sourcemod-central: extensions/sqlite/sqlite-source/select.c@b7aa2b626807 (annotated)

ds@1952	1	/*
ds@1952	2	** 2001 September 15
ds@1952	3	**
ds@1952	4	** The author disclaims copyright to this source code. In place of
ds@1952	5	** a legal notice, here is a blessing:
ds@1952	6	**
ds@1952	7	** May you do good and not evil.
ds@1952	8	** May you find forgiveness for yourself and forgive others.
ds@1952	9	** May you share freely, never taking more than you give.
ds@1952	10	**
ds@1952	11	*************************************************************************
ds@1952	12	** This file contains C code routines that are called by the parser
ds@1952	13	** to handle SELECT statements in SQLite.
ds@1952	14	**
ds@1952	15	** $Id$
ds@1952	16	*/
ds@1952	17	#include "sqliteInt.h"
ds@1952	18
ds@1952	19
ds@1952	20	/*
ds@1952	21	** Delete all the content of a Select structure but do not deallocate
ds@1952	22	** the select structure itself.
ds@1952	23	*/
ds@1952	24	static void clearSelect(Select *p){
ds@1952	25	sqlite3ExprListDelete(p->pEList);
ds@1952	26	sqlite3SrcListDelete(p->pSrc);
ds@1952	27	sqlite3ExprDelete(p->pWhere);
ds@1952	28	sqlite3ExprListDelete(p->pGroupBy);
ds@1952	29	sqlite3ExprDelete(p->pHaving);
ds@1952	30	sqlite3ExprListDelete(p->pOrderBy);
ds@1952	31	sqlite3SelectDelete(p->pPrior);
ds@1952	32	sqlite3ExprDelete(p->pLimit);
ds@1952	33	sqlite3ExprDelete(p->pOffset);
ds@1952	34	}
ds@1952	35
ds@1952	36
ds@1952	37	/*
ds@1952	38	** Allocate a new Select structure and return a pointer to that
ds@1952	39	** structure.
ds@1952	40	*/
ds@1952	41	Select *sqlite3SelectNew(
ds@1952	42	Parse pParse, / Parsing context */
ds@1952	43	ExprList pEList, / which columns to include in the result */
ds@1952	44	SrcList pSrc, / the FROM clause -- which tables to scan */
ds@1952	45	Expr pWhere, / the WHERE clause */
ds@1952	46	ExprList pGroupBy, / the GROUP BY clause */
ds@1952	47	Expr pHaving, / the HAVING clause */
ds@1952	48	ExprList pOrderBy, / the ORDER BY clause */
ds@1952	49	int isDistinct, /* true if the DISTINCT keyword is present */
ds@1952	50	Expr pLimit, / LIMIT value. NULL means not used */
ds@1952	51	Expr pOffset / OFFSET value. NULL means no offset */
ds@1952	52	){
ds@1952	53	Select *pNew;
ds@1952	54	Select standin;
ds@1952	55	sqlite3 *db = pParse->db;
ds@1952	56	pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
ds@1952	57	assert( !pOffset \|\| pLimit ); /* Can't have OFFSET without LIMIT. */
ds@1952	58	if( pNew==0 ){
ds@1952	59	pNew = &standin;
ds@1952	60	memset(pNew, 0, sizeof(*pNew));
ds@1952	61	}
ds@1952	62	if( pEList==0 ){
ds@1952	63	pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db,TK_ALL,0,0,0), 0);
ds@1952	64	}
ds@1952	65	pNew->pEList = pEList;
ds@1952	66	pNew->pSrc = pSrc;
ds@1952	67	pNew->pWhere = pWhere;
ds@1952	68	pNew->pGroupBy = pGroupBy;
ds@1952	69	pNew->pHaving = pHaving;
ds@1952	70	pNew->pOrderBy = pOrderBy;
ds@1952	71	pNew->isDistinct = isDistinct;
ds@1952	72	pNew->op = TK_SELECT;
ds@1952	73	assert( pOffset==0 \|\| pLimit!=0 );
ds@1952	74	pNew->pLimit = pLimit;
ds@1952	75	pNew->pOffset = pOffset;
ds@1952	76	pNew->iLimit = -1;
ds@1952	77	pNew->iOffset = -1;
ds@1952	78	pNew->addrOpenEphm[0] = -1;
ds@1952	79	pNew->addrOpenEphm[1] = -1;
ds@1952	80	pNew->addrOpenEphm[2] = -1;
ds@1952	81	if( pNew==&standin) {
ds@1952	82	clearSelect(pNew);
ds@1952	83	pNew = 0;
ds@1952	84	}
ds@1952	85	return pNew;
ds@1952	86	}
ds@1952	87
ds@1952	88	/*
ds@1952	89	** Delete the given Select structure and all of its substructures.
ds@1952	90	*/
ds@1952	91	void sqlite3SelectDelete(Select *p){
ds@1952	92	if( p ){
ds@1952	93	clearSelect(p);
ds@1952	94	sqlite3_free(p);
ds@1952	95	}
ds@1952	96	}
ds@1952	97
ds@1952	98	/*
ds@1952	99	** Given 1 to 3 identifiers preceeding the JOIN keyword, determine the
ds@1952	100	** type of join. Return an integer constant that expresses that type
ds@1952	101	** in terms of the following bit values:
ds@1952	102	**
ds@1952	103	** JT_INNER
ds@1952	104	** JT_CROSS
ds@1952	105	** JT_OUTER
ds@1952	106	** JT_NATURAL
ds@1952	107	** JT_LEFT
ds@1952	108	** JT_RIGHT
ds@1952	109	**
ds@1952	110	** A full outer join is the combination of JT_LEFT and JT_RIGHT.
ds@1952	111	**
ds@1952	112	** If an illegal or unsupported join type is seen, then still return
ds@1952	113	** a join type, but put an error in the pParse structure.
ds@1952	114	*/
ds@1952	115	int sqlite3JoinType(Parse pParse, Token pA, Token pB, Token pC){
ds@1952	116	int jointype = 0;
ds@1952	117	Token *apAll[3];
ds@1952	118	Token *p;
ds@1952	119	static const struct {
ds@1952	120	const char zKeyword[8];
ds@1952	121	u8 nChar;
ds@1952	122	u8 code;
ds@1952	123	} keywords[] = {
ds@1952	124	{ "natural", 7, JT_NATURAL },
ds@1952	125	{ "left", 4, JT_LEFT\|JT_OUTER },
ds@1952	126	{ "right", 5, JT_RIGHT\|JT_OUTER },
ds@1952	127	{ "full", 4, JT_LEFT\|JT_RIGHT\|JT_OUTER },
ds@1952	128	{ "outer", 5, JT_OUTER },
ds@1952	129	{ "inner", 5, JT_INNER },
ds@1952	130	{ "cross", 5, JT_INNER\|JT_CROSS },
ds@1952	131	};
ds@1952	132	int i, j;
ds@1952	133	apAll[0] = pA;
ds@1952	134	apAll[1] = pB;
ds@1952	135	apAll[2] = pC;
ds@1952	136	for(i=0; i<3 && apAll[i]; i++){
ds@1952	137	p = apAll[i];
ds@1952	138	for(j=0; j<sizeof(keywords)/sizeof(keywords[0]); j++){
ds@1952	139	if( p->n==keywords[j].nChar
ds@1952	140	&& sqlite3StrNICmp((char*)p->z, keywords[j].zKeyword, p->n)==0 ){
ds@1952	141	jointype \|= keywords[j].code;
ds@1952	142	break;
ds@1952	143	}
ds@1952	144	}
ds@1952	145	if( j>=sizeof(keywords)/sizeof(keywords[0]) ){
ds@1952	146	jointype \|= JT_ERROR;
ds@1952	147	break;
ds@1952	148	}
ds@1952	149	}
ds@1952	150	if(
ds@1952	151	(jointype & (JT_INNER\|JT_OUTER))==(JT_INNER\|JT_OUTER) \|\|
ds@1952	152	(jointype & JT_ERROR)!=0
ds@1952	153	){
ds@1952	154	const char *zSp1 = " ";
ds@1952	155	const char *zSp2 = " ";
ds@1952	156	if( pB==0 ){ zSp1++; }
ds@1952	157	if( pC==0 ){ zSp2++; }
ds@1952	158	sqlite3ErrorMsg(pParse, "unknown or unsupported join type: "
ds@1952	159	"%T%s%T%s%T", pA, zSp1, pB, zSp2, pC);
ds@1952	160	jointype = JT_INNER;
ds@1952	161	}else if( jointype & JT_RIGHT ){
ds@1952	162	sqlite3ErrorMsg(pParse,
ds@1952	163	"RIGHT and FULL OUTER JOINs are not currently supported");
ds@1952	164	jointype = JT_INNER;
ds@1952	165	}
ds@1952	166	return jointype;
ds@1952	167	}
ds@1952	168
ds@1952	169	/*
ds@1952	170	** Return the index of a column in a table. Return -1 if the column
ds@1952	171	** is not contained in the table.
ds@1952	172	*/
ds@1952	173	static int columnIndex(Table pTab, const char zCol){
ds@1952	174	int i;
ds@1952	175	for(i=0; i<pTab->nCol; i++){
ds@1952	176	if( sqlite3StrICmp(pTab->aCol[i].zName, zCol)==0 ) return i;
ds@1952	177	}
ds@1952	178	return -1;
ds@1952	179	}
ds@1952	180
ds@1952	181	/*
ds@1952	182	** Set the value of a token to a '\000'-terminated string.
ds@1952	183	*/
ds@1952	184	static void setToken(Token p, const char z){
ds@1952	185	p->z = (u8*)z;
ds@1952	186	p->n = z ? strlen(z) : 0;
ds@1952	187	p->dyn = 0;
ds@1952	188	}
ds@1952	189
ds@1952	190	/*
ds@1952	191	** Set the token to the double-quoted and escaped version of the string pointed
ds@1952	192	** to by z. For example;
ds@1952	193	**
ds@1952	194	** {a"bc} -> {"a""bc"}
ds@1952	195	*/
ds@1952	196	static void setQuotedToken(Parse pParse, Token p, const char *z){
ds@1952	197	p->z = (u8 *)sqlite3MPrintf(0, "\"%w\"", z);
ds@1952	198	p->dyn = 1;
ds@1952	199	if( p->z ){
ds@1952	200	p->n = strlen((char *)p->z);
ds@1952	201	}else{
ds@1952	202	pParse->db->mallocFailed = 1;
ds@1952	203	}
ds@1952	204	}
ds@1952	205
ds@1952	206	/*
ds@1952	207	** Create an expression node for an identifier with the name of zName
ds@1952	208	*/
ds@1952	209	Expr sqlite3CreateIdExpr(Parse pParse, const char *zName){
ds@1952	210	Token dummy;
ds@1952	211	setToken(&dummy, zName);
ds@1952	212	return sqlite3PExpr(pParse, TK_ID, 0, 0, &dummy);
ds@1952	213	}
ds@1952	214
ds@1952	215
ds@1952	216	/*
ds@1952	217	** Add a term to the WHERE expression in *ppExpr that requires the
ds@1952	218	** zCol column to be equal in the two tables pTab1 and pTab2.
ds@1952	219	*/
ds@1952	220	static void addWhereTerm(
ds@1952	221	Parse pParse, / Parsing context */
ds@1952	222	const char zCol, / Name of the column */
ds@1952	223	const Table pTab1, / First table */
ds@1952	224	const char zAlias1, / Alias for first table. May be NULL */
ds@1952	225	const Table pTab2, / Second table */
ds@1952	226	const char zAlias2, / Alias for second table. May be NULL */
ds@1952	227	int iRightJoinTable, /* VDBE cursor for the right table */
ds@1952	228	Expr *ppExpr / Add the equality term to this expression */
ds@1952	229	){
ds@1952	230	Expr pE1a, pE1b, *pE1c;
ds@1952	231	Expr pE2a, pE2b, *pE2c;
ds@1952	232	Expr *pE;
ds@1952	233
ds@1952	234	pE1a = sqlite3CreateIdExpr(pParse, zCol);
ds@1952	235	pE2a = sqlite3CreateIdExpr(pParse, zCol);
ds@1952	236	if( zAlias1==0 ){
ds@1952	237	zAlias1 = pTab1->zName;
ds@1952	238	}
ds@1952	239	pE1b = sqlite3CreateIdExpr(pParse, zAlias1);
ds@1952	240	if( zAlias2==0 ){
ds@1952	241	zAlias2 = pTab2->zName;
ds@1952	242	}
ds@1952	243	pE2b = sqlite3CreateIdExpr(pParse, zAlias2);
ds@1952	244	pE1c = sqlite3PExpr(pParse, TK_DOT, pE1b, pE1a, 0);
ds@1952	245	pE2c = sqlite3PExpr(pParse, TK_DOT, pE2b, pE2a, 0);
ds@1952	246	pE = sqlite3PExpr(pParse, TK_EQ, pE1c, pE2c, 0);
ds@1952	247	if( pE ){
ds@1952	248	ExprSetProperty(pE, EP_FromJoin);
ds@1952	249	pE->iRightJoinTable = iRightJoinTable;
ds@1952	250	}
ds@1952	251	pE = sqlite3ExprAnd(pParse->db,*ppExpr, pE);
ds@1952	252	if( pE ){
ds@1952	253	*ppExpr = pE;
ds@1952	254	}
ds@1952	255	}
ds@1952	256
ds@1952	257	/*
ds@1952	258	** Set the EP_FromJoin property on all terms of the given expression.
ds@1952	259	** And set the Expr.iRightJoinTable to iTable for every term in the
ds@1952	260	** expression.
ds@1952	261	**
ds@1952	262	** The EP_FromJoin property is used on terms of an expression to tell
ds@1952	263	** the LEFT OUTER JOIN processing logic that this term is part of the
ds@1952	264	** join restriction specified in the ON or USING clause and not a part
ds@1952	265	** of the more general WHERE clause. These terms are moved over to the
ds@1952	266	** WHERE clause during join processing but we need to remember that they
ds@1952	267	** originated in the ON or USING clause.
ds@1952	268	**
ds@1952	269	** The Expr.iRightJoinTable tells the WHERE clause processing that the
ds@1952	270	** expression depends on table iRightJoinTable even if that table is not
ds@1952	271	** explicitly mentioned in the expression. That information is needed
ds@1952	272	** for cases like this:
ds@1952	273	**
ds@1952	274	** SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.b AND t1.x=5
ds@1952	275	**
ds@1952	276	** The where clause needs to defer the handling of the t1.x=5
ds@1952	277	** term until after the t2 loop of the join. In that way, a
ds@1952	278	** NULL t2 row will be inserted whenever t1.x!=5. If we do not
ds@1952	279	** defer the handling of t1.x=5, it will be processed immediately
ds@1952	280	** after the t1 loop and rows with t1.x!=5 will never appear in
ds@1952	281	** the output, which is incorrect.
ds@1952	282	*/
ds@1952	283	static void setJoinExpr(Expr *p, int iTable){
ds@1952	284	while( p ){
ds@1952	285	ExprSetProperty(p, EP_FromJoin);
ds@1952	286	p->iRightJoinTable = iTable;
ds@1952	287	setJoinExpr(p->pLeft, iTable);
ds@1952	288	p = p->pRight;
ds@1952	289	}
ds@1952	290	}
ds@1952	291
ds@1952	292	/*
ds@1952	293	** This routine processes the join information for a SELECT statement.
ds@1952	294	** ON and USING clauses are converted into extra terms of the WHERE clause.
ds@1952	295	** NATURAL joins also create extra WHERE clause terms.
ds@1952	296	**
ds@1952	297	** The terms of a FROM clause are contained in the Select.pSrc structure.
ds@1952	298	** The left most table is the first entry in Select.pSrc. The right-most
ds@1952	299	** table is the last entry. The join operator is held in the entry to
ds@1952	300	** the left. Thus entry 0 contains the join operator for the join between
ds@1952	301	** entries 0 and 1. Any ON or USING clauses associated with the join are
ds@1952	302	** also attached to the left entry.
ds@1952	303	**
ds@1952	304	** This routine returns the number of errors encountered.
ds@1952	305	*/
ds@1952	306	static int sqliteProcessJoin(Parse pParse, Select p){
ds@1952	307	SrcList pSrc; / All tables in the FROM clause */
ds@1952	308	int i, j; /* Loop counters */
ds@1952	309	struct SrcList_item pLeft; / Left table being joined */
ds@1952	310	struct SrcList_item pRight; / Right table being joined */
ds@1952	311
ds@1952	312	pSrc = p->pSrc;
ds@1952	313	pLeft = &pSrc->a[0];
ds@1952	314	pRight = &pLeft[1];
ds@1952	315	for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){
ds@1952	316	Table *pLeftTab = pLeft->pTab;
ds@1952	317	Table *pRightTab = pRight->pTab;
ds@1952	318
ds@1952	319	if( pLeftTab==0 \|\| pRightTab==0 ) continue;
ds@1952	320
ds@1952	321	/* When the NATURAL keyword is present, add WHERE clause terms for
ds@1952	322	** every column that the two tables have in common.
ds@1952	323	*/
ds@1952	324	if( pRight->jointype & JT_NATURAL ){
ds@1952	325	if( pRight->pOn \|\| pRight->pUsing ){
ds@1952	326	sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
ds@1952	327	"an ON or USING clause", 0);
ds@1952	328	return 1;
ds@1952	329	}
ds@1952	330	for(j=0; j<pLeftTab->nCol; j++){
ds@1952	331	char *zName = pLeftTab->aCol[j].zName;
ds@1952	332	if( columnIndex(pRightTab, zName)>=0 ){
ds@1952	333	addWhereTerm(pParse, zName, pLeftTab, pLeft->zAlias,
ds@1952	334	pRightTab, pRight->zAlias,
ds@1952	335	pRight->iCursor, &p->pWhere);
ds@1952	336
ds@1952	337	}
ds@1952	338	}
ds@1952	339	}
ds@1952	340
ds@1952	341	/* Disallow both ON and USING clauses in the same join
ds@1952	342	*/
ds@1952	343	if( pRight->pOn && pRight->pUsing ){
ds@1952	344	sqlite3ErrorMsg(pParse, "cannot have both ON and USING "
ds@1952	345	"clauses in the same join");
ds@1952	346	return 1;
ds@1952	347	}
ds@1952	348
ds@1952	349	/* Add the ON clause to the end of the WHERE clause, connected by
ds@1952	350	** an AND operator.
ds@1952	351	*/
ds@1952	352	if( pRight->pOn ){
ds@1952	353	setJoinExpr(pRight->pOn, pRight->iCursor);
ds@1952	354	p->pWhere = sqlite3ExprAnd(pParse->db, p->pWhere, pRight->pOn);
ds@1952	355	pRight->pOn = 0;
ds@1952	356	}
ds@1952	357
ds@1952	358	/* Create extra terms on the WHERE clause for each column named
ds@1952	359	** in the USING clause. Example: If the two tables to be joined are
ds@1952	360	** A and B and the USING clause names X, Y, and Z, then add this
ds@1952	361	** to the WHERE clause: A.X=B.X AND A.Y=B.Y AND A.Z=B.Z
ds@1952	362	** Report an error if any column mentioned in the USING clause is
ds@1952	363	** not contained in both tables to be joined.
ds@1952	364	*/
ds@1952	365	if( pRight->pUsing ){
ds@1952	366	IdList *pList = pRight->pUsing;
ds@1952	367	for(j=0; j<pList->nId; j++){
ds@1952	368	char *zName = pList->a[j].zName;
ds@1952	369	if( columnIndex(pLeftTab, zName)<0 \|\| columnIndex(pRightTab, zName)<0 ){
ds@1952	370	sqlite3ErrorMsg(pParse, "cannot join using column %s - column "
ds@1952	371	"not present in both tables", zName);
ds@1952	372	return 1;
ds@1952	373	}
ds@1952	374	addWhereTerm(pParse, zName, pLeftTab, pLeft->zAlias,
ds@1952	375	pRightTab, pRight->zAlias,
ds@1952	376	pRight->iCursor, &p->pWhere);
ds@1952	377	}
ds@1952	378	}
ds@1952	379	}
ds@1952	380	return 0;
ds@1952	381	}
ds@1952	382
ds@1952	383	/*
ds@1952	384	** Insert code into "v" that will push the record on the top of the
ds@1952	385	** stack into the sorter.
