b01d52008-06-24 00:32:35 +00003276 /* Generate a coroutine to evaluate the SELECT statement to the
drh0acb7e42008-06-25 00:12:41 +00003277 ** left of the compound operator - the "A" select.
3278 */
drhed71a832014-02-07 19:18:10 +00003279 addrSelectA = sqlite3VdbeCurrentAddr(v) + 1;
drh728e0f92015-10-10 14:41:28 +00003280 addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrA, 0, addrSelectA);
drhed71a832014-02-07 19:18:10 +00003281 VdbeComment((v, "left SELECT"));
drh92b01d52008-06-24 00:32:35 +00003282 pPrior->iLimit = regLimitA;
drhc631ded2018-05-02 02:22:22 +00003283 ExplainQueryPlan((pParse, 1, "LEFT"));
drh7d10d5a2008-08-20 16:35:10 +00003284 sqlite3Select(pParse, pPrior, &destA);
drh2fade2f2016-02-09 02:12:20 +00003285 sqlite3VdbeEndCoroutine(v, regAddrA);
drh728e0f92015-10-10 14:41:28 +00003286 sqlite3VdbeJumpHere(v, addr1);
drhb21e7c72008-06-22 12:37:57 +00003287
drh92b01d52008-06-24 00:32:35 +00003288 /* Generate a coroutine to evaluate the SELECT statement on
3289 ** the right - the "B" select
3290 */
drhed71a832014-02-07 19:18:10 +00003291 addrSelectB = sqlite3VdbeCurrentAddr(v) + 1;
drh728e0f92015-10-10 14:41:28 +00003292 addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrB, 0, addrSelectB);
drhed71a832014-02-07 19:18:10 +00003293 VdbeComment((v, "right SELECT"));
drh92b01d52008-06-24 00:32:35 +00003294 savedLimit = p->iLimit;
3295 savedOffset = p->iOffset;
3296 p->iLimit = regLimitB;
3297 p->iOffset = 0;
drhc631ded2018-05-02 02:22:22 +00003298 ExplainQueryPlan((pParse, 1, "RIGHT"));
drh7d10d5a2008-08-20 16:35:10 +00003299 sqlite3Select(pParse, p, &destB);
drh92b01d52008-06-24 00:32:35 +00003300 p->iLimit = savedLimit;
3301 p->iOffset = savedOffset;
drh2fade2f2016-02-09 02:12:20 +00003302 sqlite3VdbeEndCoroutine(v, regAddrB);
drhb21e7c72008-06-22 12:37:57 +00003303
drh92b01d52008-06-24 00:32:35 +00003304 /* Generate a subroutine that outputs the current row of the A
drh0acb7e42008-06-25 00:12:41 +00003305 ** select as the next output row of the compound select.
drh92b01d52008-06-24 00:32:35 +00003306 */
drhb21e7c72008-06-22 12:37:57 +00003307 VdbeNoopComment((v, "Output routine for A"));
drh0acb7e42008-06-25 00:12:41 +00003308 addrOutA = generateOutputSubroutine(pParse,
3309 p, &destA, pDest, regOutA,
drh2ec2fb22013-11-06 19:59:23 +00003310 regPrev, pKeyDup, labelEnd);
drhb21e7c72008-06-22 12:37:57 +00003311
drh92b01d52008-06-24 00:32:35 +00003312 /* Generate a subroutine that outputs the current row of the B
drh0acb7e42008-06-25 00:12:41 +00003313 ** select as the next output row of the compound select.
drh92b01d52008-06-24 00:32:35 +00003314 */
drh0acb7e42008-06-25 00:12:41 +00003315 if( op==TK_ALL || op==TK_UNION ){
3316 VdbeNoopComment((v, "Output routine for B"));
3317 addrOutB = generateOutputSubroutine(pParse,
3318 p, &destB, pDest, regOutB,
drh2ec2fb22013-11-06 19:59:23 +00003319 regPrev, pKeyDup, labelEnd);
drh0acb7e42008-06-25 00:12:41 +00003320 }
drh2ec2fb22013-11-06 19:59:23 +00003321 sqlite3KeyInfoUnref(pKeyDup);
drhb21e7c72008-06-22 12:37:57 +00003322
drh92b01d52008-06-24 00:32:35 +00003323 /* Generate a subroutine to run when the results from select A
3324 ** are exhausted and only data in select B remains.
3325 */
drhb21e7c72008-06-22 12:37:57 +00003326 if( op==TK_EXCEPT || op==TK_INTERSECT ){
drh81cf13e2014-02-07 18:27:53 +00003327 addrEofA_noB = addrEofA = labelEnd;
drhb21e7c72008-06-22 12:37:57 +00003328 }else{
drh81cf13e2014-02-07 18:27:53 +00003329 VdbeNoopComment((v, "eof-A subroutine"));
3330 addrEofA = sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
3331 addrEofA_noB = sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, labelEnd);
drh688852a2014-02-17 22:40:43 +00003332 VdbeCoverage(v);
drh076e85f2015-09-03 13:46:12 +00003333 sqlite3VdbeGoto(v, addrEofA);
drhc3489bb2016-02-25 16:04:59 +00003334 p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
drhb21e7c72008-06-22 12:37:57 +00003335 }
3336
drh92b01d52008-06-24 00:32:35 +00003337 /* Generate a subroutine to run when the results from select B
3338 ** are exhausted and only data in select A remains.
3339 */
drhb21e7c72008-06-22 12:37:57 +00003340 if( op==TK_INTERSECT ){
drh92b01d52008-06-24 00:32:35 +00003341 addrEofB = addrEofA;
drh95aa47b2010-11-16 02:49:15 +00003342 if( p->nSelectRow > pPrior->nSelectRow ) p->nSelectRow = pPrior->nSelectRow;
drhb21e7c72008-06-22 12:37:57 +00003343 }else{
drh92b01d52008-06-24 00:32:35 +00003344 VdbeNoopComment((v, "eof-B subroutine"));
drh81cf13e2014-02-07 18:27:53 +00003345 addrEofB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
drh688852a2014-02-17 22:40:43 +00003346 sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, labelEnd); VdbeCoverage(v);
drh076e85f2015-09-03 13:46:12 +00003347 sqlite3VdbeGoto(v, addrEofB);
drhb21e7c72008-06-22 12:37:57 +00003348 }
3349
drh92b01d52008-06-24 00:32:35 +00003350 /* Generate code to handle the case of A<B
3351 */
drhb21e7c72008-06-22 12:37:57 +00003352 VdbeNoopComment((v, "A-lt-B subroutine"));
drh0acb7e42008-06-25 00:12:41 +00003353 addrAltB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
drh688852a2014-02-17 22:40:43 +00003354 sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA); VdbeCoverage(v);
drh076e85f2015-09-03 13:46:12 +00003355 sqlite3VdbeGoto(v, labelCmpr);
drhb21e7c72008-06-22 12:37:57 +00003356
drh92b01d52008-06-24 00:32:35 +00003357 /* Generate code to handle the case of A==B
3358 */
drhb21e7c72008-06-22 12:37:57 +00003359 if( op==TK_ALL ){
3360 addrAeqB = addrAltB;
drh0acb7e42008-06-25 00:12:41 +00003361 }else if( op==TK_INTERSECT ){
3362 addrAeqB = addrAltB;
3363 addrAltB++;
drh92b01d52008-06-24 00:32:35 +00003364 }else{
drhb21e7c72008-06-22 12:37:57 +00003365 VdbeNoopComment((v, "A-eq-B subroutine"));
drh0acb7e42008-06-25 00:12:41 +00003366 addrAeqB =
drh688852a2014-02-17 22:40:43 +00003367 sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA); VdbeCoverage(v);
drh076e85f2015-09-03 13:46:12 +00003368 sqlite3VdbeGoto(v, labelCmpr);
drhb21e7c72008-06-22 12:37:57 +00003369 }
3370
drh92b01d52008-06-24 00:32:35 +00003371 /* Generate code to handle the case of A>B
3372 */
drhb21e7c72008-06-22 12:37:57 +00003373 VdbeNoopComment((v, "A-gt-B subroutine"));
3374 addrAgtB = sqlite3VdbeCurrentAddr(v);
3375 if( op==TK_ALL || op==TK_UNION ){
3376 sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
3377 }
drh688852a2014-02-17 22:40:43 +00003378 sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);
drh076e85f2015-09-03 13:46:12 +00003379 sqlite3VdbeGoto(v, labelCmpr);
drhb21e7c72008-06-22 12:37:57 +00003380
drh92b01d52008-06-24 00:32:35 +00003381 /* This code runs once to initialize everything.
3382 */
drh728e0f92015-10-10 14:41:28 +00003383 sqlite3VdbeJumpHere(v, addr1);
drh688852a2014-02-17 22:40:43 +00003384 sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA_noB); VdbeCoverage(v);
3385 sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);
drh92b01d52008-06-24 00:32:35 +00003386
3387 /* Implement the main merge loop
3388 */
3389 sqlite3VdbeResolveLabel(v, labelCmpr);
drh0acb7e42008-06-25 00:12:41 +00003390 sqlite3VdbeAddOp4(v, OP_Permutation, 0, 0, 0, (char*)aPermute, P4_INTARRAY);
drh2b596da2012-07-23 21:43:19 +00003391 sqlite3VdbeAddOp4(v, OP_Compare, destA.iSdst, destB.iSdst, nOrderBy,
drh2ec2fb22013-11-06 19:59:23 +00003392 (char*)pKeyMerge, P4_KEYINFO);
drh953f7612012-12-07 22:18:54 +00003393 sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE);
drh688852a2014-02-17 22:40:43 +00003394 sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); VdbeCoverage(v);
drh92b01d52008-06-24 00:32:35 +00003395
3396 /* Jump to the this point in order to terminate the query.
3397 */
drhb21e7c72008-06-22 12:37:57 +00003398 sqlite3VdbeResolveLabel(v, labelEnd);
drh92b01d52008-06-24 00:32:35 +00003399
drh0acb7e42008-06-25 00:12:41 +00003400 /* Reassembly the compound query so that it will be freed correctly
3401 ** by the calling function */
danielk19775e7ad502008-07-01 17:39:27 +00003402 if( p->pPrior ){
drh633e6d52008-07-28 19:34:53 +00003403 sqlite3SelectDelete(db, p->pPrior);
danielk19775e7ad502008-07-01 17:39:27 +00003404 }
drh0acb7e42008-06-25 00:12:41 +00003405 p->pPrior = pPrior;
drhd227a292014-02-09 18:02:09 +00003406 pPrior->pNext = p;
drh92b01d52008-06-24 00:32:35 +00003407
drh92b01d52008-06-24 00:32:35 +00003408 /*** TBD: Insert subroutine calls to close cursors on incomplete
3409 **** subqueries ****/
drhe2ca99c2018-05-02 00:33:43 +00003410 ExplainQueryPlanPop(pParse);
drh3dc4cc62015-04-15 07:10:25 +00003411 return pParse->nErr!=0;
drhb21e7c72008-06-22 12:37:57 +00003412}
danielk1977de3e41e2008-08-04 03:51:24 +00003413#endif
drhb21e7c72008-06-22 12:37:57 +00003414
shane3514b6f2008-07-22 05:00:55 +00003415#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
drh46967de2017-04-14 12:39:37 +00003416
3417/* An instance of the SubstContext object describes an substitution edit
3418** to be performed on a parse tree.
3419**
3420** All references to columns in table iTable are to be replaced by corresponding
3421** expressions in pEList.
3422*/
3423typedef struct SubstContext {
3424 Parse *pParse; /* The parsing context */
3425 int iTable; /* Replace references to this table */
drh31d6fd52017-04-14 19:03:10 +00003426 int iNewTable; /* New table number */
3427 int isLeftJoin; /* Add TK_IF_NULL_ROW opcodes on each replacement */
drh46967de2017-04-14 12:39:37 +00003428 ExprList *pEList; /* Replacement expressions */
3429} SubstContext;
3430
drh17435752007-08-16 04:30:38 +00003431/* Forward Declarations */
drh46967de2017-04-14 12:39:37 +00003432static void substExprList(SubstContext*, ExprList*);
3433static void substSelect(SubstContext*, Select*, int);
drh17435752007-08-16 04:30:38 +00003434
drh22827922000-06-06 17:27:05 +00003435/*
drh832508b2002-03-02 17:04:07 +00003436** Scan through the expression pExpr. Replace every reference to
drh6a3ea0e2003-05-02 14:32:12 +00003437** a column in table number iTable with a copy of the iColumn-th
drh84e59202002-03-14 14:33:31 +00003438** entry in pEList. (But leave references to the ROWID column
drh6a3ea0e2003-05-02 14:32:12 +00003439** unchanged.)
drh832508b2002-03-02 17:04:07 +00003440**
3441** This routine is part of the flattening procedure. A subquery
3442** whose result set is defined by pEList appears as entry in the
3443** FROM clause of a SELECT such that the VDBE cursor assigned to that
drhaca19e12017-04-07 19:41:31 +00003444** FORM clause entry is iTable. This routine makes the necessary
drh832508b2002-03-02 17:04:07 +00003445** changes to pExpr so that it refers directly to the source table
3446** of the subquery rather the result set of the subquery.
3447*/
drhb7916a72009-05-27 10:31:29 +00003448static Expr *substExpr(
drh46967de2017-04-14 12:39:37 +00003449 SubstContext *pSubst, /* Description of the substitution */
3450 Expr *pExpr /* Expr in which substitution occurs */
drh17435752007-08-16 04:30:38 +00003451){
drhb7916a72009-05-27 10:31:29 +00003452 if( pExpr==0 ) return 0;
drh3d240d22017-09-28 16:56:55 +00003453 if( ExprHasProperty(pExpr, EP_FromJoin)
3454 && pExpr->iRightJoinTable==pSubst->iTable
3455 ){
drh399c7e22017-04-14 17:18:45 +00003456 pExpr->iRightJoinTable = pSubst->iNewTable;
3457 }
drh46967de2017-04-14 12:39:37 +00003458 if( pExpr->op==TK_COLUMN && pExpr->iTable==pSubst->iTable ){
drh50350a12004-02-13 16:22:22 +00003459 if( pExpr->iColumn<0 ){
3460 pExpr->op = TK_NULL;
3461 }else{
3462 Expr *pNew;
drh46967de2017-04-14 12:39:37 +00003463 Expr *pCopy = pSubst->pEList->a[pExpr->iColumn].pExpr;
drh31d6fd52017-04-14 19:03:10 +00003464 Expr ifNullRow;
drh46967de2017-04-14 12:39:37 +00003465 assert( pSubst->pEList!=0 && pExpr->iColumn<pSubst->pEList->nExpr );
danielk19776ab3a2e2009-02-19 14:39:25 +00003466 assert( pExpr->pLeft==0 && pExpr->pRight==0 );
dan44c56042016-12-07 15:38:37 +00003467 if( sqlite3ExprIsVector(pCopy) ){
drh46967de2017-04-14 12:39:37 +00003468 sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
dan44c56042016-12-07 15:38:37 +00003469 }else{
drh46967de2017-04-14 12:39:37 +00003470 sqlite3 *db = pSubst->pParse->db;
drh31d6fd52017-04-14 19:03:10 +00003471 if( pSubst->isLeftJoin && pCopy->op!=TK_COLUMN ){
3472 memset(&ifNullRow, 0, sizeof(ifNullRow));
3473 ifNullRow.op = TK_IF_NULL_ROW;
3474 ifNullRow.pLeft = pCopy;
3475 ifNullRow.iTable = pSubst->iNewTable;
3476 pCopy = &ifNullRow;
3477 }
dan44c56042016-12-07 15:38:37 +00003478 pNew = sqlite3ExprDup(db, pCopy, 0);
danbd11a2a2017-06-20 17:43:26 +00003479 if( pNew && pSubst->isLeftJoin ){
3480 ExprSetProperty(pNew, EP_CanBeNull);
3481 }
3482 if( pNew && ExprHasProperty(pExpr,EP_FromJoin) ){
dan44c56042016-12-07 15:38:37 +00003483 pNew->iRightJoinTable = pExpr->iRightJoinTable;
danbd11a2a2017-06-20 17:43:26 +00003484 ExprSetProperty(pNew, EP_FromJoin);
dan44c56042016-12-07 15:38:37 +00003485 }
3486 sqlite3ExprDelete(db, pExpr);
3487 pExpr = pNew;
dan92ddb3b2016-12-01 19:38:05 +00003488 }
drh50350a12004-02-13 16:22:22 +00003489 }
drh832508b2002-03-02 17:04:07 +00003490 }else{
drh7c1544e2017-05-23 12:44:57 +00003491 if( pExpr->op==TK_IF_NULL_ROW && pExpr->iTable==pSubst->iTable ){
3492 pExpr->iTable = pSubst->iNewTable;
3493 }
drh46967de2017-04-14 12:39:37 +00003494 pExpr->pLeft = substExpr(pSubst, pExpr->pLeft);
3495 pExpr->pRight = substExpr(pSubst, pExpr->pRight);
danielk19776ab3a2e2009-02-19 14:39:25 +00003496 if( ExprHasProperty(pExpr, EP_xIsSelect) ){
drh46967de2017-04-14 12:39:37 +00003497 substSelect(pSubst, pExpr->x.pSelect, 1);
danielk19776ab3a2e2009-02-19 14:39:25 +00003498 }else{
drh46967de2017-04-14 12:39:37 +00003499 substExprList(pSubst, pExpr->x.pList);
danielk19776ab3a2e2009-02-19 14:39:25 +00003500 }
drh832508b2002-03-02 17:04:07 +00003501 }
drhb7916a72009-05-27 10:31:29 +00003502 return pExpr;
drh832508b2002-03-02 17:04:07 +00003503}
drh17435752007-08-16 04:30:38 +00003504static void substExprList(
drh46967de2017-04-14 12:39:37 +00003505 SubstContext *pSubst, /* Description of the substitution */
3506 ExprList *pList /* List to scan and in which to make substitutes */
drh17435752007-08-16 04:30:38 +00003507){
drh832508b2002-03-02 17:04:07 +00003508 int i;
3509 if( pList==0 ) return;
3510 for(i=0; i<pList->nExpr; i++){
drh46967de2017-04-14 12:39:37 +00003511 pList->a[i].pExpr = substExpr(pSubst, pList->a[i].pExpr);
drh832508b2002-03-02 17:04:07 +00003512 }
3513}
drh17435752007-08-16 04:30:38 +00003514static void substSelect(
drh46967de2017-04-14 12:39:37 +00003515 SubstContext *pSubst, /* Description of the substitution */
3516 Select *p, /* SELECT statement in which to make substitutions */
3517 int doPrior /* Do substitutes on p->pPrior too */
drh17435752007-08-16 04:30:38 +00003518){
drh588a9a12008-09-01 15:52:10 +00003519 SrcList *pSrc;
3520 struct SrcList_item *pItem;
3521 int i;
danielk1977b3bce662005-01-29 08:32:43 +00003522 if( !p ) return;
drhd12b6362015-10-11 19:46:59 +00003523 do{
drh46967de2017-04-14 12:39:37 +00003524 substExprList(pSubst, p->pEList);
3525 substExprList(pSubst, p->pGroupBy);
3526 substExprList(pSubst, p->pOrderBy);
3527 p->pHaving = substExpr(pSubst, p->pHaving);
3528 p->pWhere = substExpr(pSubst, p->pWhere);
drhd12b6362015-10-11 19:46:59 +00003529 pSrc = p->pSrc;
drh29064902015-10-11 20:08:31 +00003530 assert( pSrc!=0 );
drh588a9a12008-09-01 15:52:10 +00003531 for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
drh46967de2017-04-14 12:39:37 +00003532 substSelect(pSubst, pItem->pSelect, 1);
drh29064902015-10-11 20:08:31 +00003533 if( pItem->fg.isTabFunc ){
drh46967de2017-04-14 12:39:37 +00003534 substExprList(pSubst, pItem->u1.pFuncArg);
drhd12b6362015-10-11 19:46:59 +00003535 }
drh588a9a12008-09-01 15:52:10 +00003536 }
drhd12b6362015-10-11 19:46:59 +00003537 }while( doPrior && (p = p->pPrior)!=0 );
danielk1977b3bce662005-01-29 08:32:43 +00003538}
shane3514b6f2008-07-22 05:00:55 +00003539#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
drh832508b2002-03-02 17:04:07 +00003540
shane3514b6f2008-07-22 05:00:55 +00003541#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
drh832508b2002-03-02 17:04:07 +00003542/*
drh630d2962011-12-11 21:51:04 +00003543** This routine attempts to flatten subqueries as a performance optimization.
3544** This routine returns 1 if it makes changes and 0 if no flattening occurs.
drh1350b032002-02-27 19:00:20 +00003545**
3546** To understand the concept of flattening, consider the following
3547** query:
3548**
3549** SELECT a FROM (SELECT x+y AS a FROM t1 WHERE z<100) WHERE a>5
3550**
3551** The default way of implementing this query is to execute the
3552** subquery first and store the results in a temporary table, then
3553** run the outer query on that temporary table. This requires two
3554** passes over the data. Furthermore, because the temporary table
3555** has no indices, the WHERE clause on the outer query cannot be
drh832508b2002-03-02 17:04:07 +00003556** optimized.
drh1350b032002-02-27 19:00:20 +00003557**
drh832508b2002-03-02 17:04:07 +00003558** This routine attempts to rewrite queries such as the above into
drh1350b032002-02-27 19:00:20 +00003559** a single flat select, like this:
3560**
3561** SELECT x+y AS a FROM t1 WHERE z<100 AND a>5
3562**
peter.d.reid60ec9142014-09-06 16:39:46 +00003563** The code generated for this simplification gives the same result
drh832508b2002-03-02 17:04:07 +00003564** but only has to scan the data once. And because indices might
3565** exist on the table t1, a complete scan of the data might be
3566** avoided.
drh1350b032002-02-27 19:00:20 +00003567**
drhd981e822017-09-29 16:07:56 +00003568** Flattening is subject to the following constraints:
drh1350b032002-02-27 19:00:20 +00003569**
drh25c221e2017-09-29 22:13:24 +00003570** (**) We no longer attempt to flatten aggregate subqueries. Was:
3571** The subquery and the outer query cannot both be aggregates.
drh1350b032002-02-27 19:00:20 +00003572**
drh25c221e2017-09-29 22:13:24 +00003573** (**) We no longer attempt to flatten aggregate subqueries. Was:
3574** (2) If the subquery is an aggregate then
drhd981e822017-09-29 16:07:56 +00003575** (2a) the outer query must not be a join and
3576** (2b) the outer query must not use subqueries
3577** other than the one FROM-clause subquery that is a candidate
3578** for flattening. (This is due to ticket [2f7170d73bf9abf80]
3579** from 2015-02-09.)
drh832508b2002-03-02 17:04:07 +00003580**
drhd981e822017-09-29 16:07:56 +00003581** (3) If the subquery is the right operand of a LEFT JOIN then
3582** (3a) the subquery may not be a join and
3583** (3b) the FROM clause of the subquery may not contain a virtual
3584** table and
3585** (3c) the outer query may not be an aggregate.
drh832508b2002-03-02 17:04:07 +00003586**
drhd981e822017-09-29 16:07:56 +00003587** (4) The subquery can not be DISTINCT.
drh832508b2002-03-02 17:04:07 +00003588**
dan49ad3302010-08-13 16:38:48 +00003589** (**) At one point restrictions (4) and (5) defined a subset of DISTINCT
3590** sub-queries that were excluded from this optimization. Restriction
3591** (4) has since been expanded to exclude all DISTINCT subqueries.
drh832508b2002-03-02 17:04:07 +00003592**
drh25c221e2017-09-29 22:13:24 +00003593** (**) We no longer attempt to flatten aggregate subqueries. Was:
3594** If the subquery is aggregate, the outer query may not be DISTINCT.
drh832508b2002-03-02 17:04:07 +00003595**
drhd981e822017-09-29 16:07:56 +00003596** (7) The subquery must have a FROM clause. TODO: For subqueries without
drh31d6fd52017-04-14 19:03:10 +00003597** A FROM clause, consider adding a FROM clause with the special
drh630d2962011-12-11 21:51:04 +00003598** table sqlite_once that consists of a single row containing a
3599** single NULL.
drh08192d52002-04-30 19:20:28 +00003600**
drhd981e822017-09-29 16:07:56 +00003601** (8) If the subquery uses LIMIT then the outer query may not be a join.
drhdf199a22002-06-14 22:38:41 +00003602**
drhd981e822017-09-29 16:07:56 +00003603** (9) If the subquery uses LIMIT then the outer query may not be aggregate.
drhdf199a22002-06-14 22:38:41 +00003604**
drh6092d2b2014-09-15 11:14:50 +00003605** (**) Restriction (10) was removed from the code on 2005-02-05 but we
3606** accidently carried the comment forward until 2014-09-15. Original
drhd981e822017-09-29 16:07:56 +00003607** constraint: "If the subquery is aggregate then the outer query
3608** may not use LIMIT."
drhdf199a22002-06-14 22:38:41 +00003609**
drhd981e822017-09-29 16:07:56 +00003610** (11) The subquery and the outer query may not both have ORDER BY clauses.
drh174b6192002-12-03 02:22:52 +00003611**
drh7b688ed2009-12-22 00:29:53 +00003612** (**) Not implemented. Subsumed into restriction (3). Was previously
drh2b300d52008-08-14 00:19:48 +00003613** a separate restriction deriving from ticket #350.
drh3fc673e2003-06-16 00:40:34 +00003614**
drhd981e822017-09-29 16:07:56 +00003615** (13) The subquery and outer query may not both use LIMIT.
drhac839632006-01-21 22:19:54 +00003616**
drhd981e822017-09-29 16:07:56 +00003617** (14) The subquery may not use OFFSET.
drhac839632006-01-21 22:19:54 +00003618**
drhd981e822017-09-29 16:07:56 +00003619** (15) If the outer query is part of a compound select, then the
3620** subquery may not use LIMIT.
drhf3913272010-04-15 23:24:29 +00003621** (See ticket #2339 and ticket [02a8e81d44]).
drhad91c6c2007-05-06 20:04:24 +00003622**
drhd981e822017-09-29 16:07:56 +00003623** (16) If the outer query is aggregate, then the subquery may not
3624** use ORDER BY. (Ticket #2942) This used to not matter
drhc52e3552008-02-15 14:33:03 +00003625** until we introduced the group_concat() function.