ds@1952	386	*/
ds@1952	387	static void pushOntoSorter(
ds@1952	388	Parse pParse, / Parser context */
ds@1952	389	ExprList pOrderBy, / The ORDER BY clause */
ds@1952	390	Select pSelect / The whole SELECT statement */
ds@1952	391	){
ds@1952	392	Vdbe *v = pParse->pVdbe;
ds@1952	393	sqlite3ExprCodeExprList(pParse, pOrderBy);
ds@1952	394	sqlite3VdbeAddOp(v, OP_Sequence, pOrderBy->iECursor, 0);
ds@1952	395	sqlite3VdbeAddOp(v, OP_Pull, pOrderBy->nExpr + 1, 0);
ds@1952	396	sqlite3VdbeAddOp(v, OP_MakeRecord, pOrderBy->nExpr + 2, 0);
ds@1952	397	sqlite3VdbeAddOp(v, OP_IdxInsert, pOrderBy->iECursor, 0);
ds@1952	398	if( pSelect->iLimit>=0 ){
ds@1952	399	int addr1, addr2;
ds@1952	400	addr1 = sqlite3VdbeAddOp(v, OP_IfMemZero, pSelect->iLimit+1, 0);
ds@1952	401	sqlite3VdbeAddOp(v, OP_MemIncr, -1, pSelect->iLimit+1);
ds@1952	402	addr2 = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
ds@1952	403	sqlite3VdbeJumpHere(v, addr1);
ds@1952	404	sqlite3VdbeAddOp(v, OP_Last, pOrderBy->iECursor, 0);
ds@1952	405	sqlite3VdbeAddOp(v, OP_Delete, pOrderBy->iECursor, 0);
ds@1952	406	sqlite3VdbeJumpHere(v, addr2);
ds@1952	407	pSelect->iLimit = -1;
ds@1952	408	}
ds@1952	409	}
ds@1952	410
ds@1952	411	/*
ds@1952	412	** Add code to implement the OFFSET
ds@1952	413	*/
ds@1952	414	static void codeOffset(
ds@1952	415	Vdbe v, / Generate code into this VM */
ds@1952	416	Select p, / The SELECT statement being coded */
ds@1952	417	int iContinue, /* Jump here to skip the current record */
ds@1952	418	int nPop /* Number of times to pop stack when jumping */
ds@1952	419	){
ds@1952	420	if( p->iOffset>=0 && iContinue!=0 ){
ds@1952	421	int addr;
ds@1952	422	sqlite3VdbeAddOp(v, OP_MemIncr, -1, p->iOffset);
ds@1952	423	addr = sqlite3VdbeAddOp(v, OP_IfMemNeg, p->iOffset, 0);
ds@1952	424	if( nPop>0 ){
ds@1952	425	sqlite3VdbeAddOp(v, OP_Pop, nPop, 0);
ds@1952	426	}
ds@1952	427	sqlite3VdbeAddOp(v, OP_Goto, 0, iContinue);
ds@1952	428	VdbeComment((v, "# skip OFFSET records"));
ds@1952	429	sqlite3VdbeJumpHere(v, addr);
ds@1952	430	}
ds@1952	431	}
ds@1952	432
ds@1952	433	/*
ds@1952	434	** Add code that will check to make sure the top N elements of the
ds@1952	435	** stack are distinct. iTab is a sorting index that holds previously
ds@1952	436	** seen combinations of the N values. A new entry is made in iTab
ds@1952	437	** if the current N values are new.
ds@1952	438	**
ds@1952	439	** A jump to addrRepeat is made and the N+1 values are popped from the
ds@1952	440	** stack if the top N elements are not distinct.
ds@1952	441	*/
ds@1952	442	static void codeDistinct(
ds@1952	443	Vdbe v, / Generate code into this VM */
ds@1952	444	int iTab, /* A sorting index used to test for distinctness */
ds@1952	445	int addrRepeat, /* Jump to here if not distinct */
ds@1952	446	int N /* The top N elements of the stack must be distinct */
ds@1952	447	){
ds@1952	448	sqlite3VdbeAddOp(v, OP_MakeRecord, -N, 0);
ds@1952	449	sqlite3VdbeAddOp(v, OP_Distinct, iTab, sqlite3VdbeCurrentAddr(v)+3);
ds@1952	450	sqlite3VdbeAddOp(v, OP_Pop, N+1, 0);
ds@1952	451	sqlite3VdbeAddOp(v, OP_Goto, 0, addrRepeat);
ds@1952	452	VdbeComment((v, "# skip indistinct records"));
ds@1952	453	sqlite3VdbeAddOp(v, OP_IdxInsert, iTab, 0);
ds@1952	454	}
ds@1952	455
ds@1952	456	/*
ds@1952	457	** Generate an error message when a SELECT is used within a subexpression
ds@1952	458	** (example: "a IN (SELECT * FROM table)") but it has more than 1 result
ds@1952	459	** column. We do this in a subroutine because the error occurs in multiple
ds@1952	460	** places.
ds@1952	461	*/
ds@1952	462	static int checkForMultiColumnSelectError(Parse *pParse, int eDest, int nExpr){
ds@1952	463	if( nExpr>1 && (eDest==SRT_Mem \|\| eDest==SRT_Set) ){
ds@1952	464	sqlite3ErrorMsg(pParse, "only a single result allowed for "
ds@1952	465	"a SELECT that is part of an expression");
ds@1952	466	return 1;
ds@1952	467	}else{
ds@1952	468	return 0;
ds@1952	469	}
ds@1952	470	}
ds@1952	471
ds@1952	472	/*
ds@1952	473	** This routine generates the code for the inside of the inner loop
ds@1952	474	** of a SELECT.
ds@1952	475	**
ds@1952	476	** If srcTab and nColumn are both zero, then the pEList expressions
ds@1952	477	** are evaluated in order to get the data for this row. If nColumn>0
ds@1952	478	** then data is pulled from srcTab and pEList is used only to get the
ds@1952	479	** datatypes for each column.
ds@1952	480	*/
ds@1952	481	static int selectInnerLoop(
ds@1952	482	Parse pParse, / The parser context */
ds@1952	483	Select p, / The complete select statement being coded */
ds@1952	484	ExprList pEList, / List of values being extracted */
ds@1952	485	int srcTab, /* Pull data from this table */
ds@1952	486	int nColumn, /* Number of columns in the source table */
ds@1952	487	ExprList pOrderBy, / If not NULL, sort results using this key */
ds@1952	488	int distinct, /* If >=0, make sure results are distinct */
ds@1952	489	int eDest, /* How to dispose of the results */
ds@1952	490	int iParm, /* An argument to the disposal method */
ds@1952	491	int iContinue, /* Jump here to continue with next row */
ds@1952	492	int iBreak, /* Jump here to break out of the inner loop */
ds@1952	493	char aff / affinity string if eDest is SRT_Union */
ds@1952	494	){
ds@1952	495	Vdbe *v = pParse->pVdbe;
ds@1952	496	int i;
ds@1952	497	int hasDistinct; /* True if the DISTINCT keyword is present */
ds@1952	498
ds@1952	499	if( v==0 ) return 0;
ds@1952	500	assert( pEList!=0 );
ds@1952	501
ds@1952	502	/* If there was a LIMIT clause on the SELECT statement, then do the check
ds@1952	503	** to see if this row should be output.
ds@1952	504	*/
ds@1952	505	hasDistinct = distinct>=0 && pEList->nExpr>0;
ds@1952	506	if( pOrderBy==0 && !hasDistinct ){
ds@1952	507	codeOffset(v, p, iContinue, 0);
ds@1952	508	}
ds@1952	509
ds@1952	510	/* Pull the requested columns.
ds@1952	511	*/
ds@1952	512	if( nColumn>0 ){
ds@1952	513	for(i=0; i<nColumn; i++){
ds@1952	514	sqlite3VdbeAddOp(v, OP_Column, srcTab, i);
ds@1952	515	}
ds@1952	516	}else{
ds@1952	517	nColumn = pEList->nExpr;
ds@1952	518	sqlite3ExprCodeExprList(pParse, pEList);
ds@1952	519	}
ds@1952	520
ds@1952	521	/* If the DISTINCT keyword was present on the SELECT statement
ds@1952	522	** and this row has been seen before, then do not make this row
ds@1952	523	** part of the result.
ds@1952	524	*/
ds@1952	525	if( hasDistinct ){
ds@1952	526	assert( pEList!=0 );
ds@1952	527	assert( pEList->nExpr==nColumn );
ds@1952	528	codeDistinct(v, distinct, iContinue, nColumn);
ds@1952	529	if( pOrderBy==0 ){
ds@1952	530	codeOffset(v, p, iContinue, nColumn);
ds@1952	531	}
ds@1952	532	}
ds@1952	533
ds@1952	534	if( checkForMultiColumnSelectError(pParse, eDest, pEList->nExpr) ){
ds@1952	535	return 0;
ds@1952	536	}
ds@1952	537
ds@1952	538	switch( eDest ){
ds@1952	539	/* In this mode, write each query result to the key of the temporary
ds@1952	540	** table iParm.
ds@1952	541	*/
ds@1952	542	#ifndef SQLITE_OMIT_COMPOUND_SELECT
ds@1952	543	case SRT_Union: {
ds@1952	544	sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
ds@1952	545	if( aff ){
ds@1952	546	sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
ds@1952	547	}
ds@1952	548	sqlite3VdbeAddOp(v, OP_IdxInsert, iParm, 0);
ds@1952	549	break;
ds@1952	550	}
ds@1952	551
ds@1952	552	/* Construct a record from the query result, but instead of
ds@1952	553	** saving that record, use it as a key to delete elements from
ds@1952	554	** the temporary table iParm.
ds@1952	555	*/
ds@1952	556	case SRT_Except: {
ds@1952	557	int addr;
ds@1952	558	addr = sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
ds@1952	559	sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
ds@1952	560	sqlite3VdbeAddOp(v, OP_NotFound, iParm, addr+3);
ds@1952	561	sqlite3VdbeAddOp(v, OP_Delete, iParm, 0);
ds@1952	562	break;
ds@1952	563	}
ds@1952	564	#endif
ds@1952	565
ds@1952	566	/* Store the result as data using a unique key.
ds@1952	567	*/
ds@1952	568	case SRT_Table:
ds@1952	569	case SRT_EphemTab: {
ds@1952	570	sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
ds@1952	571	if( pOrderBy ){
ds@1952	572	pushOntoSorter(pParse, pOrderBy, p);
ds@1952	573	}else{
ds@1952	574	sqlite3VdbeAddOp(v, OP_NewRowid, iParm, 0);
ds@1952	575	sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
ds@1952	576	sqlite3VdbeAddOp(v, OP_Insert, iParm, OPFLAG_APPEND);
ds@1952	577	}
ds@1952	578	break;
ds@1952	579	}
ds@1952	580
ds@1952	581	#ifndef SQLITE_OMIT_SUBQUERY
ds@1952	582	/* If we are creating a set for an "expr IN (SELECT ...)" construct,
ds@1952	583	** then there should be a single item on the stack. Write this
ds@1952	584	** item into the set table with bogus data.
ds@1952	585	*/
ds@1952	586	case SRT_Set: {
ds@1952	587	int addr1 = sqlite3VdbeCurrentAddr(v);
ds@1952	588	int addr2;
ds@1952	589
ds@1952	590	assert( nColumn==1 );
ds@1952	591	sqlite3VdbeAddOp(v, OP_NotNull, -1, addr1+3);
ds@1952	592	sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
ds@1952	593	addr2 = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
ds@1952	594	p->affinity = sqlite3CompareAffinity(pEList->a[0].pExpr,(iParm>>16)&0xff);
ds@1952	595	if( pOrderBy ){
ds@1952	596	/* At first glance you would think we could optimize out the
ds@1952	597	** ORDER BY in this case since the order of entries in the set
ds@1952	598	** does not matter. But there might be a LIMIT clause, in which
ds@1952	599	** case the order does matter */
ds@1952	600	pushOntoSorter(pParse, pOrderBy, p);
ds@1952	601	}else{
ds@1952	602	sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &p->affinity, 1);
ds@1952	603	sqlite3VdbeAddOp(v, OP_IdxInsert, (iParm&0x0000FFFF), 0);
ds@1952	604	}
ds@1952	605	sqlite3VdbeJumpHere(v, addr2);
ds@1952	606	break;
ds@1952	607	}
ds@1952	608
ds@1952	609	/* If any row exist in the result set, record that fact and abort.
ds@1952	610	*/
ds@1952	611	case SRT_Exists: {
ds@1952	612	sqlite3VdbeAddOp(v, OP_MemInt, 1, iParm);
ds@1952	613	sqlite3VdbeAddOp(v, OP_Pop, nColumn, 0);
ds@1952	614	/* The LIMIT clause will terminate the loop for us */
ds@1952	615	break;
ds@1952	616	}
ds@1952	617
ds@1952	618	/* If this is a scalar select that is part of an expression, then
ds@1952	619	** store the results in the appropriate memory cell and break out
ds@1952	620	** of the scan loop.
ds@1952	621	*/
ds@1952	622	case SRT_Mem: {
ds@1952	623	assert( nColumn==1 );
ds@1952	624	if( pOrderBy ){
ds@1952	625	pushOntoSorter(pParse, pOrderBy, p);
ds@1952	626	}else{
ds@1952	627	sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
ds@1952	628	/* The LIMIT clause will jump out of the loop for us */
ds@1952	629	}
ds@1952	630	break;
ds@1952	631	}
ds@1952	632	#endif /* #ifndef SQLITE_OMIT_SUBQUERY */
ds@1952	633
ds@1952	634	/* Send the data to the callback function or to a subroutine. In the
ds@1952	635	** case of a subroutine, the subroutine itself is responsible for
ds@1952	636	** popping the data from the stack.
ds@1952	637	*/
ds@1952	638	case SRT_Subroutine:
ds@1952	639	case SRT_Callback: {
ds@1952	640	if( pOrderBy ){
ds@1952	641	sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
ds@1952	642	pushOntoSorter(pParse, pOrderBy, p);
ds@1952	643	}else if( eDest==SRT_Subroutine ){
ds@1952	644	sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
ds@1952	645	}else{
ds@1952	646	sqlite3VdbeAddOp(v, OP_Callback, nColumn, 0);
ds@1952	647	}
ds@1952	648	break;
ds@1952	649	}
ds@1952	650
ds@1952	651	#if !defined(SQLITE_OMIT_TRIGGER)
ds@1952	652	/* Discard the results. This is used for SELECT statements inside
ds@1952	653	** the body of a TRIGGER. The purpose of such selects is to call
ds@1952	654	** user-defined functions that have side effects. We do not care
ds@1952	655	** about the actual results of the select.
ds@1952	656	*/
ds@1952	657	default: {
ds@1952	658	assert( eDest==SRT_Discard );
ds@1952	659	sqlite3VdbeAddOp(v, OP_Pop, nColumn, 0);
ds@1952	660	break;
ds@1952	661	}
ds@1952	662	#endif
ds@1952	663	}
ds@1952	664
ds@1952	665	/* Jump to the end of the loop if the LIMIT is reached.
ds@1952	666	*/
ds@1952	667	if( p->iLimit>=0 && pOrderBy==0 ){
ds@1952	668	sqlite3VdbeAddOp(v, OP_MemIncr, -1, p->iLimit);
ds@1952	669	sqlite3VdbeAddOp(v, OP_IfMemZero, p->iLimit, iBreak);
ds@1952	670	}
ds@1952	671	return 0;
ds@1952	672	}
ds@1952	673
ds@1952	674	/*
ds@1952	675	** Given an expression list, generate a KeyInfo structure that records
ds@1952	676	** the collating sequence for each expression in that expression list.
ds@1952	677	**
ds@1952	678	** If the ExprList is an ORDER BY or GROUP BY clause then the resulting
ds@1952	679	** KeyInfo structure is appropriate for initializing a virtual index to
ds@1952	680	** implement that clause. If the ExprList is the result set of a SELECT
ds@1952	681	** then the KeyInfo structure is appropriate for initializing a virtual
ds@1952	682	** index to implement a DISTINCT test.
ds@1952	683	**
ds@1952	684	** Space to hold the KeyInfo structure is obtain from malloc. The calling
ds@1952	685	** function is responsible for seeing that this structure is eventually
ds@1952	686	** freed. Add the KeyInfo structure to the P3 field of an opcode using
ds@1952	687	** P3_KEYINFO_HANDOFF is the usual way of dealing with this.
ds@1952	688	*/
ds@1952	689	static KeyInfo keyInfoFromExprList(Parse pParse, ExprList *pList){
ds@1952	690	sqlite3 *db = pParse->db;
ds@1952	691	int nExpr;
ds@1952	692	KeyInfo *pInfo;
ds@1952	693	struct ExprList_item *pItem;
ds@1952	694	int i;
ds@1952	695
ds@1952	696	nExpr = pList->nExpr;
ds@1952	697	pInfo = sqlite3DbMallocZero(db, sizeof(pInfo) + nExpr(sizeof(CollSeq*)+1) );
ds@1952	698	if( pInfo ){
ds@1952	699	pInfo->aSortOrder = (u8*)&pInfo->aColl[nExpr];
ds@1952	700	pInfo->nField = nExpr;
ds@1952	701	pInfo->enc = ENC(db);
ds@1952	702	for(i=0, pItem=pList->a; i<nExpr; i++, pItem++){
ds@1952	703	CollSeq *pColl;
ds@1952	704	pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
ds@1952	705	if( !pColl ){
ds@1952	706	pColl = db->pDfltColl;
ds@1952	707	}
ds@1952	708	pInfo->aColl[i] = pColl;
ds@1952	709	pInfo->aSortOrder[i] = pItem->sortOrder;
ds@1952	710	}
ds@1952	711	}
ds@1952	712	return pInfo;
ds@1952	713	}
ds@1952	714
ds@1952	715
ds@1952	716	/*
ds@1952	717	** If the inner loop was generated using a non-null pOrderBy argument,
ds@1952	718	** then the results were placed in a sorter. After the loop is terminated
ds@1952	719	** we need to run the sorter and output the results. The following
ds@1952	720	** routine generates the code needed to do that.
ds@1952	721	*/
ds@1952	722	static void generateSortTail(
ds@1952	723	Parse pParse, / Parsing context */
ds@1952	724	Select p, / The SELECT statement */
ds@1952	725	Vdbe v, / Generate code into this VDBE */
ds@1952	726	int nColumn, /* Number of columns of data */
ds@1952	727	int eDest, /* Write the sorted results here */
ds@1952	728	int iParm /* Optional parameter associated with eDest */
ds@1952	729	){
ds@1952	730	int brk = sqlite3VdbeMakeLabel(v);
ds@1952	731	int cont = sqlite3VdbeMakeLabel(v);
ds@1952	732	int addr;
ds@1952	733	int iTab;
ds@1952	734	int pseudoTab = 0;
ds@1952	735	ExprList *pOrderBy = p->pOrderBy;
ds@1952	736
ds@1952	737	iTab = pOrderBy->iECursor;
ds@1952	738	if( eDest==SRT_Callback \|\| eDest==SRT_Subroutine ){
ds@1952	739	pseudoTab = pParse->nTab++;
ds@1952	740	sqlite3VdbeAddOp(v, OP_OpenPseudo, pseudoTab, 0);
ds@1952	741	sqlite3VdbeAddOp(v, OP_SetNumColumns, pseudoTab, nColumn);
ds@1952	742	}
ds@1952	743	addr = 1 + sqlite3VdbeAddOp(v, OP_Sort, iTab, brk);
ds@1952	744	codeOffset(v, p, cont, 0);
ds@1952	745	if( eDest==SRT_Callback \|\| eDest==SRT_Subroutine ){
ds@1952	746	sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
ds@1952	747	}
ds@1952	748	sqlite3VdbeAddOp(v, OP_Column, iTab, pOrderBy->nExpr + 1);
ds@1952	749	switch( eDest ){
ds@1952	750	case SRT_Table:
ds@1952	751	case SRT_EphemTab: {
ds@1952	752	sqlite3VdbeAddOp(v, OP_NewRowid, iParm, 0);
ds@1952	753	sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
ds@1952	754	sqlite3VdbeAddOp(v, OP_Insert, iParm, OPFLAG_APPEND);
ds@1952	755	break;
ds@1952	756	}
ds@1952	757	#ifndef SQLITE_OMIT_SUBQUERY
ds@1952	758	case SRT_Set: {
ds@1952	759	assert( nColumn==1 );
ds@1952	760	sqlite3VdbeAddOp(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
ds@1952	761	sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
ds@1952	762	sqlite3VdbeAddOp(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+3);
ds@1952	763	sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &p->affinity, 1);
ds@1952	764	sqlite3VdbeAddOp(v, OP_IdxInsert, (iParm&0x0000FFFF), 0);
ds@1952	765	break;
ds@1952	766	}
ds@1952	767	case SRT_Mem: {
ds@1952	768	assert( nColumn==1 );
ds@1952	769	sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
ds@1952	770	/* The LIMIT clause will terminate the loop for us */
ds@1952	771	break;
ds@1952	772	}
ds@1952	773	#endif
ds@1952	774	case SRT_Callback:
ds@1952	775	case SRT_Subroutine: {
ds@1952	776	int i;
ds@1952	777	sqlite3VdbeAddOp(v, OP_Insert, pseudoTab, 0);
ds@1952	778	for(i=0; i<nColumn; i++){
ds@1952	779	sqlite3VdbeAddOp(v, OP_Column, pseudoTab, i);
ds@1952	780	}
ds@1952	781	if( eDest==SRT_Callback ){
ds@1952	782	sqlite3VdbeAddOp(v, OP_Callback, nColumn, 0);
ds@1952	783	}else{
ds@1952	784	sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
ds@1952	785	}
ds@1952	786	break;
ds@1952	787	}
ds@1952	788	default: {
ds@1952	789	/* Do nothing */
ds@1952	790	break;
ds@1952	791	}
ds@1952	792	}
ds@1952	793
ds@1952	794	/* Jump to the end of the loop when the LIMIT is reached
ds@1952	795	*/
ds@1952	796	if( p->iLimit>=0 ){
ds@1952	797	sqlite3VdbeAddOp(v, OP_MemIncr, -1, p->iLimit);
ds@1952	798	sqlite3VdbeAddOp(v, OP_IfMemZero, p->iLimit, brk);
ds@1952	799	}
ds@1952	800
ds@1952	801	/* The bottom of the loop
ds@1952	802	*/
ds@1952	803	sqlite3VdbeResolveLabel(v, cont);
ds@1952	804	sqlite3VdbeAddOp(v, OP_Next, iTab, addr);
ds@1952	805	sqlite3VdbeResolveLabel(v, brk);
ds@1952	806	if( eDest==SRT_Callback \|\| eDest==SRT_Subroutine ){
ds@1952	807	sqlite3VdbeAddOp(v, OP_Close, pseudoTab, 0);
ds@1952	808	}
ds@1952	809
ds@1952	810	}
ds@1952	811
ds@1952	812	/*
ds@1952	813	** Return a pointer to a string containing the 'declaration type' of the
ds@1952	814	** expression pExpr. The string may be treated as static by the caller.
ds@1952	815	**
ds@1952	816	** The declaration type is the exact datatype definition extracted from the
ds@1952	817	** original CREATE TABLE statement if the expression is a column. The
ds@1952	818	** declaration type for a ROWID field is INTEGER. Exactly when an expression
ds@1952	819	** is considered a column can be complex in the presence of subqueries. The
ds@1952	820	** result-set expression in all of the following SELECT statements is
ds@1952	821	** considered a column by this function.
ds@1952	822	**
ds@1952	823	** SELECT col FROM tbl;
ds@1952	824	** SELECT (SELECT col FROM tbl;
ds@1952	825	** SELECT (SELECT col FROM tbl);
ds@1952	826	** SELECT abc FROM (SELECT col AS abc FROM tbl);
ds@1952	827	**
ds@1952	828	** The declaration type for any expression other than a column is NULL.
ds@1952	829	*/
ds@1952	830	static const char *columnType(
ds@1952	831	NameContext *pNC,
ds@1952	832	Expr *pExpr,
ds@1952	833	const char **pzOriginDb,
ds@1952	834	const char **pzOriginTab,
ds@1952	835	const char **pzOriginCol
ds@1952	836	){
ds@1952	837	char const *zType = 0;
ds@1952	838	char const *zOriginDb = 0;
ds@1952	839	char const *zOriginTab = 0;
ds@1952	840	char const *zOriginCol = 0;
ds@1952	841	int j;
ds@1952	842	if( pExpr==0 \|\| pNC->pSrcList==0 ) return 0;
ds@1952	843
ds@1952	844	switch( pExpr->op ){
ds@1952	845	case TK_AGG_COLUMN:
ds@1952	846	case TK_COLUMN: {
ds@1952	847	/* The expression is a column. Locate the table the column is being
ds@1952	848	** extracted from in NameContext.pSrcList. This table may be real
ds@1952	849	** database table or a subquery.
ds@1952	850	*/
ds@1952	851	Table pTab = 0; / Table structure column is extracted from */
ds@1952	852	Select pS = 0; / Select the column is extracted from */
ds@1952	853	int iCol = pExpr->iColumn; /* Index of column in pTab */
ds@1952	854	while( pNC && !pTab ){
ds@1952	855	SrcList *pTabList = pNC->pSrcList;
ds@1952	856	for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
ds@1952	857	if( j<pTabList->nSrc ){
ds@1952	858	pTab = pTabList->a[j].pTab;
ds@1952	859	pS = pTabList->a[j].pSelect;
ds@1952	860	}else{
ds@1952	861	pNC = pNC->pNext;
ds@1952	862	}
ds@1952	863	}
ds@1952	864
ds@1952	865	if( pTab==0 ){
ds@1952	866	/* FIX ME:
ds@1952	867	** This can occurs if you have something like "SELECT new.x;" inside
ds@1952	868	** a trigger. In other words, if you reference the special "new"
ds@1952	869	** table in the result set of a select. We do not have a good way
ds@1952	870	** to find the actual table type, so call it "TEXT". This is really
ds@1952	871	** something of a bug, but I do not know how to fix it.
ds@1952	872	**
ds@1952	873	** This code does not produce the correct answer - it just prevents
ds@1952	874	** a segfault. See ticket #1229.
ds@1952	875	*/
ds@1952	876	zType = "TEXT";
ds@1952	877	break;
ds@1952	878	}
ds@1952	879
ds@1952	880	assert( pTab );
ds@1952	881	if( pS ){
ds@1952	882	/* The "table" is actually a sub-select or a view in the FROM clause
ds@1952	883	** of the SELECT statement. Return the declaration type and origin
ds@1952	884	** data for the result-set column of the sub-select.
ds@1952	885	*/
ds@1952	886	if( iCol>=0 && iCol<pS->pEList->nExpr ){
ds@1952	887	/* If iCol is less than zero, then the expression requests the
ds@1952	888	** rowid of the sub-select or view. This expression is legal (see
ds@1952	889	** test case misc2.2.2) - it always evaluates to NULL.
ds@1952	890	*/
ds@1952	891	NameContext sNC;
ds@1952	892	Expr *p = pS->pEList->a[iCol].pExpr;
ds@1952	893	sNC.pSrcList = pS->pSrc;
ds@1952	894	sNC.pNext = 0;
ds@1952	895	sNC.pParse = pNC->pParse;
ds@1952	896	zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol);
ds@1952	897	}
ds@1952	898	}else if( pTab->pSchema ){
ds@1952	899	/* A real table */
ds@1952	900	assert( !pS );
ds@1952	901	if( iCol<0 ) iCol = pTab->iPKey;
ds@1952	902	assert( iCol==-1 \|\| (iCol>=0 && iCol<pTab->nCol) );
ds@1952	903	if( iCol<0 ){
ds@1952	904	zType = "INTEGER";
ds@1952	905	zOriginCol = "rowid";
ds@1952	906	}else{
ds@1952	907	zType = pTab->aCol[iCol].zType;
ds@1952	908	zOriginCol = pTab->aCol[iCol].zName;
ds@1952	909	}
ds@1952	910	zOriginTab = pTab->zName;
ds@1952	911	if( pNC->pParse ){
ds@1952	912	int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);
ds@1952	913	zOriginDb = pNC->pParse->db->aDb[iDb].zName;
ds@1952	914	}
ds@1952	915	}
ds@1952	916	break;
ds@1952	917	}
ds@1952	918	#ifndef SQLITE_OMIT_SUBQUERY
ds@1952	919	case TK_SELECT: {
ds@1952	920	/* The expression is a sub-select. Return the declaration type and
ds@1952	921	** origin info for the single column in the result set of the SELECT
ds@1952	922	** statement.
ds@1952	923	*/
ds@1952	924	NameContext sNC;
ds@1952	925	Select *pS = pExpr->pSelect;
ds@1952	926	Expr *p = pS->pEList->a[0].pExpr;
ds@1952	927	sNC.pSrcList = pS->pSrc;
ds@1952	928	sNC.pNext = pNC;
ds@1952	929	sNC.pParse = pNC->pParse;
ds@1952	930	zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol);
ds@1952	931	break;
ds@1952	932	}
ds@1952	933	#endif
ds@1952	934	}
ds@1952	935
ds@1952	936	if( pzOriginDb ){
ds@1952	937	assert( pzOriginTab && pzOriginCol );
ds@1952	938	*pzOriginDb = zOriginDb;
ds@1952	939	*pzOriginTab = zOriginTab;
ds@1952	940	*pzOriginCol = zOriginCol;
ds@1952	941	}
ds@1952	942	return zType;
ds@1952	943	}
ds@1952	944
ds@1952	945	/*
ds@1952	946	** Generate code that will tell the VDBE the declaration types of columns
ds@1952	947	** in the result set.
ds@1952	948	*/
ds@1952	949	static void generateColumnTypes(
ds@1952	950	Parse pParse, / Parser context */
ds@1952	951	SrcList pTabList, / List of tables */
ds@1952	952	ExprList pEList / Expressions defining the result set */
ds@1952	953	){
ds@1952	954	Vdbe *v = pParse->pVdbe;
ds@1952	955	int i;
ds@1952	956	NameContext sNC;
ds@1952	957	sNC.pSrcList = pTabList;
ds@1952	958	sNC.pParse = pParse;
ds@1952	959	for(i=0; i<pEList->nExpr; i++){
ds@1952	960	Expr *p = pEList->a[i].pExpr;
ds@1952	961	const char *zOrigDb = 0;
ds@1952	962	const char *zOrigTab = 0;
ds@1952	963	const char *zOrigCol = 0;
ds@1952	964	const char *zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);
ds@1952	965
ds@1952	966	/* The vdbe must make it's own copy of the column-type and other
ds@1952	967	** column specific strings, in case the schema is reset before this
ds@1952	968	** virtual machine is deleted.
ds@1952	969	*/
ds@1952	970	sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, P3_TRANSIENT);
ds@1952	971	sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, P3_TRANSIENT);
ds@1952	972	sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, P3_TRANSIENT);
ds@1952	973	sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, P3_TRANSIENT);
ds@1952	974	}
ds@1952	975	}
ds@1952	976
ds@1952	977	/*
ds@1952	978	** Generate code that will tell the VDBE the names of columns
ds@1952	979	** in the result set. This information is used to provide the
ds@1952	980	** azCol[] values in the callback.
ds@1952	981	*/
ds@1952	982	static void generateColumnNames(
ds@1952	983	Parse pParse, / Parser context */
ds@1952	984	SrcList pTabList, / List of tables */
ds@1952	985	ExprList pEList / Expressions defining the result set */
ds@1952	986	){
ds@1952	987	Vdbe *v = pParse->pVdbe;
ds@1952	988	int i, j;
ds@1952	989	sqlite3 *db = pParse->db;
ds@1952	990	int fullNames, shortNames;
ds@1952	991
ds@1952	992	#ifndef SQLITE_OMIT_EXPLAIN
ds@1952	993	/* If this is an EXPLAIN, skip this step */
ds@1952	994	if( pParse->explain ){
ds@1952	995	return;
ds@1952	996	}
ds@1952	997	#endif
ds@1952	998
ds@1952	999	assert( v!=0 );
ds@1952	1000	if( pParse->colNamesSet \|\| v==0 \|\| db->mallocFailed ) return;
ds@1952	1001	pParse->colNamesSet = 1;
ds@1952	1002	fullNames = (db->flags & SQLITE_FullColNames)!=0;
ds@1952	1003	shortNames = (db->flags & SQLITE_ShortColNames)!=0;
ds@1952	1004	sqlite3VdbeSetNumCols(v, pEList->nExpr);
ds@1952	1005	for(i=0; i<pEList->nExpr; i++){
ds@1952	1006	Expr *p;
ds@1952	1007	p = pEList->a[i].pExpr;
ds@1952	1008	if( p==0 ) continue;
ds@1952	1009	if( pEList->a[i].zName ){
ds@1952	1010	char *zName = pEList->a[i].zName;
ds@1952	1011	sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, strlen(zName));
ds@1952	1012	continue;
ds@1952	1013	}
ds@1952	1014	if( p->op==TK_COLUMN && pTabList ){
ds@1952	1015	Table *pTab;
ds@1952	1016	char *zCol;
ds@1952	1017	int iCol = p->iColumn;
ds@1952	1018	for(j=0; j<pTabList->nSrc && pTabList->a[j].iCursor!=p->iTable; j++){}
ds@1952	1019	assert( j<pTabList->nSrc );
ds@1952	1020	pTab = pTabList->a[j].pTab;
ds@1952	1021	if( iCol<0 ) iCol = pTab->iPKey;
ds@1952	1022	assert( iCol==-1 \|\| (iCol>=0 && iCol<pTab->nCol) );
ds@1952	1023	if( iCol<0 ){
ds@1952	1024	zCol = "rowid";
ds@1952	1025	}else{
ds@1952	1026	zCol = pTab->aCol[iCol].zName;
ds@1952	1027	}
ds@1952	1028	if( !shortNames && !fullNames && p->span.z && p->span.z[0] ){
ds@1952	1029	sqlite3VdbeSetColName(v, i, COLNAME_NAME, (char*)p->span.z, p->span.n);
ds@1952	1030	}else if( fullNames \|\| (!shortNames && pTabList->nSrc>1) ){
ds@1952	1031	char *zName = 0;
ds@1952	1032	char *zTab;
ds@1952	1033
ds@1952	1034	zTab = pTabList->a[j].zAlias;
ds@1952	1035	if( fullNames \|\| zTab==0 ) zTab = pTab->zName;
ds@1952	1036	sqlite3SetString(&zName, zTab, ".", zCol, (char*)0);
ds@1952	1037	sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, P3_DYNAMIC);
ds@1952	1038	}else{
ds@1952	1039	sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, strlen(zCol));
ds@1952	1040	}
ds@1952	1041	}else if( p->span.z && p->span.z[0] ){
ds@1952	1042	sqlite3VdbeSetColName(v, i, COLNAME_NAME, (char*)p->span.z, p->span.n);
ds@1952	1043	/* sqlite3VdbeCompressSpace(v, addr); */
ds@1952	1044	}else{
ds@1952	1045	char zName[30];
ds@1952	1046	assert( p->op!=TK_COLUMN \|\| pTabList==0 );
ds@1952	1047	sqlite3_snprintf(sizeof(zName), zName, "column%d", i+1);
ds@1952	1048	sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, 0);
ds@1952	1049	}
ds@1952	1050	}
ds@1952	1051	generateColumnTypes(pParse, pTabList, pEList);
ds@1952	1052	}
ds@1952	1053
ds@1952	1054	#ifndef SQLITE_OMIT_COMPOUND_SELECT
ds@1952	1055	/*
ds@1952	1056	** Name of the connection operator, used for error messages.
ds@1952	1057	*/
ds@1952	1058	static const char *selectOpName(int id){
ds@1952	1059	char *z;
ds@1952	1060	switch( id ){
ds@1952	1061	case TK_ALL: z = "UNION ALL"; break;
ds@1952	1062	case TK_INTERSECT: z = "INTERSECT"; break;
ds@1952	1063	case TK_EXCEPT: z = "EXCEPT"; break;
ds@1952	1064	default: z = "UNION"; break;
ds@1952	1065	}
ds@1952	1066	return z;
ds@1952	1067	}
ds@1952	1068	#endif /* SQLITE_OMIT_COMPOUND_SELECT */
ds@1952	1069
ds@1952	1070	/*
ds@1952	1071	** Forward declaration
ds@1952	1072	*/
ds@1952	1073	static int prepSelectStmt(Parse, Select);
ds@1952	1074
ds@1952	1075	/*
ds@1952	1076	** Given a SELECT statement, generate a Table structure that describes
ds@1952	1077	** the result set of that SELECT.
ds@1952	1078	*/
ds@1952	1079	Table sqlite3ResultSetOfSelect(Parse pParse, char zTabName, Select pSelect){
ds@1952	1080	Table *pTab;
ds@1952	1081	int i, j;
ds@1952	1082	ExprList *pEList;
ds@1952	1083	Column aCol, pCol;
ds@1952	1084	sqlite3 *db = pParse->db;
ds@1952	1085
ds@1952	1086	while( pSelect->pPrior ) pSelect = pSelect->pPrior;
ds@1952	1087	if( prepSelectStmt(pParse, pSelect) ){
ds@1952	1088	return 0;
ds@1952	1089	}
ds@1952	1090	if( sqlite3SelectResolve(pParse, pSelect, 0) ){
ds@1952	1091	return 0;
ds@1952	1092	}
ds@1952	1093	pTab = sqlite3DbMallocZero(db, sizeof(Table) );
ds@1952	1094	if( pTab==0 ){
ds@1952	1095	return 0;
ds@1952	1096	}
ds@1952	1097	pTab->nRef = 1;
ds@1952	1098	pTab->zName = zTabName ? sqlite3DbStrDup(db, zTabName) : 0;
ds@1952	1099	pEList = pSelect->pEList;
ds@1952	1100	pTab->nCol = pEList->nExpr;
ds@1952	1101	assert( pTab->nCol>0 );
ds@1952	1102	pTab->aCol = aCol = sqlite3DbMallocZero(db, sizeof(pTab->aCol[0])*pTab->nCol);
ds@1952	1103	for(i=0, pCol=aCol; i<pTab->nCol; i++, pCol++){
ds@1952	1104	Expr p, pR;
ds@1952	1105	char *zType;
ds@1952	1106	char *zName;
ds@1952	1107	int nName;
ds@1952	1108	CollSeq *pColl;
ds@1952	1109	int cnt;
ds@1952	1110	NameContext sNC;
ds@1952	1111
ds@1952	1112	/* Get an appropriate name for the column
ds@1952	1113	*/
ds@1952	1114	p = pEList->a[i].pExpr;
ds@1952	1115	assert( p->pRight==0 \|\| p->pRight->token.z==0 \|\| p->pRight->token.z[0]!=0 );
ds@1952	1116	if( (zName = pEList->a[i].zName)!=0 ){
ds@1952	1117	/* If the column contains an "AS <name>" phrase, use <name> as the name */
ds@1952	1118	zName = sqlite3DbStrDup(db, zName);
ds@1952	1119	}else if( p->op==TK_DOT
ds@1952	1120	&& (pR=p->pRight)!=0 && pR->token.z && pR->token.z[0] ){
ds@1952	1121	/* For columns of the from A.B use B as the name */
ds@1952	1122	zName = sqlite3MPrintf(db, "%T", &pR->token);
ds@1952	1123	}else if( p->span.z && p->span.z[0] ){
ds@1952	1124	/* Use the original text of the column expression as its name */
ds@1952	1125	zName = sqlite3MPrintf(db, "%T", &p->span);
ds@1952	1126	}else{
ds@1952	1127	/* If all else fails, make up a name */
ds@1952	1128	zName = sqlite3MPrintf(db, "column%d", i+1);
ds@1952	1129	}
ds@1952	1130	if( !zName \|\| db->mallocFailed ){
ds@1952	1131	db->mallocFailed = 1;
ds@1952	1132	sqlite3_free(zName);
ds@1952	1133	sqlite3DeleteTable(pTab);
ds@1952	1134	return 0;
ds@1952	1135	}
ds@1952	1136	sqlite3Dequote(zName);
ds@1952	1137
ds@1952	1138	/* Make sure the column name is unique. If the name is not unique,
ds@1952	1139	** append a integer to the name so that it becomes unique.
ds@1952	1140	*/
ds@1952	1141	nName = strlen(zName);
ds@1952	1142	for(j=cnt=0; j<i; j++){
ds@1952	1143	if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){
ds@1952	1144	zName[nName] = 0;
ds@1952	1145	zName = sqlite3MPrintf(db, "%z:%d", zName, ++cnt);
ds@1952	1146	j = -1;
ds@1952	1147	if( zName==0 ) break;
ds@1952	1148	}
ds@1952	1149	}
ds@1952	1150	pCol->zName = zName;
ds@1952	1151
ds@1952	1152	/* Get the typename, type affinity, and collating sequence for the
ds@1952	1153	** column.
ds@1952	1154	*/
ds@1952	1155	memset(&sNC, 0, sizeof(sNC));
ds@1952	1156	sNC.pSrcList = pSelect->pSrc;
ds@1952	1157	zType = sqlite3DbStrDup(db, columnType(&sNC, p, 0, 0, 0));
ds@1952	1158	pCol->zType = zType;
ds@1952	1159	pCol->affinity = sqlite3ExprAffinity(p);
ds@1952	1160	pColl = sqlite3ExprCollSeq(pParse, p);
ds@1952	1161	if( pColl ){
ds@1952	1162	pCol->zColl = sqlite3DbStrDup(db, pColl->zName);
ds@1952	1163	}
ds@1952	1164	}
ds@1952	1165	pTab->iPKey = -1;
ds@1952	1166	return pTab;
ds@1952	1167	}
ds@1952	1168
ds@1952	1169	/*
ds@1952	1170	** Prepare a SELECT statement for processing by doing the following
ds@1952	1171	** things:
ds@1952	1172	**
ds@1952	1173	** (1) Make sure VDBE cursor numbers have been assigned to every
ds@1952	1174	** element of the FROM clause.
ds@1952	1175	**
ds@1952	1176	** (2) Fill in the pTabList->a[].pTab fields in the SrcList that
ds@1952	1177	** defines FROM clause. When views appear in the FROM clause,
ds@1952	1178	** fill pTabList->a[].pSelect with a copy of the SELECT statement
ds@1952	1179	** that implements the view. A copy is made of the view's SELECT
ds@1952	1180	** statement so that we can freely modify or delete that statement
ds@1952	1181	** without worrying about messing up the presistent representation
ds@1952	1182	** of the view.
ds@1952	1183	**
ds@1952	1184	** (3) Add terms to the WHERE clause to accomodate the NATURAL keyword
ds@1952	1185	** on joins and the ON and USING clause of joins.
ds@1952	1186	**
ds@1952	1187	** (4) Scan the list of columns in the result set (pEList) looking
ds@1952	1188	** for instances of the "" operator or the TABLE. operator.
ds@1952	1189	** If found, expand each "*" to be every column in every table
ds@1952	1190	** and TABLE.* to be every column in TABLE.
ds@1952	1191	**
ds@1952	1192	** Return 0 on success. If there are problems, leave an error message
ds@1952	1193	** in pParse and return non-zero.
ds@1952	1194	*/
ds@1952	1195	static int prepSelectStmt(Parse pParse, Select p){
ds@1952	1196	int i, j, k, rc;
ds@1952	1197	SrcList *pTabList;
ds@1952	1198	ExprList *pEList;
ds@1952	1199	struct SrcList_item *pFrom;
ds@1952	1200	sqlite3 *db = pParse->db;
ds@1952	1201
ds@1952	1202	if( p==0 \|\| p->pSrc==0 \|\| db->mallocFailed ){
ds@1952	1203	return 1;
ds@1952	1204	}
ds@1952	1205	pTabList = p->pSrc;
ds@1952	1206	pEList = p->pEList;
ds@1952	1207
ds@1952	1208	/* Make sure cursor numbers have been assigned to all entries in
ds@1952	1209	** the FROM clause of the SELECT statement.