3626**
drhd981e822017-09-29 16:07:56 +00003627** (17) If the subquery is a compound select, then
3628** (17a) all compound operators must be a UNION ALL, and
3629** (17b) no terms within the subquery compound may be aggregate
drhe76acc62017-10-04 02:30:45 +00003630** or DISTINCT, and
drhd981e822017-09-29 16:07:56 +00003631** (17c) every term within the subquery compound must have a FROM clause
3632** (17d) the outer query may not be
3633** (17d1) aggregate, or
3634** (17d2) DISTINCT, or
3635** (17d3) a join.
danielk1977f23329a2008-07-01 14:09:13 +00003636**
danielk19774914cf92008-07-01 18:26:49 +00003637** The parent and sub-query may contain WHERE clauses. Subject to
3638** rules (11), (13) and (14), they may also contain ORDER BY,
drh630d2962011-12-11 21:51:04 +00003639** LIMIT and OFFSET clauses. The subquery cannot use any compound
3640** operator other than UNION ALL because all the other compound
3641** operators have an implied DISTINCT which is disallowed by
3642** restriction (4).
danielk1977f23329a2008-07-01 14:09:13 +00003643**
dan67c70142012-08-28 14:45:50 +00003644** Also, each component of the sub-query must return the same number
3645** of result columns. This is actually a requirement for any compound
3646** SELECT statement, but all the code here does is make sure that no
3647** such (illegal) sub-query is flattened. The caller will detect the
3648** syntax error and return a detailed message.
3649**
danielk197749fc1f62008-07-08 17:43:56 +00003650** (18) If the sub-query is a compound select, then all terms of the
drhd981e822017-09-29 16:07:56 +00003651** ORDER BY clause of the parent must be simple references to
danielk197749fc1f62008-07-08 17:43:56 +00003652** columns of the sub-query.
3653**
drhd981e822017-09-29 16:07:56 +00003654** (19) If the subquery uses LIMIT then the outer query may not
drh229cf702008-08-26 12:56:14 +00003655** have a WHERE clause.
3656**
drhfca23552017-10-28 20:51:54 +00003657** (20) If the sub-query is a compound select, then it must not use
3658** an ORDER BY clause. Ticket #3773. We could relax this constraint
3659** somewhat by saying that the terms of the ORDER BY clause must
3660** appear as unmodified result columns in the outer query. But we
3661** have other optimizations in mind to deal with that case.
drhe8902a72009-04-02 16:59:47 +00003662**
drhd981e822017-09-29 16:07:56 +00003663** (21) If the subquery uses LIMIT then the outer query may not be
shaneha91491e2011-02-11 20:52:20 +00003664** DISTINCT. (See ticket [752e1646fc]).
3665**
drhd981e822017-09-29 16:07:56 +00003666** (22) The subquery may not be a recursive CTE.
dan8290c2a2014-01-16 10:58:39 +00003667**
drhcdb2f602017-10-04 05:59:54 +00003668** (**) Subsumed into restriction (17d3). Was: If the outer query is
3669** a recursive CTE, then the sub-query may not be a compound query.
3670** This restriction is because transforming the
dan8290c2a2014-01-16 10:58:39 +00003671** parent to a compound query confuses the code that handles
3672** recursive queries in multiSelect().
3673**
drh508e2d02017-09-30 01:25:04 +00003674** (**) We no longer attempt to flatten aggregate subqueries. Was:
3675** The subquery may not be an aggregate that uses the built-in min() or
drh9588ad92014-09-15 14:46:02 +00003676** or max() functions. (Without this restriction, a query like:
3677** "SELECT x FROM (SELECT max(y), x FROM t1)" would not necessarily
3678** return the value X for which Y was maximal.)
3679**
dan9a947222018-06-14 19:06:36 +00003680** (25) If either the subquery or the parent query contains a window
3681** function in the select list or ORDER BY clause, flattening
3682** is not attempted.
3683**
dan8290c2a2014-01-16 10:58:39 +00003684**
drh832508b2002-03-02 17:04:07 +00003685** In this routine, the "p" parameter is a pointer to the outer query.
3686** The subquery is p->pSrc->a[iFrom]. isAgg is true if the outer query
drh25c221e2017-09-29 22:13:24 +00003687** uses aggregates.
drh832508b2002-03-02 17:04:07 +00003688**
drh665de472003-03-31 13:36:09 +00003689** If flattening is not attempted, this routine is a no-op and returns 0.
drh832508b2002-03-02 17:04:07 +00003690** If flattening is attempted this routine returns 1.
3691**
3692** All of the expression analysis must occur on both the outer query and
3693** the subquery before this routine runs.
drh1350b032002-02-27 19:00:20 +00003694*/
drh8c74a8c2002-08-25 19:20:40 +00003695static int flattenSubquery(
danielk1977524cc212008-07-02 13:13:51 +00003696 Parse *pParse, /* Parsing context */
drh8c74a8c2002-08-25 19:20:40 +00003697 Select *p, /* The parent or outer SELECT statement */
3698 int iFrom, /* Index in p->pSrc->a[] of the inner subquery */
drh25c221e2017-09-29 22:13:24 +00003699 int isAgg /* True if outer SELECT uses aggregate functions */
drh8c74a8c2002-08-25 19:20:40 +00003700){
danielk1977524cc212008-07-02 13:13:51 +00003701 const char *zSavedAuthContext = pParse->zAuthContext;
drhd12b6362015-10-11 19:46:59 +00003702 Select *pParent; /* Current UNION ALL term of the other query */
drh0bb28102002-05-08 11:54:14 +00003703 Select *pSub; /* The inner query or "subquery" */
danielk1977f23329a2008-07-01 14:09:13 +00003704 Select *pSub1; /* Pointer to the rightmost select in sub-query */
drhad3cab52002-05-24 02:04:32 +00003705 SrcList *pSrc; /* The FROM clause of the outer query */
3706 SrcList *pSubSrc; /* The FROM clause of the subquery */
drh6a3ea0e2003-05-02 14:32:12 +00003707 int iParent; /* VDBE cursor number of the pSub result set temp table */
drh399c7e22017-04-14 17:18:45 +00003708 int iNewParent = -1;/* Replacement table for iParent */
3709 int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */
drh91bb0ee2004-09-01 03:06:34 +00003710 int i; /* Loop counter */
3711 Expr *pWhere; /* The WHERE clause */
3712 struct SrcList_item *pSubitem; /* The subquery */
danielk1977524cc212008-07-02 13:13:51 +00003713 sqlite3 *db = pParse->db;
drh1350b032002-02-27 19:00:20 +00003714
drh832508b2002-03-02 17:04:07 +00003715 /* Check to see if flattening is permitted. Return 0 if not.
3716 */
drha78c22c2008-11-11 18:28:58 +00003717 assert( p!=0 );
drhd981e822017-09-29 16:07:56 +00003718 assert( p->pPrior==0 );
drh7e5418e2012-09-27 15:05:54 +00003719 if( OptimizationDisabled(db, SQLITE_QueryFlattener) ) return 0;
drh832508b2002-03-02 17:04:07 +00003720 pSrc = p->pSrc;
drhad3cab52002-05-24 02:04:32 +00003721 assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
drh91bb0ee2004-09-01 03:06:34 +00003722 pSubitem = &pSrc->a[iFrom];
danielk197749fc1f62008-07-08 17:43:56 +00003723 iParent = pSubitem->iCursor;
drh91bb0ee2004-09-01 03:06:34 +00003724 pSub = pSubitem->pSelect;
drh832508b2002-03-02 17:04:07 +00003725 assert( pSub!=0 );
drh399c7e22017-04-14 17:18:45 +00003726
dan67a9b8e2018-06-22 20:51:35 +00003727#ifndef SQLITE_OMIT_WINDOWFUNC
dan9a947222018-06-14 19:06:36 +00003728 if( p->pWin || pSub->pWin ) return 0; /* Restriction (25) */
dan67a9b8e2018-06-22 20:51:35 +00003729#endif
dan86fb6e12018-05-16 20:58:07 +00003730
drh832508b2002-03-02 17:04:07 +00003731 pSubSrc = pSub->pSrc;
3732 assert( pSubSrc );
drhac839632006-01-21 22:19:54 +00003733 /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
peter.d.reid60ec9142014-09-06 16:39:46 +00003734 ** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET
drhac839632006-01-21 22:19:54 +00003735 ** because they could be computed at compile-time. But when LIMIT and OFFSET
3736 ** became arbitrary expressions, we were forced to add restrictions (13)
3737 ** and (14). */
3738 if( pSub->pLimit && p->pLimit ) return 0; /* Restriction (13) */
drh8c0833f2017-11-14 23:48:23 +00003739 if( pSub->pLimit && pSub->pLimit->pRight ) return 0; /* Restriction (14) */
drhd227a292014-02-09 18:02:09 +00003740 if( (p->selFlags & SF_Compound)!=0 && pSub->pLimit ){
drhad91c6c2007-05-06 20:04:24 +00003741 return 0; /* Restriction (15) */
3742 }
drhac839632006-01-21 22:19:54 +00003743 if( pSubSrc->nSrc==0 ) return 0; /* Restriction (7) */
drhd981e822017-09-29 16:07:56 +00003744 if( pSub->selFlags & SF_Distinct ) return 0; /* Restriction (4) */
dan49ad3302010-08-13 16:38:48 +00003745 if( pSub->pLimit && (pSrc->nSrc>1 || isAgg) ){
3746 return 0; /* Restrictions (8)(9) */
drhdf199a22002-06-14 22:38:41 +00003747 }
drh7d10d5a2008-08-20 16:35:10 +00003748 if( p->pOrderBy && pSub->pOrderBy ){
drhac839632006-01-21 22:19:54 +00003749 return 0; /* Restriction (11) */
3750 }
drhc52e3552008-02-15 14:33:03 +00003751 if( isAgg && pSub->pOrderBy ) return 0; /* Restriction (16) */
drh229cf702008-08-26 12:56:14 +00003752 if( pSub->pLimit && p->pWhere ) return 0; /* Restriction (19) */
shaneha91491e2011-02-11 20:52:20 +00003753 if( pSub->pLimit && (p->selFlags & SF_Distinct)!=0 ){
3754 return 0; /* Restriction (21) */
3755 }
drh508e2d02017-09-30 01:25:04 +00003756 if( pSub->selFlags & (SF_Recursive) ){
3757 return 0; /* Restrictions (22) */
drh9588ad92014-09-15 14:46:02 +00003758 }
drh832508b2002-03-02 17:04:07 +00003759
drh399c7e22017-04-14 17:18:45 +00003760 /*
3761 ** If the subquery is the right operand of a LEFT JOIN, then the
drhd981e822017-09-29 16:07:56 +00003762 ** subquery may not be a join itself (3a). Example of why this is not
3763 ** allowed:
drh8af4d3a2003-05-06 20:35:16 +00003764 **
3765 ** t1 LEFT OUTER JOIN (t2 JOIN t3)
3766 **
3767 ** If we flatten the above, we would get
3768 **
3769 ** (t1 LEFT OUTER JOIN t2) JOIN t3
3770 **
3771 ** which is not at all the same thing.
drh2b300d52008-08-14 00:19:48 +00003772 **
drh3c790f22017-05-23 15:33:41 +00003773 ** If the subquery is the right operand of a LEFT JOIN, then the outer
drhd981e822017-09-29 16:07:56 +00003774 ** query cannot be an aggregate. (3c) This is an artifact of the way
3775 ** aggregates are processed - there is no mechanism to determine if
3776 ** the LEFT JOIN table should be all-NULL.
drh3c790f22017-05-23 15:33:41 +00003777 **
drh31d6fd52017-04-14 19:03:10 +00003778 ** See also tickets #306, #350, and #3300.
drh3fc673e2003-06-16 00:40:34 +00003779 */
drh8a48b9c2015-08-19 15:20:00 +00003780 if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
drh399c7e22017-04-14 17:18:45 +00003781 isLeftJoin = 1;
dan46133d92017-07-18 17:34:41 +00003782 if( pSubSrc->nSrc>1 || isAgg || IsVirtual(pSubSrc->a[0].pTab) ){
drhd981e822017-09-29 16:07:56 +00003783 /* (3a) (3c) (3b) */
3784 return 0;
drh399c7e22017-04-14 17:18:45 +00003785 }
drh3fc673e2003-06-16 00:40:34 +00003786 }
drhdc6de472017-05-25 11:39:50 +00003787#ifdef SQLITE_EXTRA_IFNULLROW
3788 else if( iFrom>0 && !isAgg ){
3789 /* Setting isLeftJoin to -1 causes OP_IfNullRow opcodes to be generated for
drh3d240d22017-09-28 16:56:55 +00003790 ** every reference to any result column from subquery in a join, even
3791 ** though they are not necessary. This will stress-test the OP_IfNullRow
3792 ** opcode. */
drhdc6de472017-05-25 11:39:50 +00003793 isLeftJoin = -1;
3794 }
3795#endif
drh3fc673e2003-06-16 00:40:34 +00003796
drhd981e822017-09-29 16:07:56 +00003797 /* Restriction (17): If the sub-query is a compound SELECT, then it must
danielk1977f23329a2008-07-01 14:09:13 +00003798 ** use only the UNION ALL operator. And none of the simple select queries
3799 ** that make up the compound SELECT are allowed to be aggregate or distinct
3800 ** queries.
3801 */
3802 if( pSub->pPrior ){
drhfca23552017-10-28 20:51:54 +00003803 if( pSub->pOrderBy ){
3804 return 0; /* Restriction (20) */
3805 }
drhe2f02ba2009-01-09 01:12:27 +00003806 if( isAgg || (p->selFlags & SF_Distinct)!=0 || pSrc->nSrc!=1 ){
drhd981e822017-09-29 16:07:56 +00003807 return 0; /* (17d1), (17d2), or (17d3) */
danielk1977f23329a2008-07-01 14:09:13 +00003808 }
3809 for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){
drhccfcbce2009-05-18 15:46:07 +00003810 testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
3811 testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
drh4b3ac732011-12-10 23:18:32 +00003812 assert( pSub->pSrc!=0 );
drh2ec18a32015-06-23 23:31:52 +00003813 assert( pSub->pEList->nExpr==pSub1->pEList->nExpr );
drhd981e822017-09-29 16:07:56 +00003814 if( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))!=0 /* (17b) */
3815 || (pSub1->pPrior && pSub1->op!=TK_ALL) /* (17a) */
3816 || pSub1->pSrc->nSrc<1 /* (17c) */
danielk197780b3c542008-07-10 17:59:12 +00003817 ){
danielk1977f23329a2008-07-01 14:09:13 +00003818 return 0;
3819 }
drh4b3ac732011-12-10 23:18:32 +00003820 testcase( pSub1->pSrc->nSrc>1 );
danielk1977f23329a2008-07-01 14:09:13 +00003821 }
danielk197749fc1f62008-07-08 17:43:56 +00003822
drhd981e822017-09-29 16:07:56 +00003823 /* Restriction (18). */
danielk197749fc1f62008-07-08 17:43:56 +00003824 if( p->pOrderBy ){
3825 int ii;
3826 for(ii=0; ii<p->pOrderBy->nExpr; ii++){
drhc2acc4e2013-11-15 18:15:19 +00003827 if( p->pOrderBy->a[ii].u.x.iOrderByCol==0 ) return 0;
danielk197749fc1f62008-07-08 17:43:56 +00003828 }
3829 }
danielk1977f23329a2008-07-01 14:09:13 +00003830 }
3831
drhcdb2f602017-10-04 05:59:54 +00003832 /* Ex-restriction (23):
3833 ** The only way that the recursive part of a CTE can contain a compound
3834 ** subquery is for the subquery to be one term of a join. But if the
3835 ** subquery is a join, then the flattening has already been stopped by
3836 ** restriction (17d3)
3837 */
3838 assert( (p->selFlags & SF_Recursive)==0 || pSub->pPrior==0 );
3839
drh7d10d5a2008-08-20 16:35:10 +00003840 /***** If we reach this point, flattening is permitted. *****/
drheb9b8842014-09-21 00:27:26 +00003841 SELECTTRACE(1,pParse,p,("flatten %s.%p from term %d\n",
3842 pSub->zSelName, pSub, iFrom));
drh7d10d5a2008-08-20 16:35:10 +00003843
3844 /* Authorize the subquery */
danielk1977524cc212008-07-02 13:13:51 +00003845 pParse->zAuthContext = pSubitem->zName;
drha2acb0d2012-04-11 23:22:37 +00003846 TESTONLY(i =) sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);
3847 testcase( i==SQLITE_DENY );
danielk1977524cc212008-07-02 13:13:51 +00003848 pParse->zAuthContext = zSavedAuthContext;
3849
drh7d10d5a2008-08-20 16:35:10 +00003850 /* If the sub-query is a compound SELECT statement, then (by restrictions
3851 ** 17 and 18 above) it must be a UNION ALL and the parent query must
3852 ** be of the form:
danielk1977f23329a2008-07-01 14:09:13 +00003853 **
3854 ** SELECT <expr-list> FROM (<sub-query>) <where-clause>
3855 **
3856 ** followed by any ORDER BY, LIMIT and/or OFFSET clauses. This block
drha78c22c2008-11-11 18:28:58 +00003857 ** creates N-1 copies of the parent query without any ORDER BY, LIMIT or
danielk1977f23329a2008-07-01 14:09:13 +00003858 ** OFFSET clauses and joins them to the left-hand-side of the original
3859 ** using UNION ALL operators. In this case N is the number of simple
3860 ** select statements in the compound sub-query.
drha78c22c2008-11-11 18:28:58 +00003861 **
3862 ** Example:
3863 **
3864 ** SELECT a+1 FROM (
3865 ** SELECT x FROM tab
3866 ** UNION ALL
3867 ** SELECT y FROM tab
3868 ** UNION ALL
3869 ** SELECT abs(z*2) FROM tab2
3870 ** ) WHERE a!=5 ORDER BY 1
3871 **
3872 ** Transformed into:
3873 **
3874 ** SELECT x+1 FROM tab WHERE x+1!=5
3875 ** UNION ALL
3876 ** SELECT y+1 FROM tab WHERE y+1!=5
3877 ** UNION ALL
3878 ** SELECT abs(z*2)+1 FROM tab2 WHERE abs(z*2)+1!=5
3879 ** ORDER BY 1
3880 **
3881 ** We call this the "compound-subquery flattening".
danielk1977f23329a2008-07-01 14:09:13 +00003882 */
3883 for(pSub=pSub->pPrior; pSub; pSub=pSub->pPrior){
3884 Select *pNew;
3885 ExprList *pOrderBy = p->pOrderBy;
danielk19774b86ef12008-07-01 14:39:35 +00003886 Expr *pLimit = p->pLimit;
danielk1977f23329a2008-07-01 14:09:13 +00003887 Select *pPrior = p->pPrior;
3888 p->pOrderBy = 0;
3889 p->pSrc = 0;
3890 p->pPrior = 0;
danielk19774b86ef12008-07-01 14:39:35 +00003891 p->pLimit = 0;
danielk19776ab3a2e2009-02-19 14:39:25 +00003892 pNew = sqlite3SelectDup(db, p, 0);
drheb9b8842014-09-21 00:27:26 +00003893 sqlite3SelectSetName(pNew, pSub->zSelName);
danielk19774b86ef12008-07-01 14:39:35 +00003894 p->pLimit = pLimit;
drha78c22c2008-11-11 18:28:58 +00003895 p->pOrderBy = pOrderBy;
3896 p->pSrc = pSrc;
3897 p->op = TK_ALL;
drha78c22c2008-11-11 18:28:58 +00003898 if( pNew==0 ){
drhd227a292014-02-09 18:02:09 +00003899 p->pPrior = pPrior;
drha78c22c2008-11-11 18:28:58 +00003900 }else{
3901 pNew->pPrior = pPrior;
drhd227a292014-02-09 18:02:09 +00003902 if( pPrior ) pPrior->pNext = pNew;
3903 pNew->pNext = p;
3904 p->pPrior = pNew;
drhe2243d22018-04-23 17:18:03 +00003905 SELECTTRACE(2,pParse,p,("compound-subquery flattener"
3906 " creates %s.%p as peer\n",pNew->zSelName, pNew));
drha78c22c2008-11-11 18:28:58 +00003907 }
drha78c22c2008-11-11 18:28:58 +00003908 if( db->mallocFailed ) return 1;
danielk1977f23329a2008-07-01 14:09:13 +00003909 }
3910
drh7d10d5a2008-08-20 16:35:10 +00003911 /* Begin flattening the iFrom-th entry of the FROM clause
3912 ** in the outer query.
drh832508b2002-03-02 17:04:07 +00003913 */
danielk1977f23329a2008-07-01 14:09:13 +00003914 pSub = pSub1 = pSubitem->pSelect;
drha78c22c2008-11-11 18:28:58 +00003915
3916 /* Delete the transient table structure associated with the
3917 ** subquery
3918 */
3919 sqlite3DbFree(db, pSubitem->zDatabase);
3920 sqlite3DbFree(db, pSubitem->zName);
3921 sqlite3DbFree(db, pSubitem->zAlias);
3922 pSubitem->zDatabase = 0;
3923 pSubitem->zName = 0;
3924 pSubitem->zAlias = 0;
3925 pSubitem->pSelect = 0;
3926
3927 /* Defer deleting the Table object associated with the
3928 ** subquery until code generation is
3929 ** complete, since there may still exist Expr.pTab entries that
3930 ** refer to the subquery even after flattening. Ticket #3346.
drhccfcbce2009-05-18 15:46:07 +00003931 **
3932 ** pSubitem->pTab is always non-NULL by test restrictions and tests above.
drha78c22c2008-11-11 18:28:58 +00003933 */
drhccfcbce2009-05-18 15:46:07 +00003934 if( ALWAYS(pSubitem->pTab!=0) ){
drha78c22c2008-11-11 18:28:58 +00003935 Table *pTabToDel = pSubitem->pTab;
drh79df7782016-12-14 14:07:35 +00003936 if( pTabToDel->nTabRef==1 ){
dan65a7cd12009-09-01 12:16:01 +00003937 Parse *pToplevel = sqlite3ParseToplevel(pParse);
3938 pTabToDel->pNextZombie = pToplevel->pZombieTab;
3939 pToplevel->pZombieTab = pTabToDel;
drha78c22c2008-11-11 18:28:58 +00003940 }else{
drh79df7782016-12-14 14:07:35 +00003941 pTabToDel->nTabRef--;
drha78c22c2008-11-11 18:28:58 +00003942 }
3943 pSubitem->pTab = 0;
3944 }
3945
3946 /* The following loop runs once for each term in a compound-subquery
3947 ** flattening (as described above). If we are doing a different kind
3948 ** of flattening - a flattening other than a compound-subquery flattening -
3949 ** then this loop only runs once.
3950 **
3951 ** This loop moves all of the FROM elements of the subquery into the
3952 ** the FROM clause of the outer query. Before doing this, remember
3953 ** the cursor number for the original outer query FROM element in
3954 ** iParent. The iParent cursor will never be used. Subsequent code
3955 ** will scan expressions looking for iParent references and replace
3956 ** those references with expressions that resolve to the subquery FROM
3957 ** elements we are now copying in.
3958 */
danielk1977f23329a2008-07-01 14:09:13 +00003959 for(pParent=p; pParent; pParent=pParent->pPrior, pSub=pSub->pPrior){
drha78c22c2008-11-11 18:28:58 +00003960 int nSubSrc;
drhea678832008-12-10 19:26:22 +00003961 u8 jointype = 0;
drha78c22c2008-11-11 18:28:58 +00003962 pSubSrc = pSub->pSrc; /* FROM clause of subquery */
3963 nSubSrc = pSubSrc->nSrc; /* Number of terms in subquery FROM clause */
3964 pSrc = pParent->pSrc; /* FROM clause of the outer query */
drhc31c2eb2003-05-02 16:04:17 +00003965
danielk1977f23329a2008-07-01 14:09:13 +00003966 if( pSrc ){
drha78c22c2008-11-11 18:28:58 +00003967 assert( pParent==p ); /* First time through the loop */
drh8a48b9c2015-08-19 15:20:00 +00003968 jointype = pSubitem->fg.jointype;
drha78c22c2008-11-11 18:28:58 +00003969 }else{
3970 assert( pParent!=p ); /* 2nd and subsequent times through the loop */
3971 pSrc = pParent->pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
3972 if( pSrc==0 ){
3973 assert( db->mallocFailed );
3974 break;
3975 }
3976 }
drh588a9a12008-09-01 15:52:10 +00003977
drha78c22c2008-11-11 18:28:58 +00003978 /* The subquery uses a single slot of the FROM clause of the outer
3979 ** query. If the subquery has more than one element in its FROM clause,
3980 ** then expand the outer query to make space for it to hold all elements
3981 ** of the subquery.
3982 **
3983 ** Example:
3984 **
3985 ** SELECT * FROM tabA, (SELECT * FROM sub1, sub2), tabB;
3986 **
3987 ** The outer query has 3 slots in its FROM clause. One slot of the
3988 ** outer query (the middle slot) is used by the subquery. The next
drhd12b6362015-10-11 19:46:59 +00003989 ** block of code will expand the outer query FROM clause to 4 slots.
3990 ** The middle slot is expanded to two slots in order to make space
3991 ** for the two elements in the FROM clause of the subquery.
drha78c22c2008-11-11 18:28:58 +00003992 */
3993 if( nSubSrc>1 ){
3994 pParent->pSrc = pSrc = sqlite3SrcListEnlarge(db, pSrc, nSubSrc-1,iFrom+1);
3995 if( db->mallocFailed ){
3996 break;
drhc31c2eb2003-05-02 16:04:17 +00003997 }
3998 }
drha78c22c2008-11-11 18:28:58 +00003999
4000 /* Transfer the FROM clause terms from the subquery into the
4001 ** outer query.
4002 */
drhc31c2eb2003-05-02 16:04:17 +00004003 for(i=0; i<nSubSrc; i++){
drhc3a84022009-06-12 03:27:26 +00004004 sqlite3IdListDelete(db, pSrc->a[i+iFrom].pUsing);
drh20292312015-11-21 13:24:46 +00004005 assert( pSrc->a[i+iFrom].fg.isTabFunc==0 );
drhc31c2eb2003-05-02 16:04:17 +00004006 pSrc->a[i+iFrom] = pSubSrc->a[i];
drh399c7e22017-04-14 17:18:45 +00004007 iNewParent = pSubSrc->a[i].iCursor;
drhc31c2eb2003-05-02 16:04:17 +00004008 memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
4009 }
drh8a48b9c2015-08-19 15:20:00 +00004010 pSrc->a[iFrom].fg.jointype = jointype;
danielk1977f23329a2008-07-01 14:09:13 +00004011
4012 /* Now begin substituting subquery result set expressions for
4013 ** references to the iParent in the outer query.
4014 **
4015 ** Example:
4016 **
4017 ** SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;
4018 ** \ \_____________ subquery __________/ /
4019 ** \_____________________ outer query ______________________________/
4020 **
4021 ** We look at every expression in the outer query and every place we see
4022 ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
4023 */
danielk1977f23329a2008-07-01 14:09:13 +00004024 if( pSub->pOrderBy ){
dan7c0a4722014-09-20 20:38:48 +00004025 /* At this point, any non-zero iOrderByCol values indicate that the
4026 ** ORDER BY column expression is identical to the iOrderByCol'th
4027 ** expression returned by SELECT statement pSub. Since these values
4028 ** do not necessarily correspond to columns in SELECT statement pParent,
4029 ** zero them before transfering the ORDER BY clause.