ds@1952	1210	*/
ds@1952	1211	sqlite3SrcListAssignCursors(pParse, p->pSrc);
ds@1952	1212
ds@1952	1213	/* Look up every table named in the FROM clause of the select. If
ds@1952	1214	** an entry of the FROM clause is a subquery instead of a table or view,
ds@1952	1215	** then create a transient table structure to describe the subquery.
ds@1952	1216	*/
ds@1952	1217	for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
ds@1952	1218	Table *pTab;
ds@1952	1219	if( pFrom->pTab!=0 ){
ds@1952	1220	/* This statement has already been prepared. There is no need
ds@1952	1221	** to go further. */
ds@1952	1222	assert( i==0 );
ds@1952	1223	return 0;
ds@1952	1224	}
ds@1952	1225	if( pFrom->zName==0 ){
ds@1952	1226	#ifndef SQLITE_OMIT_SUBQUERY
ds@1952	1227	/* A sub-query in the FROM clause of a SELECT */
ds@1952	1228	assert( pFrom->pSelect!=0 );
ds@1952	1229	if( pFrom->zAlias==0 ){
ds@1952	1230	pFrom->zAlias =
ds@1952	1231	sqlite3MPrintf(db, "sqlite_subquery_%p_", (void*)pFrom->pSelect);
ds@1952	1232	}
ds@1952	1233	assert( pFrom->pTab==0 );
ds@1952	1234	pFrom->pTab = pTab =
ds@1952	1235	sqlite3ResultSetOfSelect(pParse, pFrom->zAlias, pFrom->pSelect);
ds@1952	1236	if( pTab==0 ){
ds@1952	1237	return 1;
ds@1952	1238	}
ds@1952	1239	/* The isEphem flag indicates that the Table structure has been
ds@1952	1240	** dynamically allocated and may be freed at any time. In other words,
ds@1952	1241	** pTab is not pointing to a persistent table structure that defines
ds@1952	1242	** part of the schema. */
ds@1952	1243	pTab->isEphem = 1;
ds@1952	1244	#endif
ds@1952	1245	}else{
ds@1952	1246	/* An ordinary table or view name in the FROM clause */
ds@1952	1247	assert( pFrom->pTab==0 );
ds@1952	1248	pFrom->pTab = pTab =
ds@1952	1249	sqlite3LocateTable(pParse,pFrom->zName,pFrom->zDatabase);
ds@1952	1250	if( pTab==0 ){
ds@1952	1251	return 1;
ds@1952	1252	}
ds@1952	1253	pTab->nRef++;
ds@1952	1254	#if !defined(SQLITE_OMIT_VIEW) \|\| !defined (SQLITE_OMIT_VIRTUALTABLE)
ds@1952	1255	if( pTab->pSelect \|\| IsVirtual(pTab) ){
ds@1952	1256	/* We reach here if the named table is a really a view */
ds@1952	1257	if( sqlite3ViewGetColumnNames(pParse, pTab) ){
ds@1952	1258	return 1;
ds@1952	1259	}
ds@1952	1260	/* If pFrom->pSelect!=0 it means we are dealing with a
ds@1952	1261	** view within a view. The SELECT structure has already been
ds@1952	1262	** copied by the outer view so we can skip the copy step here
ds@1952	1263	** in the inner view.
ds@1952	1264	*/
ds@1952	1265	if( pFrom->pSelect==0 ){
ds@1952	1266	pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect);
ds@1952	1267	}
ds@1952	1268	}
ds@1952	1269	#endif
ds@1952	1270	}
ds@1952	1271	}
ds@1952	1272
ds@1952	1273	/* Process NATURAL keywords, and ON and USING clauses of joins.
ds@1952	1274	*/
ds@1952	1275	if( sqliteProcessJoin(pParse, p) ) return 1;
ds@1952	1276
ds@1952	1277	/* For every "*" that occurs in the column list, insert the names of
ds@1952	1278	** all columns in all tables. And for every TABLE.* insert the names
ds@1952	1279	** of all columns in TABLE. The parser inserted a special expression
ds@1952	1280	** with the TK_ALL operator for each "*" that it found in the column list.
ds@1952	1281	** The following code just has to locate the TK_ALL expressions and expand
ds@1952	1282	** each one to the list of all columns in all tables.
ds@1952	1283	**
ds@1952	1284	** The first loop just checks to see if there are any "*" operators
ds@1952	1285	** that need expanding.
ds@1952	1286	*/
ds@1952	1287	for(k=0; k<pEList->nExpr; k++){
ds@1952	1288	Expr *pE = pEList->a[k].pExpr;
ds@1952	1289	if( pE->op==TK_ALL ) break;
ds@1952	1290	if( pE->op==TK_DOT && pE->pRight && pE->pRight->op==TK_ALL
ds@1952	1291	&& pE->pLeft && pE->pLeft->op==TK_ID ) break;
ds@1952	1292	}
ds@1952	1293	rc = 0;
ds@1952	1294	if( k<pEList->nExpr ){
ds@1952	1295	/*
ds@1952	1296	** If we get here it means the result set contains one or more "*"
ds@1952	1297	** operators that need to be expanded. Loop through each expression
ds@1952	1298	** in the result set and expand them one by one.
ds@1952	1299	*/
ds@1952	1300	struct ExprList_item *a = pEList->a;
ds@1952	1301	ExprList *pNew = 0;
ds@1952	1302	int flags = pParse->db->flags;
ds@1952	1303	int longNames = (flags & SQLITE_FullColNames)!=0 &&
ds@1952	1304	(flags & SQLITE_ShortColNames)==0;
ds@1952	1305
ds@1952	1306	for(k=0; k<pEList->nExpr; k++){
ds@1952	1307	Expr *pE = a[k].pExpr;
ds@1952	1308	if( pE->op!=TK_ALL &&
ds@1952	1309	(pE->op!=TK_DOT \|\| pE->pRight==0 \|\| pE->pRight->op!=TK_ALL) ){
ds@1952	1310	/* This particular expression does not need to be expanded.
ds@1952	1311	*/
ds@1952	1312	pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr, 0);
ds@1952	1313	if( pNew ){
ds@1952	1314	pNew->a[pNew->nExpr-1].zName = a[k].zName;
ds@1952	1315	}else{
ds@1952	1316	rc = 1;
ds@1952	1317	}
ds@1952	1318	a[k].pExpr = 0;
ds@1952	1319	a[k].zName = 0;
ds@1952	1320	}else{
ds@1952	1321	/* This expression is a "" or a "TABLE." and needs to be
ds@1952	1322	** expanded. */
ds@1952	1323	int tableSeen = 0; /* Set to 1 when TABLE matches */
ds@1952	1324	char zTName; / text of name of TABLE */
ds@1952	1325	if( pE->op==TK_DOT && pE->pLeft ){
ds@1952	1326	zTName = sqlite3NameFromToken(db, &pE->pLeft->token);
ds@1952	1327	}else{
ds@1952	1328	zTName = 0;
ds@1952	1329	}
ds@1952	1330	for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
ds@1952	1331	Table *pTab = pFrom->pTab;
ds@1952	1332	char *zTabName = pFrom->zAlias;
ds@1952	1333	if( zTabName==0 \|\| zTabName[0]==0 ){
ds@1952	1334	zTabName = pTab->zName;
ds@1952	1335	}
ds@1952	1336	if( zTName && (zTabName==0 \|\| zTabName[0]==0 \|\|
ds@1952	1337	sqlite3StrICmp(zTName, zTabName)!=0) ){
ds@1952	1338	continue;
ds@1952	1339	}
ds@1952	1340	tableSeen = 1;
ds@1952	1341	for(j=0; j<pTab->nCol; j++){
ds@1952	1342	Expr pExpr, pRight;
ds@1952	1343	char *zName = pTab->aCol[j].zName;
ds@1952	1344
ds@1952	1345	/* If a column is marked as 'hidden' (currently only possible
ds@1952	1346	** for virtual tables), do not include it in the expanded
ds@1952	1347	** result-set list.
ds@1952	1348	*/
ds@1952	1349	if( IsHiddenColumn(&pTab->aCol[j]) ){
ds@1952	1350	assert(IsVirtual(pTab));
ds@1952	1351	continue;
ds@1952	1352	}
ds@1952	1353
ds@1952	1354	if( i>0 ){
ds@1952	1355	struct SrcList_item *pLeft = &pTabList->a[i-1];
ds@1952	1356	if( (pLeft[1].jointype & JT_NATURAL)!=0 &&
ds@1952	1357	columnIndex(pLeft->pTab, zName)>=0 ){
ds@1952	1358	/* In a NATURAL join, omit the join columns from the
ds@1952	1359	** table on the right */
ds@1952	1360	continue;
ds@1952	1361	}
ds@1952	1362	if( sqlite3IdListIndex(pLeft[1].pUsing, zName)>=0 ){
ds@1952	1363	/* In a join with a USING clause, omit columns in the
ds@1952	1364	** using clause from the table on the right. */
ds@1952	1365	continue;
ds@1952	1366	}
ds@1952	1367	}
ds@1952	1368	pRight = sqlite3PExpr(pParse, TK_ID, 0, 0, 0);
ds@1952	1369	if( pRight==0 ) break;
ds@1952	1370	setQuotedToken(pParse, &pRight->token, zName);
ds@1952	1371	if( zTabName && (longNames \|\| pTabList->nSrc>1) ){
ds@1952	1372	Expr *pLeft = sqlite3PExpr(pParse, TK_ID, 0, 0, 0);
ds@1952	1373	pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
ds@1952	1374	if( pExpr==0 ) break;
ds@1952	1375	setQuotedToken(pParse, &pLeft->token, zTabName);
ds@1952	1376	setToken(&pExpr->span,
ds@1952	1377	sqlite3MPrintf(db, "%s.%s", zTabName, zName));
ds@1952	1378	pExpr->span.dyn = 1;
ds@1952	1379	pExpr->token.z = 0;
ds@1952	1380	pExpr->token.n = 0;
ds@1952	1381	pExpr->token.dyn = 0;
ds@1952	1382	}else{
ds@1952	1383	pExpr = pRight;
ds@1952	1384	pExpr->span = pExpr->token;
ds@1952	1385	pExpr->span.dyn = 0;
ds@1952	1386	}
ds@1952	1387	if( longNames ){
ds@1952	1388	pNew = sqlite3ExprListAppend(pParse, pNew, pExpr, &pExpr->span);
ds@1952	1389	}else{
ds@1952	1390	pNew = sqlite3ExprListAppend(pParse, pNew, pExpr, &pRight->token);
ds@1952	1391	}
ds@1952	1392	}
ds@1952	1393	}
ds@1952	1394	if( !tableSeen ){
ds@1952	1395	if( zTName ){
ds@1952	1396	sqlite3ErrorMsg(pParse, "no such table: %s", zTName);
ds@1952	1397	}else{
ds@1952	1398	sqlite3ErrorMsg(pParse, "no tables specified");
ds@1952	1399	}
ds@1952	1400	rc = 1;
ds@1952	1401	}
ds@1952	1402	sqlite3_free(zTName);
ds@1952	1403	}
ds@1952	1404	}
ds@1952	1405	sqlite3ExprListDelete(pEList);
ds@1952	1406	p->pEList = pNew;
ds@1952	1407	}
ds@1952	1408	if( p->pEList && p->pEList->nExpr>SQLITE_MAX_COLUMN ){
ds@1952	1409	sqlite3ErrorMsg(pParse, "too many columns in result set");
ds@1952	1410	rc = SQLITE_ERROR;
ds@1952	1411	}
ds@1952	1412	if( db->mallocFailed ){
ds@1952	1413	rc = SQLITE_NOMEM;
ds@1952	1414	}
ds@1952	1415	return rc;
ds@1952	1416	}
ds@1952	1417
ds@1952	1418	#ifndef SQLITE_OMIT_COMPOUND_SELECT
ds@1952	1419	/*
ds@1952	1420	** This routine associates entries in an ORDER BY expression list with
ds@1952	1421	** columns in a result. For each ORDER BY expression, the opcode of
ds@1952	1422	** the top-level node is changed to TK_COLUMN and the iColumn value of
ds@1952	1423	** the top-level node is filled in with column number and the iTable
ds@1952	1424	** value of the top-level node is filled with iTable parameter.
ds@1952	1425	**
ds@1952	1426	** If there are prior SELECT clauses, they are processed first. A match
ds@1952	1427	** in an earlier SELECT takes precedence over a later SELECT.
ds@1952	1428	**
ds@1952	1429	** Any entry that does not match is flagged as an error. The number
ds@1952	1430	** of errors is returned.
ds@1952	1431	*/
ds@1952	1432	static int matchOrderbyToColumn(
ds@1952	1433	Parse pParse, / A place to leave error messages */
ds@1952	1434	Select pSelect, / Match to result columns of this SELECT */
ds@1952	1435	ExprList pOrderBy, / The ORDER BY values to match against columns */
ds@1952	1436	int iTable, /* Insert this value in iTable */
ds@1952	1437	int mustComplete /* If TRUE all ORDER BYs must match */
ds@1952	1438	){
ds@1952	1439	int nErr = 0;
ds@1952	1440	int i, j;
ds@1952	1441	ExprList *pEList;
ds@1952	1442	sqlite3 *db = pParse->db;
ds@1952	1443
ds@1952	1444	if( pSelect==0 \|\| pOrderBy==0 ) return 1;
ds@1952	1445	if( mustComplete ){
ds@1952	1446	for(i=0; i<pOrderBy->nExpr; i++){ pOrderBy->a[i].done = 0; }
ds@1952	1447	}
ds@1952	1448	if( prepSelectStmt(pParse, pSelect) ){
ds@1952	1449	return 1;
ds@1952	1450	}
ds@1952	1451	if( pSelect->pPrior ){
ds@1952	1452	if( matchOrderbyToColumn(pParse, pSelect->pPrior, pOrderBy, iTable, 0) ){
ds@1952	1453	return 1;
ds@1952	1454	}
ds@1952	1455	}
ds@1952	1456	pEList = pSelect->pEList;
ds@1952	1457	for(i=0; i<pOrderBy->nExpr; i++){
ds@1952	1458	struct ExprList_item *pItem;
ds@1952	1459	Expr *pE = pOrderBy->a[i].pExpr;
ds@1952	1460	int iCol = -1;
ds@1952	1461	char *zLabel;
ds@1952	1462
ds@1952	1463	if( pOrderBy->a[i].done ) continue;
ds@1952	1464	if( sqlite3ExprIsInteger(pE, &iCol) ){
ds@1952	1465	if( iCol<=0 \|\| iCol>pEList->nExpr ){
ds@1952	1466	sqlite3ErrorMsg(pParse,
ds@1952	1467	"ORDER BY position %d should be between 1 and %d",
ds@1952	1468	iCol, pEList->nExpr);
ds@1952	1469	nErr++;
ds@1952	1470	break;
ds@1952	1471	}
ds@1952	1472	if( !mustComplete ) continue;
ds@1952	1473	iCol--;
ds@1952	1474	}
ds@1952	1475	if( iCol<0 && (zLabel = sqlite3NameFromToken(db, &pE->token))!=0 ){
ds@1952	1476	for(j=0, pItem=pEList->a; j<pEList->nExpr; j++, pItem++){
ds@1952	1477	char *zName;
ds@1952	1478	int isMatch;
ds@1952	1479	if( pItem->zName ){
ds@1952	1480	zName = sqlite3DbStrDup(db, pItem->zName);
ds@1952	1481	}else{
ds@1952	1482	zName = sqlite3NameFromToken(db, &pItem->pExpr->token);
ds@1952	1483	}
ds@1952	1484	isMatch = zName && sqlite3StrICmp(zName, zLabel)==0;
ds@1952	1485	sqlite3_free(zName);
ds@1952	1486	if( isMatch ){
ds@1952	1487	iCol = j;
ds@1952	1488	break;
ds@1952	1489	}
ds@1952	1490	}
ds@1952	1491	sqlite3_free(zLabel);
ds@1952	1492	}
ds@1952	1493	if( iCol>=0 ){
ds@1952	1494	pE->op = TK_COLUMN;
ds@1952	1495	pE->iColumn = iCol;
ds@1952	1496	pE->iTable = iTable;
ds@1952	1497	pE->iAgg = -1;
ds@1952	1498	pOrderBy->a[i].done = 1;
ds@1952	1499	}else if( mustComplete ){
ds@1952	1500	sqlite3ErrorMsg(pParse,
ds@1952	1501	"ORDER BY term number %d does not match any result column", i+1);
ds@1952	1502	nErr++;
ds@1952	1503	break;
ds@1952	1504	}
ds@1952	1505	}
ds@1952	1506	return nErr;
ds@1952	1507	}
ds@1952	1508	#endif /* #ifndef SQLITE_OMIT_COMPOUND_SELECT */
ds@1952	1509
ds@1952	1510	/*
ds@1952	1511	** Get a VDBE for the given parser context. Create a new one if necessary.
ds@1952	1512	** If an error occurs, return NULL and leave a message in pParse.
ds@1952	1513	*/
ds@1952	1514	Vdbe sqlite3GetVdbe(Parse pParse){
ds@1952	1515	Vdbe *v = pParse->pVdbe;
ds@1952	1516	if( v==0 ){
ds@1952	1517	v = pParse->pVdbe = sqlite3VdbeCreate(pParse->db);
ds@1952	1518	}
ds@1952	1519	return v;
ds@1952	1520	}
ds@1952	1521
ds@1952	1522
ds@1952	1523	/*
ds@1952	1524	** Compute the iLimit and iOffset fields of the SELECT based on the
ds@1952	1525	** pLimit and pOffset expressions. pLimit and pOffset hold the expressions
ds@1952	1526	** that appear in the original SQL statement after the LIMIT and OFFSET
ds@1952	1527	** keywords. Or NULL if those keywords are omitted. iLimit and iOffset
ds@1952	1528	** are the integer memory register numbers for counters used to compute
ds@1952	1529	** the limit and offset. If there is no limit and/or offset, then
ds@1952	1530	** iLimit and iOffset are negative.
ds@1952	1531	**
ds@1952	1532	** This routine changes the values of iLimit and iOffset only if
ds@1952	1533	** a limit or offset is defined by pLimit and pOffset. iLimit and
ds@1952	1534	** iOffset should have been preset to appropriate default values
ds@1952	1535	** (usually but not always -1) prior to calling this routine.
ds@1952	1536	** Only if pLimit!=0 or pOffset!=0 do the limit registers get
ds@1952	1537	** redefined. The UNION ALL operator uses this property to force
ds@1952	1538	** the reuse of the same limit and offset registers across multiple
ds@1952	1539	** SELECT statements.
ds@1952	1540	*/
ds@1952	1541	static void computeLimitRegisters(Parse pParse, Select p, int iBreak){
ds@1952	1542	Vdbe *v = 0;
ds@1952	1543	int iLimit = 0;
ds@1952	1544	int iOffset;
ds@1952	1545	int addr1, addr2;
ds@1952	1546
ds@1952	1547	/*
ds@1952	1548	** "LIMIT -1" always shows all rows. There is some
ds@1952	1549	** contraversy about what the correct behavior should be.
ds@1952	1550	** The current implementation interprets "LIMIT 0" to mean
ds@1952	1551	** no rows.
ds@1952	1552	*/
ds@1952	1553	if( p->pLimit ){
ds@1952	1554	p->iLimit = iLimit = pParse->nMem;
ds@1952	1555	pParse->nMem += 2;
ds@1952	1556	v = sqlite3GetVdbe(pParse);
ds@1952	1557	if( v==0 ) return;
ds@1952	1558	sqlite3ExprCode(pParse, p->pLimit);
ds@1952	1559	sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
ds@1952	1560	sqlite3VdbeAddOp(v, OP_MemStore, iLimit, 1);
ds@1952	1561	VdbeComment((v, "# LIMIT counter"));
ds@1952	1562	sqlite3VdbeAddOp(v, OP_IfMemZero, iLimit, iBreak);
ds@1952	1563	sqlite3VdbeAddOp(v, OP_MemLoad, iLimit, 0);
ds@1952	1564	}
ds@1952	1565	if( p->pOffset ){
ds@1952	1566	p->iOffset = iOffset = pParse->nMem++;
ds@1952	1567	v = sqlite3GetVdbe(pParse);
ds@1952	1568	if( v==0 ) return;
ds@1952	1569	sqlite3ExprCode(pParse, p->pOffset);
ds@1952	1570	sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
ds@1952	1571	sqlite3VdbeAddOp(v, OP_MemStore, iOffset, p->pLimit==0);
ds@1952	1572	VdbeComment((v, "# OFFSET counter"));
ds@1952	1573	addr1 = sqlite3VdbeAddOp(v, OP_IfMemPos, iOffset, 0);
ds@1952	1574	sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
ds@1952	1575	sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
ds@1952	1576	sqlite3VdbeJumpHere(v, addr1);
ds@1952	1577	if( p->pLimit ){
ds@1952	1578	sqlite3VdbeAddOp(v, OP_Add, 0, 0);
ds@1952	1579	}
ds@1952	1580	}
ds@1952	1581	if( p->pLimit ){
ds@1952	1582	addr1 = sqlite3VdbeAddOp(v, OP_IfMemPos, iLimit, 0);
ds@1952	1583	sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
ds@1952	1584	sqlite3VdbeAddOp(v, OP_MemInt, -1, iLimit+1);
ds@1952	1585	addr2 = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
ds@1952	1586	sqlite3VdbeJumpHere(v, addr1);
ds@1952	1587	sqlite3VdbeAddOp(v, OP_MemStore, iLimit+1, 1);
ds@1952	1588	VdbeComment((v, "# LIMIT+OFFSET"));
ds@1952	1589	sqlite3VdbeJumpHere(v, addr2);
ds@1952	1590	}
ds@1952	1591	}
ds@1952	1592
ds@1952	1593	/*
ds@1952	1594	** Allocate a virtual index to use for sorting.
ds@1952	1595	*/
ds@1952	1596	static void createSortingIndex(Parse pParse, Select p, ExprList *pOrderBy){
ds@1952	1597	if( pOrderBy ){
ds@1952	1598	int addr;
ds@1952	1599	assert( pOrderBy->iECursor==0 );
ds@1952	1600	pOrderBy->iECursor = pParse->nTab++;
ds@1952	1601	addr = sqlite3VdbeAddOp(pParse->pVdbe, OP_OpenEphemeral,
ds@1952	1602	pOrderBy->iECursor, pOrderBy->nExpr+1);
ds@1952	1603	assert( p->addrOpenEphm[2] == -1 );
ds@1952	1604	p->addrOpenEphm[2] = addr;
ds@1952	1605	}
ds@1952	1606	}
ds@1952	1607
ds@1952	1608	#ifndef SQLITE_OMIT_COMPOUND_SELECT
ds@1952	1609	/*
ds@1952	1610	** Return the appropriate collating sequence for the iCol-th column of
ds@1952	1611	** the result set for the compound-select statement "p". Return NULL if
ds@1952	1612	** the column has no default collating sequence.
ds@1952	1613	**
ds@1952	1614	** The collating sequence for the compound select is taken from the
ds@1952	1615	** left-most term of the select that has a collating sequence.
ds@1952	1616	*/
ds@1952	1617	static CollSeq multiSelectCollSeq(Parse pParse, Select *p, int iCol){
ds@1952	1618	CollSeq *pRet;
ds@1952	1619	if( p->pPrior ){
ds@1952	1620	pRet = multiSelectCollSeq(pParse, p->pPrior, iCol);
ds@1952	1621	}else{
ds@1952	1622	pRet = 0;
ds@1952	1623	}
ds@1952	1624	if( pRet==0 ){
ds@1952	1625	pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr);
ds@1952	1626	}
ds@1952	1627	return pRet;
ds@1952	1628	}
ds@1952	1629	#endif /* SQLITE_OMIT_COMPOUND_SELECT */
ds@1952	1630
ds@1952	1631	#ifndef SQLITE_OMIT_COMPOUND_SELECT
ds@1952	1632	/*
ds@1952	1633	** This routine is called to process a query that is really the union
ds@1952	1634	** or intersection of two or more separate queries.
ds@1952	1635	**
ds@1952	1636	** "p" points to the right-most of the two queries. the query on the
ds@1952	1637	** left is p->pPrior. The left query could also be a compound query
ds@1952	1638	** in which case this routine will be called recursively.
ds@1952	1639	**
ds@1952	1640	** The results of the total query are to be written into a destination
ds@1952	1641	** of type eDest with parameter iParm.
ds@1952	1642	**
ds@1952	1643	** Example 1: Consider a three-way compound SQL statement.
ds@1952	1644	**
ds@1952	1645	** SELECT a FROM t1 UNION SELECT b FROM t2 UNION SELECT c FROM t3
ds@1952	1646	**
ds@1952	1647	** This statement is parsed up as follows:
ds@1952	1648	**
ds@1952	1649	** SELECT c FROM t3
ds@1952	1650	** \|
ds@1952	1651	** `-----> SELECT b FROM t2
ds@1952	1652	** \|
ds@1952	1653	** `------> SELECT a FROM t1
ds@1952	1654	**
ds@1952	1655	** The arrows in the diagram above represent the Select.pPrior pointer.
ds@1952	1656	** So if this routine is called with p equal to the t3 query, then
ds@1952	1657	** pPrior will be the t2 query. p->op will be TK_UNION in this case.
ds@1952	1658	**
ds@1952	1659	** Notice that because of the way SQLite parses compound SELECTs, the
ds@1952	1660	** individual selects always group from left to right.
ds@1952	1661	*/
ds@1952	1662	static int multiSelect(
ds@1952	1663	Parse pParse, / Parsing context */
ds@1952	1664	Select p, / The right-most of SELECTs to be coded */
ds@1952	1665	int eDest, /* \___ Store query results as specified */
ds@1952	1666	int iParm, /* / by these two parameters. */
ds@1952	1667	char aff / If eDest is SRT_Union, the affinity string */
ds@1952	1668	){
ds@1952	1669	int rc = SQLITE_OK; /* Success code from a subroutine */
ds@1952	1670	Select pPrior; / Another SELECT immediately to our left */
ds@1952	1671	Vdbe v; / Generate code to this VDBE */
ds@1952	1672	int nCol; /* Number of columns in the result set */
ds@1952	1673	ExprList pOrderBy; / The ORDER BY clause on p */
ds@1952	1674	int aSetP2[2]; /* Set P2 value of these op to number of columns */
ds@1952	1675	int nSetP2 = 0; /* Number of slots in aSetP2[] used */
ds@1952	1676
ds@1952	1677	/* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs. Only
ds@1952	1678	** the last (right-most) SELECT in the series may have an ORDER BY or LIMIT.
ds@1952	1679	*/
ds@1952	1680	if( p==0 \|\| p->pPrior==0 ){
ds@1952	1681	rc = 1;
ds@1952	1682	goto multi_select_end;
ds@1952	1683	}
ds@1952	1684	pPrior = p->pPrior;
ds@1952	1685	assert( pPrior->pRightmost!=pPrior );
ds@1952	1686	assert( pPrior->pRightmost==p->pRightmost );
ds@1952	1687	if( pPrior->pOrderBy ){
ds@1952	1688	sqlite3ErrorMsg(pParse,"ORDER BY clause should come after %s not before",
ds@1952	1689	selectOpName(p->op));
ds@1952	1690	rc = 1;
ds@1952	1691	goto multi_select_end;
ds@1952	1692	}
ds@1952	1693	if( pPrior->pLimit ){
ds@1952	1694	sqlite3ErrorMsg(pParse,"LIMIT clause should come after %s not before",
ds@1952	1695	selectOpName(p->op));
ds@1952	1696	rc = 1;
ds@1952	1697	goto multi_select_end;
ds@1952	1698	}
ds@1952	1699
ds@1952	1700	/* Make sure we have a valid query engine. If not, create a new one.
ds@1952	1701	*/
ds@1952	1702	v = sqlite3GetVdbe(pParse);
ds@1952	1703	if( v==0 ){
ds@1952	1704	rc = 1;
ds@1952	1705	goto multi_select_end;
ds@1952	1706	}
ds@1952	1707
ds@1952	1708	/* Create the destination temporary table if necessary
ds@1952	1709	*/
ds@1952	1710	if( eDest==SRT_EphemTab ){
ds@1952	1711	assert( p->pEList );
ds@1952	1712	assert( nSetP2<sizeof(aSetP2)/sizeof(aSetP2[0]) );
ds@1952	1713	aSetP2[nSetP2++] = sqlite3VdbeAddOp(v, OP_OpenEphemeral, iParm, 0);
ds@1952	1714	eDest = SRT_Table;
ds@1952	1715	}
ds@1952	1716
ds@1952	1717	/* Generate code for the left and right SELECT statements.
ds@1952	1718	*/
ds@1952	1719	pOrderBy = p->pOrderBy;
ds@1952	1720	switch( p->op ){
ds@1952	1721	case TK_ALL: {
ds@1952	1722	if( pOrderBy==0 ){
ds@1952	1723	int addr = 0;
ds@1952	1724	assert( !pPrior->pLimit );
ds@1952	1725	pPrior->pLimit = p->pLimit;
ds@1952	1726	pPrior->pOffset = p->pOffset;
ds@1952	1727	rc = sqlite3Select(pParse, pPrior, eDest, iParm, 0, 0, 0, aff);
ds@1952	1728	p->pLimit = 0;
ds@1952	1729	p->pOffset = 0;
ds@1952	1730	if( rc ){
ds@1952	1731	goto multi_select_end;
ds@1952	1732	}
ds@1952	1733	p->pPrior = 0;
ds@1952	1734	p->iLimit = pPrior->iLimit;
ds@1952	1735	p->iOffset = pPrior->iOffset;
ds@1952	1736	if( p->iLimit>=0 ){
ds@1952	1737	addr = sqlite3VdbeAddOp(v, OP_IfMemZero, p->iLimit, 0);
ds@1952	1738	VdbeComment((v, "# Jump ahead if LIMIT reached"));
ds@1952	1739	}
ds@1952	1740	rc = sqlite3Select(pParse, p, eDest, iParm, 0, 0, 0, aff);
ds@1952	1741	p->pPrior = pPrior;
ds@1952	1742	if( rc ){
ds@1952	1743	goto multi_select_end;
ds@1952	1744	}
ds@1952	1745	if( addr ){
ds@1952	1746	sqlite3VdbeJumpHere(v, addr);
ds@1952	1747	}
ds@1952	1748	break;
ds@1952	1749	}
ds@1952	1750	/* For UNION ALL ... ORDER BY fall through to the next case */
ds@1952	1751	}
ds@1952	1752	case TK_EXCEPT:
ds@1952	1753	case TK_UNION: {
ds@1952	1754	int unionTab; /* Cursor number of the temporary table holding result */
ds@1952	1755	int op = 0; /* One of the SRT_ operations to apply to self */
ds@1952	1756	int priorOp; /* The SRT_ operation to apply to prior selects */
ds@1952	1757	Expr pLimit, pOffset; /* Saved values of p->nLimit and p->nOffset */
ds@1952	1758	int addr;
ds@1952	1759
ds@1952	1760	priorOp = p->op==TK_ALL ? SRT_Table : SRT_Union;
ds@1952	1761	if( eDest==priorOp && pOrderBy==0 && !p->pLimit && !p->pOffset ){
ds@1952	1762	/* We can reuse a temporary table generated by a SELECT to our
ds@1952	1763	** right.
ds@1952	1764	*/
ds@1952	1765	unionTab = iParm;
ds@1952	1766	}else{
ds@1952	1767	/* We will need to create our own temporary table to hold the
ds@1952	1768	** intermediate results.
ds@1952	1769	*/
ds@1952	1770	unionTab = pParse->nTab++;
ds@1952	1771	if( pOrderBy && matchOrderbyToColumn(pParse, p, pOrderBy, unionTab,1) ){
ds@1952	1772	rc = 1;
ds@1952	1773	goto multi_select_end;
ds@1952	1774	}
ds@1952	1775	addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, unionTab, 0);
ds@1952	1776	if( priorOp==SRT_Table ){
ds@1952	1777	assert( nSetP2<sizeof(aSetP2)/sizeof(aSetP2[0]) );
ds@1952	1778	aSetP2[nSetP2++] = addr;
ds@1952	1779	}else{
ds@1952	1780	assert( p->addrOpenEphm[0] == -1 );
ds@1952	1781	p->addrOpenEphm[0] = addr;
ds@1952	1782	p->pRightmost->usesEphm = 1;
ds@1952	1783	}
ds@1952	1784	createSortingIndex(pParse, p, pOrderBy);
ds@1952	1785	assert( p->pEList );
ds@1952	1786	}
ds@1952	1787
ds@1952	1788	/* Code the SELECT statements to our left
ds@1952	1789	*/
ds@1952	1790	assert( !pPrior->pOrderBy );
ds@1952	1791	rc = sqlite3Select(pParse, pPrior, priorOp, unionTab, 0, 0, 0, aff);
ds@1952	1792	if( rc ){
ds@1952	1793	goto multi_select_end;
ds@1952	1794	}
ds@1952	1795
ds@1952	1796	/* Code the current SELECT statement
ds@1952	1797	*/
ds@1952	1798	switch( p->op ){
ds@1952	1799	case TK_EXCEPT: op = SRT_Except; break;
ds@1952	1800	case TK_UNION: op = SRT_Union; break;
ds@1952	1801	case TK_ALL: op = SRT_Table; break;
ds@1952	1802	}
ds@1952	1803	p->pPrior = 0;
ds@1952	1804	p->pOrderBy = 0;
ds@1952	1805	p->disallowOrderBy = pOrderBy!=0;
ds@1952	1806	pLimit = p->pLimit;
ds@1952	1807	p->pLimit = 0;
ds@1952	1808	pOffset = p->pOffset;
ds@1952	1809	p->pOffset = 0;
ds@1952	1810	rc = sqlite3Select(pParse, p, op, unionTab, 0, 0, 0, aff);
ds@1952	1811	/* Query flattening in sqlite3Select() might refill p->pOrderBy.
ds@1952	1812	** Be sure to delete p->pOrderBy, therefore, to avoid a memory leak. */
ds@1952	1813	sqlite3ExprListDelete(p->pOrderBy);
ds@1952	1814	p->pPrior = pPrior;
ds@1952	1815	p->pOrderBy = pOrderBy;
ds@1952	1816	sqlite3ExprDelete(p->pLimit);
ds@1952	1817	p->pLimit = pLimit;
ds@1952	1818	p->pOffset = pOffset;
ds@1952	1819	p->iLimit = -1;
ds@1952	1820	p->iOffset = -1;
ds@1952	1821	if( rc ){
ds@1952	1822	goto multi_select_end;
ds@1952	1823	}
ds@1952	1824
ds@1952	1825
ds@1952	1826	/* Convert the data in the temporary table into whatever form
ds@1952	1827	** it is that we currently need.
ds@1952	1828	*/
ds@1952	1829	if( eDest!=priorOp \|\| unionTab!=iParm ){
ds@1952	1830	int iCont, iBreak, iStart;
ds@1952	1831	assert( p->pEList );
ds@1952	1832	if( eDest==SRT_Callback ){
ds@1952	1833	Select *pFirst = p;
ds@1952	1834	while( pFirst->pPrior ) pFirst = pFirst->pPrior;
ds@1952	1835	generateColumnNames(pParse, 0, pFirst->pEList);
ds@1952	1836	}
ds@1952	1837	iBreak = sqlite3VdbeMakeLabel(v);
ds@1952	1838	iCont = sqlite3VdbeMakeLabel(v);
ds@1952	1839	computeLimitRegisters(pParse, p, iBreak);
ds@1952	1840	sqlite3VdbeAddOp(v, OP_Rewind, unionTab, iBreak);
ds@1952	1841	iStart = sqlite3VdbeCurrentAddr(v);
ds@1952	1842	rc = selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr,
ds@1952	1843	pOrderBy, -1, eDest, iParm,
ds@1952	1844	iCont, iBreak, 0);
ds@1952	1845	if( rc ){
ds@1952	1846	rc = 1;
ds@1952	1847	goto multi_select_end;
ds@1952	1848	}
ds@1952	1849	sqlite3VdbeResolveLabel(v, iCont);
ds@1952	1850	sqlite3VdbeAddOp(v, OP_Next, unionTab, iStart);
ds@1952	1851	sqlite3VdbeResolveLabel(v, iBreak);
ds@1952	1852	sqlite3VdbeAddOp(v, OP_Close, unionTab, 0);
ds@1952	1853	}
ds@1952	1854	break;
ds@1952	1855	}
ds@1952	1856	case TK_INTERSECT: {
ds@1952	1857	int tab1, tab2;
ds@1952	1858	int iCont, iBreak, iStart;
ds@1952	1859	Expr pLimit, pOffset;
ds@1952	1860	int addr;
ds@1952	1861
ds@1952	1862	/* INTERSECT is different from the others since it requires
ds@1952	1863	** two temporary tables. Hence it has its own case. Begin
ds@1952	1864	** by allocating the tables we will need.
ds@1952	1865	*/
ds@1952	1866	tab1 = pParse->nTab++;
ds@1952	1867	tab2 = pParse->nTab++;
ds@1952	1868	if( pOrderBy && matchOrderbyToColumn(pParse,p,pOrderBy,tab1,1) ){
ds@1952	1869	rc = 1;
ds@1952	1870	goto multi_select_end;
ds@1952	1871	}
ds@1952	1872	createSortingIndex(pParse, p, pOrderBy);
ds@1952	1873
ds@1952	1874	addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, tab1, 0);
ds@1952	1875	assert( p->addrOpenEphm[0] == -1 );
ds@1952	1876	p->addrOpenEphm[0] = addr;
ds@1952	1877	p->pRightmost->usesEphm = 1;
ds@1952	1878	assert( p->pEList );
ds@1952	1879
ds@1952	1880	/* Code the SELECTs to our left into temporary table "tab1".
ds@1952	1881	*/
ds@1952	1882	rc = sqlite3Select(pParse, pPrior, SRT_Union, tab1, 0, 0, 0, aff);
ds@1952	1883	if( rc ){
ds@1952	1884	goto multi_select_end;
ds@1952	1885	}
ds@1952	1886
ds@1952	1887	/* Code the current SELECT into temporary table "tab2"
ds@1952	1888	*/
ds@1952	1889	addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, tab2, 0);
ds@1952	1890	assert( p->addrOpenEphm[1] == -1 );
ds@1952	1891	p->addrOpenEphm[1] = addr;
ds@1952	1892	p->pPrior = 0;
ds@1952	1893	pLimit = p->pLimit;
ds@1952	1894	p->pLimit = 0;
ds@1952	1895	pOffset = p->pOffset;
ds@1952	1896	p->pOffset = 0;
ds@1952	1897	rc = sqlite3Select(pParse, p, SRT_Union, tab2, 0, 0, 0, aff);
ds@1952	1898	p->pPrior = pPrior;
ds@1952	1899	sqlite3ExprDelete(p->pLimit);
ds@1952	1900	p->pLimit = pLimit;
ds@1952	1901	p->pOffset = pOffset;
ds@1952	1902	if( rc ){
ds@1952	1903	goto multi_select_end;
ds@1952	1904	}
ds@1952	1905
ds@1952	1906	/* Generate code to take the intersection of the two temporary
ds@1952	1907	** tables.
ds@1952	1908	*/
ds@1952	1909	assert( p->pEList );
ds@1952	1910	if( eDest==SRT_Callback ){
ds@1952	1911	Select *pFirst = p;
ds@1952	1912	while( pFirst->pPrior ) pFirst = pFirst->pPrior;
ds@1952	1913	generateColumnNames(pParse, 0, pFirst->pEList);
ds@1952	1914	}
ds@1952	1915	iBreak = sqlite3VdbeMakeLabel(v);
ds@1952	1916	iCont = sqlite3VdbeMakeLabel(v);
ds@1952	1917	computeLimitRegisters(pParse, p, iBreak);
ds@1952	1918	sqlite3VdbeAddOp(v, OP_Rewind, tab1, iBreak);
ds@1952	1919	iStart = sqlite3VdbeAddOp(v, OP_RowKey, tab1, 0);
ds@1952	1920	sqlite3VdbeAddOp(v, OP_NotFound, tab2, iCont);
ds@1952	1921	rc = selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr,
ds@1952	1922	pOrderBy, -1, eDest, iParm,
ds@1952	1923	iCont, iBreak, 0);
ds@1952	1924	if( rc ){
ds@1952	1925	rc = 1;
ds@1952	1926	goto multi_select_end;
ds@1952	1927	}
ds@1952	1928	sqlite3VdbeResolveLabel(v, iCont);
ds@1952	1929	sqlite3VdbeAddOp(v, OP_Next, tab1, iStart);
ds@1952	1930	sqlite3VdbeResolveLabel(v, iBreak);
ds@1952	1931	sqlite3VdbeAddOp(v, OP_Close, tab2, 0);
ds@1952	1932	sqlite3VdbeAddOp(v, OP_Close, tab1, 0);
ds@1952	1933	break;
ds@1952	1934	}
ds@1952	1935	}
ds@1952	1936
ds@1952	1937	/* Make sure all SELECTs in the statement have the same number of elements
ds@1952	1938	** in their result sets.
ds@1952	1939	*/
ds@1952	1940	assert( p->pEList && pPrior->pEList );
ds@1952	1941	if( p->pEList->nExpr!=pPrior->pEList->nExpr ){
ds@1952	1942	sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
ds@1952	1943	" do not have the same number of result columns", selectOpName(p->op));
ds@1952	1944	rc = 1;
ds@1952	1945	goto multi_select_end;
ds@1952	1946	}
ds@1952	1947
ds@1952	1948	/* Set the number of columns in temporary tables
ds@1952	1949	*/
ds@1952	1950	nCol = p->pEList->nExpr;
ds@1952	1951	while( nSetP2 ){
ds@1952	1952	sqlite3VdbeChangeP2(v, aSetP2[--nSetP2], nCol);
ds@1952	1953	}
ds@1952	1954
ds@1952	1955	/* Compute collating sequences used by either the ORDER BY clause or
ds@1952	1956	** by any temporary tables needed to implement the compound select.
ds@1952	1957	** Attach the KeyInfo structure to all temporary tables. Invoke the
ds@1952	1958	** ORDER BY processing if there is an ORDER BY clause.
ds@1952	1959	**
ds@1952	1960	** This section is run by the right-most SELECT statement only.
ds@1952	1961	** SELECT statements to the left always skip this part. The right-most
ds@1952	1962	** SELECT might also skip this part if it has no ORDER BY clause and
ds@1952	1963	** no temp tables are required.