4030 **
4031 ** Not doing this may cause an error if a subsequent call to this
4032 ** function attempts to flatten a compound sub-query into pParent
4033 ** (the only way this can happen is if the compound sub-query is
4034 ** currently part of pSub->pSrc). See ticket [d11a6e908f]. */
4035 ExprList *pOrderBy = pSub->pOrderBy;
4036 for(i=0; i<pOrderBy->nExpr; i++){
4037 pOrderBy->a[i].u.x.iOrderByCol = 0;
4038 }
danielk1977f23329a2008-07-01 14:09:13 +00004039 assert( pParent->pOrderBy==0 );
dan7c0a4722014-09-20 20:38:48 +00004040 pParent->pOrderBy = pOrderBy;
danielk1977f23329a2008-07-01 14:09:13 +00004041 pSub->pOrderBy = 0;
danielk1977f23329a2008-07-01 14:09:13 +00004042 }
drhd12b6362015-10-11 19:46:59 +00004043 pWhere = sqlite3ExprDup(db, pSub->pWhere, 0);
drhdc6de472017-05-25 11:39:50 +00004044 if( isLeftJoin>0 ){
drh399c7e22017-04-14 17:18:45 +00004045 setJoinExpr(pWhere, iNewParent);
4046 }
drh25c221e2017-09-29 22:13:24 +00004047 pParent->pWhere = sqlite3ExprAnd(db, pWhere, pParent->pWhere);
danc3becdd2017-03-13 14:30:40 +00004048 if( db->mallocFailed==0 ){
drh46967de2017-04-14 12:39:37 +00004049 SubstContext x;
4050 x.pParse = pParse;
4051 x.iTable = iParent;
drh399c7e22017-04-14 17:18:45 +00004052 x.iNewTable = iNewParent;
drh31d6fd52017-04-14 19:03:10 +00004053 x.isLeftJoin = isLeftJoin;
drh46967de2017-04-14 12:39:37 +00004054 x.pEList = pSub->pEList;
4055 substSelect(&x, pParent, 0);
danc3becdd2017-03-13 14:30:40 +00004056 }
danielk1977f23329a2008-07-01 14:09:13 +00004057
4058 /* The flattened query is distinct if either the inner or the
4059 ** outer query is distinct.
4060 */
drh7d10d5a2008-08-20 16:35:10 +00004061 pParent->selFlags |= pSub->selFlags & SF_Distinct;
danielk1977f23329a2008-07-01 14:09:13 +00004062
4063 /*
4064 ** SELECT ... FROM (SELECT ... LIMIT a OFFSET b) LIMIT x OFFSET y;
4065 **
4066 ** One is tempted to try to add a and b to combine the limits. But this
4067 ** does not work if either limit is negative.
4068 */
4069 if( pSub->pLimit ){
4070 pParent->pLimit = pSub->pLimit;
4071 pSub->pLimit = 0;
4072 }
drhdf199a22002-06-14 22:38:41 +00004073 }
drh8c74a8c2002-08-25 19:20:40 +00004074
drhc31c2eb2003-05-02 16:04:17 +00004075 /* Finially, delete what is left of the subquery and return
4076 ** success.
4077 */
drh633e6d52008-07-28 19:34:53 +00004078 sqlite3SelectDelete(db, pSub1);
danielk1977f23329a2008-07-01 14:09:13 +00004079
drhc90713d2014-09-30 13:46:49 +00004080#if SELECTTRACE_ENABLED
4081 if( sqlite3SelectTrace & 0x100 ){
drhbc8edba2015-06-05 20:27:26 +00004082 SELECTTRACE(0x100,pParse,p,("After flattening:\n"));
drhc90713d2014-09-30 13:46:49 +00004083 sqlite3TreeViewSelect(0, p, 0);
4084 }
4085#endif
4086
drh832508b2002-03-02 17:04:07 +00004087 return 1;
4088}
shane3514b6f2008-07-22 05:00:55 +00004089#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
drh1350b032002-02-27 19:00:20 +00004090
drh69b72d52015-06-01 20:28:03 +00004091
4092
4093#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
4094/*
4095** Make copies of relevant WHERE clause terms of the outer query into
4096** the WHERE clause of subquery. Example:
4097**
4098** SELECT * FROM (SELECT a AS x, c-d AS y FROM t1) WHERE x=5 AND y=10;
4099**
4100** Transformed into:
4101**
4102** SELECT * FROM (SELECT a AS x, c-d AS y FROM t1 WHERE a=5 AND c-d=10)
4103** WHERE x=5 AND y=10;
4104**
4105** The hope is that the terms added to the inner query will make it more
4106** efficient.
4107**
4108** Do not attempt this optimization if:
4109**
drh25c221e2017-09-29 22:13:24 +00004110** (1) (** This restriction was removed on 2017-09-29. We used to
4111** disallow this optimization for aggregate subqueries, but now
drh67cc51a2017-09-30 11:47:06 +00004112** it is allowed by putting the extra terms on the HAVING clause.
4113** The added HAVING clause is pointless if the subquery lacks
4114** a GROUP BY clause. But such a HAVING clause is also harmless
4115** so there does not appear to be any reason to add extra logic
4116** to suppress it. **)
drh69b72d52015-06-01 20:28:03 +00004117**
4118** (2) The inner query is the recursive part of a common table expression.
4119**
4120** (3) The inner query has a LIMIT clause (since the changes to the WHERE
4121** close would change the meaning of the LIMIT).
4122**
drh6a9b9522018-03-27 15:13:43 +00004123** (4) The inner query is the right operand of a LEFT JOIN and the
4124** expression to be pushed down does not come from the ON clause
4125** on that LEFT JOIN.
drh69b72d52015-06-01 20:28:03 +00004126**
drh38978dd2015-08-22 01:32:29 +00004127** (5) The WHERE clause expression originates in the ON or USING clause
drh7fbb1012018-03-21 01:59:46 +00004128** of a LEFT JOIN where iCursor is not the right-hand table of that
4129** left join. An example:
4130**
4131** SELECT *
4132** FROM (SELECT 1 AS a1 UNION ALL SELECT 2) AS aa
4133** JOIN (SELECT 1 AS b2 UNION ALL SELECT 2) AS bb ON (a1=b2)
4134** LEFT JOIN (SELECT 8 AS c3 UNION ALL SELECT 9) AS cc ON (b2=2);
4135**
4136** The correct answer is three rows: (1,1,NULL),(2,2,8),(2,2,9).
4137** But if the (b2=2) term were to be pushed down into the bb subquery,
4138** then the (1,1,NULL) row would be suppressed.
drh38978dd2015-08-22 01:32:29 +00004139**
drh69b72d52015-06-01 20:28:03 +00004140** Return 0 if no changes are made and non-zero if one or more WHERE clause
4141** terms are duplicated into the subquery.
4142*/
4143static int pushDownWhereTerms(
dan44c56042016-12-07 15:38:37 +00004144 Parse *pParse, /* Parse context (for malloc() and error reporting) */
drh69b72d52015-06-01 20:28:03 +00004145 Select *pSubq, /* The subquery whose WHERE clause is to be augmented */
4146 Expr *pWhere, /* The WHERE clause of the outer query */
drh6a9b9522018-03-27 15:13:43 +00004147 int iCursor, /* Cursor number of the subquery */
4148 int isLeftJoin /* True if pSubq is the right term of a LEFT JOIN */
drh69b72d52015-06-01 20:28:03 +00004149){
4150 Expr *pNew;
4151 int nChng = 0;
4152 if( pWhere==0 ) return 0;
drh508e2d02017-09-30 01:25:04 +00004153 if( pSubq->selFlags & SF_Recursive ) return 0; /* restriction (2) */
4154
4155#ifdef SQLITE_DEBUG
4156 /* Only the first term of a compound can have a WITH clause. But make
4157 ** sure no other terms are marked SF_Recursive in case something changes
4158 ** in the future.
4159 */
4160 {
4161 Select *pX;
4162 for(pX=pSubq; pX; pX=pX->pPrior){
4163 assert( (pX->selFlags & (SF_Recursive))==0 );
drhb1ec87a2016-04-25 02:20:10 +00004164 }
drh69b72d52015-06-01 20:28:03 +00004165 }
drh508e2d02017-09-30 01:25:04 +00004166#endif
4167
drh69b72d52015-06-01 20:28:03 +00004168 if( pSubq->pLimit!=0 ){
drhb1ec87a2016-04-25 02:20:10 +00004169 return 0; /* restriction (3) */
drh69b72d52015-06-01 20:28:03 +00004170 }
4171 while( pWhere->op==TK_AND ){
drh6a9b9522018-03-27 15:13:43 +00004172 nChng += pushDownWhereTerms(pParse, pSubq, pWhere->pRight,
4173 iCursor, isLeftJoin);
drh69b72d52015-06-01 20:28:03 +00004174 pWhere = pWhere->pLeft;
4175 }
drh6a9b9522018-03-27 15:13:43 +00004176 if( isLeftJoin
4177 && (ExprHasProperty(pWhere,EP_FromJoin)==0
4178 || pWhere->iRightJoinTable!=iCursor)
4179 ){
4180 return 0; /* restriction (4) */
4181 }
drh7fbb1012018-03-21 01:59:46 +00004182 if( ExprHasProperty(pWhere,EP_FromJoin) && pWhere->iRightJoinTable!=iCursor ){
4183 return 0; /* restriction (5) */
4184 }
drh69b72d52015-06-01 20:28:03 +00004185 if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){
4186 nChng++;
4187 while( pSubq ){
drh46967de2017-04-14 12:39:37 +00004188 SubstContext x;
dan44c56042016-12-07 15:38:37 +00004189 pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
drh7fbb1012018-03-21 01:59:46 +00004190 unsetJoinExpr(pNew, -1);
drh46967de2017-04-14 12:39:37 +00004191 x.pParse = pParse;
4192 x.iTable = iCursor;
drh399c7e22017-04-14 17:18:45 +00004193 x.iNewTable = iCursor;
drh31d6fd52017-04-14 19:03:10 +00004194 x.isLeftJoin = 0;
drh46967de2017-04-14 12:39:37 +00004195 x.pEList = pSubq->pEList;
4196 pNew = substExpr(&x, pNew);
drh25c221e2017-09-29 22:13:24 +00004197 if( pSubq->selFlags & SF_Aggregate ){
4198 pSubq->pHaving = sqlite3ExprAnd(pParse->db, pSubq->pHaving, pNew);
4199 }else{
4200 pSubq->pWhere = sqlite3ExprAnd(pParse->db, pSubq->pWhere, pNew);
4201 }
drh69b72d52015-06-01 20:28:03 +00004202 pSubq = pSubq->pPrior;
4203 }
4204 }
4205 return nChng;
4206}
4207#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
4208
drh1350b032002-02-27 19:00:20 +00004209/*
drh47d9f832017-10-26 20:04:28 +00004210** The pFunc is the only aggregate function in the query. Check to see
4211** if the query is a candidate for the min/max optimization.
danielk1977a9d1ccb2008-01-05 17:39:29 +00004212**
drh47d9f832017-10-26 20:04:28 +00004213** If the query is a candidate for the min/max optimization, then set
4214** *ppMinMax to be an ORDER BY clause to be used for the optimization
4215** and return either WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX depending on
4216** whether pFunc is a min() or max() function.
danielk1977738bdcf2008-01-07 10:16:40 +00004217**
drh47d9f832017-10-26 20:04:28 +00004218** If the query is not a candidate for the min/max optimization, return
4219** WHERE_ORDERBY_NORMAL (which must be zero).
dan4ac391f2012-12-13 16:37:10 +00004220**
drh47d9f832017-10-26 20:04:28 +00004221** This routine must be called after aggregate functions have been
4222** located but before their arguments have been subjected to aggregate
4223** analysis.
danielk1977a9d1ccb2008-01-05 17:39:29 +00004224*/
drh47d9f832017-10-26 20:04:28 +00004225static u8 minMaxQuery(sqlite3 *db, Expr *pFunc, ExprList **ppMinMax){
4226 int eRet = WHERE_ORDERBY_NORMAL; /* Return value */
4227 ExprList *pEList = pFunc->x.pList; /* Arguments to agg function */
4228 const char *zFunc; /* Name of aggregate function pFunc */
4229 ExprList *pOrderBy;
4230 u8 sortOrder;
danielk1977a9d1ccb2008-01-05 17:39:29 +00004231
drh47d9f832017-10-26 20:04:28 +00004232 assert( *ppMinMax==0 );
4233 assert( pFunc->op==TK_AGG_FUNCTION );
4234 if( pEList==0 || pEList->nExpr!=1 ) return eRet;
4235 zFunc = pFunc->u.zToken;
4236 if( sqlite3StrICmp(zFunc, "min")==0 ){
4237 eRet = WHERE_ORDERBY_MIN;
4238 sortOrder = SQLITE_SO_ASC;
4239 }else if( sqlite3StrICmp(zFunc, "max")==0 ){
4240 eRet = WHERE_ORDERBY_MAX;
4241 sortOrder = SQLITE_SO_DESC;
4242 }else{
4243 return eRet;
danielk1977a9d1ccb2008-01-05 17:39:29 +00004244 }
drh47d9f832017-10-26 20:04:28 +00004245 *ppMinMax = pOrderBy = sqlite3ExprListDup(db, pEList, 0);
4246 assert( pOrderBy!=0 || db->mallocFailed );
4247 if( pOrderBy ) pOrderBy->a[0].sortOrder = sortOrder;
dan4ac391f2012-12-13 16:37:10 +00004248 return eRet;
danielk1977a9d1ccb2008-01-05 17:39:29 +00004249}
4250
4251/*
danielk1977a5533162009-02-24 10:01:51 +00004252** The select statement passed as the first argument is an aggregate query.
peter.d.reid60ec9142014-09-06 16:39:46 +00004253** The second argument is the associated aggregate-info object. This
danielk1977a5533162009-02-24 10:01:51 +00004254** function tests if the SELECT is of the form:
4255**
4256** SELECT count(*) FROM <tbl>
4257**
4258** where table is a database table, not a sub-select or view. If the query
4259** does match this pattern, then a pointer to the Table object representing
4260** <tbl> is returned. Otherwise, 0 is returned.
4261*/
4262static Table *isSimpleCount(Select *p, AggInfo *pAggInfo){
4263 Table *pTab;
4264 Expr *pExpr;
4265
4266 assert( !p->pGroupBy );
4267
danielk19777a895a82009-02-24 18:33:15 +00004268 if( p->pWhere || p->pEList->nExpr!=1
danielk1977a5533162009-02-24 10:01:51 +00004269 || p->pSrc->nSrc!=1 || p->pSrc->a[0].pSelect
4270 ){
4271 return 0;
4272 }
danielk1977a5533162009-02-24 10:01:51 +00004273 pTab = p->pSrc->a[0].pTab;
4274 pExpr = p->pEList->a[0].pExpr;
danielk197702f33722009-02-25 08:56:47 +00004275 assert( pTab && !pTab->pSelect && pExpr );
4276
4277 if( IsVirtual(pTab) ) return 0;
danielk1977a5533162009-02-24 10:01:51 +00004278 if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
drhfb0a6082012-08-24 01:07:52 +00004279 if( NEVER(pAggInfo->nFunc==0) ) return 0;
drhd36e1042013-09-06 13:10:12 +00004280 if( (pAggInfo->aFunc[0].pFunc->funcFlags&SQLITE_FUNC_COUNT)==0 ) return 0;
danielk1977a5533162009-02-24 10:01:51 +00004281 if( pExpr->flags&EP_Distinct ) return 0;
4282
4283 return pTab;
4284}
4285
4286/*
danielk1977b1c685b2008-10-06 16:18:39 +00004287** If the source-list item passed as an argument was augmented with an
4288** INDEXED BY clause, then try to locate the specified index. If there
4289** was such a clause and the named index cannot be found, return
4290** SQLITE_ERROR and leave an error in pParse. Otherwise, populate
4291** pFrom->pIndex and return SQLITE_OK.
4292*/
4293int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){
drh8a48b9c2015-08-19 15:20:00 +00004294 if( pFrom->pTab && pFrom->fg.isIndexedBy ){
danielk1977b1c685b2008-10-06 16:18:39 +00004295 Table *pTab = pFrom->pTab;
drh8a48b9c2015-08-19 15:20:00 +00004296 char *zIndexedBy = pFrom->u1.zIndexedBy;
danielk1977b1c685b2008-10-06 16:18:39 +00004297 Index *pIdx;
4298 for(pIdx=pTab->pIndex;
drhd62fbb52015-06-04 12:08:53 +00004299 pIdx && sqlite3StrICmp(pIdx->zName, zIndexedBy);
danielk1977b1c685b2008-10-06 16:18:39 +00004300 pIdx=pIdx->pNext
4301 );
4302 if( !pIdx ){
drhd62fbb52015-06-04 12:08:53 +00004303 sqlite3ErrorMsg(pParse, "no such index: %s", zIndexedBy, 0);
dan1db95102010-06-28 10:15:19 +00004304 pParse->checkSchema = 1;
danielk1977b1c685b2008-10-06 16:18:39 +00004305 return SQLITE_ERROR;
4306 }
drh8a48b9c2015-08-19 15:20:00 +00004307 pFrom->pIBIndex = pIdx;
danielk1977b1c685b2008-10-06 16:18:39 +00004308 }
4309 return SQLITE_OK;
4310}
drhc01b7302013-05-07 17:49:08 +00004311/*
4312** Detect compound SELECT statements that use an ORDER BY clause with
4313** an alternative collating sequence.
4314**
4315** SELECT ... FROM t1 EXCEPT SELECT ... FROM t2 ORDER BY .. COLLATE ...
4316**
4317** These are rewritten as a subquery:
4318**
4319** SELECT * FROM (SELECT ... FROM t1 EXCEPT SELECT ... FROM t2)
4320** ORDER BY ... COLLATE ...
4321**
4322** This transformation is necessary because the multiSelectOrderBy() routine
4323** above that generates the code for a compound SELECT with an ORDER BY clause
4324** uses a merge algorithm that requires the same collating sequence on the
4325** result columns as on the ORDER BY clause. See ticket
4326** http://www.sqlite.org/src/info/6709574d2a
4327**
4328** This transformation is only needed for EXCEPT, INTERSECT, and UNION.
4329** The UNION ALL operator works fine with multiSelectOrderBy() even when
4330** there are COLLATE terms in the ORDER BY.
4331*/
4332static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){
4333 int i;
4334 Select *pNew;
4335 Select *pX;
4336 sqlite3 *db;
4337 struct ExprList_item *a;
4338 SrcList *pNewSrc;
4339 Parse *pParse;
4340 Token dummy;
4341
4342 if( p->pPrior==0 ) return WRC_Continue;
4343 if( p->pOrderBy==0 ) return WRC_Continue;
4344 for(pX=p; pX && (pX->op==TK_ALL || pX->op==TK_SELECT); pX=pX->pPrior){}
4345 if( pX==0 ) return WRC_Continue;
4346 a = p->pOrderBy->a;
4347 for(i=p->pOrderBy->nExpr-1; i>=0; i--){
4348 if( a[i].pExpr->flags & EP_Collate ) break;
4349 }
4350 if( i<0 ) return WRC_Continue;
4351
4352 /* If we reach this point, that means the transformation is required. */
4353
4354 pParse = pWalker->pParse;
4355 db = pParse->db;
4356 pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
4357 if( pNew==0 ) return WRC_Abort;
4358 memset(&dummy, 0, sizeof(dummy));
4359 pNewSrc = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&dummy,pNew,0,0);
4360 if( pNewSrc==0 ) return WRC_Abort;
4361 *pNew = *p;
4362 p->pSrc = pNewSrc;
drh1a1d3cd2015-11-19 16:33:31 +00004363 p->pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ASTERISK, 0));
drhc01b7302013-05-07 17:49:08 +00004364 p->op = TK_SELECT;
4365 p->pWhere = 0;
4366 pNew->pGroupBy = 0;
4367 pNew->pHaving = 0;
4368 pNew->pOrderBy = 0;
4369 p->pPrior = 0;
drh8af9ad92014-02-10 18:56:05 +00004370 p->pNext = 0;
drhf932f712015-04-12 17:35:27 +00004371 p->pWith = 0;
drh8af9ad92014-02-10 18:56:05 +00004372 p->selFlags &= ~SF_Compound;
danb33c50f2015-04-04 16:43:16 +00004373 assert( (p->selFlags & SF_Converted)==0 );
4374 p->selFlags |= SF_Converted;
drha6e3a8c2014-02-10 21:07:51 +00004375 assert( pNew->pPrior!=0 );
4376 pNew->pPrior->pNext = pNew;
drhc01b7302013-05-07 17:49:08 +00004377 pNew->pLimit = 0;
drhc01b7302013-05-07 17:49:08 +00004378 return WRC_Continue;
4379}
danielk1977b1c685b2008-10-06 16:18:39 +00004380
drh20292312015-11-21 13:24:46 +00004381/*
4382** Check to see if the FROM clause term pFrom has table-valued function
4383** arguments. If it does, leave an error message in pParse and return
4384** non-zero, since pFrom is not allowed to be a table-valued function.
4385*/
4386static int cannotBeFunction(Parse *pParse, struct SrcList_item *pFrom){
4387 if( pFrom->fg.isTabFunc ){
4388 sqlite3ErrorMsg(pParse, "'%s' is not a function", pFrom->zName);
4389 return 1;
4390 }
4391 return 0;
4392}
4393
daneede6a52014-01-15 19:42:23 +00004394#ifndef SQLITE_OMIT_CTE
4395/*
4396** Argument pWith (which may be NULL) points to a linked list of nested
4397** WITH contexts, from inner to outermost. If the table identified by
4398** FROM clause element pItem is really a common-table-expression (CTE)
4399** then return a pointer to the CTE definition for that table. Otherwise
4400** return NULL.
dan98f45e52014-01-17 17:40:46 +00004401**
4402** If a non-NULL value is returned, set *ppContext to point to the With
4403** object that the returned CTE belongs to.
drh60c1a2f2014-01-15 18:23:00 +00004404*/
dan98f45e52014-01-17 17:40:46 +00004405static struct Cte *searchWith(
drh2476a6f2015-11-07 15:19:59 +00004406 With *pWith, /* Current innermost WITH clause */
dan98f45e52014-01-17 17:40:46 +00004407 struct SrcList_item *pItem, /* FROM clause element to resolve */
4408 With **ppContext /* OUT: WITH clause return value belongs to */
4409){
drh7b19f252014-01-16 04:37:13 +00004410 const char *zName;
4411 if( pItem->zDatabase==0 && (zName = pItem->zName)!=0 ){
daneede6a52014-01-15 19:42:23 +00004412 With *p;
4413 for(p=pWith; p; p=p->pOuter){
dan4e9119d2014-01-13 15:12:23 +00004414 int i;
daneede6a52014-01-15 19:42:23 +00004415 for(i=0; i<p->nCte; i++){
4416 if( sqlite3StrICmp(zName, p->a[i].zName)==0 ){
dan98f45e52014-01-17 17:40:46 +00004417 *ppContext = p;
daneede6a52014-01-15 19:42:23 +00004418 return &p->a[i];
dan4e9119d2014-01-13 15:12:23 +00004419 }
4420 }
4421 }
4422 }
4423 return 0;
4424}
4425
drhc49832c2014-01-15 18:35:52 +00004426/* The code generator maintains a stack of active WITH clauses
4427** with the inner-most WITH clause being at the top of the stack.
4428**
danb290f112014-01-17 14:59:27 +00004429** This routine pushes the WITH clause passed as the second argument
4430** onto the top of the stack. If argument bFree is true, then this
4431** WITH clause will never be popped from the stack. In this case it
4432** should be freed along with the Parse object. In other cases, when
4433** bFree==0, the With object will be freed along with the SELECT
4434** statement with which it is associated.
drhc49832c2014-01-15 18:35:52 +00004435*/
danb290f112014-01-17 14:59:27 +00004436void sqlite3WithPush(Parse *pParse, With *pWith, u8 bFree){
drh6e772262015-11-07 17:48:21 +00004437 assert( bFree==0 || (pParse->pWith==0 && pParse->pWithToFree==0) );
dan4e9119d2014-01-13 15:12:23 +00004438 if( pWith ){
drh2476a6f2015-11-07 15:19:59 +00004439 assert( pParse->pWith!=pWith );
dan4e9119d2014-01-13 15:12:23 +00004440 pWith->pOuter = pParse->pWith;
4441 pParse->pWith = pWith;
drh6e772262015-11-07 17:48:21 +00004442 if( bFree ) pParse->pWithToFree = pWith;
dan4e9119d2014-01-13 15:12:23 +00004443 }
4444}
dan4e9119d2014-01-13 15:12:23 +00004445
daneede6a52014-01-15 19:42:23 +00004446/*
daneede6a52014-01-15 19:42:23 +00004447** This function checks if argument pFrom refers to a CTE declared by
4448** a WITH clause on the stack currently maintained by the parser. And,
4449** if currently processing a CTE expression, if it is a recursive
4450** reference to the current CTE.
4451**
4452** If pFrom falls into either of the two categories above, pFrom->pTab
4453** and other fields are populated accordingly. The caller should check
4454** (pFrom->pTab!=0) to determine whether or not a successful match
4455** was found.
4456**
4457** Whether or not a match is found, SQLITE_OK is returned if no error
4458** occurs. If an error does occur, an error message is stored in the
4459** parser and some error code other than SQLITE_OK returned.