ds@1952	1964	*/
ds@1952	1965	if( pOrderBy \|\| p->usesEphm ){
ds@1952	1966	int i; /* Loop counter */
ds@1952	1967	KeyInfo pKeyInfo; / Collating sequence for the result set */
ds@1952	1968	Select pLoop; / For looping through SELECT statements */
ds@1952	1969	int nKeyCol; /* Number of entries in pKeyInfo->aCol[] */
ds@1952	1970	CollSeq *apColl; / For looping through pKeyInfo->aColl[] */
ds@1952	1971	CollSeq *aCopy; / A copy of pKeyInfo->aColl[] */
ds@1952	1972
ds@1952	1973	assert( p->pRightmost==p );
ds@1952	1974	nKeyCol = nCol + (pOrderBy ? pOrderBy->nExpr : 0);
ds@1952	1975	pKeyInfo = sqlite3DbMallocZero(pParse->db,
ds@1952	1976	sizeof(pKeyInfo)+nKeyCol(sizeof(CollSeq*) + 1));
ds@1952	1977	if( !pKeyInfo ){
ds@1952	1978	rc = SQLITE_NOMEM;
ds@1952	1979	goto multi_select_end;
ds@1952	1980	}
ds@1952	1981
ds@1952	1982	pKeyInfo->enc = ENC(pParse->db);
ds@1952	1983	pKeyInfo->nField = nCol;
ds@1952	1984
ds@1952	1985	for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){
ds@1952	1986	*apColl = multiSelectCollSeq(pParse, p, i);
ds@1952	1987	if( 0==*apColl ){
ds@1952	1988	*apColl = pParse->db->pDfltColl;
ds@1952	1989	}
ds@1952	1990	}
ds@1952	1991
ds@1952	1992	for(pLoop=p; pLoop; pLoop=pLoop->pPrior){
ds@1952	1993	for(i=0; i<2; i++){
ds@1952	1994	int addr = pLoop->addrOpenEphm[i];
ds@1952	1995	if( addr<0 ){
ds@1952	1996	/* If [0] is unused then [1] is also unused. So we can
ds@1952	1997	** always safely abort as soon as the first unused slot is found */
ds@1952	1998	assert( pLoop->addrOpenEphm[1]<0 );
ds@1952	1999	break;
ds@1952	2000	}
ds@1952	2001	sqlite3VdbeChangeP2(v, addr, nCol);
ds@1952	2002	sqlite3VdbeChangeP3(v, addr, (char*)pKeyInfo, P3_KEYINFO);
ds@1952	2003	pLoop->addrOpenEphm[i] = -1;
ds@1952	2004	}
ds@1952	2005	}
ds@1952	2006
ds@1952	2007	if( pOrderBy ){
ds@1952	2008	struct ExprList_item *pOTerm = pOrderBy->a;
ds@1952	2009	int nOrderByExpr = pOrderBy->nExpr;
ds@1952	2010	int addr;
ds@1952	2011	u8 *pSortOrder;
ds@1952	2012
ds@1952	2013	/* Reuse the same pKeyInfo for the ORDER BY as was used above for
ds@1952	2014	** the compound select statements. Except we have to change out the
ds@1952	2015	** pKeyInfo->aColl[] values. Some of the aColl[] values will be
ds@1952	2016	** reused when constructing the pKeyInfo for the ORDER BY, so make
ds@1952	2017	** a copy. Sufficient space to hold both the nCol entries for
ds@1952	2018	** the compound select and the nOrderbyExpr entries for the ORDER BY
ds@1952	2019	** was allocated above. But we need to move the compound select
ds@1952	2020	** entries out of the way before constructing the ORDER BY entries.
ds@1952	2021	** Move the compound select entries into aCopy[] where they can be
ds@1952	2022	** accessed and reused when constructing the ORDER BY entries.
ds@1952	2023	** Because nCol might be greater than or less than nOrderByExpr
ds@1952	2024	** we have to use memmove() when doing the copy.
ds@1952	2025	*/
ds@1952	2026	aCopy = &pKeyInfo->aColl[nOrderByExpr];
ds@1952	2027	pSortOrder = pKeyInfo->aSortOrder = (u8*)&aCopy[nCol];
ds@1952	2028	memmove(aCopy, pKeyInfo->aColl, nColsizeof(CollSeq));
ds@1952	2029
ds@1952	2030	apColl = pKeyInfo->aColl;
ds@1952	2031	for(i=0; i<nOrderByExpr; i++, pOTerm++, apColl++, pSortOrder++){
ds@1952	2032	Expr *pExpr = pOTerm->pExpr;
ds@1952	2033	if( (pExpr->flags & EP_ExpCollate) ){
ds@1952	2034	assert( pExpr->pColl!=0 );
ds@1952	2035	*apColl = pExpr->pColl;
ds@1952	2036	}else{
ds@1952	2037	*apColl = aCopy[pExpr->iColumn];
ds@1952	2038	}
ds@1952	2039	*pSortOrder = pOTerm->sortOrder;
ds@1952	2040	}
ds@1952	2041	assert( p->pRightmost==p );
ds@1952	2042	assert( p->addrOpenEphm[2]>=0 );
ds@1952	2043	addr = p->addrOpenEphm[2];
ds@1952	2044	sqlite3VdbeChangeP2(v, addr, p->pOrderBy->nExpr+2);
ds@1952	2045	pKeyInfo->nField = nOrderByExpr;
ds@1952	2046	sqlite3VdbeChangeP3(v, addr, (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
ds@1952	2047	pKeyInfo = 0;
ds@1952	2048	generateSortTail(pParse, p, v, p->pEList->nExpr, eDest, iParm);
ds@1952	2049	}
ds@1952	2050
ds@1952	2051	sqlite3_free(pKeyInfo);
ds@1952	2052	}
ds@1952	2053
ds@1952	2054	multi_select_end:
ds@1952	2055	return rc;
ds@1952	2056	}
ds@1952	2057	#endif /* SQLITE_OMIT_COMPOUND_SELECT */
ds@1952	2058
ds@1952	2059	#ifndef SQLITE_OMIT_VIEW
ds@1952	2060	/* Forward Declarations */
ds@1952	2061	static void substExprList(sqlite3, ExprList, int, ExprList*);
ds@1952	2062	static void substSelect(sqlite3, Select , int, ExprList *);
ds@1952	2063
ds@1952	2064	/*
ds@1952	2065	** Scan through the expression pExpr. Replace every reference to
ds@1952	2066	** a column in table number iTable with a copy of the iColumn-th
ds@1952	2067	** entry in pEList. (But leave references to the ROWID column
ds@1952	2068	** unchanged.)
ds@1952	2069	**
ds@1952	2070	** This routine is part of the flattening procedure. A subquery
ds@1952	2071	** whose result set is defined by pEList appears as entry in the
ds@1952	2072	** FROM clause of a SELECT such that the VDBE cursor assigned to that
ds@1952	2073	** FORM clause entry is iTable. This routine make the necessary
ds@1952	2074	** changes to pExpr so that it refers directly to the source table
ds@1952	2075	** of the subquery rather the result set of the subquery.
ds@1952	2076	*/
ds@1952	2077	static void substExpr(
ds@1952	2078	sqlite3 db, / Report malloc errors to this connection */
ds@1952	2079	Expr pExpr, / Expr in which substitution occurs */
ds@1952	2080	int iTable, /* Table to be substituted */
ds@1952	2081	ExprList pEList / Substitute expressions */
ds@1952	2082	){
ds@1952	2083	if( pExpr==0 ) return;
ds@1952	2084	if( pExpr->op==TK_COLUMN && pExpr->iTable==iTable ){
ds@1952	2085	if( pExpr->iColumn<0 ){
ds@1952	2086	pExpr->op = TK_NULL;
ds@1952	2087	}else{
ds@1952	2088	Expr *pNew;
ds@1952	2089	assert( pEList!=0 && pExpr->iColumn<pEList->nExpr );
ds@1952	2090	assert( pExpr->pLeft==0 && pExpr->pRight==0 && pExpr->pList==0 );
ds@1952	2091	pNew = pEList->a[pExpr->iColumn].pExpr;
ds@1952	2092	assert( pNew!=0 );
ds@1952	2093	pExpr->op = pNew->op;
ds@1952	2094	assert( pExpr->pLeft==0 );
ds@1952	2095	pExpr->pLeft = sqlite3ExprDup(db, pNew->pLeft);
ds@1952	2096	assert( pExpr->pRight==0 );
ds@1952	2097	pExpr->pRight = sqlite3ExprDup(db, pNew->pRight);
ds@1952	2098	assert( pExpr->pList==0 );
ds@1952	2099	pExpr->pList = sqlite3ExprListDup(db, pNew->pList);
ds@1952	2100	pExpr->iTable = pNew->iTable;
ds@1952	2101	pExpr->pTab = pNew->pTab;
ds@1952	2102	pExpr->iColumn = pNew->iColumn;
ds@1952	2103	pExpr->iAgg = pNew->iAgg;
ds@1952	2104	sqlite3TokenCopy(db, &pExpr->token, &pNew->token);
ds@1952	2105	sqlite3TokenCopy(db, &pExpr->span, &pNew->span);
ds@1952	2106	pExpr->pSelect = sqlite3SelectDup(db, pNew->pSelect);
ds@1952	2107	pExpr->flags = pNew->flags;
ds@1952	2108	}
ds@1952	2109	}else{
ds@1952	2110	substExpr(db, pExpr->pLeft, iTable, pEList);
ds@1952	2111	substExpr(db, pExpr->pRight, iTable, pEList);
ds@1952	2112	substSelect(db, pExpr->pSelect, iTable, pEList);
ds@1952	2113	substExprList(db, pExpr->pList, iTable, pEList);
ds@1952	2114	}
ds@1952	2115	}
ds@1952	2116	static void substExprList(
ds@1952	2117	sqlite3 db, / Report malloc errors here */
ds@1952	2118	ExprList pList, / List to scan and in which to make substitutes */
ds@1952	2119	int iTable, /* Table to be substituted */
ds@1952	2120	ExprList pEList / Substitute values */
ds@1952	2121	){
ds@1952	2122	int i;
ds@1952	2123	if( pList==0 ) return;
ds@1952	2124	for(i=0; i<pList->nExpr; i++){
ds@1952	2125	substExpr(db, pList->a[i].pExpr, iTable, pEList);
ds@1952	2126	}
ds@1952	2127	}
ds@1952	2128	static void substSelect(
ds@1952	2129	sqlite3 db, / Report malloc errors here */
ds@1952	2130	Select p, / SELECT statement in which to make substitutions */
ds@1952	2131	int iTable, /* Table to be replaced */
ds@1952	2132	ExprList pEList / Substitute values */
ds@1952	2133	){
ds@1952	2134	if( !p ) return;
ds@1952	2135	substExprList(db, p->pEList, iTable, pEList);
ds@1952	2136	substExprList(db, p->pGroupBy, iTable, pEList);
ds@1952	2137	substExprList(db, p->pOrderBy, iTable, pEList);
ds@1952	2138	substExpr(db, p->pHaving, iTable, pEList);
ds@1952	2139	substExpr(db, p->pWhere, iTable, pEList);
ds@1952	2140	substSelect(db, p->pPrior, iTable, pEList);
ds@1952	2141	}
ds@1952	2142	#endif /* !defined(SQLITE_OMIT_VIEW) */
ds@1952	2143
ds@1952	2144	#ifndef SQLITE_OMIT_VIEW
ds@1952	2145	/*
ds@1952	2146	** This routine attempts to flatten subqueries in order to speed
ds@1952	2147	** execution. It returns 1 if it makes changes and 0 if no flattening
ds@1952	2148	** occurs.
ds@1952	2149	**
ds@1952	2150	** To understand the concept of flattening, consider the following
ds@1952	2151	** query:
ds@1952	2152	**
ds@1952	2153	** SELECT a FROM (SELECT x+y AS a FROM t1 WHERE z<100) WHERE a>5
ds@1952	2154	**
ds@1952	2155	** The default way of implementing this query is to execute the
ds@1952	2156	** subquery first and store the results in a temporary table, then
ds@1952	2157	** run the outer query on that temporary table. This requires two
ds@1952	2158	** passes over the data. Furthermore, because the temporary table
ds@1952	2159	** has no indices, the WHERE clause on the outer query cannot be
ds@1952	2160	** optimized.
ds@1952	2161	**
ds@1952	2162	** This routine attempts to rewrite queries such as the above into
ds@1952	2163	** a single flat select, like this:
ds@1952	2164	**
ds@1952	2165	** SELECT x+y AS a FROM t1 WHERE z<100 AND a>5
ds@1952	2166	**
ds@1952	2167	** The code generated for this simpification gives the same result
ds@1952	2168	** but only has to scan the data once. And because indices might
ds@1952	2169	** exist on the table t1, a complete scan of the data might be
ds@1952	2170	** avoided.
ds@1952	2171	**
ds@1952	2172	** Flattening is only attempted if all of the following are true:
ds@1952	2173	**
ds@1952	2174	** (1) The subquery and the outer query do not both use aggregates.
ds@1952	2175	**
ds@1952	2176	** (2) The subquery is not an aggregate or the outer query is not a join.
ds@1952	2177	**
ds@1952	2178	** (3) The subquery is not the right operand of a left outer join, or
ds@1952	2179	** the subquery is not itself a join. (Ticket #306)
ds@1952	2180	**
ds@1952	2181	** (4) The subquery is not DISTINCT or the outer query is not a join.
ds@1952	2182	**
ds@1952	2183	** (5) The subquery is not DISTINCT or the outer query does not use
ds@1952	2184	** aggregates.
ds@1952	2185	**
ds@1952	2186	** (6) The subquery does not use aggregates or the outer query is not
ds@1952	2187	** DISTINCT.
ds@1952	2188	**
ds@1952	2189	** (7) The subquery has a FROM clause.
ds@1952	2190	**
ds@1952	2191	** (8) The subquery does not use LIMIT or the outer query is not a join.
ds@1952	2192	**
ds@1952	2193	** (9) The subquery does not use LIMIT or the outer query does not use
ds@1952	2194	** aggregates.
ds@1952	2195	**
ds@1952	2196	** (10) The subquery does not use aggregates or the outer query does not
ds@1952	2197	** use LIMIT.
ds@1952	2198	**
ds@1952	2199	** (11) The subquery and the outer query do not both have ORDER BY clauses.
ds@1952	2200	**
ds@1952	2201	** (12) The subquery is not the right term of a LEFT OUTER JOIN or the
ds@1952	2202	** subquery has no WHERE clause. (added by ticket #350)
ds@1952	2203	**
ds@1952	2204	** (13) The subquery and outer query do not both use LIMIT
ds@1952	2205	**
ds@1952	2206	** (14) The subquery does not use OFFSET
ds@1952	2207	**
ds@1952	2208	** (15) The outer query is not part of a compound select or the
ds@1952	2209	** subquery does not have both an ORDER BY and a LIMIT clause.
ds@1952	2210	** (See ticket #2339)
ds@1952	2211	**
ds@1952	2212	** In this routine, the "p" parameter is a pointer to the outer query.
ds@1952	2213	** The subquery is p->pSrc->a[iFrom]. isAgg is true if the outer query
ds@1952	2214	** uses aggregates and subqueryIsAgg is true if the subquery uses aggregates.
ds@1952	2215	**
ds@1952	2216	** If flattening is not attempted, this routine is a no-op and returns 0.
ds@1952	2217	** If flattening is attempted this routine returns 1.
ds@1952	2218	**
ds@1952	2219	** All of the expression analysis must occur on both the outer query and
ds@1952	2220	** the subquery before this routine runs.
ds@1952	2221	*/
ds@1952	2222	static int flattenSubquery(
ds@1952	2223	sqlite3 db, / Database connection */
ds@1952	2224	Select p, / The parent or outer SELECT statement */
ds@1952	2225	int iFrom, /* Index in p->pSrc->a[] of the inner subquery */
ds@1952	2226	int isAgg, /* True if outer SELECT uses aggregate functions */
ds@1952	2227	int subqueryIsAgg /* True if the subquery uses aggregate functions */
ds@1952	2228	){
ds@1952	2229	Select pSub; / The inner query or "subquery" */
ds@1952	2230	SrcList pSrc; / The FROM clause of the outer query */
ds@1952	2231	SrcList pSubSrc; / The FROM clause of the subquery */
ds@1952	2232	ExprList pList; / The result set of the outer query */
ds@1952	2233	int iParent; /* VDBE cursor number of the pSub result set temp table */
ds@1952	2234	int i; /* Loop counter */
ds@1952	2235	Expr pWhere; / The WHERE clause */
ds@1952	2236	struct SrcList_item pSubitem; / The subquery */
ds@1952	2237
ds@1952	2238	/* Check to see if flattening is permitted. Return 0 if not.
ds@1952	2239	*/
ds@1952	2240	if( p==0 ) return 0;
ds@1952	2241	pSrc = p->pSrc;
ds@1952	2242	assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
ds@1952	2243	pSubitem = &pSrc->a[iFrom];
ds@1952	2244	pSub = pSubitem->pSelect;
ds@1952	2245	assert( pSub!=0 );
ds@1952	2246	if( isAgg && subqueryIsAgg ) return 0; /* Restriction (1) */
ds@1952	2247	if( subqueryIsAgg && pSrc->nSrc>1 ) return 0; /* Restriction (2) */
ds@1952	2248	pSubSrc = pSub->pSrc;
ds@1952	2249	assert( pSubSrc );
ds@1952	2250	/* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
ds@1952	2251	** not arbitrary expresssions, we allowed some combining of LIMIT and OFFSET
ds@1952	2252	** because they could be computed at compile-time. But when LIMIT and OFFSET
ds@1952	2253	** became arbitrary expressions, we were forced to add restrictions (13)
ds@1952	2254	** and (14). */
ds@1952	2255	if( pSub->pLimit && p->pLimit ) return 0; /* Restriction (13) */
ds@1952	2256	if( pSub->pOffset ) return 0; /* Restriction (14) */
ds@1952	2257	if( p->pRightmost && pSub->pLimit && pSub->pOrderBy ){
ds@1952	2258	return 0; /* Restriction (15) */
ds@1952	2259	}
ds@1952	2260	if( pSubSrc->nSrc==0 ) return 0; /* Restriction (7) */
ds@1952	2261	if( (pSub->isDistinct \|\| pSub->pLimit)
ds@1952	2262	&& (pSrc->nSrc>1 \|\| isAgg) ){ /* Restrictions (4)(5)(8)(9) */
ds@1952	2263	return 0;
ds@1952	2264	}
ds@1952	2265	if( p->isDistinct && subqueryIsAgg ) return 0; /* Restriction (6) */
ds@1952	2266	if( (p->disallowOrderBy \|\| p->pOrderBy) && pSub->pOrderBy ){
ds@1952	2267	return 0; /* Restriction (11) */
ds@1952	2268	}
ds@1952	2269
ds@1952	2270	/* Restriction 3: If the subquery is a join, make sure the subquery is
ds@1952	2271	** not used as the right operand of an outer join. Examples of why this
ds@1952	2272	** is not allowed:
ds@1952	2273	**
ds@1952	2274	** t1 LEFT OUTER JOIN (t2 JOIN t3)
ds@1952	2275	**
ds@1952	2276	** If we flatten the above, we would get
ds@1952	2277	**
ds@1952	2278	** (t1 LEFT OUTER JOIN t2) JOIN t3
ds@1952	2279	**
ds@1952	2280	** which is not at all the same thing.
ds@1952	2281	*/
ds@1952	2282	if( pSubSrc->nSrc>1 && (pSubitem->jointype & JT_OUTER)!=0 ){
ds@1952	2283	return 0;
ds@1952	2284	}
ds@1952	2285
ds@1952	2286	/* Restriction 12: If the subquery is the right operand of a left outer
ds@1952	2287	** join, make sure the subquery has no WHERE clause.
ds@1952	2288	** An examples of why this is not allowed:
ds@1952	2289	**
ds@1952	2290	** t1 LEFT OUTER JOIN (SELECT * FROM t2 WHERE t2.x>0)
ds@1952	2291	**
ds@1952	2292	** If we flatten the above, we would get
ds@1952	2293	**
ds@1952	2294	** (t1 LEFT OUTER JOIN t2) WHERE t2.x>0
ds@1952	2295	**
ds@1952	2296	** But the t2.x>0 test will always fail on a NULL row of t2, which
ds@1952	2297	** effectively converts the OUTER JOIN into an INNER JOIN.
ds@1952	2298	*/
ds@1952	2299	if( (pSubitem->jointype & JT_OUTER)!=0 && pSub->pWhere!=0 ){
ds@1952	2300	return 0;
ds@1952	2301	}
ds@1952	2302
ds@1952	2303	/* If we reach this point, it means flattening is permitted for the
ds@1952	2304	** iFrom-th entry of the FROM clause in the outer query.
ds@1952	2305	*/
ds@1952	2306
ds@1952	2307	/* Move all of the FROM elements of the subquery into the
ds@1952	2308	** the FROM clause of the outer query. Before doing this, remember
ds@1952	2309	** the cursor number for the original outer query FROM element in
ds@1952	2310	** iParent. The iParent cursor will never be used. Subsequent code
ds@1952	2311	** will scan expressions looking for iParent references and replace
ds@1952	2312	** those references with expressions that resolve to the subquery FROM
ds@1952	2313	** elements we are now copying in.