4460*/
dan8ce71842014-01-14 20:14:09 +00004461static int withExpand(
4462 Walker *pWalker,
daneede6a52014-01-15 19:42:23 +00004463 struct SrcList_item *pFrom
dan8ce71842014-01-14 20:14:09 +00004464){
dan8ce71842014-01-14 20:14:09 +00004465 Parse *pParse = pWalker->pParse;
4466 sqlite3 *db = pParse->db;
dan98f45e52014-01-17 17:40:46 +00004467 struct Cte *pCte; /* Matched CTE (or NULL if no match) */
4468 With *pWith; /* WITH clause that pCte belongs to */
dan8ce71842014-01-14 20:14:09 +00004469
dan8ce71842014-01-14 20:14:09 +00004470 assert( pFrom->pTab==0 );
4471
dan98f45e52014-01-17 17:40:46 +00004472 pCte = searchWith(pParse->pWith, pFrom, &pWith);
daneae73fb2014-01-16 18:34:33 +00004473 if( pCte ){
dan98f45e52014-01-17 17:40:46 +00004474 Table *pTab;
dan8ce71842014-01-14 20:14:09 +00004475 ExprList *pEList;
4476 Select *pSel;
dan60e70682014-01-15 15:27:51 +00004477 Select *pLeft; /* Left-most SELECT statement */
danf2655fe2014-01-16 21:02:02 +00004478 int bMayRecursive; /* True if compound joined by UNION [ALL] */
dan98f45e52014-01-17 17:40:46 +00004479 With *pSavedWith; /* Initial value of pParse->pWith */
danf2655fe2014-01-16 21:02:02 +00004480
drh0576bc52015-08-26 11:40:11 +00004481 /* If pCte->zCteErr is non-NULL at this point, then this is an illegal
danf2655fe2014-01-16 21:02:02 +00004482 ** recursive reference to CTE pCte. Leave an error in pParse and return
drh0576bc52015-08-26 11:40:11 +00004483 ** early. If pCte->zCteErr is NULL, then this is not a recursive reference.
danf2655fe2014-01-16 21:02:02 +00004484 ** In this case, proceed. */
drh0576bc52015-08-26 11:40:11 +00004485 if( pCte->zCteErr ){
4486 sqlite3ErrorMsg(pParse, pCte->zCteErr, pCte->zName);
dan98f45e52014-01-17 17:40:46 +00004487 return SQLITE_ERROR;
danf2655fe2014-01-16 21:02:02 +00004488 }
drh20292312015-11-21 13:24:46 +00004489 if( cannotBeFunction(pParse, pFrom) ) return SQLITE_ERROR;
dan8ce71842014-01-14 20:14:09 +00004490
drhc25e2eb2014-01-20 14:58:55 +00004491 assert( pFrom->pTab==0 );
dan8ce71842014-01-14 20:14:09 +00004492 pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
4493 if( pTab==0 ) return WRC_Abort;
drh79df7782016-12-14 14:07:35 +00004494 pTab->nTabRef = 1;
dan2d4dc5f2014-01-17 11:48:24 +00004495 pTab->zName = sqlite3DbStrDup(db, pCte->zName);
dan8ce71842014-01-14 20:14:09 +00004496 pTab->iPKey = -1;
dancfc9df72014-04-25 15:01:01 +00004497 pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
drhfccda8a2015-05-27 13:06:55 +00004498 pTab->tabFlags |= TF_Ephemeral | TF_NoVisibleRowid;
dan8ce71842014-01-14 20:14:09 +00004499 pFrom->pSelect = sqlite3SelectDup(db, pCte->pSelect, 0);
mistachkinfad30392016-02-13 23:43:46 +00004500 if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;
dan8ce71842014-01-14 20:14:09 +00004501 assert( pFrom->pSelect );
4502
daneae73fb2014-01-16 18:34:33 +00004503 /* Check if this is a recursive CTE. */
dan8ce71842014-01-14 20:14:09 +00004504 pSel = pFrom->pSelect;
danf2655fe2014-01-16 21:02:02 +00004505 bMayRecursive = ( pSel->op==TK_ALL || pSel->op==TK_UNION );
4506 if( bMayRecursive ){
daneae73fb2014-01-16 18:34:33 +00004507 int i;
4508 SrcList *pSrc = pFrom->pSelect->pSrc;
4509 for(i=0; i<pSrc->nSrc; i++){
4510 struct SrcList_item *pItem = &pSrc->a[i];
4511 if( pItem->zDatabase==0
4512 && pItem->zName!=0
4513 && 0==sqlite3StrICmp(pItem->zName, pCte->zName)
4514 ){
4515 pItem->pTab = pTab;
drh8a48b9c2015-08-19 15:20:00 +00004516 pItem->fg.isRecursive = 1;
drh79df7782016-12-14 14:07:35 +00004517 pTab->nTabRef++;
daneae73fb2014-01-16 18:34:33 +00004518 pSel->selFlags |= SF_Recursive;
4519 }
4520 }
dan8ce71842014-01-14 20:14:09 +00004521 }
4522
daneae73fb2014-01-16 18:34:33 +00004523 /* Only one recursive reference is permitted. */
drh79df7782016-12-14 14:07:35 +00004524 if( pTab->nTabRef>2 ){
daneae73fb2014-01-16 18:34:33 +00004525 sqlite3ErrorMsg(
drh727a99f2014-01-16 21:59:51 +00004526 pParse, "multiple references to recursive table: %s", pCte->zName
daneae73fb2014-01-16 18:34:33 +00004527 );
dan98f45e52014-01-17 17:40:46 +00004528 return SQLITE_ERROR;
daneae73fb2014-01-16 18:34:33 +00004529 }
drh3d240d22017-09-28 16:56:55 +00004530 assert( pTab->nTabRef==1 ||
4531 ((pSel->selFlags&SF_Recursive) && pTab->nTabRef==2 ));
daneae73fb2014-01-16 18:34:33 +00004532
drh0576bc52015-08-26 11:40:11 +00004533 pCte->zCteErr = "circular reference: %s";
dan98f45e52014-01-17 17:40:46 +00004534 pSavedWith = pParse->pWith;
4535 pParse->pWith = pWith;
dan067cd832017-02-03 19:16:39 +00004536 if( bMayRecursive ){
4537 Select *pPrior = pSel->pPrior;
4538 assert( pPrior->pWith==0 );
4539 pPrior->pWith = pSel->pWith;
4540 sqlite3WalkSelect(pWalker, pPrior);
4541 pPrior->pWith = 0;
4542 }else{
4543 sqlite3WalkSelect(pWalker, pSel);
4544 }
drh6e772262015-11-07 17:48:21 +00004545 pParse->pWith = pWith;
daneae73fb2014-01-16 18:34:33 +00004546
dan60e70682014-01-15 15:27:51 +00004547 for(pLeft=pSel; pLeft->pPrior; pLeft=pLeft->pPrior);
4548 pEList = pLeft->pEList;
dan8ce71842014-01-14 20:14:09 +00004549 if( pCte->pCols ){
drh8f9d0b22015-03-21 03:18:22 +00004550 if( pEList && pEList->nExpr!=pCte->pCols->nExpr ){
drh727a99f2014-01-16 21:59:51 +00004551 sqlite3ErrorMsg(pParse, "table %s has %d values for %d columns",
dan60e70682014-01-15 15:27:51 +00004552 pCte->zName, pEList->nExpr, pCte->pCols->nExpr
4553 );
dan98f45e52014-01-17 17:40:46 +00004554 pParse->pWith = pSavedWith;
4555 return SQLITE_ERROR;
dan60e70682014-01-15 15:27:51 +00004556 }
dan8ce71842014-01-14 20:14:09 +00004557 pEList = pCte->pCols;
dan8ce71842014-01-14 20:14:09 +00004558 }
dan8ce71842014-01-14 20:14:09 +00004559
drh8981b902015-08-24 17:42:49 +00004560 sqlite3ColumnsFromExprList(pParse, pEList, &pTab->nCol, &pTab->aCol);
danf2655fe2014-01-16 21:02:02 +00004561 if( bMayRecursive ){
4562 if( pSel->selFlags & SF_Recursive ){
drh0576bc52015-08-26 11:40:11 +00004563 pCte->zCteErr = "multiple recursive references: %s";
danf2655fe2014-01-16 21:02:02 +00004564 }else{
drh0576bc52015-08-26 11:40:11 +00004565 pCte->zCteErr = "recursive reference in a subquery: %s";
danf2655fe2014-01-16 21:02:02 +00004566 }
4567 sqlite3WalkSelect(pWalker, pSel);
4568 }
drh0576bc52015-08-26 11:40:11 +00004569 pCte->zCteErr = 0;
dan98f45e52014-01-17 17:40:46 +00004570 pParse->pWith = pSavedWith;
dan8ce71842014-01-14 20:14:09 +00004571 }
4572
4573 return SQLITE_OK;
4574}
daneede6a52014-01-15 19:42:23 +00004575#endif
dan4e9119d2014-01-13 15:12:23 +00004576
danb290f112014-01-17 14:59:27 +00004577#ifndef SQLITE_OMIT_CTE
dan71856942014-01-17 15:15:10 +00004578/*
4579** If the SELECT passed as the second argument has an associated WITH
4580** clause, pop it from the stack stored as part of the Parse object.
4581**
4582** This function is used as the xSelectCallback2() callback by
4583** sqlite3SelectExpand() when walking a SELECT tree to resolve table
4584** names and other FROM clause elements.
4585*/
danb290f112014-01-17 14:59:27 +00004586static void selectPopWith(Walker *pWalker, Select *p){
4587 Parse *pParse = pWalker->pParse;
drh2f65b2f2017-10-02 21:29:51 +00004588 if( OK_IF_ALWAYS_TRUE(pParse->pWith) && p->pPrior==0 ){
dan067cd832017-02-03 19:16:39 +00004589 With *pWith = findRightmost(p)->pWith;
4590 if( pWith!=0 ){
4591 assert( pParse->pWith==pWith );
4592 pParse->pWith = pWith->pOuter;
4593 }
danb290f112014-01-17 14:59:27 +00004594 }
danb290f112014-01-17 14:59:27 +00004595}
4596#else
4597#define selectPopWith 0
4598#endif
4599
dan9a947222018-06-14 19:06:36 +00004600/*
4601** The SrcList_item structure passed as the second argument represents a
4602** sub-query in the FROM clause of a SELECT statement. This function
4603** allocates and populates the SrcList_item.pTab object. If successful,
4604** SQLITE_OK is returned. Otherwise, if an OOM error is encountered,
4605** SQLITE_NOMEM.
4606*/
dandfa552f2018-06-02 21:04:28 +00004607int sqlite3ExpandSubquery(Parse *pParse, struct SrcList_item *pFrom){
dan86fb6e12018-05-16 20:58:07 +00004608 Select *pSel = pFrom->pSelect;
4609 Table *pTab;
4610
dan9a947222018-06-14 19:06:36 +00004611 assert( pSel );
dan86fb6e12018-05-16 20:58:07 +00004612 pFrom->pTab = pTab = sqlite3DbMallocZero(pParse->db, sizeof(Table));
dan9a947222018-06-14 19:06:36 +00004613 if( pTab==0 ) return SQLITE_NOMEM;
dan86fb6e12018-05-16 20:58:07 +00004614 pTab->nTabRef = 1;
4615 if( pFrom->zAlias ){
4616 pTab->zName = sqlite3DbStrDup(pParse->db, pFrom->zAlias);
4617 }else{
4618 pTab->zName = sqlite3MPrintf(pParse->db, "subquery_%p", (void*)pTab);
4619 }
4620 while( pSel->pPrior ){ pSel = pSel->pPrior; }
4621 sqlite3ColumnsFromExprList(pParse, pSel->pEList,&pTab->nCol,&pTab->aCol);
4622 pTab->iPKey = -1;
4623 pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
4624 pTab->tabFlags |= TF_Ephemeral;
4625
dan9a947222018-06-14 19:06:36 +00004626 return SQLITE_OK;
dan86fb6e12018-05-16 20:58:07 +00004627}
4628
danielk1977b1c685b2008-10-06 16:18:39 +00004629/*
drh7d10d5a2008-08-20 16:35:10 +00004630** This routine is a Walker callback for "expanding" a SELECT statement.
4631** "Expanding" means to do the following:
4632**
4633** (1) Make sure VDBE cursor numbers have been assigned to every
4634** element of the FROM clause.
4635**
4636** (2) Fill in the pTabList->a[].pTab fields in the SrcList that
4637** defines FROM clause. When views appear in the FROM clause,
4638** fill pTabList->a[].pSelect with a copy of the SELECT statement
4639** that implements the view. A copy is made of the view's SELECT
4640** statement so that we can freely modify or delete that statement
peter.d.reid60ec9142014-09-06 16:39:46 +00004641** without worrying about messing up the persistent representation
drh7d10d5a2008-08-20 16:35:10 +00004642** of the view.
4643**
peter.d.reid60ec9142014-09-06 16:39:46 +00004644** (3) Add terms to the WHERE clause to accommodate the NATURAL keyword
drh7d10d5a2008-08-20 16:35:10 +00004645** on joins and the ON and USING clause of joins.
4646**
4647** (4) Scan the list of columns in the result set (pEList) looking
4648** for instances of the "*" operator or the TABLE.* operator.
4649** If found, expand each "*" to be every column in every table
4650** and TABLE.* to be every column in TABLE.
4651**
danielk1977b3bce662005-01-29 08:32:43 +00004652*/
drh7d10d5a2008-08-20 16:35:10 +00004653static int selectExpander(Walker *pWalker, Select *p){
4654 Parse *pParse = pWalker->pParse;
4655 int i, j, k;
4656 SrcList *pTabList;
4657 ExprList *pEList;
4658 struct SrcList_item *pFrom;
4659 sqlite3 *db = pParse->db;
drh3e3f1a52013-01-03 00:45:56 +00004660 Expr *pE, *pRight, *pExpr;
drh785097d2013-02-12 22:09:48 +00004661 u16 selFlags = p->selFlags;
drhfca23552017-10-28 20:51:54 +00004662 u32 elistFlags = 0;
danielk1977b3bce662005-01-29 08:32:43 +00004663
drh785097d2013-02-12 22:09:48 +00004664 p->selFlags |= SF_Expanded;
drh7d10d5a2008-08-20 16:35:10 +00004665 if( db->mallocFailed ){
4666 return WRC_Abort;
danielk1977b3bce662005-01-29 08:32:43 +00004667 }
drh9d9c41e2017-10-31 03:40:15 +00004668 assert( p->pSrc!=0 );
4669 if( (selFlags & SF_Expanded)!=0 ){
drh7d10d5a2008-08-20 16:35:10 +00004670 return WRC_Prune;
danielk1977b3bce662005-01-29 08:32:43 +00004671 }
drh7d10d5a2008-08-20 16:35:10 +00004672 pTabList = p->pSrc;
danielk1977b3bce662005-01-29 08:32:43 +00004673 pEList = p->pEList;
drha5746e02018-04-09 20:36:09 +00004674 sqlite3WithPush(pParse, p->pWith, 0);
drh7d10d5a2008-08-20 16:35:10 +00004675
4676 /* Make sure cursor numbers have been assigned to all entries in
4677 ** the FROM clause of the SELECT statement.
4678 */
4679 sqlite3SrcListAssignCursors(pParse, pTabList);
4680
4681 /* Look up every table named in the FROM clause of the select. If
4682 ** an entry of the FROM clause is a subquery instead of a table or view,
4683 ** then create a transient table structure to describe the subquery.
4684 */
4685 for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
4686 Table *pTab;
drhe2b7d7a2015-09-29 15:50:04 +00004687 assert( pFrom->fg.isRecursive==0 || pFrom->pTab!=0 );
drh8a48b9c2015-08-19 15:20:00 +00004688 if( pFrom->fg.isRecursive ) continue;
drhe2b7d7a2015-09-29 15:50:04 +00004689 assert( pFrom->pTab==0 );
dan4e9119d2014-01-13 15:12:23 +00004690#ifndef SQLITE_OMIT_CTE
daneede6a52014-01-15 19:42:23 +00004691 if( withExpand(pWalker, pFrom) ) return WRC_Abort;
4692 if( pFrom->pTab ) {} else
dan4e9119d2014-01-13 15:12:23 +00004693#endif
drh7d10d5a2008-08-20 16:35:10 +00004694 if( pFrom->zName==0 ){
4695#ifndef SQLITE_OMIT_SUBQUERY
4696 Select *pSel = pFrom->pSelect;
4697 /* A sub-query in the FROM clause of a SELECT */
4698 assert( pSel!=0 );
4699 assert( pFrom->pTab==0 );
drh2b8c5a02015-01-22 12:00:17 +00004700 if( sqlite3WalkSelect(pWalker, pSel) ) return WRC_Abort;
dandfa552f2018-06-02 21:04:28 +00004701 if( sqlite3ExpandSubquery(pParse, pFrom) ) return WRC_Abort;
dan86fb6e12018-05-16 20:58:07 +00004702#endif
drh7d10d5a2008-08-20 16:35:10 +00004703 }else{
4704 /* An ordinary table or view name in the FROM clause */
4705 assert( pFrom->pTab==0 );
dan41fb5cd2012-10-04 19:33:00 +00004706 pFrom->pTab = pTab = sqlite3LocateTableItem(pParse, 0, pFrom);
drh7d10d5a2008-08-20 16:35:10 +00004707 if( pTab==0 ) return WRC_Abort;
drh79df7782016-12-14 14:07:35 +00004708 if( pTab->nTabRef>=0xffff ){
drhd2a56232013-01-28 19:00:20 +00004709 sqlite3ErrorMsg(pParse, "too many references to \"%s\": max 65535",
4710 pTab->zName);
4711 pFrom->pTab = 0;
4712 return WRC_Abort;
4713 }
drh79df7782016-12-14 14:07:35 +00004714 pTab->nTabRef++;
drh20292312015-11-21 13:24:46 +00004715 if( !IsVirtual(pTab) && cannotBeFunction(pParse, pFrom) ){
4716 return WRC_Abort;
4717 }
drh7d10d5a2008-08-20 16:35:10 +00004718#if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE)
drh20292312015-11-21 13:24:46 +00004719 if( IsVirtual(pTab) || pTab->pSelect ){
drhbfad7be2015-10-11 20:39:46 +00004720 i16 nCol;
drh7d10d5a2008-08-20 16:35:10 +00004721 if( sqlite3ViewGetColumnNames(pParse, pTab) ) return WRC_Abort;
drh43152cf2009-05-19 19:04:58 +00004722 assert( pFrom->pSelect==0 );
4723 pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect, 0);
drheb9b8842014-09-21 00:27:26 +00004724 sqlite3SelectSetName(pFrom->pSelect, pTab->zName);
drhbfad7be2015-10-11 20:39:46 +00004725 nCol = pTab->nCol;
4726 pTab->nCol = -1;
drh43152cf2009-05-19 19:04:58 +00004727 sqlite3WalkSelect(pWalker, pFrom->pSelect);
drhbfad7be2015-10-11 20:39:46 +00004728 pTab->nCol = nCol;
drh7d10d5a2008-08-20 16:35:10 +00004729 }
4730#endif
danielk1977b3bce662005-01-29 08:32:43 +00004731 }
danielk197785574e32008-10-06 05:32:18 +00004732
4733 /* Locate the index named by the INDEXED BY clause, if any. */
danielk1977b1c685b2008-10-06 16:18:39 +00004734 if( sqlite3IndexedByLookup(pParse, pFrom) ){
4735 return WRC_Abort;
danielk197785574e32008-10-06 05:32:18 +00004736 }
danielk1977b3bce662005-01-29 08:32:43 +00004737 }
4738
drh7d10d5a2008-08-20 16:35:10 +00004739 /* Process NATURAL keywords, and ON and USING clauses of joins.
danielk1977b3bce662005-01-29 08:32:43 +00004740 */
drh7d10d5a2008-08-20 16:35:10 +00004741 if( db->mallocFailed || sqliteProcessJoin(pParse, p) ){
4742 return WRC_Abort;
danielk1977b3bce662005-01-29 08:32:43 +00004743 }
4744
drh7d10d5a2008-08-20 16:35:10 +00004745 /* For every "*" that occurs in the column list, insert the names of
4746 ** all columns in all tables. And for every TABLE.* insert the names
4747 ** of all columns in TABLE. The parser inserted a special expression
drh1a1d3cd2015-11-19 16:33:31 +00004748 ** with the TK_ASTERISK operator for each "*" that it found in the column
4749 ** list. The following code just has to locate the TK_ASTERISK
4750 ** expressions and expand each one to the list of all columns in
4751 ** all tables.
danielk1977b3bce662005-01-29 08:32:43 +00004752 **
drh7d10d5a2008-08-20 16:35:10 +00004753 ** The first loop just checks to see if there are any "*" operators
4754 ** that need expanding.
danielk1977b3bce662005-01-29 08:32:43 +00004755 */
drh7d10d5a2008-08-20 16:35:10 +00004756 for(k=0; k<pEList->nExpr; k++){
drh3e3f1a52013-01-03 00:45:56 +00004757 pE = pEList->a[k].pExpr;
drh1a1d3cd2015-11-19 16:33:31 +00004758 if( pE->op==TK_ASTERISK ) break;
drh43152cf2009-05-19 19:04:58 +00004759 assert( pE->op!=TK_DOT || pE->pRight!=0 );
4760 assert( pE->op!=TK_DOT || (pE->pLeft!=0 && pE->pLeft->op==TK_ID) );
drh1a1d3cd2015-11-19 16:33:31 +00004761 if( pE->op==TK_DOT && pE->pRight->op==TK_ASTERISK ) break;
drhfca23552017-10-28 20:51:54 +00004762 elistFlags |= pE->flags;
danielk1977b3bce662005-01-29 08:32:43 +00004763 }
drh7d10d5a2008-08-20 16:35:10 +00004764 if( k<pEList->nExpr ){
4765 /*
4766 ** If we get here it means the result set contains one or more "*"
4767 ** operators that need to be expanded. Loop through each expression
4768 ** in the result set and expand them one by one.
4769 */
4770 struct ExprList_item *a = pEList->a;
4771 ExprList *pNew = 0;
4772 int flags = pParse->db->flags;
4773 int longNames = (flags & SQLITE_FullColNames)!=0
drh38b384a2013-01-03 17:34:28 +00004774 && (flags & SQLITE_ShortColNames)==0;
4775
drh7d10d5a2008-08-20 16:35:10 +00004776 for(k=0; k<pEList->nExpr; k++){
drh3e3f1a52013-01-03 00:45:56 +00004777 pE = a[k].pExpr;
drhfca23552017-10-28 20:51:54 +00004778 elistFlags |= pE->flags;
drh3e3f1a52013-01-03 00:45:56 +00004779 pRight = pE->pRight;
4780 assert( pE->op!=TK_DOT || pRight!=0 );
drh1a1d3cd2015-11-19 16:33:31 +00004781 if( pE->op!=TK_ASTERISK
4782 && (pE->op!=TK_DOT || pRight->op!=TK_ASTERISK)
4783 ){
drh7d10d5a2008-08-20 16:35:10 +00004784 /* This particular expression does not need to be expanded.
4785 */
drhb7916a72009-05-27 10:31:29 +00004786 pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr);
drh7d10d5a2008-08-20 16:35:10 +00004787 if( pNew ){
4788 pNew->a[pNew->nExpr-1].zName = a[k].zName;
drhb7916a72009-05-27 10:31:29 +00004789 pNew->a[pNew->nExpr-1].zSpan = a[k].zSpan;
4790 a[k].zName = 0;
4791 a[k].zSpan = 0;
drh7d10d5a2008-08-20 16:35:10 +00004792 }
4793 a[k].pExpr = 0;
drh7d10d5a2008-08-20 16:35:10 +00004794 }else{
4795 /* This expression is a "*" or a "TABLE.*" and needs to be
4796 ** expanded. */
4797 int tableSeen = 0; /* Set to 1 when TABLE matches */
drh3e3f1a52013-01-03 00:45:56 +00004798 char *zTName = 0; /* text of name of TABLE */
drh43152cf2009-05-19 19:04:58 +00004799 if( pE->op==TK_DOT ){
4800 assert( pE->pLeft!=0 );
drh33e619f2009-05-28 01:00:55 +00004801 assert( !ExprHasProperty(pE->pLeft, EP_IntValue) );
4802 zTName = pE->pLeft->u.zToken;
drh7d10d5a2008-08-20 16:35:10 +00004803 }
4804 for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
4805 Table *pTab = pFrom->pTab;
drh3e3f1a52013-01-03 00:45:56 +00004806 Select *pSub = pFrom->pSelect;
drh7d10d5a2008-08-20 16:35:10 +00004807 char *zTabName = pFrom->zAlias;
drh3e3f1a52013-01-03 00:45:56 +00004808 const char *zSchemaName = 0;
drhc75e09c2013-01-03 16:54:20 +00004809 int iDb;
drh43152cf2009-05-19 19:04:58 +00004810 if( zTabName==0 ){
drh7d10d5a2008-08-20 16:35:10 +00004811 zTabName = pTab->zName;
4812 }
4813 if( db->mallocFailed ) break;
drh3e3f1a52013-01-03 00:45:56 +00004814 if( pSub==0 || (pSub->selFlags & SF_NestedFrom)==0 ){
drh3e3f1a52013-01-03 00:45:56 +00004815 pSub = 0;
4816 if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){
4817 continue;
4818 }
4819 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
drh69c33822016-08-18 14:33:11 +00004820 zSchemaName = iDb>=0 ? db->aDb[iDb].zDbSName : "*";
drh7d10d5a2008-08-20 16:35:10 +00004821 }
drh7d10d5a2008-08-20 16:35:10 +00004822 for(j=0; j<pTab->nCol; j++){
drh7d10d5a2008-08-20 16:35:10 +00004823 char *zName = pTab->aCol[j].zName;
drhb7916a72009-05-27 10:31:29 +00004824 char *zColname; /* The computed column name */
4825 char *zToFree; /* Malloced string that needs to be freed */
4826 Token sColname; /* Computed column name as a token */
drh7d10d5a2008-08-20 16:35:10 +00004827
drhc75e09c2013-01-03 16:54:20 +00004828 assert( zName );
drh3e3f1a52013-01-03 00:45:56 +00004829 if( zTName && pSub
4830 && sqlite3MatchSpanName(pSub->pEList->a[j].zSpan, 0, zTName, 0)==0
4831 ){
4832 continue;
4833 }
4834
drh80090f92015-11-19 17:55:11 +00004835 /* If a column is marked as 'hidden', omit it from the expanded
4836 ** result-set list unless the SELECT has the SF_IncludeHidden
4837 ** bit set.
drh7d10d5a2008-08-20 16:35:10 +00004838 */
drh80090f92015-11-19 17:55:11 +00004839 if( (p->selFlags & SF_IncludeHidden)==0
4840 && IsHiddenColumn(&pTab->aCol[j])
4841 ){
drh7d10d5a2008-08-20 16:35:10 +00004842 continue;
4843 }
drh3e3f1a52013-01-03 00:45:56 +00004844 tableSeen = 1;
drh7d10d5a2008-08-20 16:35:10 +00004845
drhda55c482008-12-05 00:00:07 +00004846 if( i>0 && zTName==0 ){
drh8a48b9c2015-08-19 15:20:00 +00004847 if( (pFrom->fg.jointype & JT_NATURAL)!=0
drh2179b432009-12-09 17:36:39 +00004848 && tableAndColumnIndex(pTabList, i, zName, 0, 0)
4849 ){
drh7d10d5a2008-08-20 16:35:10 +00004850 /* In a NATURAL join, omit the join columns from the
drh2179b432009-12-09 17:36:39 +00004851 ** table to the right of the join */
drh7d10d5a2008-08-20 16:35:10 +00004852 continue;
4853 }
drh2179b432009-12-09 17:36:39 +00004854 if( sqlite3IdListIndex(pFrom->pUsing, zName)>=0 ){
drh7d10d5a2008-08-20 16:35:10 +00004855 /* In a join with a USING clause, omit columns in the
4856 ** using clause from the table on the right. */
4857 continue;
4858 }
4859 }
drhb7916a72009-05-27 10:31:29 +00004860 pRight = sqlite3Expr(db, TK_ID, zName);
4861 zColname = zName;
4862 zToFree = 0;
drh7d10d5a2008-08-20 16:35:10 +00004863 if( longNames || pTabList->nSrc>1 ){
drhb7916a72009-05-27 10:31:29 +00004864 Expr *pLeft;
4865 pLeft = sqlite3Expr(db, TK_ID, zTabName);
drhabfd35e2016-12-06 22:47:23 +00004866 pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight);
drh38b384a2013-01-03 17:34:28 +00004867 if( zSchemaName ){
drhc75e09c2013-01-03 16:54:20 +00004868 pLeft = sqlite3Expr(db, TK_ID, zSchemaName);
drhabfd35e2016-12-06 22:47:23 +00004869 pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pExpr);
drhc75e09c2013-01-03 16:54:20 +00004870 }
drhb7916a72009-05-27 10:31:29 +00004871 if( longNames ){
4872 zColname = sqlite3MPrintf(db, "%s.%s", zTabName, zName);
4873 zToFree = zColname;
4874 }
drh7d10d5a2008-08-20 16:35:10 +00004875 }else{
4876 pExpr = pRight;
drh7d10d5a2008-08-20 16:35:10 +00004877 }
drhb7916a72009-05-27 10:31:29 +00004878 pNew = sqlite3ExprListAppend(pParse, pNew, pExpr);
drh40aced52016-01-22 17:48:09 +00004879 sqlite3TokenInit(&sColname, zColname);
drhb7916a72009-05-27 10:31:29 +00004880 sqlite3ExprListSetName(pParse, pNew, &sColname, 0);
drh8f25d182012-12-19 02:36:45 +00004881 if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){
drh3e3f1a52013-01-03 00:45:56 +00004882 struct ExprList_item *pX = &pNew->a[pNew->nExpr-1];
4883 if( pSub ){
4884 pX->zSpan = sqlite3DbStrDup(db, pSub->pEList->a[j].zSpan);
drhc75e09c2013-01-03 16:54:20 +00004885 testcase( pX->zSpan==0 );
drh3e3f1a52013-01-03 00:45:56 +00004886 }else{
4887 pX->zSpan = sqlite3MPrintf(db, "%s.%s.%s",
4888 zSchemaName, zTabName, zColname);
drhc75e09c2013-01-03 16:54:20 +00004889 testcase( pX->zSpan==0 );
drh3e3f1a52013-01-03 00:45:56 +00004890 }
4891 pX->bSpanIsTab = 1;
drh8f25d182012-12-19 02:36:45 +00004892 }
drhb7916a72009-05-27 10:31:29 +00004893 sqlite3DbFree(db, zToFree);
drh7d10d5a2008-08-20 16:35:10 +00004894 }
4895 }
4896 if( !tableSeen ){
4897 if( zTName ){
4898 sqlite3ErrorMsg(pParse, "no such table: %s", zTName);
4899 }else{
4900 sqlite3ErrorMsg(pParse, "no tables specified");
4901 }
4902 }
drh7d10d5a2008-08-20 16:35:10 +00004903 }
drh9a993342007-12-13 02:45:31 +00004904 }
drh7d10d5a2008-08-20 16:35:10 +00004905 sqlite3ExprListDelete(db, pEList);
4906 p->pEList = pNew;
drh4c774312007-12-08 21:10:20 +00004907 }
drhfca23552017-10-28 20:51:54 +00004908 if( p->pEList ){
4909 if( p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
4910 sqlite3ErrorMsg(pParse, "too many columns in result set");
4911 return WRC_Abort;
4912 }
4913 if( (elistFlags & (EP_HasFunc|EP_Subquery))!=0 ){
4914 p->selFlags |= SF_ComplexResult;
4915 }
drh994c80a2007-04-12 21:25:01 +00004916 }
drh7d10d5a2008-08-20 16:35:10 +00004917 return WRC_Continue;
4918}
danielk1977b3bce662005-01-29 08:32:43 +00004919
drh7d10d5a2008-08-20 16:35:10 +00004920/*
4921** No-op routine for the parse-tree walker.