ds@1952	2314	*/
ds@1952	2315	iParent = pSubitem->iCursor;
ds@1952	2316	{
ds@1952	2317	int nSubSrc = pSubSrc->nSrc;
ds@1952	2318	int jointype = pSubitem->jointype;
ds@1952	2319
ds@1952	2320	sqlite3DeleteTable(pSubitem->pTab);
ds@1952	2321	sqlite3_free(pSubitem->zDatabase);
ds@1952	2322	sqlite3_free(pSubitem->zName);
ds@1952	2323	sqlite3_free(pSubitem->zAlias);
ds@1952	2324	if( nSubSrc>1 ){
ds@1952	2325	int extra = nSubSrc - 1;
ds@1952	2326	for(i=1; i<nSubSrc; i++){
ds@1952	2327	pSrc = sqlite3SrcListAppend(db, pSrc, 0, 0);
ds@1952	2328	}
ds@1952	2329	p->pSrc = pSrc;
ds@1952	2330	for(i=pSrc->nSrc-1; i-extra>=iFrom; i--){
ds@1952	2331	pSrc->a[i] = pSrc->a[i-extra];
ds@1952	2332	}
ds@1952	2333	}
ds@1952	2334	for(i=0; i<nSubSrc; i++){
ds@1952	2335	pSrc->a[i+iFrom] = pSubSrc->a[i];
ds@1952	2336	memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
ds@1952	2337	}
ds@1952	2338	pSrc->a[iFrom].jointype = jointype;
ds@1952	2339	}
ds@1952	2340
ds@1952	2341	/* Now begin substituting subquery result set expressions for
ds@1952	2342	** references to the iParent in the outer query.
ds@1952	2343	**
ds@1952	2344	** Example:
ds@1952	2345	**
ds@1952	2346	** SELECT a+5, b10 FROM (SELECT x3 AS a, y+10 AS b FROM t1) WHERE a>b;
ds@1952	2347	** \ \_____________ subquery __________/ /
ds@1952	2348	** \_____________________ outer query ______________________________/
ds@1952	2349	**
ds@1952	2350	** We look at every expression in the outer query and every place we see
ds@1952	2351	** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
ds@1952	2352	*/
ds@1952	2353	pList = p->pEList;
ds@1952	2354	for(i=0; i<pList->nExpr; i++){
ds@1952	2355	Expr *pExpr;
ds@1952	2356	if( pList->a[i].zName==0 && (pExpr = pList->a[i].pExpr)->span.z!=0 ){
ds@1952	2357	pList->a[i].zName =
ds@1952	2358	sqlite3DbStrNDup(db, (char*)pExpr->span.z, pExpr->span.n);
ds@1952	2359	}
ds@1952	2360	}
ds@1952	2361	substExprList(db, p->pEList, iParent, pSub->pEList);
ds@1952	2362	if( isAgg ){
ds@1952	2363	substExprList(db, p->pGroupBy, iParent, pSub->pEList);
ds@1952	2364	substExpr(db, p->pHaving, iParent, pSub->pEList);
ds@1952	2365	}
ds@1952	2366	if( pSub->pOrderBy ){
ds@1952	2367	assert( p->pOrderBy==0 );
ds@1952	2368	p->pOrderBy = pSub->pOrderBy;
ds@1952	2369	pSub->pOrderBy = 0;
ds@1952	2370	}else if( p->pOrderBy ){
ds@1952	2371	substExprList(db, p->pOrderBy, iParent, pSub->pEList);
ds@1952	2372	}
ds@1952	2373	if( pSub->pWhere ){
ds@1952	2374	pWhere = sqlite3ExprDup(db, pSub->pWhere);
ds@1952	2375	}else{
ds@1952	2376	pWhere = 0;
ds@1952	2377	}
ds@1952	2378	if( subqueryIsAgg ){
ds@1952	2379	assert( p->pHaving==0 );
ds@1952	2380	p->pHaving = p->pWhere;
ds@1952	2381	p->pWhere = pWhere;
ds@1952	2382	substExpr(db, p->pHaving, iParent, pSub->pEList);
ds@1952	2383	p->pHaving = sqlite3ExprAnd(db, p->pHaving,
ds@1952	2384	sqlite3ExprDup(db, pSub->pHaving));
ds@1952	2385	assert( p->pGroupBy==0 );
ds@1952	2386	p->pGroupBy = sqlite3ExprListDup(db, pSub->pGroupBy);
ds@1952	2387	}else{
ds@1952	2388	substExpr(db, p->pWhere, iParent, pSub->pEList);
ds@1952	2389	p->pWhere = sqlite3ExprAnd(db, p->pWhere, pWhere);
ds@1952	2390	}
ds@1952	2391
ds@1952	2392	/* The flattened query is distinct if either the inner or the
ds@1952	2393	** outer query is distinct.
ds@1952	2394	*/
ds@1952	2395	p->isDistinct = p->isDistinct \|\| pSub->isDistinct;
ds@1952	2396
ds@1952	2397	/*
ds@1952	2398	** SELECT ... FROM (SELECT ... LIMIT a OFFSET b) LIMIT x OFFSET y;
ds@1952	2399	**
ds@1952	2400	** One is tempted to try to add a and b to combine the limits. But this
ds@1952	2401	** does not work if either limit is negative.
ds@1952	2402	*/
ds@1952	2403	if( pSub->pLimit ){
ds@1952	2404	p->pLimit = pSub->pLimit;
ds@1952	2405	pSub->pLimit = 0;
ds@1952	2406	}
ds@1952	2407
ds@1952	2408	/* Finially, delete what is left of the subquery and return
ds@1952	2409	** success.
ds@1952	2410	*/
ds@1952	2411	sqlite3SelectDelete(pSub);
ds@1952	2412	return 1;
ds@1952	2413	}
ds@1952	2414	#endif /* SQLITE_OMIT_VIEW */
ds@1952	2415
ds@1952	2416	/*
ds@1952	2417	** Analyze the SELECT statement passed in as an argument to see if it
ds@1952	2418	** is a simple min() or max() query. If it is and this query can be
ds@1952	2419	** satisfied using a single seek to the beginning or end of an index,
ds@1952	2420	** then generate the code for this SELECT and return 1. If this is not a
ds@1952	2421	** simple min() or max() query, then return 0;
ds@1952	2422	**
ds@1952	2423	** A simply min() or max() query looks like this:
ds@1952	2424	**
ds@1952	2425	** SELECT min(a) FROM table;
ds@1952	2426	** SELECT max(a) FROM table;
ds@1952	2427	**
ds@1952	2428	** The query may have only a single table in its FROM argument. There
ds@1952	2429	** can be no GROUP BY or HAVING or WHERE clauses. The result set must
ds@1952	2430	** be the min() or max() of a single column of the table. The column
ds@1952	2431	** in the min() or max() function must be indexed.
ds@1952	2432	**
ds@1952	2433	** The parameters to this routine are the same as for sqlite3Select().
ds@1952	2434	** See the header comment on that routine for additional information.
ds@1952	2435	*/
ds@1952	2436	static int simpleMinMaxQuery(Parse pParse, Select p, int eDest, int iParm){
ds@1952	2437	Expr *pExpr;
ds@1952	2438	int iCol;
ds@1952	2439	Table *pTab;
ds@1952	2440	Index *pIdx;
ds@1952	2441	int base;
ds@1952	2442	Vdbe *v;
ds@1952	2443	int seekOp;
ds@1952	2444	ExprList pEList, pList, eList;
ds@1952	2445	struct ExprList_item eListItem;
ds@1952	2446	SrcList *pSrc;
ds@1952	2447	int brk;
ds@1952	2448	int iDb;
ds@1952	2449
ds@1952	2450	/* Check to see if this query is a simple min() or max() query. Return
ds@1952	2451	** zero if it is not.
ds@1952	2452	*/
ds@1952	2453	if( p->pGroupBy \|\| p->pHaving \|\| p->pWhere ) return 0;
ds@1952	2454	pSrc = p->pSrc;
ds@1952	2455	if( pSrc->nSrc!=1 ) return 0;
ds@1952	2456	pEList = p->pEList;
ds@1952	2457	if( pEList->nExpr!=1 ) return 0;
ds@1952	2458	pExpr = pEList->a[0].pExpr;
ds@1952	2459	if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
ds@1952	2460	pList = pExpr->pList;
ds@1952	2461	if( pList==0 \|\| pList->nExpr!=1 ) return 0;
ds@1952	2462	if( pExpr->token.n!=3 ) return 0;
ds@1952	2463	if( sqlite3StrNICmp((char*)pExpr->token.z,"min",3)==0 ){
ds@1952	2464	seekOp = OP_Rewind;
ds@1952	2465	}else if( sqlite3StrNICmp((char*)pExpr->token.z,"max",3)==0 ){
ds@1952	2466	seekOp = OP_Last;
ds@1952	2467	}else{
ds@1952	2468	return 0;
ds@1952	2469	}
ds@1952	2470	pExpr = pList->a[0].pExpr;
ds@1952	2471	if( pExpr->op!=TK_COLUMN ) return 0;
ds@1952	2472	iCol = pExpr->iColumn;
ds@1952	2473	pTab = pSrc->a[0].pTab;
ds@1952	2474
ds@1952	2475	/* This optimization cannot be used with virtual tables. */
ds@1952	2476	if( IsVirtual(pTab) ) return 0;
ds@1952	2477
ds@1952	2478	/* If we get to here, it means the query is of the correct form.
ds@1952	2479	** Check to make sure we have an index and make pIdx point to the
ds@1952	2480	** appropriate index. If the min() or max() is on an INTEGER PRIMARY
ds@1952	2481	** key column, no index is necessary so set pIdx to NULL. If no
ds@1952	2482	** usable index is found, return 0.
ds@1952	2483	*/
ds@1952	2484	if( iCol<0 ){
ds@1952	2485	pIdx = 0;
ds@1952	2486	}else{
ds@1952	2487	CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr);
ds@1952	2488	if( pColl==0 ) return 0;
ds@1952	2489	for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
ds@1952	2490	assert( pIdx->nColumn>=1 );
ds@1952	2491	if( pIdx->aiColumn[0]==iCol &&
ds@1952	2492	0==sqlite3StrICmp(pIdx->azColl[0], pColl->zName) ){
ds@1952	2493	break;
ds@1952	2494	}
ds@1952	2495	}
ds@1952	2496	if( pIdx==0 ) return 0;
ds@1952	2497	}
ds@1952	2498
ds@1952	2499	/* Identify column types if we will be using the callback. This
ds@1952	2500	** step is skipped if the output is going to a table or a memory cell.
ds@1952	2501	** The column names have already been generated in the calling function.
ds@1952	2502	*/
ds@1952	2503	v = sqlite3GetVdbe(pParse);
ds@1952	2504	if( v==0 ) return 0;
ds@1952	2505
ds@1952	2506	/* If the output is destined for a temporary table, open that table.
ds@1952	2507	*/
ds@1952	2508	if( eDest==SRT_EphemTab ){
ds@1952	2509	sqlite3VdbeAddOp(v, OP_OpenEphemeral, iParm, 1);
ds@1952	2510	}
ds@1952	2511
ds@1952	2512	/* Generating code to find the min or the max. Basically all we have
ds@1952	2513	** to do is find the first or the last entry in the chosen index. If
ds@1952	2514	** the min() or max() is on the INTEGER PRIMARY KEY, then find the first
ds@1952	2515	** or last entry in the main table.
ds@1952	2516	*/
ds@1952	2517	iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
ds@1952	2518	assert( iDb>=0 \|\| pTab->isEphem );
ds@1952	2519	sqlite3CodeVerifySchema(pParse, iDb);
ds@1952	2520	sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
ds@1952	2521	base = pSrc->a[0].iCursor;
ds@1952	2522	brk = sqlite3VdbeMakeLabel(v);
ds@1952	2523	computeLimitRegisters(pParse, p, brk);
ds@1952	2524	if( pSrc->a[0].pSelect==0 ){
ds@1952	2525	sqlite3OpenTable(pParse, base, iDb, pTab, OP_OpenRead);
ds@1952	2526	}
ds@1952	2527	if( pIdx==0 ){
ds@1952	2528	sqlite3VdbeAddOp(v, seekOp, base, 0);
ds@1952	2529	}else{
ds@1952	2530	/* Even though the cursor used to open the index here is closed
ds@1952	2531	** as soon as a single value has been read from it, allocate it
ds@1952	2532	** using (pParse->nTab++) to prevent the cursor id from being
ds@1952	2533	** reused. This is important for statements of the form
ds@1952	2534	** "INSERT INTO x SELECT max() FROM x".
ds@1952	2535	*/
ds@1952	2536	int iIdx;
ds@1952	2537	KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
ds@1952	2538	iIdx = pParse->nTab++;
ds@1952	2539	assert( pIdx->pSchema==pTab->pSchema );
ds@1952	2540	sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
ds@1952	2541	sqlite3VdbeOp3(v, OP_OpenRead, iIdx, pIdx->tnum,
ds@1952	2542	(char*)pKey, P3_KEYINFO_HANDOFF);
ds@1952	2543	if( seekOp==OP_Rewind ){
ds@1952	2544	sqlite3VdbeAddOp(v, OP_Null, 0, 0);
ds@1952	2545	sqlite3VdbeAddOp(v, OP_MakeRecord, 1, 0);
ds@1952	2546	seekOp = OP_MoveGt;
ds@1952	2547	}
ds@1952	2548	if( pIdx->aSortOrder[0]==SQLITE_SO_DESC ){
ds@1952	2549	/* Ticket #2514: invert the seek operator if we are using
ds@1952	2550	** a descending index. */
ds@1952	2551	if( seekOp==OP_Last ){
ds@1952	2552	seekOp = OP_Rewind;
ds@1952	2553	}else{
ds@1952	2554	assert( seekOp==OP_MoveGt );
ds@1952	2555	seekOp = OP_MoveLt;
ds@1952	2556	}
ds@1952	2557	}
ds@1952	2558	sqlite3VdbeAddOp(v, seekOp, iIdx, 0);
ds@1952	2559	sqlite3VdbeAddOp(v, OP_IdxRowid, iIdx, 0);
ds@1952	2560	sqlite3VdbeAddOp(v, OP_Close, iIdx, 0);
ds@1952	2561	sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
ds@1952	2562	}
ds@1952	2563	eList.nExpr = 1;
ds@1952	2564	memset(&eListItem, 0, sizeof(eListItem));
ds@1952	2565	eList.a = &eListItem;
ds@1952	2566	eList.a[0].pExpr = pExpr;
ds@1952	2567	selectInnerLoop(pParse, p, &eList, 0, 0, 0, -1, eDest, iParm, brk, brk, 0);
ds@1952	2568	sqlite3VdbeResolveLabel(v, brk);
ds@1952	2569	sqlite3VdbeAddOp(v, OP_Close, base, 0);
ds@1952	2570
ds@1952	2571	return 1;
ds@1952	2572	}
ds@1952	2573
ds@1952	2574	/*
ds@1952	2575	** Analyze and ORDER BY or GROUP BY clause in a SELECT statement. Return
ds@1952	2576	** the number of errors seen.
ds@1952	2577	**
ds@1952	2578	** An ORDER BY or GROUP BY is a list of expressions. If any expression
ds@1952	2579	** is an integer constant, then that expression is replaced by the
ds@1952	2580	** corresponding entry in the result set.
ds@1952	2581	*/
ds@1952	2582	static int processOrderGroupBy(
ds@1952	2583	NameContext pNC, / Name context of the SELECT statement. */
ds@1952	2584	ExprList pOrderBy, / The ORDER BY or GROUP BY clause to be processed */
ds@1952	2585	const char zType / Either "ORDER" or "GROUP", as appropriate */
ds@1952	2586	){
ds@1952	2587	int i;
ds@1952	2588	ExprList pEList = pNC->pEList; / The result set of the SELECT */
ds@1952	2589	Parse pParse = pNC->pParse; / The result set of the SELECT */
ds@1952	2590	assert( pEList );
ds@1952	2591
ds@1952	2592	if( pOrderBy==0 ) return 0;
ds@1952	2593	if( pOrderBy->nExpr>SQLITE_MAX_COLUMN ){
ds@1952	2594	sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType);
ds@1952	2595	return 1;
ds@1952	2596	}
ds@1952	2597	for(i=0; i<pOrderBy->nExpr; i++){
ds@1952	2598	int iCol;
ds@1952	2599	Expr *pE = pOrderBy->a[i].pExpr;
ds@1952	2600	if( sqlite3ExprIsInteger(pE, &iCol) ){
ds@1952	2601	if( iCol>0 && iCol<=pEList->nExpr ){
ds@1952	2602	CollSeq *pColl = pE->pColl;
ds@1952	2603	int flags = pE->flags & EP_ExpCollate;
ds@1952	2604	sqlite3ExprDelete(pE);
ds@1952	2605	pE = sqlite3ExprDup(pParse->db, pEList->a[iCol-1].pExpr);
ds@1952	2606	pOrderBy->a[i].pExpr = pE;
ds@1952	2607	if( pColl && flags ){
ds@1952	2608	pE->pColl = pColl;
ds@1952	2609	pE->flags \|= flags;
ds@1952	2610	}
ds@1952	2611	}else{
ds@1952	2612	sqlite3ErrorMsg(pParse,
ds@1952	2613	"%s BY column number %d out of range - should be "
ds@1952	2614	"between 1 and %d", zType, iCol, pEList->nExpr);
ds@1952	2615	return 1;
ds@1952	2616	}
ds@1952	2617	}
ds@1952	2618	if( sqlite3ExprResolveNames(pNC, pE) ){
ds@1952	2619	return 1;
ds@1952	2620	}
ds@1952	2621	}
ds@1952	2622	return 0;
ds@1952	2623	}
ds@1952	2624
ds@1952	2625	/*
ds@1952	2626	** This routine resolves any names used in the result set of the
ds@1952	2627	** supplied SELECT statement. If the SELECT statement being resolved
ds@1952	2628	** is a sub-select, then pOuterNC is a pointer to the NameContext
ds@1952	2629	** of the parent SELECT.
ds@1952	2630	*/
ds@1952	2631	int sqlite3SelectResolve(
ds@1952	2632	Parse pParse, / The parser context */
ds@1952	2633	Select p, / The SELECT statement being coded. */
ds@1952	2634	NameContext pOuterNC / The outer name context. May be NULL. */
ds@1952	2635	){
ds@1952	2636	ExprList pEList; / Result set. */
ds@1952	2637	int i; /* For-loop variable used in multiple places */
ds@1952	2638	NameContext sNC; /* Local name-context */
ds@1952	2639	ExprList pGroupBy; / The group by clause */
ds@1952	2640
ds@1952	2641	/* If this routine has run before, return immediately. */
ds@1952	2642	if( p->isResolved ){
ds@1952	2643	assert( !pOuterNC );
ds@1952	2644	return SQLITE_OK;
ds@1952	2645	}
ds@1952	2646	p->isResolved = 1;
ds@1952	2647
ds@1952	2648	/* If there have already been errors, do nothing. */
ds@1952	2649	if( pParse->nErr>0 ){
ds@1952	2650	return SQLITE_ERROR;
ds@1952	2651	}
ds@1952	2652
ds@1952	2653	/* Prepare the select statement. This call will allocate all cursors
ds@1952	2654	** required to handle the tables and subqueries in the FROM clause.
ds@1952	2655	*/
ds@1952	2656	if( prepSelectStmt(pParse, p) ){
ds@1952	2657	return SQLITE_ERROR;
ds@1952	2658	}
ds@1952	2659
ds@1952	2660	/* Resolve the expressions in the LIMIT and OFFSET clauses. These
ds@1952	2661	** are not allowed to refer to any names, so pass an empty NameContext.
ds@1952	2662	*/
ds@1952	2663	memset(&sNC, 0, sizeof(sNC));
ds@1952	2664	sNC.pParse = pParse;
ds@1952	2665	if( sqlite3ExprResolveNames(&sNC, p->pLimit) \|\|
ds@1952	2666	sqlite3ExprResolveNames(&sNC, p->pOffset) ){
ds@1952	2667	return SQLITE_ERROR;
ds@1952	2668	}
ds@1952	2669
ds@1952	2670	/* Set up the local name-context to pass to ExprResolveNames() to
ds@1952	2671	** resolve the expression-list.
ds@1952	2672	*/
ds@1952	2673	sNC.allowAgg = 1;
ds@1952	2674	sNC.pSrcList = p->pSrc;
ds@1952	2675	sNC.pNext = pOuterNC;
ds@1952	2676
ds@1952	2677	/* Resolve names in the result set. */
ds@1952	2678	pEList = p->pEList;
ds@1952	2679	if( !pEList ) return SQLITE_ERROR;
ds@1952	2680	for(i=0; i<pEList->nExpr; i++){
ds@1952	2681	Expr *pX = pEList->a[i].pExpr;
ds@1952	2682	if( sqlite3ExprResolveNames(&sNC, pX) ){
ds@1952	2683	return SQLITE_ERROR;
ds@1952	2684	}
ds@1952	2685	}
ds@1952	2686
ds@1952	2687	/* If there are no aggregate functions in the result-set, and no GROUP BY
ds@1952	2688	** expression, do not allow aggregates in any of the other expressions.
ds@1952	2689	*/
ds@1952	2690	assert( !p->isAgg );
ds@1952	2691	pGroupBy = p->pGroupBy;
ds@1952	2692	if( pGroupBy \|\| sNC.hasAgg ){
ds@1952	2693	p->isAgg = 1;
ds@1952	2694	}else{
ds@1952	2695	sNC.allowAgg = 0;
ds@1952	2696	}
ds@1952	2697
ds@1952	2698	/* If a HAVING clause is present, then there must be a GROUP BY clause.
ds@1952	2699	*/
ds@1952	2700	if( p->pHaving && !pGroupBy ){
ds@1952	2701	sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING");
ds@1952	2702	return SQLITE_ERROR;
ds@1952	2703	}
ds@1952	2704
ds@1952	2705	/* Add the expression list to the name-context before parsing the
ds@1952	2706	** other expressions in the SELECT statement. This is so that
ds@1952	2707	** expressions in the WHERE clause (etc.) can refer to expressions by
ds@1952	2708	** aliases in the result set.
ds@1952	2709	**
ds@1952	2710	** Minor point: If this is the case, then the expression will be
ds@1952	2711	** re-evaluated for each reference to it.