4922**
4923** When this routine is the Walker.xExprCallback then expression trees
4924** are walked without any actions being taken at each node. Presumably,
4925** when this routine is used for Walker.xExprCallback then
4926** Walker.xSelectCallback is set to do something useful for every
4927** subquery in the parser tree.
4928*/
drh5b88bc42013-12-07 23:35:21 +00004929int sqlite3ExprWalkNoop(Walker *NotUsed, Expr *NotUsed2){
danielk197762c14b32008-11-19 09:05:26 +00004930 UNUSED_PARAMETER2(NotUsed, NotUsed2);
drh7d10d5a2008-08-20 16:35:10 +00004931 return WRC_Continue;
4932}
danielk19779afe6892007-05-31 08:20:43 +00004933
drh7d10d5a2008-08-20 16:35:10 +00004934/*
drh979dd1b2017-05-29 14:26:07 +00004935** No-op routine for the parse-tree walker for SELECT statements.
4936** subquery in the parser tree.
4937*/
4938int sqlite3SelectWalkNoop(Walker *NotUsed, Select *NotUsed2){
4939 UNUSED_PARAMETER2(NotUsed, NotUsed2);
4940 return WRC_Continue;
4941}
4942
4943#if SQLITE_DEBUG
4944/*
4945** Always assert. This xSelectCallback2 implementation proves that the
4946** xSelectCallback2 is never invoked.
4947*/
4948void sqlite3SelectWalkAssert2(Walker *NotUsed, Select *NotUsed2){
4949 UNUSED_PARAMETER2(NotUsed, NotUsed2);
4950 assert( 0 );
4951}
4952#endif
4953/*
drh7d10d5a2008-08-20 16:35:10 +00004954** This routine "expands" a SELECT statement and all of its subqueries.
4955** For additional information on what it means to "expand" a SELECT
4956** statement, see the comment on the selectExpand worker callback above.
4957**
4958** Expanding a SELECT statement is the first step in processing a
4959** SELECT statement. The SELECT statement must be expanded before
4960** name resolution is performed.
4961**
4962** If anything goes wrong, an error message is written into pParse.
4963** The calling function can detect the problem by looking at pParse->nErr
4964** and/or pParse->db->mallocFailed.
4965*/
4966static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
4967 Walker w;
drh5b88bc42013-12-07 23:35:21 +00004968 w.xExprCallback = sqlite3ExprWalkNoop;
drh7d10d5a2008-08-20 16:35:10 +00004969 w.pParse = pParse;
drh878fcf92017-10-02 23:50:08 +00004970 if( OK_IF_ALWAYS_TRUE(pParse->hasCompound) ){
drhd58d3272013-08-05 22:05:02 +00004971 w.xSelectCallback = convertCompoundSelectToSubquery;
drh979dd1b2017-05-29 14:26:07 +00004972 w.xSelectCallback2 = 0;
drhd58d3272013-08-05 22:05:02 +00004973 sqlite3WalkSelect(&w, pSelect);
4974 }
drhc01b7302013-05-07 17:49:08 +00004975 w.xSelectCallback = selectExpander;
dan067cd832017-02-03 19:16:39 +00004976 w.xSelectCallback2 = selectPopWith;
drhc01b7302013-05-07 17:49:08 +00004977 sqlite3WalkSelect(&w, pSelect);
drh7d10d5a2008-08-20 16:35:10 +00004978}
4979
4980
4981#ifndef SQLITE_OMIT_SUBQUERY
4982/*
4983** This is a Walker.xSelectCallback callback for the sqlite3SelectTypeInfo()
4984** interface.
4985**
4986** For each FROM-clause subquery, add Column.zType and Column.zColl
4987** information to the Table structure that represents the result set
4988** of that subquery.
4989**
4990** The Table structure that represents the result set was constructed
4991** by selectExpander() but the type and collation information was omitted
4992** at that point because identifiers had not yet been resolved. This
4993** routine is called after identifier resolution.
4994*/
danb290f112014-01-17 14:59:27 +00004995static void selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
drh7d10d5a2008-08-20 16:35:10 +00004996 Parse *pParse;
4997 int i;
4998 SrcList *pTabList;
4999 struct SrcList_item *pFrom;
5000
drh9d8b3072008-08-22 16:29:51 +00005001 assert( p->selFlags & SF_Resolved );
dancc464412018-06-19 18:11:05 +00005002 if( p->selFlags & SF_HasTypeInfo ) return;
drhe2b7d7a2015-09-29 15:50:04 +00005003 p->selFlags |= SF_HasTypeInfo;
5004 pParse = pWalker->pParse;
5005 pTabList = p->pSrc;
5006 for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
5007 Table *pTab = pFrom->pTab;
5008 assert( pTab!=0 );
5009 if( (pTab->tabFlags & TF_Ephemeral)!=0 ){
5010 /* A sub-query in the FROM clause of a SELECT */
5011 Select *pSel = pFrom->pSelect;
5012 if( pSel ){
5013 while( pSel->pPrior ) pSel = pSel->pPrior;
drhed06a132016-04-05 20:59:12 +00005014 sqlite3SelectAddColumnTypeAndCollation(pParse, pTab, pSel);
drh5a29d9c2010-02-24 15:10:14 +00005015 }
drh13449892005-09-07 21:22:45 +00005016 }
5017 }
drh7d10d5a2008-08-20 16:35:10 +00005018}
5019#endif
drh13449892005-09-07 21:22:45 +00005020
drh7d10d5a2008-08-20 16:35:10 +00005021
5022/*
5023** This routine adds datatype and collating sequence information to
5024** the Table structures of all FROM-clause subqueries in a
5025** SELECT statement.
5026**
5027** Use this routine after name resolution.
5028*/
5029static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){
5030#ifndef SQLITE_OMIT_SUBQUERY
5031 Walker w;
drh979dd1b2017-05-29 14:26:07 +00005032 w.xSelectCallback = sqlite3SelectWalkNoop;
danb290f112014-01-17 14:59:27 +00005033 w.xSelectCallback2 = selectAddSubqueryTypeInfo;
drh5b88bc42013-12-07 23:35:21 +00005034 w.xExprCallback = sqlite3ExprWalkNoop;
drh7d10d5a2008-08-20 16:35:10 +00005035 w.pParse = pParse;
5036 sqlite3WalkSelect(&w, pSelect);
5037#endif
5038}
5039
5040
5041/*
drh030796d2012-08-23 16:18:10 +00005042** This routine sets up a SELECT statement for processing. The
drh7d10d5a2008-08-20 16:35:10 +00005043** following is accomplished:
5044**
5045** * VDBE Cursor numbers are assigned to all FROM-clause terms.
5046** * Ephemeral Table objects are created for all FROM-clause subqueries.
5047** * ON and USING clauses are shifted into WHERE statements
5048** * Wildcards "*" and "TABLE.*" in result sets are expanded.
5049** * Identifiers in expression are matched to tables.
5050**
5051** This routine acts recursively on all subqueries within the SELECT.
5052*/
5053void sqlite3SelectPrep(
5054 Parse *pParse, /* The parser context */
5055 Select *p, /* The SELECT statement being coded. */
5056 NameContext *pOuterNC /* Name context for container */
5057){
drhe2463392017-10-03 14:24:24 +00005058 assert( p!=0 || pParse->db->mallocFailed );
5059 if( pParse->db->mallocFailed ) return;
drh7d10d5a2008-08-20 16:35:10 +00005060 if( p->selFlags & SF_HasTypeInfo ) return;
drh7d10d5a2008-08-20 16:35:10 +00005061 sqlite3SelectExpand(pParse, p);
drhb7651e62017-10-02 23:30:45 +00005062 if( pParse->nErr || pParse->db->mallocFailed ) return;
drh7d10d5a2008-08-20 16:35:10 +00005063 sqlite3ResolveSelectNames(pParse, p, pOuterNC);
drhb7651e62017-10-02 23:30:45 +00005064 if( pParse->nErr || pParse->db->mallocFailed ) return;
drh7d10d5a2008-08-20 16:35:10 +00005065 sqlite3SelectAddTypeInfo(pParse, p);
danielk1977b3bce662005-01-29 08:32:43 +00005066}
5067
5068/*
drh13449892005-09-07 21:22:45 +00005069** Reset the aggregate accumulator.
5070**
5071** The aggregate accumulator is a set of memory cells that hold
5072** intermediate results while calculating an aggregate. This
drh030796d2012-08-23 16:18:10 +00005073** routine generates code that stores NULLs in all of those memory
5074** cells.
danielk1977b3bce662005-01-29 08:32:43 +00005075*/
drh13449892005-09-07 21:22:45 +00005076static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
5077 Vdbe *v = pParse->pVdbe;
5078 int i;
drhc99130f2005-09-11 11:56:27 +00005079 struct AggInfo_func *pFunc;
drh7e61d182013-12-20 13:11:45 +00005080 int nReg = pAggInfo->nFunc + pAggInfo->nColumn;
5081 if( nReg==0 ) return;
5082#ifdef SQLITE_DEBUG
5083 /* Verify that all AggInfo registers are within the range specified by
5084 ** AggInfo.mnReg..AggInfo.mxReg */
5085 assert( nReg==pAggInfo->mxReg-pAggInfo->mnReg+1 );
drh13449892005-09-07 21:22:45 +00005086 for(i=0; i<pAggInfo->nColumn; i++){
drh7e61d182013-12-20 13:11:45 +00005087 assert( pAggInfo->aCol[i].iMem>=pAggInfo->mnReg
5088 && pAggInfo->aCol[i].iMem<=pAggInfo->mxReg );
drh13449892005-09-07 21:22:45 +00005089 }
drh7e61d182013-12-20 13:11:45 +00005090 for(i=0; i<pAggInfo->nFunc; i++){
5091 assert( pAggInfo->aFunc[i].iMem>=pAggInfo->mnReg
5092 && pAggInfo->aFunc[i].iMem<=pAggInfo->mxReg );
5093 }
5094#endif
5095 sqlite3VdbeAddOp3(v, OP_Null, 0, pAggInfo->mnReg, pAggInfo->mxReg);
drhc99130f2005-09-11 11:56:27 +00005096 for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
drhc99130f2005-09-11 11:56:27 +00005097 if( pFunc->iDistinct>=0 ){
5098 Expr *pE = pFunc->pExpr;
danielk19776ab3a2e2009-02-19 14:39:25 +00005099 assert( !ExprHasProperty(pE, EP_xIsSelect) );
5100 if( pE->x.pList==0 || pE->x.pList->nExpr!=1 ){
drh0daa0022009-02-09 13:19:28 +00005101 sqlite3ErrorMsg(pParse, "DISTINCT aggregates must have exactly one "
5102 "argument");
drhc99130f2005-09-11 11:56:27 +00005103 pFunc->iDistinct = -1;
5104 }else{
danf9eae182018-05-21 19:45:11 +00005105 KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pE->x.pList,0,0);
drh66a51672008-01-03 00:01:23 +00005106 sqlite3VdbeAddOp4(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 0,
drh2ec2fb22013-11-06 19:59:23 +00005107 (char*)pKeyInfo, P4_KEYINFO);
drhc99130f2005-09-11 11:56:27 +00005108 }
5109 }
drh13449892005-09-07 21:22:45 +00005110 }
danielk1977b3bce662005-01-29 08:32:43 +00005111}
5112
5113/*
drh13449892005-09-07 21:22:45 +00005114** Invoke the OP_AggFinalize opcode for every aggregate function
5115** in the AggInfo structure.
danielk1977b3bce662005-01-29 08:32:43 +00005116*/
drh13449892005-09-07 21:22:45 +00005117static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
5118 Vdbe *v = pParse->pVdbe;
5119 int i;
5120 struct AggInfo_func *pF;
5121 for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
danielk19776ab3a2e2009-02-19 14:39:25 +00005122 ExprList *pList = pF->pExpr->x.pList;
5123 assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) );
drh2700aca2016-12-08 01:38:24 +00005124 sqlite3VdbeAddOp2(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0);
5125 sqlite3VdbeAppendP4(v, pF->pFunc, P4_FUNCDEF);
drh13449892005-09-07 21:22:45 +00005126 }
danielk1977b3bce662005-01-29 08:32:43 +00005127}
drh13449892005-09-07 21:22:45 +00005128
dan280c8942018-06-05 20:04:28 +00005129
drh13449892005-09-07 21:22:45 +00005130/*
5131** Update the accumulator memory cells for an aggregate based on
5132** the current cursor position.
dan280c8942018-06-05 20:04:28 +00005133**
5134** If regAcc is non-zero and there are no min() or max() aggregates
5135** in pAggInfo, then only populate the pAggInfo->nAccumulator accumulator
5136** registers i register regAcc contains 0. The caller will take care
5137** of setting and clearing regAcc.
drh13449892005-09-07 21:22:45 +00005138*/
dan280c8942018-06-05 20:04:28 +00005139static void updateAccumulator(Parse *pParse, int regAcc, AggInfo *pAggInfo){
drh13449892005-09-07 21:22:45 +00005140 Vdbe *v = pParse->pVdbe;
5141 int i;
drh7a957892012-02-02 17:35:43 +00005142 int regHit = 0;
5143 int addrHitTest = 0;
drh13449892005-09-07 21:22:45 +00005144 struct AggInfo_func *pF;
5145 struct AggInfo_col *pC;
drh13449892005-09-07 21:22:45 +00005146
5147 pAggInfo->directMode = 1;
5148 for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
5149 int nArg;
drhc99130f2005-09-11 11:56:27 +00005150 int addrNext = 0;
drh98757152008-01-09 23:04:12 +00005151 int regAgg;
danielk19776ab3a2e2009-02-19 14:39:25 +00005152 ExprList *pList = pF->pExpr->x.pList;
5153 assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) );
drh13449892005-09-07 21:22:45 +00005154 if( pList ){
5155 nArg = pList->nExpr;
drh892d3172008-01-10 03:46:36 +00005156 regAgg = sqlite3GetTempRange(pParse, nArg);
drh5579d592015-08-26 14:01:41 +00005157 sqlite3ExprCodeExprList(pParse, pList, regAgg, 0, SQLITE_ECEL_DUP);
drh13449892005-09-07 21:22:45 +00005158 }else{
5159 nArg = 0;
drh98757152008-01-09 23:04:12 +00005160 regAgg = 0;
drh13449892005-09-07 21:22:45 +00005161 }
drhc99130f2005-09-11 11:56:27 +00005162 if( pF->iDistinct>=0 ){
5163 addrNext = sqlite3VdbeMakeLabel(v);
drh7c052da2015-04-21 15:16:48 +00005164 testcase( nArg==0 ); /* Error condition */
5165 testcase( nArg>1 ); /* Also an error */
drh2dcef112008-01-12 19:03:48 +00005166 codeDistinct(pParse, pF->iDistinct, addrNext, 1, regAgg);
drhc99130f2005-09-11 11:56:27 +00005167 }
drhd36e1042013-09-06 13:10:12 +00005168 if( pF->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){
drh13449892005-09-07 21:22:45 +00005169 CollSeq *pColl = 0;
5170 struct ExprList_item *pItem;
5171 int j;
drhe82f5d02008-10-07 19:53:14 +00005172 assert( pList!=0 ); /* pList!=0 if pF->pFunc has NEEDCOLL */
drh43617e92006-03-06 20:55:46 +00005173 for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){
drh13449892005-09-07 21:22:45 +00005174 pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
5175 }
5176 if( !pColl ){
5177 pColl = pParse->db->pDfltColl;
5178 }
drh7a957892012-02-02 17:35:43 +00005179 if( regHit==0 && pAggInfo->nAccumulator ) regHit = ++pParse->nMem;
5180 sqlite3VdbeAddOp4(v, OP_CollSeq, regHit, 0, 0, (char *)pColl, P4_COLLSEQ);
drh13449892005-09-07 21:22:45 +00005181 }
drh2700aca2016-12-08 01:38:24 +00005182 sqlite3VdbeAddOp3(v, OP_AggStep0, 0, regAgg, pF->iMem);
5183 sqlite3VdbeAppendP4(v, pF->pFunc, P4_FUNCDEF);
drhea678832008-12-10 19:26:22 +00005184 sqlite3VdbeChangeP5(v, (u8)nArg);
drhda250ea2008-04-01 05:07:14 +00005185 sqlite3ExprCacheAffinityChange(pParse, regAgg, nArg);
drhf49f3522009-12-30 14:12:38 +00005186 sqlite3ReleaseTempRange(pParse, regAgg, nArg);
drhc99130f2005-09-11 11:56:27 +00005187 if( addrNext ){
5188 sqlite3VdbeResolveLabel(v, addrNext);
drhceea3322009-04-23 13:22:42 +00005189 sqlite3ExprCacheClear(pParse);
drhc99130f2005-09-11 11:56:27 +00005190 }
drh13449892005-09-07 21:22:45 +00005191 }
dan67a6a402010-03-31 15:02:56 +00005192
5193 /* Before populating the accumulator registers, clear the column cache.
5194 ** Otherwise, if any of the required column values are already present
5195 ** in registers, sqlite3ExprCode() may use OP_SCopy to copy the value
5196 ** to pC->iMem. But by the time the value is used, the original register
5197 ** may have been used, invalidating the underlying buffer holding the
5198 ** text or blob value. See ticket [883034dcb5].
5199 **
5200 ** Another solution would be to change the OP_SCopy used to copy cached
5201 ** values to an OP_Copy.
5202 */
dan280c8942018-06-05 20:04:28 +00005203 if( regHit==0 && pAggInfo->nAccumulator ){
5204 regHit = regAcc;
5205 }
drh7a957892012-02-02 17:35:43 +00005206 if( regHit ){
drh688852a2014-02-17 22:40:43 +00005207 addrHitTest = sqlite3VdbeAddOp1(v, OP_If, regHit); VdbeCoverage(v);
drh7a957892012-02-02 17:35:43 +00005208 }
dan67a6a402010-03-31 15:02:56 +00005209 sqlite3ExprCacheClear(pParse);
drh13449892005-09-07 21:22:45 +00005210 for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
drh389a1ad2008-01-03 23:44:53 +00005211 sqlite3ExprCode(pParse, pC->pExpr, pC->iMem);
drh13449892005-09-07 21:22:45 +00005212 }
5213 pAggInfo->directMode = 0;
drhceea3322009-04-23 13:22:42 +00005214 sqlite3ExprCacheClear(pParse);
drh7a957892012-02-02 17:35:43 +00005215 if( addrHitTest ){
5216 sqlite3VdbeJumpHere(v, addrHitTest);
5217 }
drh13449892005-09-07 21:22:45 +00005218}
5219
danielk1977b3bce662005-01-29 08:32:43 +00005220/*
danef7075d2011-02-21 17:49:49 +00005221** Add a single OP_Explain instruction to the VDBE to explain a simple
5222** count(*) query ("SELECT count(*) FROM pTab").
5223*/
5224#ifndef SQLITE_OMIT_EXPLAIN
5225static void explainSimpleCount(
5226 Parse *pParse, /* Parse context */
5227 Table *pTab, /* Table being queried */
5228 Index *pIdx /* Index used to optimize scan, or NULL */
5229){
5230 if( pParse->explain==2 ){
drh48dd1d82014-05-27 18:18:58 +00005231 int bCover = (pIdx!=0 && (HasRowid(pTab) || !IsPrimaryKeyIndex(pIdx)));
drhe2ca99c2018-05-02 00:33:43 +00005232 sqlite3VdbeExplain(pParse, 0, "SCAN TABLE %s%s%s",
dane96f2df2014-05-23 17:17:06 +00005233 pTab->zName,
5234 bCover ? " USING COVERING INDEX " : "",
5235 bCover ? pIdx->zName : ""
danef7075d2011-02-21 17:49:49 +00005236 );
danef7075d2011-02-21 17:49:49 +00005237 }
5238}
5239#else
5240# define explainSimpleCount(a,b,c)
5241#endif
5242
5243/*
danab31a842017-04-29 20:53:09 +00005244** sqlite3WalkExpr() callback used by havingToWhere().
5245**
5246** If the node passed to the callback is a TK_AND node, return
5247** WRC_Continue to tell sqlite3WalkExpr() to iterate through child nodes.
5248**
5249** Otherwise, return WRC_Prune. In this case, also check if the
5250** sub-expression matches the criteria for being moved to the WHERE
5251** clause. If so, add it to the WHERE clause and replace the sub-expression
5252** within the HAVING expression with a constant "1".
5253*/
5254static int havingToWhereExprCb(Walker *pWalker, Expr *pExpr){
5255 if( pExpr->op!=TK_AND ){
drhcd0abc22018-03-20 18:08:33 +00005256 Select *pS = pWalker->u.pSelect;
5257 if( sqlite3ExprIsConstantOrGroupBy(pWalker->pParse, pExpr, pS->pGroupBy) ){
danab31a842017-04-29 20:53:09 +00005258 sqlite3 *db = pWalker->pParse->db;
5259 Expr *pNew = sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[1], 0);
5260 if( pNew ){
drhcd0abc22018-03-20 18:08:33 +00005261 Expr *pWhere = pS->pWhere;
danab31a842017-04-29 20:53:09 +00005262 SWAP(Expr, *pNew, *pExpr);
drhc478c8d2017-05-01 19:53:12 +00005263 pNew = sqlite3ExprAnd(db, pWhere, pNew);
drhcd0abc22018-03-20 18:08:33 +00005264 pS->pWhere = pNew;
5265 pWalker->eCode = 1;
danab31a842017-04-29 20:53:09 +00005266 }
5267 }
5268 return WRC_Prune;
5269 }
5270 return WRC_Continue;
5271}
5272
5273/*
5274** Transfer eligible terms from the HAVING clause of a query, which is
5275** processed after grouping, to the WHERE clause, which is processed before
5276** grouping. For example, the query:
5277**
5278** SELECT * FROM <tables> WHERE a=? GROUP BY b HAVING b=? AND c=?
5279**
5280** can be rewritten as:
5281**
5282** SELECT * FROM <tables> WHERE a=? AND b=? GROUP BY b HAVING c=?
5283**
5284** A term of the HAVING expression is eligible for transfer if it consists
5285** entirely of constants and expressions that are also GROUP BY terms that
5286** use the "BINARY" collation sequence.
5287*/
drhcd0abc22018-03-20 18:08:33 +00005288static void havingToWhere(Parse *pParse, Select *p){
danab31a842017-04-29 20:53:09 +00005289 Walker sWalker;
danab31a842017-04-29 20:53:09 +00005290 memset(&sWalker, 0, sizeof(sWalker));
5291 sWalker.pParse = pParse;
5292 sWalker.xExprCallback = havingToWhereExprCb;
drhcd0abc22018-03-20 18:08:33 +00005293 sWalker.u.pSelect = p;
5294 sqlite3WalkExpr(&sWalker, p->pHaving);
5295#if SELECTTRACE_ENABLED
5296 if( sWalker.eCode && (sqlite3SelectTrace & 0x100)!=0 ){
5297 SELECTTRACE(0x100,pParse,p,("Move HAVING terms into WHERE:\n"));
5298 sqlite3TreeViewSelect(0, p, 0);
5299 }
5300#endif
danab31a842017-04-29 20:53:09 +00005301}
5302
5303/*
drhe08e8d62017-05-01 15:15:41 +00005304** Check to see if the pThis entry of pTabList is a self-join of a prior view.
5305** If it is, then return the SrcList_item for the prior view. If it is not,
5306** then return 0.
5307*/
5308static struct SrcList_item *isSelfJoinView(
5309 SrcList *pTabList, /* Search for self-joins in this FROM clause */
5310 struct SrcList_item *pThis /* Search for prior reference to this subquery */
5311){
5312 struct SrcList_item *pItem;
5313 for(pItem = pTabList->a; pItem<pThis; pItem++){
5314 if( pItem->pSelect==0 ) continue;
5315 if( pItem->fg.viaCoroutine ) continue;
drh33543c22017-05-01 16:37:20 +00005316 if( pItem->zName==0 ) continue;
5317 if( sqlite3_stricmp(pItem->zDatabase, pThis->zDatabase)!=0 ) continue;
drhed712982017-05-01 17:04:35 +00005318 if( sqlite3_stricmp(pItem->zName, pThis->zName)!=0 ) continue;
dan5aa550c2017-06-24 18:10:29 +00005319 if( sqlite3ExprCompare(0,
5320 pThis->pSelect->pWhere, pItem->pSelect->pWhere, -1)
5321 ){
drhed712982017-05-01 17:04:35 +00005322 /* The view was modified by some other optimization such as
5323 ** pushDownWhereTerms() */
5324 continue;
5325 }
5326 return pItem;
drhe08e8d62017-05-01 15:15:41 +00005327 }
5328 return 0;
5329}
5330
drh269ba802017-07-04 19:34:36 +00005331#ifdef SQLITE_COUNTOFVIEW_OPTIMIZATION
5332/*
5333** Attempt to transform a query of the form
5334**
5335** SELECT count(*) FROM (SELECT x FROM t1 UNION ALL SELECT y FROM t2)
5336**
5337** Into this:
5338**
5339** SELECT (SELECT count(*) FROM t1)+(SELECT count(*) FROM t2)
5340**
5341** The transformation only works if all of the following are true:
5342**
5343** * The subquery is a UNION ALL of two or more terms
5344** * There is no WHERE or GROUP BY or HAVING clauses on the subqueries
5345** * The outer query is a simple count(*)
5346**
5347** Return TRUE if the optimization is undertaken.
5348*/
5349static int countOfViewOptimization(Parse *pParse, Select *p){
5350 Select *pSub, *pPrior;
5351 Expr *pExpr;
5352 Expr *pCount;
5353 sqlite3 *db;
drh3d240d22017-09-28 16:56:55 +00005354 if( (p->selFlags & SF_Aggregate)==0 ) return 0; /* This is an aggregate */
drh269ba802017-07-04 19:34:36 +00005355 if( p->pEList->nExpr!=1 ) return 0; /* Single result column */
5356 pExpr = p->pEList->a[0].pExpr;
5357 if( pExpr->op!=TK_AGG_FUNCTION ) return 0; /* Result is an aggregate */
drh3d240d22017-09-28 16:56:55 +00005358 if( sqlite3_stricmp(pExpr->u.zToken,"count") ) return 0; /* Is count() */
drh269ba802017-07-04 19:34:36 +00005359 if( pExpr->x.pList!=0 ) return 0; /* Must be count(*) */
drh3d240d22017-09-28 16:56:55 +00005360 if( p->pSrc->nSrc!=1 ) return 0; /* One table in FROM */
drh269ba802017-07-04 19:34:36 +00005361 pSub = p->pSrc->a[0].pSelect;
5362 if( pSub==0 ) return 0; /* The FROM is a subquery */
drh3d240d22017-09-28 16:56:55 +00005363 if( pSub->pPrior==0 ) return 0; /* Must be a compound ry */
drh269ba802017-07-04 19:34:36 +00005364 do{
5365 if( pSub->op!=TK_ALL && pSub->pPrior ) return 0; /* Must be UNION ALL */
5366 if( pSub->pWhere ) return 0; /* No WHERE clause */
5367 if( pSub->selFlags & SF_Aggregate ) return 0; /* Not an aggregate */
drh3d240d22017-09-28 16:56:55 +00005368 pSub = pSub->pPrior; /* Repeat over compound */
drh269ba802017-07-04 19:34:36 +00005369 }while( pSub );
5370
drh3d240d22017-09-28 16:56:55 +00005371 /* If we reach this point then it is OK to perform the transformation */
drh269ba802017-07-04 19:34:36 +00005372
5373 db = pParse->db;
5374 pCount = pExpr;
5375 pExpr = 0;
5376 pSub = p->pSrc->a[0].pSelect;
5377 p->pSrc->a[0].pSelect = 0;
5378 sqlite3SrcListDelete(db, p->pSrc);
5379 p->pSrc = sqlite3DbMallocZero(pParse->db, sizeof(*p->pSrc));
5380 while( pSub ){
5381 Expr *pTerm;
5382 pPrior = pSub->pPrior;
5383 pSub->pPrior = 0;
5384 pSub->pNext = 0;
5385 pSub->selFlags |= SF_Aggregate;
5386 pSub->selFlags &= ~SF_Compound;
5387 pSub->nSelectRow = 0;
5388 sqlite3ExprListDelete(db, pSub->pEList);
5389 pTerm = pPrior ? sqlite3ExprDup(db, pCount, 0) : pCount;
5390 pSub->pEList = sqlite3ExprListAppend(pParse, 0, pTerm);
5391 pTerm = sqlite3PExpr(pParse, TK_SELECT, 0, 0);
5392 sqlite3PExprAddSelect(pParse, pTerm, pSub);
5393 if( pExpr==0 ){
5394 pExpr = pTerm;
5395 }else{
5396 pExpr = sqlite3PExpr(pParse, TK_PLUS, pTerm, pExpr);
5397 }
5398 pSub = pPrior;
5399 }
5400 p->pEList->a[0].pExpr = pExpr;
5401 p->selFlags &= ~SF_Aggregate;
5402
5403#if SELECTTRACE_ENABLED
5404 if( sqlite3SelectTrace & 0x400 ){
5405 SELECTTRACE(0x400,pParse,p,("After count-of-view optimization:\n"));
5406 sqlite3TreeViewSelect(0, p, 0);
5407 }
5408#endif
5409 return 1;
5410}
5411#endif /* SQLITE_COUNTOFVIEW_OPTIMIZATION */
5412
drhe08e8d62017-05-01 15:15:41 +00005413/*
drh7d10d5a2008-08-20 16:35:10 +00005414** Generate code for the SELECT statement given in the p argument.
drh9bb61fe2000-06-05 16:01:39 +00005415**
drh340309f2014-01-22 00:23:49 +00005416** The results are returned according to the SelectDest structure.
5417** See comments in sqliteInt.h for further information.
drhe78e8282003-01-19 03:59:45 +00005418**
drh9bb61fe2000-06-05 16:01:39 +00005419** This routine returns the number of errors. If any errors are
5420** encountered, then an appropriate error message is left in
5421** pParse->zErrMsg.
5422**
5423** This routine does NOT free the Select structure passed in. The
5424** calling function needs to do that.
5425*/
danielk19774adee202004-05-08 08:23:19 +00005426int sqlite3Select(
drhcce7d172000-05-31 15:34:51 +00005427 Parse *pParse, /* The parser context */
drh9bb61fe2000-06-05 16:01:39 +00005428 Select *p, /* The SELECT statement being coded. */
drh7d10d5a2008-08-20 16:35:10 +00005429 SelectDest *pDest /* What to do with the query results */
drhcce7d172000-05-31 15:34:51 +00005430){
drh13449892005-09-07 21:22:45 +00005431 int i, j; /* Loop counters */
5432 WhereInfo *pWInfo; /* Return from sqlite3WhereBegin() */
5433 Vdbe *v; /* The virtual machine under construction */
danielk1977b3bce662005-01-29 08:32:43 +00005434 int isAgg; /* True for select lists like "count(*)" */
mistachkinc29cbb02015-07-02 16:52:01 +00005435 ExprList *pEList = 0; /* List of columns to extract. */
drhad3cab52002-05-24 02:04:32 +00005436 SrcList *pTabList; /* List of tables to select from */
drh9bb61fe2000-06-05 16:01:39 +00005437 Expr *pWhere; /* The WHERE clause. May be NULL */
drh22827922000-06-06 17:27:05 +00005438 ExprList *pGroupBy; /* The GROUP BY clause. May be NULL */
5439 Expr *pHaving; /* The HAVING clause. May be NULL */
drh1d83f052002-02-17 00:30:36 +00005440 int rc = 1; /* Value to return from this function */
drhe8e4af72012-09-21 00:04:28 +00005441 DistinctCtx sDistinct; /* Info on how to code the DISTINCT keyword */
drh079a3072014-03-19 14:10:55 +00005442 SortCtx sSort; /* Info on how to code the ORDER BY clause */
drh13449892005-09-07 21:22:45 +00005443 AggInfo sAggInfo; /* Information used by aggregate queries */
drhec7429a2005-10-06 16:53:14 +00005444 int iEnd; /* Address of the end of the query */
drh17435752007-08-16 04:30:38 +00005445 sqlite3 *db; /* The database connection */
drh47d9f832017-10-26 20:04:28 +00005446 ExprList *pMinMaxOrderBy = 0; /* Added ORDER BY for min/max queries */
5447 u8 minMaxFlag; /* Flag for min/max queries */
drh9bb61fe2000-06-05 16:01:39 +00005448
drh17435752007-08-16 04:30:38 +00005449 db = pParse->db;
drhe2ca99c2018-05-02 00:33:43 +00005450 v = sqlite3GetVdbe(pParse);
drh17435752007-08-16 04:30:38 +00005451 if( p==0 || db->mallocFailed || pParse->nErr ){
drh6f7adc82006-01-11 21:41:20 +00005452 return 1;
5453 }
danielk19774adee202004-05-08 08:23:19 +00005454 if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
drh13449892005-09-07 21:22:45 +00005455 memset(&sAggInfo, 0, sizeof(sAggInfo));
drhe2ca99c2018-05-02 00:33:43 +00005456#if SELECTTRACE_ENABLED
5457 SELECTTRACE(1,pParse,p, ("begin processing:\n", pParse->addrExplain));
drhc90713d2014-09-30 13:46:49 +00005458 if( sqlite3SelectTrace & 0x100 ){
5459 sqlite3TreeViewSelect(0, p, 0);
5460 }
drheb9b8842014-09-21 00:27:26 +00005461#endif
drhdaffd0e2001-04-11 14:28:42 +00005462
drh8e1ee882014-03-21 19:56:09 +00005463 assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistFifo );
5464 assert( p->pOrderBy==0 || pDest->eDest!=SRT_Fifo );
dan9afccba2014-03-21 19:27:54 +00005465 assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistQueue );
5466 assert( p->pOrderBy==0 || pDest->eDest!=SRT_Queue );
danielk19776c8c8ce2008-01-02 16:27:09 +00005467 if( IgnorableOrderby(pDest) ){
danielk19779ed1dfa2008-01-02 17:11:14 +00005468 assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union ||
dan9afccba2014-03-21 19:27:54 +00005469 pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard ||
drh8e1ee882014-03-21 19:56:09 +00005470 pDest->eDest==SRT_Queue || pDest->eDest==SRT_DistFifo ||
5471 pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_Fifo);
drhccfcbce2009-05-18 15:46:07 +00005472 /* If ORDER BY makes no difference in the output then neither does
5473 ** DISTINCT so it can be removed too. */
5474 sqlite3ExprListDelete(db, p->pOrderBy);
5475 p->pOrderBy = 0;
drh7d10d5a2008-08-20 16:35:10 +00005476 p->selFlags &= ~SF_Distinct;
drh9a993342007-12-13 02:45:31 +00005477 }
drh7d10d5a2008-08-20 16:35:10 +00005478 sqlite3SelectPrep(pParse, p, 0);
drh079a3072014-03-19 14:10:55 +00005479 memset(&sSort, 0, sizeof(sSort));
5480 sSort.pOrderBy = p->pOrderBy;
danielk1977956f4312008-11-21 09:43:20 +00005481 if( pParse->nErr || db->mallocFailed ){
drh9a993342007-12-13 02:45:31 +00005482 goto select_end;
5483 }
drhadc57f62015-06-06 00:18:01 +00005484 assert( p->pEList!=0 );
drh17645f52015-02-09 13:42:59 +00005485#if SELECTTRACE_ENABLED
drhe2243d22018-04-23 17:18:03 +00005486 if( sqlite3SelectTrace & 0x104 ){
5487 SELECTTRACE(0x104,pParse,p, ("after name resolution:\n"));
drh17645f52015-02-09 13:42:59 +00005488 sqlite3TreeViewSelect(0, p, 0);
5489 }
5490#endif
drhcce7d172000-05-31 15:34:51 +00005491
drhf35f2f92017-07-29 16:01:55 +00005492 if( pDest->eDest==SRT_Output ){
5493 generateColumnNames(pParse, p);
5494 }
5495
dan67a9b8e2018-06-22 20:51:35 +00005496#ifndef SQLITE_OMIT_WINDOWFUNC
5497 if( sqlite3WindowRewrite(pParse, p) ){
dan86fb6e12018-05-16 20:58:07 +00005498 goto select_end;
5499 }
dandfa552f2018-06-02 21:04:28 +00005500#if SELECTTRACE_ENABLED
5501 if( sqlite3SelectTrace & 0x108 ){
5502 SELECTTRACE(0x104,pParse,p, ("after window rewrite:\n"));
5503 sqlite3TreeViewSelect(0, p, 0);
5504 }
5505#endif
dan67a9b8e2018-06-22 20:51:35 +00005506#endif /* SQLITE_OMIT_WINDOWFUNC */
dan86fb6e12018-05-16 20:58:07 +00005507 pTabList = p->pSrc;
dan73925692018-06-12 18:40:17 +00005508 isAgg = (p->selFlags & SF_Aggregate)!=0;
dan86fb6e12018-05-16 20:58:07 +00005509
drh25897872018-03-20 21:16:15 +00005510 /* Try to various optimizations (flattening subqueries, and strength
5511 ** reduction of join operators) in the FROM clause up into the main query
drhd820cb12002-02-18 03:21:45 +00005512 */
drh51522cd2005-01-20 13:36:19 +00005513#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
danielk1977f23329a2008-07-01 14:09:13 +00005514 for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
drh13449892005-09-07 21:22:45 +00005515 struct SrcList_item *pItem = &pTabList->a[i];
danielk1977daf79ac2008-06-30 18:12:28 +00005516 Select *pSub = pItem->pSelect;
drh2679f142015-09-25 13:42:55 +00005517 Table *pTab = pItem->pTab;
drh25897872018-03-20 21:16:15 +00005518
5519 /* Convert LEFT JOIN into JOIN if there are terms of the right table
5520 ** of the LEFT JOIN used in the WHERE clause.
5521 */
5522 if( (pItem->fg.jointype & JT_LEFT)!=0
5523 && sqlite3ExprImpliesNonNullRow(p->pWhere, pItem->iCursor)
5524 && OptimizationEnabled(db, SQLITE_SimplifyJoin)
5525 ){
5526 SELECTTRACE(0x100,pParse,p,
5527 ("LEFT-JOIN simplifies to JOIN on term %d\n",i));
drhefce69d2018-03-20 22:52:27 +00005528 pItem->fg.jointype &= ~(JT_LEFT|JT_OUTER);
drh25897872018-03-20 21:16:15 +00005529 unsetJoinExpr(p->pWhere, pItem->iCursor);
5530 }
5531
5532 /* No futher action if this term of the FROM clause is no a subquery */
drh4490c402015-06-05 22:33:39 +00005533 if( pSub==0 ) continue;
drh2679f142015-09-25 13:42:55 +00005534
5535 /* Catch mismatch in the declared columns of a view and the number of
5536 ** columns in the SELECT on the RHS */
5537 if( pTab->nCol!=pSub->pEList->nExpr ){
5538 sqlite3ErrorMsg(pParse, "expected %d columns for '%s' but got %d",
5539 pTab->nCol, pTab->zName, pSub->pEList->nExpr);
5540 goto select_end;
5541 }
5542
drh25c221e2017-09-29 22:13:24 +00005543 /* Do not try to flatten an aggregate subquery.
5544 **
5545 ** Flattening an aggregate subquery is only possible if the outer query
5546 ** is not a join. But if the outer query is not a join, then the subquery
5547 ** will be implemented as a co-routine and there is no advantage to
5548 ** flattening in that case.
5549 */
5550 if( (pSub->selFlags & SF_Aggregate)!=0 ) continue;
5551 assert( pSub->pGroupBy==0 );
5552
drhfca23552017-10-28 20:51:54 +00005553 /* If the outer query contains a "complex" result set (that is,
5554 ** if the result set of the outer query uses functions or subqueries)
5555 ** and if the subquery contains an ORDER BY clause and if
drh648fe492017-09-28 20:06:53 +00005556 ** it will be implemented as a co-routine, then do not flatten. This
5557 ** restriction allows SQL constructs like this:
5558 **
5559 ** SELECT expensive_function(x)
5560 ** FROM (SELECT x FROM tab ORDER BY y LIMIT 10);
5561 **
5562 ** The expensive_function() is only computed on the 10 rows that
5563 ** are output, rather than every row of the table.
drhfca23552017-10-28 20:51:54 +00005564 **
5565 ** The requirement that the outer query have a complex result set
5566 ** means that flattening does occur on simpler SQL constraints without
5567 ** the expensive_function() like:
5568 **
5569 ** SELECT x FROM (SELECT x FROM tab ORDER BY y LIMIT 10);
drh648fe492017-09-28 20:06:53 +00005570 */
drh25c221e2017-09-29 22:13:24 +00005571 if( pSub->pOrderBy!=0
drh648fe492017-09-28 20:06:53 +00005572 && i==0
drhfca23552017-10-28 20:51:54 +00005573 && (p->selFlags & SF_ComplexResult)!=0
drh648fe492017-09-28 20:06:53 +00005574 && (pTabList->nSrc==1
5575 || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)
drh648fe492017-09-28 20:06:53 +00005576 ){
5577 continue;
5578 }
5579
drh25c221e2017-09-29 22:13:24 +00005580 if( flattenSubquery(pParse, p, i, isAgg) ){
drh4490c402015-06-05 22:33:39 +00005581 /* This subquery can be absorbed into its parent. */
drh4490c402015-06-05 22:33:39 +00005582 i = -1;
5583 }
5584 pTabList = p->pSrc;
5585 if( db->mallocFailed ) goto select_end;
5586 if( !IgnorableOrderby(pDest) ){
5587 sSort.pOrderBy = p->pOrderBy;
5588 }
5589 }
5590#endif
5591
drh4490c402015-06-05 22:33:39 +00005592#ifndef SQLITE_OMIT_COMPOUND_SELECT
5593 /* Handle compound SELECT statements using the separate multiSelect()
5594 ** procedure.
5595 */
5596 if( p->pPrior ){
5597 rc = multiSelect(pParse, p, pDest);
drh4490c402015-06-05 22:33:39 +00005598#if SELECTTRACE_ENABLED
drhf20609d2018-04-23 17:43:35 +00005599 SELECTTRACE(0x1,pParse,p,("end compound-select processing\n"));
drhe2ca99c2018-05-02 00:33:43 +00005600 if( (sqlite3SelectTrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){
drhf20609d2018-04-23 17:43:35 +00005601 sqlite3TreeViewSelect(0, p, 0);
5602 }
drh4490c402015-06-05 22:33:39 +00005603#endif
drhc631ded2018-05-02 02:22:22 +00005604 if( p->pNext==0 ) ExplainQueryPlanPop(pParse);
drh4490c402015-06-05 22:33:39 +00005605 return rc;
5606 }
5607#endif
5608
drh701caf12017-05-10 16:12:00 +00005609 /* For each term in the FROM clause, do two things:
5610 ** (1) Authorized unreferenced tables
5611 ** (2) Generate code for all sub-queries
drhd820cb12002-02-18 03:21:45 +00005612 */
drh4490c402015-06-05 22:33:39 +00005613 for(i=0; i<pTabList->nSrc; i++){
danielk1977742f9472004-06-16 12:02:43 +00005614 struct SrcList_item *pItem = &pTabList->a[i];
drhc31c2eb2003-05-02 16:04:17 +00005615 SelectDest dest;
drh701caf12017-05-10 16:12:00 +00005616 Select *pSub;
drh824d21a2017-09-29 12:44:52 +00005617#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
5618 const char *zSavedAuthContext;
5619#endif
drh701caf12017-05-10 16:12:00 +00005620
drh3d240d22017-09-28 16:56:55 +00005621 /* Issue SQLITE_READ authorizations with a fake column name for any
5622 ** tables that are referenced but from which no values are extracted.
5623 ** Examples of where these kinds of null SQLITE_READ authorizations
5624 ** would occur:
drh701caf12017-05-10 16:12:00 +00005625 **
drh2336c932017-05-11 12:05:23 +00005626 ** SELECT count(*) FROM t1; -- SQLITE_READ t1.""
5627 ** SELECT t1.* FROM t1, t2; -- SQLITE_READ t2.""
5628 **
5629 ** The fake column name is an empty string. It is possible for a table to
5630 ** have a column named by the empty string, in which case there is no way to
5631 ** distinguish between an unreferenced table and an actual reference to the
drh3d240d22017-09-28 16:56:55 +00005632 ** "" column. The original design was for the fake column name to be a NULL,
drh2336c932017-05-11 12:05:23 +00005633 ** which would be unambiguous. But legacy authorization callbacks might
drh3d240d22017-09-28 16:56:55 +00005634 ** assume the column name is non-NULL and segfault. The use of an empty
5635 ** string for the fake column name seems safer.
drh701caf12017-05-10 16:12:00 +00005636 */
5637 if( pItem->colUsed==0 ){
drh2336c932017-05-11 12:05:23 +00005638 sqlite3AuthCheck(pParse, SQLITE_READ, pItem->zName, "", pItem->zDatabase);
drh701caf12017-05-10 16:12:00 +00005639 }
5640
5641#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
5642 /* Generate code for all sub-queries in the FROM clause
5643 */
5644 pSub = pItem->pSelect;
drh5b6a9ed2011-09-15 23:58:14 +00005645 if( pSub==0 ) continue;
drh21172c42012-10-30 00:29:07 +00005646
5647 /* Sometimes the code for a subquery will be generated more than
5648 ** once, if the subquery is part of the WHERE clause in a LEFT JOIN,
5649 ** for example. In that case, do not regenerate the code to manifest
5650 ** a view or the co-routine to implement a view. The first instance
5651 ** is sufficient, though the subroutine to manifest the view does need
5652 ** to be invoked again. */
danccb9eb72018-04-24 18:59:18 +00005653 if( pItem->addrFillSub ){
drh8a48b9c2015-08-19 15:20:00 +00005654 if( pItem->fg.viaCoroutine==0 ){
drh75555812017-04-29 19:29:49 +00005655 /* The subroutine that manifests the view might be a one-time routine,
5656 ** or it might need to be rerun on each iteration because it
5657 ** encodes a correlated subquery. */
5658 testcase( sqlite3VdbeGetOp(v, pItem->addrFillSub)->opcode==OP_Once );
drh21172c42012-10-30 00:29:07 +00005659 sqlite3VdbeAddOp2(v, OP_Gosub, pItem->regReturn, pItem->addrFillSub);
5660 }
drh5b6a9ed2011-09-15 23:58:14 +00005661 continue;
5662 }
danielk1977daf79ac2008-06-30 18:12:28 +00005663
danielk1977fc976062007-05-10 10:46:56 +00005664 /* Increment Parse.nHeight by the height of the largest expression
drhf7b54962013-05-28 12:11:54 +00005665 ** tree referred to by this, the parent select. The child select
danielk1977fc976062007-05-10 10:46:56 +00005666 ** may contain expression trees of at most
5667 ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
5668 ** more conservative than necessary, but much easier than enforcing
5669 ** an exact limit.
5670 */
5671 pParse->nHeight += sqlite3SelectExprHeight(p);
danielk1977daf79ac2008-06-30 18:12:28 +00005672
drhadc57f62015-06-06 00:18:01 +00005673 /* Make copies of constant WHERE-clause terms in the outer query down
5674 ** inside the subquery. This can help the subquery to run more efficiently.
5675 */
drh7fbb1012018-03-21 01:59:46 +00005676 if( OptimizationEnabled(db, SQLITE_PushDown)
drh6a9b9522018-03-27 15:13:43 +00005677 && pushDownWhereTerms(pParse, pSub, p->pWhere, pItem->iCursor,
5678 (pItem->fg.jointype & JT_OUTER)!=0)
drh4490c402015-06-05 22:33:39 +00005679 ){
drh69b72d52015-06-01 20:28:03 +00005680#if SELECTTRACE_ENABLED
drh4490c402015-06-05 22:33:39 +00005681 if( sqlite3SelectTrace & 0x100 ){
5682 SELECTTRACE(0x100,pParse,p,("After WHERE-clause push-down:\n"));
5683 sqlite3TreeViewSelect(0, p, 0);
danielk1977daf79ac2008-06-30 18:12:28 +00005684 }
drh69b72d52015-06-01 20:28:03 +00005685#endif
drh2d277bb2018-03-20 11:24:30 +00005686 }else{
5687 SELECTTRACE(0x100,pParse,p,("Push-down not possible\n"));
drh4490c402015-06-05 22:33:39 +00005688 }
drhadc57f62015-06-06 00:18:01 +00005689
drh824d21a2017-09-29 12:44:52 +00005690 zSavedAuthContext = pParse->zAuthContext;
5691 pParse->zAuthContext = pItem->zName;
5692
drhadc57f62015-06-06 00:18:01 +00005693 /* Generate code to implement the subquery
drh0ff47e92016-03-15 17:52:12 +00005694 **
drh25c221e2017-09-29 22:13:24 +00005695 ** The subquery is implemented as a co-routine if the subquery is
5696 ** guaranteed to be the outer loop (so that it does not need to be
5697 ** computed more than once)
drh0ff47e92016-03-15 17:52:12 +00005698 **
5699 ** TODO: Are there other reasons beside (1) to use a co-routine
5700 ** implementation?
drhadc57f62015-06-06 00:18:01 +00005701 */
drh0ff47e92016-03-15 17:52:12 +00005702 if( i==0
5703 && (pTabList->nSrc==1
5704 || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0) /* (1) */
drha5759672012-10-30 14:39:12 +00005705 ){
drh21172c42012-10-30 00:29:07 +00005706 /* Implement a co-routine that will return a single row of the result
5707 ** set on each invocation.
5708 */
drh4490c402015-06-05 22:33:39 +00005709 int addrTop = sqlite3VdbeCurrentAddr(v)+1;
drh824d21a2017-09-29 12:44:52 +00005710
drh21172c42012-10-30 00:29:07 +00005711 pItem->regReturn = ++pParse->nMem;
drh4490c402015-06-05 22:33:39 +00005712 sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);
5713 VdbeComment((v, "%s", pItem->pTab->zName));
drh21172c42012-10-30 00:29:07 +00005714 pItem->addrFillSub = addrTop;
drh21172c42012-10-30 00:29:07 +00005715 sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
drh03c39052018-05-02 14:24:34 +00005716 ExplainQueryPlan((pParse, 1, "CO-ROUTINE 0x%p", pSub));
drh21172c42012-10-30 00:29:07 +00005717 sqlite3Select(pParse, pSub, &dest);
drhc3489bb2016-02-25 16:04:59 +00005718 pItem->pTab->nRowLogEst = pSub->nSelectRow;
drh8a48b9c2015-08-19 15:20:00 +00005719 pItem->fg.viaCoroutine = 1;
drh4490c402015-06-05 22:33:39 +00005720 pItem->regResult = dest.iSdst;
drh2fade2f2016-02-09 02:12:20 +00005721 sqlite3VdbeEndCoroutine(v, pItem->regReturn);
drh21172c42012-10-30 00:29:07 +00005722 sqlite3VdbeJumpHere(v, addrTop-1);
5723 sqlite3ClearTempRegCache(pParse);
danielk1977daf79ac2008-06-30 18:12:28 +00005724 }else{
drh5b6a9ed2011-09-15 23:58:14 +00005725 /* Generate a subroutine that will fill an ephemeral table with
5726 ** the content of this subquery. pItem->addrFillSub will point
5727 ** to the address of the generated subroutine. pItem->regReturn
5728 ** is a register allocated to hold the subroutine return address
5729 */
drh7157e8e2011-09-16 16:00:51 +00005730 int topAddr;
drh48f2d3b2011-09-16 01:34:43 +00005731 int onceAddr = 0;
drh7157e8e2011-09-16 16:00:51 +00005732 int retAddr;
drhe08e8d62017-05-01 15:15:41 +00005733 struct SrcList_item *pPrior;
5734
drh5b6a9ed2011-09-15 23:58:14 +00005735 assert( pItem->addrFillSub==0 );
drh5b6a9ed2011-09-15 23:58:14 +00005736 pItem->regReturn = ++pParse->nMem;
drh7157e8e2011-09-16 16:00:51 +00005737 topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);
5738 pItem->addrFillSub = topAddr+1;
drh8a48b9c2015-08-19 15:20:00 +00005739 if( pItem->fg.isCorrelated==0 ){
drhed171672013-04-24 13:50:09 +00005740 /* If the subquery is not correlated and if we are not inside of
drh5b6a9ed2011-09-15 23:58:14 +00005741 ** a trigger, then we only need to compute the value of the subquery
5742 ** once. */
drh511f9e82016-09-22 18:53:13 +00005743 onceAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
drh4490c402015-06-05 22:33:39 +00005744 VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName));
drh69b72d52015-06-01 20:28:03 +00005745 }else{
drh4490c402015-06-05 22:33:39 +00005746 VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName));
drh5b6a9ed2011-09-15 23:58:14 +00005747 }
drhe08e8d62017-05-01 15:15:41 +00005748 pPrior = isSelfJoinView(pTabList, pItem);
5749 if( pPrior ){
5750 sqlite3VdbeAddOp2(v, OP_OpenDup, pItem->iCursor, pPrior->iCursor);
drheafc6df2017-06-11 19:51:36 +00005751 assert( pPrior->pSelect!=0 );
5752 pSub->nSelectRow = pPrior->pSelect->nSelectRow;
drhe08e8d62017-05-01 15:15:41 +00005753 }else{
5754 sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
drh03c39052018-05-02 14:24:34 +00005755 ExplainQueryPlan((pParse, 1, "MATERIALIZE 0x%p", pSub));
drhe08e8d62017-05-01 15:15:41 +00005756 sqlite3Select(pParse, pSub, &dest);
5757 }
drhc3489bb2016-02-25 16:04:59 +00005758 pItem->pTab->nRowLogEst = pSub->nSelectRow;
drh48f2d3b2011-09-16 01:34:43 +00005759 if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);
drh7157e8e2011-09-16 16:00:51 +00005760 retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
5761 VdbeComment((v, "end %s", pItem->pTab->zName));
5762 sqlite3VdbeChangeP1(v, topAddr, retAddr);
drhcdc69552011-12-06 13:24:59 +00005763 sqlite3ClearTempRegCache(pParse);
danielk1977daf79ac2008-06-30 18:12:28 +00005764 }
drhadc57f62015-06-06 00:18:01 +00005765 if( db->mallocFailed ) goto select_end;
danielk1977fc976062007-05-10 10:46:56 +00005766 pParse->nHeight -= sqlite3SelectExprHeight(p);
drh824d21a2017-09-29 12:44:52 +00005767 pParse->zAuthContext = zSavedAuthContext;
drh51522cd2005-01-20 13:36:19 +00005768#endif
drh701caf12017-05-10 16:12:00 +00005769 }
drhadc57f62015-06-06 00:18:01 +00005770
drh38b41492015-06-08 15:08:15 +00005771 /* Various elements of the SELECT copied into local variables for
5772 ** convenience */
drhadc57f62015-06-06 00:18:01 +00005773 pEList = p->pEList;
danielk1977daf79ac2008-06-30 18:12:28 +00005774 pWhere = p->pWhere;
5775 pGroupBy = p->pGroupBy;
5776 pHaving = p->pHaving;
drhe8e4af72012-09-21 00:04:28 +00005777 sDistinct.isTnct = (p->selFlags & SF_Distinct)!=0;
drh832508b2002-03-02 17:04:07 +00005778
drhbc8edba2015-06-05 20:27:26 +00005779#if SELECTTRACE_ENABLED
5780 if( sqlite3SelectTrace & 0x400 ){
5781 SELECTTRACE(0x400,pParse,p,("After all FROM-clause analysis:\n"));
5782 sqlite3TreeViewSelect(0, p, 0);
danielk1977f23329a2008-07-01 14:09:13 +00005783 }
5784#endif
5785
drh269ba802017-07-04 19:34:36 +00005786#ifdef SQLITE_COUNTOFVIEW_OPTIMIZATION
5787 if( OptimizationEnabled(db, SQLITE_QueryFlattener|SQLITE_CountOfView)
5788 && countOfViewOptimization(pParse, p)
5789 ){
5790 if( db->mallocFailed ) goto select_end;
5791 pEList = p->pEList;
5792 pTabList = p->pSrc;
5793 }
5794#endif
5795
dan50118cd2011-07-01 14:21:38 +00005796 /* If the query is DISTINCT with an ORDER BY but is not an aggregate, and
5797 ** if the select-list is the same as the ORDER BY list, then this query
5798 ** can be rewritten as a GROUP BY. In other words, this:
5799 **
5800 ** SELECT DISTINCT xyz FROM ... ORDER BY xyz
5801 **
5802 ** is transformed to:
5803 **
drhdea7d702014-12-04 21:54:58 +00005804 ** SELECT xyz FROM ... GROUP BY xyz ORDER BY xyz
dan50118cd2011-07-01 14:21:38 +00005805 **
5806 ** The second form is preferred as a single index (or temp-table) may be
5807 ** used for both the ORDER BY and DISTINCT processing. As originally
5808 ** written the query must use a temp-table for at least one of the ORDER
5809 ** BY and DISTINCT, and an index or separate temp-table for the other.
5810 */
5811 if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct
drhadc57f62015-06-06 00:18:01 +00005812 && sqlite3ExprListCompare(sSort.pOrderBy, pEList, -1)==0
dan50118cd2011-07-01 14:21:38 +00005813 ){
5814 p->selFlags &= ~SF_Distinct;
drhadc57f62015-06-06 00:18:01 +00005815 pGroupBy = p->pGroupBy = sqlite3ExprListDup(db, pEList, 0);
drhe8e4af72012-09-21 00:04:28 +00005816 /* Notice that even thought SF_Distinct has been cleared from p->selFlags,
5817 ** the sDistinct.isTnct is still set. Hence, isTnct represents the
5818 ** original setting of the SF_Distinct flag, not the current setting */
5819 assert( sDistinct.isTnct );
drh7512cb42016-04-14 13:06:49 +00005820
5821#if SELECTTRACE_ENABLED
5822 if( sqlite3SelectTrace & 0x400 ){
5823 SELECTTRACE(0x400,pParse,p,("Transform DISTINCT into GROUP BY:\n"));
5824 sqlite3TreeViewSelect(0, p, 0);
5825 }
5826#endif
dan50118cd2011-07-01 14:21:38 +00005827 }
5828
drhadc57f62015-06-06 00:18:01 +00005829 /* If there is an ORDER BY clause, then create an ephemeral index to
5830 ** do the sorting. But this sorting ephemeral index might end up
5831 ** being unused if the data can be extracted in pre-sorted order.
5832 ** If that is the case, then the OP_OpenEphemeral instruction will be
5833 ** changed to an OP_Noop once we figure out that the sorting index is
5834 ** not needed. The sSort.addrSortIndex variable is used to facilitate
5835 ** that change.
danielk19777cedc8d2004-06-10 10:50:08 +00005836 */
drh079a3072014-03-19 14:10:55 +00005837 if( sSort.pOrderBy ){
drh0342b1f2005-09-01 03:07:44 +00005838 KeyInfo *pKeyInfo;
danf9eae182018-05-21 19:45:11 +00005839 pKeyInfo = sqlite3KeyInfoFromExprList(
5840 pParse, sSort.pOrderBy, 0, pEList->nExpr);
drh079a3072014-03-19 14:10:55 +00005841 sSort.iECursor = pParse->nTab++;
5842 sSort.addrSortIndex =
drh66a51672008-01-03 00:01:23 +00005843 sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
drhf45f2322014-03-23 17:45:03 +00005844 sSort.iECursor, sSort.pOrderBy->nExpr+1+pEList->nExpr, 0,
5845 (char*)pKeyInfo, P4_KEYINFO
5846 );
drh9d2985c2005-09-08 01:58:42 +00005847 }else{
drh079a3072014-03-19 14:10:55 +00005848 sSort.addrSortIndex = -1;
danielk19777cedc8d2004-06-10 10:50:08 +00005849 }
5850
drh2d0794e2002-03-03 03:03:52 +00005851 /* If the output is destined for a temporary table, open that table.
5852 */
danielk19776c8c8ce2008-01-02 16:27:09 +00005853 if( pDest->eDest==SRT_EphemTab ){
drh2b596da2012-07-23 21:43:19 +00005854 sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iSDParm, pEList->nExpr);
drh2d0794e2002-03-03 03:03:52 +00005855 }
5856
drhf42bacc2006-04-26 17:39:34 +00005857 /* Set the limiter.
5858 */
5859 iEnd = sqlite3VdbeMakeLabel(v);
dan69b93832016-12-16 15:05:40 +00005860 if( (p->selFlags & SF_FixedLimit)==0 ){
5861 p->nSelectRow = 320; /* 4 billion rows */
5862 }
drhf42bacc2006-04-26 17:39:34 +00005863 computeLimitRegisters(pParse, p, iEnd);
drh079a3072014-03-19 14:10:55 +00005864 if( p->iLimit==0 && sSort.addrSortIndex>=0 ){
drh0ff287f2015-09-02 18:40:33 +00005865 sqlite3VdbeChangeOpcode(v, sSort.addrSortIndex, OP_SorterOpen);
drh079a3072014-03-19 14:10:55 +00005866 sSort.sortFlags |= SORTFLAG_UseSorter;
drhc6aff302011-09-01 15:32:47 +00005867 }
drhf42bacc2006-04-26 17:39:34 +00005868
drhadc57f62015-06-06 00:18:01 +00005869 /* Open an ephemeral index to use for the distinct set.
drhefb72512000-05-31 20:00:52 +00005870 */
dan2ce22452010-11-08 19:01:16 +00005871 if( p->selFlags & SF_Distinct ){
drhe8e4af72012-09-21 00:04:28 +00005872 sDistinct.tabTnct = pParse->nTab++;
5873 sDistinct.addrTnct = sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
danf9eae182018-05-21 19:45:11 +00005874 sDistinct.tabTnct, 0, 0,
5875 (char*)sqlite3KeyInfoFromExprList(pParse, p->pEList,0,0),
5876 P4_KEYINFO);
drhd4187c72010-08-30 22:15:45 +00005877 sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
drhe8e4af72012-09-21 00:04:28 +00005878 sDistinct.eTnctType = WHERE_DISTINCT_UNORDERED;
drh832508b2002-03-02 17:04:07 +00005879 }else{
drhe8e4af72012-09-21 00:04:28 +00005880 sDistinct.eTnctType = WHERE_DISTINCT_NOOP;
drhefb72512000-05-31 20:00:52 +00005881 }
drh832508b2002-03-02 17:04:07 +00005882
drh13449892005-09-07 21:22:45 +00005883 if( !isAgg && pGroupBy==0 ){
drhe8e4af72012-09-21 00:04:28 +00005884 /* No aggregate functions and no GROUP BY clause */
dan67a9b8e2018-06-22 20:51:35 +00005885 u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0)
5886 | (p->selFlags & SF_FixedLimit);
5887#ifndef SQLITE_OMIT_WINDOWFUNC
5888 Window *pWin = p->pWin; /* Master window object (or NULL) */
danf9eae182018-05-21 19:45:11 +00005889 if( pWin ){
5890 sqlite3WindowCodeInit(pParse, pWin);
dan86fb6e12018-05-16 20:58:07 +00005891 }
dan67a9b8e2018-06-22 20:51:35 +00005892#endif
5893 assert( WHERE_USE_LIMIT==SF_FixedLimit );
5894
dan86fb6e12018-05-16 20:58:07 +00005895
dan38cc40c2011-06-30 20:17:15 +00005896 /* Begin the database scan. */
drhcfd74702018-03-19 22:28:34 +00005897 SELECTTRACE(1,pParse,p,("WhereBegin\n"));
drh079a3072014-03-19 14:10:55 +00005898 pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, sSort.pOrderBy,
drhc3489bb2016-02-25 16:04:59 +00005899 p->pEList, wctrlFlags, p->nSelectRow);
drh13449892005-09-07 21:22:45 +00005900 if( pWInfo==0 ) goto select_end;
drh6f328482013-06-05 23:39:34 +00005901 if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){
5902 p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);
5903 }
drh6457a352013-06-21 00:35:37 +00005904 if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){
drh6f328482013-06-05 23:39:34 +00005905 sDistinct.eTnctType = sqlite3WhereIsDistinct(pWInfo);
5906 }
drh079a3072014-03-19 14:10:55 +00005907 if( sSort.pOrderBy ){
5908 sSort.nOBSat = sqlite3WhereIsOrdered(pWInfo);
drha536df42016-05-19 22:13:37 +00005909 sSort.bOrderedInnerLoop = sqlite3WhereOrderedInnerLoop(pWInfo);
drh079a3072014-03-19 14:10:55 +00005910 if( sSort.nOBSat==sSort.pOrderBy->nExpr ){
5911 sSort.pOrderBy = 0;
5912 }
5913 }
drhcce7d172000-05-31 15:34:51 +00005914
drhb9bb7c12006-06-11 23:41:55 +00005915 /* If sorting index that was created by a prior OP_OpenEphemeral
5916 ** instruction ended up not being needed, then change the OP_OpenEphemeral
drh9d2985c2005-09-08 01:58:42 +00005917 ** into an OP_Noop.
5918 */
drh079a3072014-03-19 14:10:55 +00005919 if( sSort.addrSortIndex>=0 && sSort.pOrderBy==0 ){
5920 sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex);
drh9d2985c2005-09-08 01:58:42 +00005921 }
5922
drh2def2f72017-09-15 17:40:34 +00005923 assert( p->pEList==pEList );
dan67a9b8e2018-06-22 20:51:35 +00005924#ifndef SQLITE_OMIT_WINDOWFUNC
danf9eae182018-05-21 19:45:11 +00005925 if( pWin ){
5926 int addrGosub = sqlite3VdbeMakeLabel(v);
dandacf1de2018-06-08 16:11:55 +00005927 int iCont = sqlite3VdbeMakeLabel(v);
danf9eae182018-05-21 19:45:11 +00005928 int regGosub = ++pParse->nMem;
danc3a20c12018-05-23 20:55:37 +00005929 int addr = 0;
drhefb72512000-05-31 20:00:52 +00005930
dandacf1de2018-06-08 16:11:55 +00005931 sqlite3WindowCodeStep(pParse, p, pWInfo, regGosub, addrGosub);
dan86fb6e12018-05-16 20:58:07 +00005932
dandacf1de2018-06-08 16:11:55 +00005933 addr = sqlite3VdbeAddOp0(v, OP_Goto);
danf9eae182018-05-21 19:45:11 +00005934 sqlite3VdbeResolveLabel(v, addrGosub);
dandacf1de2018-06-08 16:11:55 +00005935 selectInnerLoop(pParse, p, -1, &sSort, &sDistinct, pDest, iCont, 0);
5936 sqlite3VdbeResolveLabel(v, iCont);
dan86fb6e12018-05-16 20:58:07 +00005937 sqlite3VdbeAddOp1(v, OP_Return, regGosub);
dandacf1de2018-06-08 16:11:55 +00005938 sqlite3VdbeJumpHere(v, addr);
dan86fb6e12018-05-16 20:58:07 +00005939
dan67a9b8e2018-06-22 20:51:35 +00005940 }else
5941#endif /* SQLITE_OMIT_WINDOWFUNC */
5942 {
dan86fb6e12018-05-16 20:58:07 +00005943 /* Use the standard inner loop. */
5944 selectInnerLoop(pParse, p, -1, &sSort, &sDistinct, pDest,
5945 sqlite3WhereContinueLabel(pWInfo),
5946 sqlite3WhereBreakLabel(pWInfo));
5947
5948 /* End the database scan loop.
5949 */
5950 sqlite3WhereEnd(pWInfo);
5951 }
drh13449892005-09-07 21:22:45 +00005952 }else{
drhe8e4af72012-09-21 00:04:28 +00005953 /* This case when there exist aggregate functions or a GROUP BY clause
5954 ** or both */
drh13449892005-09-07 21:22:45 +00005955 NameContext sNC; /* Name context for processing aggregate information */
5956 int iAMem; /* First Mem address for storing current GROUP BY */
5957 int iBMem; /* First Mem address for previous GROUP BY */
5958 int iUseFlag; /* Mem address holding flag indicating that at least
5959 ** one row of the input to the aggregator has been
5960 ** processed */
5961 int iAbortFlag; /* Mem address which causes query abort if positive */
5962 int groupBySort; /* Rows come from source in GROUP BY order */
drhd1766112008-09-17 00:13:12 +00005963 int addrEnd; /* End of processing for this SELECT */
drh1c9d8352011-09-01 16:01:27 +00005964 int sortPTab = 0; /* Pseudotable used to decode sorting results */
5965 int sortOut = 0; /* Output register from the sorter */
dan374cd782014-04-21 13:21:56 +00005966 int orderByGrp = 0; /* True if the GROUP BY and ORDER BY are the same */
drhcce7d172000-05-31 15:34:51 +00005967
drhd1766112008-09-17 00:13:12 +00005968 /* Remove any and all aliases between the result set and the
5969 ** GROUP BY clause.
5970 */
5971 if( pGroupBy ){
drhdc5ea5c2008-12-10 17:19:59 +00005972 int k; /* Loop counter */
drhd1766112008-09-17 00:13:12 +00005973 struct ExprList_item *pItem; /* For looping over expression in a list */
drhcce7d172000-05-31 15:34:51 +00005974
drhdc5ea5c2008-12-10 17:19:59 +00005975 for(k=p->pEList->nExpr, pItem=p->pEList->a; k>0; k--, pItem++){
drhc2acc4e2013-11-15 18:15:19 +00005976 pItem->u.x.iAlias = 0;
drhd1766112008-09-17 00:13:12 +00005977 }
drhdc5ea5c2008-12-10 17:19:59 +00005978 for(k=pGroupBy->nExpr, pItem=pGroupBy->a; k>0; k--, pItem++){
drhc2acc4e2013-11-15 18:15:19 +00005979 pItem->u.x.iAlias = 0;
drhd1766112008-09-17 00:13:12 +00005980 }
drhc3489bb2016-02-25 16:04:59 +00005981 assert( 66==sqlite3LogEst(100) );
5982 if( p->nSelectRow>66 ) p->nSelectRow = 66;
drh95aa47b2010-11-16 02:49:15 +00005983 }else{
drhc3489bb2016-02-25 16:04:59 +00005984 assert( 0==sqlite3LogEst(1) );
5985 p->nSelectRow = 0;
drhd1766112008-09-17 00:13:12 +00005986 }
drh13449892005-09-07 21:22:45 +00005987
dan374cd782014-04-21 13:21:56 +00005988 /* If there is both a GROUP BY and an ORDER BY clause and they are
5989 ** identical, then it may be possible to disable the ORDER BY clause
5990 ** on the grounds that the GROUP BY will cause elements to come out
drhadc57f62015-06-06 00:18:01 +00005991 ** in the correct order. It also may not - the GROUP BY might use a
dan374cd782014-04-21 13:21:56 +00005992 ** database index that causes rows to be grouped together as required
5993 ** but not actually sorted. Either way, record the fact that the
5994 ** ORDER BY and GROUP BY clauses are the same by setting the orderByGrp
5995 ** variable. */
5996 if( sqlite3ExprListCompare(pGroupBy, sSort.pOrderBy, -1)==0 ){
5997 orderByGrp = 1;
5998 }
drhd1766112008-09-17 00:13:12 +00005999
6000 /* Create a label to jump to when we want to abort the query */
drh13449892005-09-07 21:22:45 +00006001 addrEnd = sqlite3VdbeMakeLabel(v);
6002
6003 /* Convert TK_COLUMN nodes into TK_AGG_COLUMN and make entries in
6004 ** sAggInfo for all TK_AGG_FUNCTION nodes in expressions of the
6005 ** SELECT statement.
6006 */
6007 memset(&sNC, 0, sizeof(sNC));
6008 sNC.pParse = pParse;
6009 sNC.pSrcList = pTabList;
drh25c3b8c2018-04-16 10:34:13 +00006010 sNC.uNC.pAggInfo = &sAggInfo;
6011 VVA_ONLY( sNC.ncFlags = NC_UAggInfo; )
drh7e61d182013-12-20 13:11:45 +00006012 sAggInfo.mnReg = pParse->nMem+1;
dandd23c6b2014-03-24 20:19:07 +00006013 sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr : 0;
drh9d2985c2005-09-08 01:58:42 +00006014 sAggInfo.pGroupBy = pGroupBy;
drhd2b3e232008-01-23 14:51:49 +00006015 sqlite3ExprAnalyzeAggList(&sNC, pEList);
drh079a3072014-03-19 14:10:55 +00006016 sqlite3ExprAnalyzeAggList(&sNC, sSort.pOrderBy);
drhd2b3e232008-01-23 14:51:49 +00006017 if( pHaving ){
danab31a842017-04-29 20:53:09 +00006018 if( pGroupBy ){
6019 assert( pWhere==p->pWhere );
drhcd0abc22018-03-20 18:08:33 +00006020 assert( pHaving==p->pHaving );
6021 assert( pGroupBy==p->pGroupBy );
6022 havingToWhere(pParse, p);
danab31a842017-04-29 20:53:09 +00006023 pWhere = p->pWhere;
6024 }
drhd2b3e232008-01-23 14:51:49 +00006025 sqlite3ExprAnalyzeAggregates(&sNC, pHaving);
drh13449892005-09-07 21:22:45 +00006026 }
6027 sAggInfo.nAccumulator = sAggInfo.nColumn;
drh47d9f832017-10-26 20:04:28 +00006028 if( p->pGroupBy==0 && p->pHaving==0 && sAggInfo.nFunc==1 ){
6029 minMaxFlag = minMaxQuery(db, sAggInfo.aFunc[0].pExpr, &pMinMaxOrderBy);
6030 }else{
6031 minMaxFlag = WHERE_ORDERBY_NORMAL;
6032 }
drh13449892005-09-07 21:22:45 +00006033 for(i=0; i<sAggInfo.nFunc; i++){
danielk19776ab3a2e2009-02-19 14:39:25 +00006034 assert( !ExprHasProperty(sAggInfo.aFunc[i].pExpr, EP_xIsSelect) );
drh3a8c4be2012-05-21 20:13:39 +00006035 sNC.ncFlags |= NC_InAggFunc;
danielk19776ab3a2e2009-02-19 14:39:25 +00006036 sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->x.pList);
drh3a8c4be2012-05-21 20:13:39 +00006037 sNC.ncFlags &= ~NC_InAggFunc;
drh13449892005-09-07 21:22:45 +00006038 }
drh7e61d182013-12-20 13:11:45 +00006039 sAggInfo.mxReg = pParse->nMem;
drh17435752007-08-16 04:30:38 +00006040 if( db->mallocFailed ) goto select_end;
drh7ea11062017-10-26 18:43:19 +00006041#if SELECTTRACE_ENABLED
6042 if( sqlite3SelectTrace & 0x400 ){
6043 int ii;
6044 SELECTTRACE(0x400,pParse,p,("After aggregate analysis:\n"));
6045 sqlite3TreeViewSelect(0, p, 0);
6046 for(ii=0; ii<sAggInfo.nColumn; ii++){
6047 sqlite3DebugPrintf("agg-column[%d] iMem=%d\n",
6048 ii, sAggInfo.aCol[ii].iMem);
6049 sqlite3TreeViewExpr(0, sAggInfo.aCol[ii].pExpr, 0);
6050 }
6051 for(ii=0; ii<sAggInfo.nFunc; ii++){
6052 sqlite3DebugPrintf("agg-func[%d]: iMem=%d\n",
6053 ii, sAggInfo.aFunc[ii].iMem);
6054 sqlite3TreeViewExpr(0, sAggInfo.aFunc[ii].pExpr, 0);
6055 }
6056 }
6057#endif
6058
drh13449892005-09-07 21:22:45 +00006059
6060 /* Processing for aggregates with GROUP BY is very different and
danielk19773c4809a2007-11-12 15:29:18 +00006061 ** much more complex than aggregates without a GROUP BY.
drh13449892005-09-07 21:22:45 +00006062 */
6063 if( pGroupBy ){
6064 KeyInfo *pKeyInfo; /* Keying information for the group by clause */
drh728e0f92015-10-10 14:41:28 +00006065 int addr1; /* A-vs-B comparision jump */
drhd1766112008-09-17 00:13:12 +00006066 int addrOutputRow; /* Start of subroutine that outputs a result row */
6067 int regOutputRow; /* Return address register for output subroutine */
6068 int addrSetAbort; /* Set the abort flag and return */
6069 int addrTopOfLoop; /* Top of the input loop */
6070 int addrSortingIdx; /* The OP_OpenEphemeral for the sorting index */
6071 int addrReset; /* Subroutine for resetting the accumulator */
6072 int regReset; /* Return address register for reset subroutine */
drh13449892005-09-07 21:22:45 +00006073
6074 /* If there is a GROUP BY clause we might need a sorting index to
6075 ** implement it. Allocate that sorting index now. If it turns out
drh1c9d8352011-09-01 16:01:27 +00006076 ** that we do not need it after all, the OP_SorterOpen instruction
drh13449892005-09-07 21:22:45 +00006077 ** will be converted into a Noop.
6078 */
6079 sAggInfo.sortingIdx = pParse->nTab++;
danf9eae182018-05-21 19:45:11 +00006080 pKeyInfo = sqlite3KeyInfoFromExprList(pParse,pGroupBy,0,sAggInfo.nColumn);
drh1c9d8352011-09-01 16:01:27 +00006081 addrSortingIdx = sqlite3VdbeAddOp4(v, OP_SorterOpen,
danielk1977cd3e8f72008-03-25 09:47:35 +00006082 sAggInfo.sortingIdx, sAggInfo.nSortingColumn,
drh2ec2fb22013-11-06 19:59:23 +00006083 0, (char*)pKeyInfo, P4_KEYINFO);
drh13449892005-09-07 21:22:45 +00006084
6085 /* Initialize memory locations used by GROUP BY aggregate processing
6086 */
drh0a07c102008-01-03 18:03:08 +00006087 iUseFlag = ++pParse->nMem;
6088 iAbortFlag = ++pParse->nMem;
drhd1766112008-09-17 00:13:12 +00006089 regOutputRow = ++pParse->nMem;
6090 addrOutputRow = sqlite3VdbeMakeLabel(v);
6091 regReset = ++pParse->nMem;
6092 addrReset = sqlite3VdbeMakeLabel(v);
drh0a07c102008-01-03 18:03:08 +00006093 iAMem = pParse->nMem + 1;
drh13449892005-09-07 21:22:45 +00006094 pParse->nMem += pGroupBy->nExpr;
drh0a07c102008-01-03 18:03:08 +00006095 iBMem = pParse->nMem + 1;
drh13449892005-09-07 21:22:45 +00006096 pParse->nMem += pGroupBy->nExpr;
drh4c583122008-01-04 22:01:03 +00006097 sqlite3VdbeAddOp2(v, OP_Integer, 0, iAbortFlag);
drhd4e70eb2008-01-02 00:34:36 +00006098 VdbeComment((v, "clear abort flag"));
drhb8475df2011-12-09 16:21:19 +00006099 sqlite3VdbeAddOp3(v, OP_Null, 0, iAMem, iAMem+pGroupBy->nExpr-1);
drhe3133822005-09-20 13:11:59 +00006100
drh13449892005-09-07 21:22:45 +00006101 /* Begin a loop that will extract all source rows in GROUP BY order.
6102 ** This might involve two separate loops with an OP_Sort in between, or
6103 ** it might be a single loop that uses an index to extract information
6104 ** in the right order to begin with.
6105 */
drh2eb95372008-06-06 15:04:36 +00006106 sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
drhcfd74702018-03-19 22:28:34 +00006107 SELECTTRACE(1,pParse,p,("WhereBegin\n"));
drh079a3072014-03-19 14:10:55 +00006108 pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0,
dan374cd782014-04-21 13:21:56 +00006109 WHERE_GROUPBY | (orderByGrp ? WHERE_SORTBYGROUP : 0), 0
6110 );
drh5360ad32005-09-08 00:13:27 +00006111 if( pWInfo==0 ) goto select_end;
drhddba0c22014-03-18 20:33:42 +00006112 if( sqlite3WhereIsOrdered(pWInfo)==pGroupBy->nExpr ){
drh13449892005-09-07 21:22:45 +00006113 /* The optimizer is able to deliver rows in group by order so
drhb9bb7c12006-06-11 23:41:55 +00006114 ** we do not have to sort. The OP_OpenEphemeral table will be
drh13449892005-09-07 21:22:45 +00006115 ** cancelled later because we still need to use the pKeyInfo
6116 */
drh13449892005-09-07 21:22:45 +00006117 groupBySort = 0;
6118 }else{
6119 /* Rows are coming out in undetermined order. We have to push
6120 ** each row into a sorting index, terminate the first loop,
6121 ** then loop over the sorting index in order to get the output
6122 ** in sorted order
6123 */
drh892d3172008-01-10 03:46:36 +00006124 int regBase;
6125 int regRecord;
6126 int nCol;
6127 int nGroupBy;
6128
dan2ce22452010-11-08 19:01:16 +00006129 explainTempTable(pParse,
drhe8e4af72012-09-21 00:04:28 +00006130 (sDistinct.isTnct && (p->selFlags&SF_Distinct)==0) ?
6131 "DISTINCT" : "GROUP BY");
dan2ce22452010-11-08 19:01:16 +00006132
drh13449892005-09-07 21:22:45 +00006133 groupBySort = 1;
drh892d3172008-01-10 03:46:36 +00006134 nGroupBy = pGroupBy->nExpr;
dandd23c6b2014-03-24 20:19:07 +00006135 nCol = nGroupBy;
6136 j = nGroupBy;
drh892d3172008-01-10 03:46:36 +00006137 for(i=0; i<sAggInfo.nColumn; i++){
6138 if( sAggInfo.aCol[i].iSorterColumn>=j ){
6139 nCol++;
6140 j++;
6141 }
6142 }
6143 regBase = sqlite3GetTempRange(pParse, nCol);
drhceea3322009-04-23 13:22:42 +00006144 sqlite3ExprCacheClear(pParse);
drh5579d592015-08-26 14:01:41 +00006145 sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0, 0);
dandd23c6b2014-03-24 20:19:07 +00006146 j = nGroupBy;
drh13449892005-09-07 21:22:45 +00006147 for(i=0; i<sAggInfo.nColumn; i++){
6148 struct AggInfo_col *pCol = &sAggInfo.aCol[i];
drh892d3172008-01-10 03:46:36 +00006149 if( pCol->iSorterColumn>=j ){
drhe55cbd72008-03-31 23:48:03 +00006150 int r1 = j + regBase;
drhce78bc62015-10-15 19:21:51 +00006151 sqlite3ExprCodeGetColumnToReg(pParse,
6152 pCol->pTab, pCol->iColumn, pCol->iTable, r1);
drh6a012f02008-08-21 14:15:59 +00006153 j++;
drh892d3172008-01-10 03:46:36 +00006154 }
drh13449892005-09-07 21:22:45 +00006155 }
drh892d3172008-01-10 03:46:36 +00006156 regRecord = sqlite3GetTempReg(pParse);
drh1db639c2008-01-17 02:36:28 +00006157 sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
drh1c9d8352011-09-01 16:01:27 +00006158 sqlite3VdbeAddOp2(v, OP_SorterInsert, sAggInfo.sortingIdx, regRecord);
drh892d3172008-01-10 03:46:36 +00006159 sqlite3ReleaseTempReg(pParse, regRecord);
6160 sqlite3ReleaseTempRange(pParse, regBase, nCol);
drh13449892005-09-07 21:22:45 +00006161 sqlite3WhereEnd(pWInfo);
dan5134d132011-09-02 10:31:11 +00006162 sAggInfo.sortingIdxPTab = sortPTab = pParse->nTab++;
drh1c9d8352011-09-01 16:01:27 +00006163 sortOut = sqlite3GetTempReg(pParse);
6164 sqlite3VdbeAddOp3(v, OP_OpenPseudo, sortPTab, sortOut, nCol);
6165 sqlite3VdbeAddOp2(v, OP_SorterSort, sAggInfo.sortingIdx, addrEnd);
drh688852a2014-02-17 22:40:43 +00006166 VdbeComment((v, "GROUP BY sort")); VdbeCoverage(v);
drh13449892005-09-07 21:22:45 +00006167 sAggInfo.useSortingIdx = 1;
drhceea3322009-04-23 13:22:42 +00006168 sqlite3ExprCacheClear(pParse);
dan374cd782014-04-21 13:21:56 +00006169
6170 }
6171
6172 /* If the index or temporary table used by the GROUP BY sort
6173 ** will naturally deliver rows in the order required by the ORDER BY
6174 ** clause, cancel the ephemeral table open coded earlier.
6175 **
6176 ** This is an optimization - the correct answer should result regardless.
6177 ** Use the SQLITE_GroupByOrder flag with SQLITE_TESTCTRL_OPTIMIZER to
6178 ** disable this optimization for testing purposes. */
6179 if( orderByGrp && OptimizationEnabled(db, SQLITE_GroupByOrder)
6180 && (groupBySort || sqlite3WhereIsSorted(pWInfo))
6181 ){
6182 sSort.pOrderBy = 0;
6183 sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex);
drh13449892005-09-07 21:22:45 +00006184 }
6185
6186 /* Evaluate the current GROUP BY terms and store in b0, b1, b2...
6187 ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
6188 ** Then compare the current GROUP BY terms against the GROUP BY terms
6189 ** from the previous row currently stored in a0, a1, a2...
6190 */
6191 addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
drhceea3322009-04-23 13:22:42 +00006192 sqlite3ExprCacheClear(pParse);
drh1c9d8352011-09-01 16:01:27 +00006193 if( groupBySort ){
drh38b41492015-06-08 15:08:15 +00006194 sqlite3VdbeAddOp3(v, OP_SorterData, sAggInfo.sortingIdx,
6195 sortOut, sortPTab);
drh1c9d8352011-09-01 16:01:27 +00006196 }
drh13449892005-09-07 21:22:45 +00006197 for(j=0; j<pGroupBy->nExpr; j++){
6198 if( groupBySort ){
drh1c9d8352011-09-01 16:01:27 +00006199 sqlite3VdbeAddOp3(v, OP_Column, sortPTab, j, iBMem+j);
drh13449892005-09-07 21:22:45 +00006200 }else{
6201 sAggInfo.directMode = 1;
drh2dcef112008-01-12 19:03:48 +00006202 sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr, iBMem+j);
drh13449892005-09-07 21:22:45 +00006203 }
drh13449892005-09-07 21:22:45 +00006204 }
drh16ee60f2008-06-20 18:13:25 +00006205 sqlite3VdbeAddOp4(v, OP_Compare, iAMem, iBMem, pGroupBy->nExpr,
drh2ec2fb22013-11-06 19:59:23 +00006206 (char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);
drh728e0f92015-10-10 14:41:28 +00006207 addr1 = sqlite3VdbeCurrentAddr(v);
6208 sqlite3VdbeAddOp3(v, OP_Jump, addr1+1, 0, addr1+1); VdbeCoverage(v);
drh13449892005-09-07 21:22:45 +00006209
6210 /* Generate code that runs whenever the GROUP BY changes.
drhe00ee6e2008-06-20 15:24:01 +00006211 ** Changes in the GROUP BY are detected by the previous code
drh13449892005-09-07 21:22:45 +00006212 ** block. If there were no changes, this block is skipped.
6213 **
6214 ** This code copies current group by terms in b0,b1,b2,...
6215 ** over to a0,a1,a2. It then calls the output subroutine
6216 ** and resets the aggregate accumulator registers in preparation
6217 ** for the next GROUP BY batch.
6218 */
drhb21e7c72008-06-22 12:37:57 +00006219 sqlite3ExprCodeMove(pParse, iBMem, iAMem, pGroupBy->nExpr);
drh2eb95372008-06-06 15:04:36 +00006220 sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
drhd4e70eb2008-01-02 00:34:36 +00006221 VdbeComment((v, "output one row"));
drh688852a2014-02-17 22:40:43 +00006222 sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd); VdbeCoverage(v);
drhd4e70eb2008-01-02 00:34:36 +00006223 VdbeComment((v, "check abort flag"));
drh2eb95372008-06-06 15:04:36 +00006224 sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
drhd4e70eb2008-01-02 00:34:36 +00006225 VdbeComment((v, "reset accumulator"));
drh13449892005-09-07 21:22:45 +00006226
6227 /* Update the aggregate accumulators based on the content of
6228 ** the current row
6229 */
drh728e0f92015-10-10 14:41:28 +00006230 sqlite3VdbeJumpHere(v, addr1);
dan280c8942018-06-05 20:04:28 +00006231 updateAccumulator(pParse, iUseFlag, &sAggInfo);
drh4c583122008-01-04 22:01:03 +00006232 sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag);
drhd4e70eb2008-01-02 00:34:36 +00006233 VdbeComment((v, "indicate data in accumulator"));
drh13449892005-09-07 21:22:45 +00006234
6235 /* End of the loop
6236 */
6237 if( groupBySort ){
drh1c9d8352011-09-01 16:01:27 +00006238 sqlite3VdbeAddOp2(v, OP_SorterNext, sAggInfo.sortingIdx, addrTopOfLoop);
drh688852a2014-02-17 22:40:43 +00006239 VdbeCoverage(v);
drh13449892005-09-07 21:22:45 +00006240 }else{
6241 sqlite3WhereEnd(pWInfo);
drh48f2d3b2011-09-16 01:34:43 +00006242 sqlite3VdbeChangeToNoop(v, addrSortingIdx);
drh13449892005-09-07 21:22:45 +00006243 }
6244
6245 /* Output the final row of result
6246 */
drh2eb95372008-06-06 15:04:36 +00006247 sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
drhd4e70eb2008-01-02 00:34:36 +00006248 VdbeComment((v, "output final row"));
drhd1766112008-09-17 00:13:12 +00006249
6250 /* Jump over the subroutines
6251 */
drh076e85f2015-09-03 13:46:12 +00006252 sqlite3VdbeGoto(v, addrEnd);
drhd1766112008-09-17 00:13:12 +00006253
6254 /* Generate a subroutine that outputs a single row of the result
6255 ** set. This subroutine first looks at the iUseFlag. If iUseFlag
6256 ** is less than or equal to zero, the subroutine is a no-op. If
6257 ** the processing calls for the query to abort, this subroutine
6258 ** increments the iAbortFlag memory location before returning in
6259 ** order to signal the caller to abort.
6260 */
6261 addrSetAbort = sqlite3VdbeCurrentAddr(v);
6262 sqlite3VdbeAddOp2(v, OP_Integer, 1, iAbortFlag);
6263 VdbeComment((v, "set abort flag"));
6264 sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
6265 sqlite3VdbeResolveLabel(v, addrOutputRow);
6266 addrOutputRow = sqlite3VdbeCurrentAddr(v);
6267 sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2);
drh38b41492015-06-08 15:08:15 +00006268 VdbeCoverage(v);
drhd1766112008-09-17 00:13:12 +00006269 VdbeComment((v, "Groupby result generator entry point"));
6270 sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
6271 finalizeAggFunctions(pParse, &sAggInfo);
drh33cd4902009-05-30 20:49:20 +00006272 sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL);
drh2def2f72017-09-15 17:40:34 +00006273 selectInnerLoop(pParse, p, -1, &sSort,
drhe8e4af72012-09-21 00:04:28 +00006274 &sDistinct, pDest,
drhd1766112008-09-17 00:13:12 +00006275 addrOutputRow+1, addrSetAbort);
6276 sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
6277 VdbeComment((v, "end groupby result generator"));
6278
6279 /* Generate a subroutine that will reset the group-by accumulator
6280 */
6281 sqlite3VdbeResolveLabel(v, addrReset);
6282 resetAccumulator(pParse, &sAggInfo);
dan280c8942018-06-05 20:04:28 +00006283 sqlite3VdbeAddOp2(v, OP_Integer, 0, iUseFlag);
6284 VdbeComment((v, "indicate accumulator empty"));
drhd1766112008-09-17 00:13:12 +00006285 sqlite3VdbeAddOp1(v, OP_Return, regReset);
6286
drh43152cf2009-05-19 19:04:58 +00006287 } /* endif pGroupBy. Begin aggregate queries without GROUP BY: */
drh13449892005-09-07 21:22:45 +00006288 else {
danielk1977a5533162009-02-24 10:01:51 +00006289#ifndef SQLITE_OMIT_BTREECOUNT
6290 Table *pTab;
6291 if( (pTab = isSimpleCount(p, &sAggInfo))!=0 ){
6292 /* If isSimpleCount() returns a pointer to a Table structure, then
6293 ** the SQL statement is of the form:
6294 **
6295 ** SELECT count(*) FROM <tbl>
6296 **
6297 ** where the Table structure returned represents table <tbl>.
6298 **
6299 ** This statement is so common that it is optimized specially. The
6300 ** OP_Count instruction is executed either on the intkey table that
6301 ** contains the data for table <tbl> or on one of its indexes. It
6302 ** is better to execute the op on an index, as indexes are almost
6303 ** always spread across less pages than their corresponding tables.
6304 */
6305 const int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
6306 const int iCsr = pParse->nTab++; /* Cursor to scan b-tree */
6307 Index *pIdx; /* Iterator variable */
6308 KeyInfo *pKeyInfo = 0; /* Keyinfo for scanned index */
6309 Index *pBest = 0; /* Best index found so far */
6310 int iRoot = pTab->tnum; /* Root page of scanned b-tree */
danielk1977a9d1ccb2008-01-05 17:39:29 +00006311
danielk1977a5533162009-02-24 10:01:51 +00006312 sqlite3CodeVerifySchema(pParse, iDb);
6313 sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
6314
drhd9e3cad2013-10-04 02:36:19 +00006315 /* Search for the index that has the lowest scan cost.
danielk1977a5533162009-02-24 10:01:51 +00006316 **
drh3e9548b2011-04-15 14:46:27 +00006317 ** (2011-04-15) Do not do a full scan of an unordered index.
6318 **
drhabcc1942013-11-12 14:55:40 +00006319 ** (2013-10-03) Do not count the entries in a partial index.
drh5f33f372013-10-04 00:00:12 +00006320 **
danielk1977a5533162009-02-24 10:01:51 +00006321 ** In practice the KeyInfo structure will not be used. It is only
6322 ** passed to keep OP_OpenRead happy.
6323 */
drh5c7917e2013-11-12 15:33:40 +00006324 if( !HasRowid(pTab) ) pBest = sqlite3PrimaryKeyIndex(pTab);
danielk1977a5533162009-02-24 10:01:51 +00006325 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
drhd9e3cad2013-10-04 02:36:19 +00006326 if( pIdx->bUnordered==0
drhe13e9f52013-10-05 19:18:00 +00006327 && pIdx->szIdxRow<pTab->szTabRow
drhd3037a42013-10-04 18:29:25 +00006328 && pIdx->pPartIdxWhere==0
drhe13e9f52013-10-05 19:18:00 +00006329 && (!pBest || pIdx->szIdxRow<pBest->szIdxRow)
drhd9e3cad2013-10-04 02:36:19 +00006330 ){
danielk1977a5533162009-02-24 10:01:51 +00006331 pBest = pIdx;
6332 }
6333 }
drhd9e3cad2013-10-04 02:36:19 +00006334 if( pBest ){
danielk1977a5533162009-02-24 10:01:51 +00006335 iRoot = pBest->tnum;
drh2ec2fb22013-11-06 19:59:23 +00006336 pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pBest);
danielk1977a5533162009-02-24 10:01:51 +00006337 }
6338
6339 /* Open a read-only cursor, execute the OP_Count, close the cursor. */
drh261c02d2013-10-25 14:46:15 +00006340 sqlite3VdbeAddOp4Int(v, OP_OpenRead, iCsr, iRoot, iDb, 1);
danielk1977a5533162009-02-24 10:01:51 +00006341 if( pKeyInfo ){
drh2ec2fb22013-11-06 19:59:23 +00006342 sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO);
danielk1977a5533162009-02-24 10:01:51 +00006343 }
6344 sqlite3VdbeAddOp2(v, OP_Count, iCsr, sAggInfo.aFunc[0].iMem);
6345 sqlite3VdbeAddOp1(v, OP_Close, iCsr);
danef7075d2011-02-21 17:49:49 +00006346 explainSimpleCount(pParse, pTab, pBest);
danielk1977a5533162009-02-24 10:01:51 +00006347 }else
6348#endif /* SQLITE_OMIT_BTREECOUNT */
6349 {
dan280c8942018-06-05 20:04:28 +00006350 int regAcc = 0; /* "populate accumulators" flag */
6351
6352 /* If there are accumulator registers but no min() or max() functions,
6353 ** allocate register regAcc. Register regAcc will contain 0 the first
6354 ** time the inner loop runs, and 1 thereafter. The code generated
6355 ** by updateAccumulator() only updates the accumulator registers if
6356 ** regAcc contains 0. */
6357 if( sAggInfo.nAccumulator ){
6358 for(i=0; i<sAggInfo.nFunc; i++){
6359 if( sAggInfo.aFunc[i].pFunc->funcFlags&SQLITE_FUNC_NEEDCOLL ) break;
6360 }
6361 if( i==sAggInfo.nFunc ){
6362 regAcc = ++pParse->nMem;
6363 sqlite3VdbeAddOp2(v, OP_Integer, 0, regAcc);
6364 }
6365 }
6366
danielk1977a5533162009-02-24 10:01:51 +00006367 /* This case runs if the aggregate has no GROUP BY clause. The
6368 ** processing is much simpler since there is only a single row
6369 ** of output.
6370 */
drh47d9f832017-10-26 20:04:28 +00006371 assert( p->pGroupBy==0 );
danielk1977a5533162009-02-24 10:01:51 +00006372 resetAccumulator(pParse, &sAggInfo);
drh47d9f832017-10-26 20:04:28 +00006373
6374 /* If this query is a candidate for the min/max optimization, then
6375 ** minMaxFlag will have been previously set to either
6376 ** WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX and pMinMaxOrderBy will
6377 ** be an appropriate ORDER BY expression for the optimization.
6378 */
6379 assert( minMaxFlag==WHERE_ORDERBY_NORMAL || pMinMaxOrderBy!=0 );
6380 assert( pMinMaxOrderBy==0 || pMinMaxOrderBy->nExpr==1 );
6381
drhcfd74702018-03-19 22:28:34 +00006382 SELECTTRACE(1,pParse,p,("WhereBegin\n"));
drh47d9f832017-10-26 20:04:28 +00006383 pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMaxOrderBy,
6384 0, minMaxFlag, 0);
danielk1977a5533162009-02-24 10:01:51 +00006385 if( pWInfo==0 ){
danielk1977a5533162009-02-24 10:01:51 +00006386 goto select_end;
6387 }
dan280c8942018-06-05 20:04:28 +00006388 updateAccumulator(pParse, regAcc, &sAggInfo);
6389 if( regAcc ) sqlite3VdbeAddOp2(v, OP_Integer, 1, regAcc);
drhddba0c22014-03-18 20:33:42 +00006390 if( sqlite3WhereIsOrdered(pWInfo)>0 ){
drh076e85f2015-09-03 13:46:12 +00006391 sqlite3VdbeGoto(v, sqlite3WhereBreakLabel(pWInfo));
danielk1977a5533162009-02-24 10:01:51 +00006392 VdbeComment((v, "%s() by index",
drh47d9f832017-10-26 20:04:28 +00006393 (minMaxFlag==WHERE_ORDERBY_MIN?"min":"max")));
danielk1977a5533162009-02-24 10:01:51 +00006394 }
6395 sqlite3WhereEnd(pWInfo);
6396 finalizeAggFunctions(pParse, &sAggInfo);
danielk1977a9d1ccb2008-01-05 17:39:29 +00006397 }
6398
drh079a3072014-03-19 14:10:55 +00006399 sSort.pOrderBy = 0;
drh33cd4902009-05-30 20:49:20 +00006400 sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL);
drh2def2f72017-09-15 17:40:34 +00006401 selectInnerLoop(pParse, p, -1, 0, 0,
drha9671a22008-07-08 23:40:20 +00006402 pDest, addrEnd, addrEnd);
drh13449892005-09-07 21:22:45 +00006403 }
6404 sqlite3VdbeResolveLabel(v, addrEnd);
6405
6406 } /* endif aggregate query */
drh22827922000-06-06 17:27:05 +00006407
drhe8e4af72012-09-21 00:04:28 +00006408 if( sDistinct.eTnctType==WHERE_DISTINCT_UNORDERED ){
dan2ce22452010-11-08 19:01:16 +00006409 explainTempTable(pParse, "DISTINCT");
6410 }
6411
drhcce7d172000-05-31 15:34:51 +00006412 /* If there is an ORDER BY clause, then we need to sort the results
6413 ** and send them to the callback one by one.
6414 */
drh079a3072014-03-19 14:10:55 +00006415 if( sSort.pOrderBy ){
drh38b41492015-06-08 15:08:15 +00006416 explainTempTable(pParse,
6417 sSort.nOBSat>0 ? "RIGHT PART OF ORDER BY":"ORDER BY");
dan24e25d32018-04-14 18:46:20 +00006418 assert( p->pEList==pEList );
drh079a3072014-03-19 14:10:55 +00006419 generateSortTail(pParse, p, &sSort, pEList->nExpr, pDest);
drhcce7d172000-05-31 15:34:51 +00006420 }
drh6a535342001-10-19 16:44:56 +00006421
drhec7429a2005-10-06 16:53:14 +00006422 /* Jump here to skip this query
6423 */
6424 sqlite3VdbeResolveLabel(v, iEnd);
6425
dan5b1c07e2015-04-16 07:19:23 +00006426 /* The SELECT has been coded. If there is an error in the Parse structure,
6427 ** set the return code to 1. Otherwise 0. */
6428 rc = (pParse->nErr>0);
drh1d83f052002-02-17 00:30:36 +00006429
6430 /* Control jumps to here if an error is encountered above, or upon
6431 ** successful coding of the SELECT.
6432 */
6433select_end:
drh47d9f832017-10-26 20:04:28 +00006434 sqlite3ExprListDelete(db, pMinMaxOrderBy);
drh633e6d52008-07-28 19:34:53 +00006435 sqlite3DbFree(db, sAggInfo.aCol);
6436 sqlite3DbFree(db, sAggInfo.aFunc);
drheb9b8842014-09-21 00:27:26 +00006437#if SELECTTRACE_ENABLED
drhf20609d2018-04-23 17:43:35 +00006438 SELECTTRACE(0x1,pParse,p,("end processing\n"));
drhe2ca99c2018-05-02 00:33:43 +00006439 if( (sqlite3SelectTrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){
drhf20609d2018-04-23 17:43:35 +00006440 sqlite3TreeViewSelect(0, p, 0);
6441 }
drheb9b8842014-09-21 00:27:26 +00006442#endif
drhe2ca99c2018-05-02 00:33:43 +00006443 ExplainQueryPlanPop(pParse);
drh1d83f052002-02-17 00:30:36 +00006444 return rc;
drhcce7d172000-05-31 15:34:51 +00006445}