ds@1952	2712	*/
ds@1952	2713	sNC.pEList = p->pEList;
ds@1952	2714	if( sqlite3ExprResolveNames(&sNC, p->pWhere) \|\|
ds@1952	2715	sqlite3ExprResolveNames(&sNC, p->pHaving) ){
ds@1952	2716	return SQLITE_ERROR;
ds@1952	2717	}
ds@1952	2718	if( p->pPrior==0 ){
ds@1952	2719	if( processOrderGroupBy(&sNC, p->pOrderBy, "ORDER") \|\|
ds@1952	2720	processOrderGroupBy(&sNC, pGroupBy, "GROUP") ){
ds@1952	2721	return SQLITE_ERROR;
ds@1952	2722	}
ds@1952	2723	}
ds@1952	2724
ds@1952	2725	if( pParse->db->mallocFailed ){
ds@1952	2726	return SQLITE_NOMEM;
ds@1952	2727	}
ds@1952	2728
ds@1952	2729	/* Make sure the GROUP BY clause does not contain aggregate functions.
ds@1952	2730	*/
ds@1952	2731	if( pGroupBy ){
ds@1952	2732	struct ExprList_item *pItem;
ds@1952	2733
ds@1952	2734	for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){
ds@1952	2735	if( ExprHasProperty(pItem->pExpr, EP_Agg) ){
ds@1952	2736	sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in "
ds@1952	2737	"the GROUP BY clause");
ds@1952	2738	return SQLITE_ERROR;
ds@1952	2739	}
ds@1952	2740	}
ds@1952	2741	}
ds@1952	2742
ds@1952	2743	/* If this is one SELECT of a compound, be sure to resolve names
ds@1952	2744	** in the other SELECTs.
ds@1952	2745	*/
ds@1952	2746	if( p->pPrior ){
ds@1952	2747	return sqlite3SelectResolve(pParse, p->pPrior, pOuterNC);
ds@1952	2748	}else{
ds@1952	2749	return SQLITE_OK;
ds@1952	2750	}
ds@1952	2751	}
ds@1952	2752
ds@1952	2753	/*
ds@1952	2754	** Reset the aggregate accumulator.
ds@1952	2755	**
ds@1952	2756	** The aggregate accumulator is a set of memory cells that hold
ds@1952	2757	** intermediate results while calculating an aggregate. This
ds@1952	2758	** routine simply stores NULLs in all of those memory cells.
ds@1952	2759	*/
ds@1952	2760	static void resetAccumulator(Parse pParse, AggInfo pAggInfo){
ds@1952	2761	Vdbe *v = pParse->pVdbe;
ds@1952	2762	int i;
ds@1952	2763	struct AggInfo_func *pFunc;
ds@1952	2764	if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){
ds@1952	2765	return;
ds@1952	2766	}
ds@1952	2767	for(i=0; i<pAggInfo->nColumn; i++){
ds@1952	2768	sqlite3VdbeAddOp(v, OP_MemNull, pAggInfo->aCol[i].iMem, 0);
ds@1952	2769	}
ds@1952	2770	for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
ds@1952	2771	sqlite3VdbeAddOp(v, OP_MemNull, pFunc->iMem, 0);
ds@1952	2772	if( pFunc->iDistinct>=0 ){
ds@1952	2773	Expr *pE = pFunc->pExpr;
ds@1952	2774	if( pE->pList==0 \|\| pE->pList->nExpr!=1 ){
ds@1952	2775	sqlite3ErrorMsg(pParse, "DISTINCT in aggregate must be followed "
ds@1952	2776	"by an expression");
ds@1952	2777	pFunc->iDistinct = -1;
ds@1952	2778	}else{
ds@1952	2779	KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->pList);
ds@1952	2780	sqlite3VdbeOp3(v, OP_OpenEphemeral, pFunc->iDistinct, 0,
ds@1952	2781	(char*)pKeyInfo, P3_KEYINFO_HANDOFF);
ds@1952	2782	}
ds@1952	2783	}
ds@1952	2784	}
ds@1952	2785	}
ds@1952	2786
ds@1952	2787	/*
ds@1952	2788	** Invoke the OP_AggFinalize opcode for every aggregate function
ds@1952	2789	** in the AggInfo structure.
ds@1952	2790	*/
ds@1952	2791	static void finalizeAggFunctions(Parse pParse, AggInfo pAggInfo){
ds@1952	2792	Vdbe *v = pParse->pVdbe;
ds@1952	2793	int i;
ds@1952	2794	struct AggInfo_func *pF;
ds@1952	2795	for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
ds@1952	2796	ExprList *pList = pF->pExpr->pList;
ds@1952	2797	sqlite3VdbeOp3(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0,
ds@1952	2798	(void*)pF->pFunc, P3_FUNCDEF);
ds@1952	2799	}
ds@1952	2800	}
ds@1952	2801
ds@1952	2802	/*
ds@1952	2803	** Update the accumulator memory cells for an aggregate based on
ds@1952	2804	** the current cursor position.
ds@1952	2805	*/
ds@1952	2806	static void updateAccumulator(Parse pParse, AggInfo pAggInfo){
ds@1952	2807	Vdbe *v = pParse->pVdbe;
ds@1952	2808	int i;
ds@1952	2809	struct AggInfo_func *pF;
ds@1952	2810	struct AggInfo_col *pC;
ds@1952	2811
ds@1952	2812	pAggInfo->directMode = 1;
ds@1952	2813	for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
ds@1952	2814	int nArg;
ds@1952	2815	int addrNext = 0;
ds@1952	2816	ExprList *pList = pF->pExpr->pList;
ds@1952	2817	if( pList ){
ds@1952	2818	nArg = pList->nExpr;
ds@1952	2819	sqlite3ExprCodeExprList(pParse, pList);
ds@1952	2820	}else{
ds@1952	2821	nArg = 0;
ds@1952	2822	}
ds@1952	2823	if( pF->iDistinct>=0 ){
ds@1952	2824	addrNext = sqlite3VdbeMakeLabel(v);
ds@1952	2825	assert( nArg==1 );
ds@1952	2826	codeDistinct(v, pF->iDistinct, addrNext, 1);
ds@1952	2827	}
ds@1952	2828	if( pF->pFunc->needCollSeq ){
ds@1952	2829	CollSeq *pColl = 0;
ds@1952	2830	struct ExprList_item *pItem;
ds@1952	2831	int j;
ds@1952	2832	assert( pList!=0 ); /* pList!=0 if pF->pFunc->needCollSeq is true */
ds@1952	2833	for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){
ds@1952	2834	pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
ds@1952	2835	}
ds@1952	2836	if( !pColl ){
ds@1952	2837	pColl = pParse->db->pDfltColl;
ds@1952	2838	}
ds@1952	2839	sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
ds@1952	2840	}
ds@1952	2841	sqlite3VdbeOp3(v, OP_AggStep, pF->iMem, nArg, (void*)pF->pFunc, P3_FUNCDEF);
ds@1952	2842	if( addrNext ){
ds@1952	2843	sqlite3VdbeResolveLabel(v, addrNext);
ds@1952	2844	}
ds@1952	2845	}
ds@1952	2846	for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
ds@1952	2847	sqlite3ExprCode(pParse, pC->pExpr);
ds@1952	2848	sqlite3VdbeAddOp(v, OP_MemStore, pC->iMem, 1);
ds@1952	2849	}
ds@1952	2850	pAggInfo->directMode = 0;
ds@1952	2851	}
ds@1952	2852
ds@1952	2853
ds@1952	2854	/*
ds@1952	2855	** Generate code for the given SELECT statement.
ds@1952	2856	**
ds@1952	2857	** The results are distributed in various ways depending on the
ds@1952	2858	** value of eDest and iParm.
ds@1952	2859	**
ds@1952	2860	** eDest Value Result
ds@1952	2861	** ------------ -------------------------------------------
ds@1952	2862	** SRT_Callback Invoke the callback for each row of the result.
ds@1952	2863	**
ds@1952	2864	** SRT_Mem Store first result in memory cell iParm
ds@1952	2865	**
ds@1952	2866	** SRT_Set Store results as keys of table iParm.
ds@1952	2867	**
ds@1952	2868	** SRT_Union Store results as a key in a temporary table iParm
ds@1952	2869	**
ds@1952	2870	** SRT_Except Remove results from the temporary table iParm.
ds@1952	2871	**
ds@1952	2872	** SRT_Table Store results in temporary table iParm
ds@1952	2873	**
ds@1952	2874	** The table above is incomplete. Additional eDist value have be added
ds@1952	2875	** since this comment was written. See the selectInnerLoop() function for
ds@1952	2876	** a complete listing of the allowed values of eDest and their meanings.
ds@1952	2877	**
ds@1952	2878	** This routine returns the number of errors. If any errors are
ds@1952	2879	** encountered, then an appropriate error message is left in
ds@1952	2880	** pParse->zErrMsg.
ds@1952	2881	**
ds@1952	2882	** This routine does NOT free the Select structure passed in. The
ds@1952	2883	** calling function needs to do that.
ds@1952	2884	**
ds@1952	2885	** The pParent, parentTab, and *pParentAgg fields are filled in if this
ds@1952	2886	** SELECT is a subquery. This routine may try to combine this SELECT
ds@1952	2887	** with its parent to form a single flat query. In so doing, it might
ds@1952	2888	** change the parent query from a non-aggregate to an aggregate query.
ds@1952	2889	** For that reason, the pParentAgg flag is passed as a pointer, so it
ds@1952	2890	** can be changed.
ds@1952	2891	**
ds@1952	2892	** Example 1: The meaning of the pParent parameter.
ds@1952	2893	**
ds@1952	2894	** SELECT * FROM t1 JOIN (SELECT x, count(*) FROM t2) JOIN t3;
ds@1952	2895	** \ \_______ subquery _______/ /
ds@1952	2896	** \ /
ds@1952	2897	** \____________________ outer query ___________________/
ds@1952	2898	**
ds@1952	2899	** This routine is called for the outer query first. For that call,
ds@1952	2900	** pParent will be NULL. During the processing of the outer query, this
ds@1952	2901	** routine is called recursively to handle the subquery. For the recursive
ds@1952	2902	** call, pParent will point to the outer query. Because the subquery is
ds@1952	2903	** the second element in a three-way join, the parentTab parameter will
ds@1952	2904	** be 1 (the 2nd value of a 0-indexed array.)
ds@1952	2905	*/
ds@1952	2906	int sqlite3Select(
ds@1952	2907	Parse pParse, / The parser context */
ds@1952	2908	Select p, / The SELECT statement being coded. */
ds@1952	2909	int eDest, /* How to dispose of the results */
ds@1952	2910	int iParm, /* A parameter used by the eDest disposal method */
ds@1952	2911	Select pParent, / Another SELECT for which this is a sub-query */
ds@1952	2912	int parentTab, /* Index in pParent->pSrc of this query */
ds@1952	2913	int pParentAgg, / True if pParent uses aggregate functions */
ds@1952	2914	char aff / If eDest is SRT_Union, the affinity string */
ds@1952	2915	){
ds@1952	2916	int i, j; /* Loop counters */
ds@1952	2917	WhereInfo pWInfo; / Return from sqlite3WhereBegin() */
ds@1952	2918	Vdbe v; / The virtual machine under construction */
ds@1952	2919	int isAgg; /* True for select lists like "count()" /
ds@1952	2920	ExprList pEList; / List of columns to extract. */
ds@1952	2921	SrcList pTabList; / List of tables to select from */
ds@1952	2922	Expr pWhere; / The WHERE clause. May be NULL */
ds@1952	2923	ExprList pOrderBy; / The ORDER BY clause. May be NULL */
ds@1952	2924	ExprList pGroupBy; / The GROUP BY clause. May be NULL */
ds@1952	2925	Expr pHaving; / The HAVING clause. May be NULL */
ds@1952	2926	int isDistinct; /* True if the DISTINCT keyword is present */
ds@1952	2927	int distinct; /* Table to use for the distinct set */
ds@1952	2928	int rc = 1; /* Value to return from this function */
ds@1952	2929	int addrSortIndex; /* Address of an OP_OpenEphemeral instruction */
ds@1952	2930	AggInfo sAggInfo; /* Information used by aggregate queries */
ds@1952	2931	int iEnd; /* Address of the end of the query */
ds@1952	2932	sqlite3 db; / The database connection */
ds@1952	2933
ds@1952	2934	db = pParse->db;
ds@1952	2935	if( p==0 \|\| db->mallocFailed \|\| pParse->nErr ){
ds@1952	2936	return 1;
ds@1952	2937	}
ds@1952	2938	if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
ds@1952	2939	memset(&sAggInfo, 0, sizeof(sAggInfo));
ds@1952	2940
ds@1952	2941	#ifndef SQLITE_OMIT_COMPOUND_SELECT
ds@1952	2942	/* If there is are a sequence of queries, do the earlier ones first.
ds@1952	2943	*/
ds@1952	2944	if( p->pPrior ){
ds@1952	2945	if( p->pRightmost==0 ){
ds@1952	2946	Select *pLoop;
ds@1952	2947	int cnt = 0;
ds@1952	2948	for(pLoop=p; pLoop; pLoop=pLoop->pPrior, cnt++){
ds@1952	2949	pLoop->pRightmost = p;
ds@1952	2950	}
ds@1952	2951	if( SQLITE_MAX_COMPOUND_SELECT>0 && cnt>SQLITE_MAX_COMPOUND_SELECT ){
ds@1952	2952	sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");
ds@1952	2953	return 1;
ds@1952	2954	}
ds@1952	2955	}
ds@1952	2956	return multiSelect(pParse, p, eDest, iParm, aff);
ds@1952	2957	}
ds@1952	2958	#endif
ds@1952	2959
ds@1952	2960	pOrderBy = p->pOrderBy;
ds@1952	2961	if( IgnorableOrderby(eDest) ){
ds@1952	2962	p->pOrderBy = 0;
ds@1952	2963	}
ds@1952	2964	if( sqlite3SelectResolve(pParse, p, 0) ){
ds@1952	2965	goto select_end;
ds@1952	2966	}
ds@1952	2967	p->pOrderBy = pOrderBy;
ds@1952	2968
ds@1952	2969	/* Make local copies of the parameters for this query.
ds@1952	2970	*/
ds@1952	2971	pTabList = p->pSrc;
ds@1952	2972	pWhere = p->pWhere;
ds@1952	2973	pGroupBy = p->pGroupBy;
ds@1952	2974	pHaving = p->pHaving;
ds@1952	2975	isAgg = p->isAgg;
ds@1952	2976	isDistinct = p->isDistinct;
ds@1952	2977	pEList = p->pEList;
ds@1952	2978	if( pEList==0 ) goto select_end;
ds@1952	2979
ds@1952	2980	/*
ds@1952	2981	** Do not even attempt to generate any code if we have already seen
ds@1952	2982	** errors before this routine starts.
ds@1952	2983	*/
ds@1952	2984	if( pParse->nErr>0 ) goto select_end;
ds@1952	2985
ds@1952	2986	/* If writing to memory or generating a set
ds@1952	2987	** only a single column may be output.
ds@1952	2988	*/
ds@1952	2989	#ifndef SQLITE_OMIT_SUBQUERY
ds@1952	2990	if( checkForMultiColumnSelectError(pParse, eDest, pEList->nExpr) ){
ds@1952	2991	goto select_end;
ds@1952	2992	}
ds@1952	2993	#endif
ds@1952	2994
ds@1952	2995	/* ORDER BY is ignored for some destinations.
ds@1952	2996	*/
ds@1952	2997	if( IgnorableOrderby(eDest) ){
ds@1952	2998	pOrderBy = 0;
ds@1952	2999	}
ds@1952	3000
ds@1952	3001	/* Begin generating code.
ds@1952	3002	*/
ds@1952	3003	v = sqlite3GetVdbe(pParse);
ds@1952	3004	if( v==0 ) goto select_end;
ds@1952	3005
ds@1952	3006	/* Generate code for all sub-queries in the FROM clause
ds@1952	3007	*/
ds@1952	3008	#if !defined(SQLITE_OMIT_SUBQUERY) \|\| !defined(SQLITE_OMIT_VIEW)
ds@1952	3009	for(i=0; i<pTabList->nSrc; i++){
ds@1952	3010	const char *zSavedAuthContext = 0;
ds@1952	3011	int needRestoreContext;
ds@1952	3012	struct SrcList_item *pItem = &pTabList->a[i];
ds@1952	3013
ds@1952	3014	if( pItem->pSelect==0 \|\| pItem->isPopulated ) continue;
ds@1952	3015	if( pItem->zName!=0 ){
ds@1952	3016	zSavedAuthContext = pParse->zAuthContext;
ds@1952	3017	pParse->zAuthContext = pItem->zName;
ds@1952	3018	needRestoreContext = 1;
ds@1952	3019	}else{
ds@1952	3020	needRestoreContext = 0;
ds@1952	3021	}
ds@1952	3022	#if defined(SQLITE_TEST) \|\| SQLITE_MAX_EXPR_DEPTH>0
ds@1952	3023	/* Increment Parse.nHeight by the height of the largest expression
ds@1952	3024	** tree refered to by this, the parent select. The child select
ds@1952	3025	** may contain expression trees of at most
ds@1952	3026	** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
ds@1952	3027	** more conservative than necessary, but much easier than enforcing
ds@1952	3028	** an exact limit.
ds@1952	3029	*/
ds@1952	3030	pParse->nHeight += sqlite3SelectExprHeight(p);
ds@1952	3031	#endif
ds@1952	3032	sqlite3Select(pParse, pItem->pSelect, SRT_EphemTab,
ds@1952	3033	pItem->iCursor, p, i, &isAgg, 0);
ds@1952	3034	#if defined(SQLITE_TEST) \|\| SQLITE_MAX_EXPR_DEPTH>0
ds@1952	3035	pParse->nHeight -= sqlite3SelectExprHeight(p);
ds@1952	3036	#endif
ds@1952	3037	if( needRestoreContext ){
ds@1952	3038	pParse->zAuthContext = zSavedAuthContext;
ds@1952	3039	}
ds@1952	3040	pTabList = p->pSrc;
ds@1952	3041	pWhere = p->pWhere;
ds@1952	3042	if( !IgnorableOrderby(eDest) ){
ds@1952	3043	pOrderBy = p->pOrderBy;
ds@1952	3044	}
ds@1952	3045	pGroupBy = p->pGroupBy;
ds@1952	3046	pHaving = p->pHaving;
ds@1952	3047	isDistinct = p->isDistinct;
ds@1952	3048	}
ds@1952	3049	#endif
ds@1952	3050
ds@1952	3051	/* Check for the special case of a min() or max() function by itself
ds@1952	3052	** in the result set.
ds@1952	3053	*/
ds@1952	3054	if( simpleMinMaxQuery(pParse, p, eDest, iParm) ){
ds@1952	3055	rc = 0;
ds@1952	3056	goto select_end;
ds@1952	3057	}
ds@1952	3058
ds@1952	3059	/* Check to see if this is a subquery that can be "flattened" into its parent.
ds@1952	3060	** If flattening is a possiblity, do so and return immediately.
ds@1952	3061	*/
ds@1952	3062	#ifndef SQLITE_OMIT_VIEW
ds@1952	3063	if( pParent && pParentAgg &&
ds@1952	3064	flattenSubquery(db, pParent, parentTab, *pParentAgg, isAgg) ){
ds@1952	3065	if( isAgg ) *pParentAgg = 1;
ds@1952	3066	goto select_end;
ds@1952	3067	}
ds@1952	3068	#endif
ds@1952	3069
ds@1952	3070	/* If there is an ORDER BY clause, then this sorting
ds@1952	3071	** index might end up being unused if the data can be
ds@1952	3072	** extracted in pre-sorted order. If that is the case, then the
ds@1952	3073	** OP_OpenEphemeral instruction will be changed to an OP_Noop once
ds@1952	3074	** we figure out that the sorting index is not needed. The addrSortIndex
ds@1952	3075	** variable is used to facilitate that change.
ds@1952	3076	*/
ds@1952	3077	if( pOrderBy ){
ds@1952	3078	KeyInfo *pKeyInfo;
ds@1952	3079	if( pParse->nErr ){
ds@1952	3080	goto select_end;
ds@1952	3081	}
ds@1952	3082	pKeyInfo = keyInfoFromExprList(pParse, pOrderBy);
ds@1952	3083	pOrderBy->iECursor = pParse->nTab++;
ds@1952	3084	p->addrOpenEphm[2] = addrSortIndex =
ds@1952	3085	sqlite3VdbeOp3(v, OP_OpenEphemeral, pOrderBy->iECursor, pOrderBy->nExpr+2, (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
ds@1952	3086	}else{
ds@1952	3087	addrSortIndex = -1;
ds@1952	3088	}
ds@1952	3089
ds@1952	3090	/* If the output is destined for a temporary table, open that table.
ds@1952	3091	*/
ds@1952	3092	if( eDest==SRT_EphemTab ){
ds@1952	3093	sqlite3VdbeAddOp(v, OP_OpenEphemeral, iParm, pEList->nExpr);
ds@1952	3094	}
ds@1952	3095
ds@1952	3096	/* Set the limiter.
ds@1952	3097	*/
ds@1952	3098	iEnd = sqlite3VdbeMakeLabel(v);
ds@1952	3099	computeLimitRegisters(pParse, p, iEnd);
ds@1952	3100
ds@1952	3101	/* Open a virtual index to use for the distinct set.
ds@1952	3102	*/
ds@1952	3103	if( isDistinct ){
ds@1952	3104	KeyInfo *pKeyInfo;
ds@1952	3105	distinct = pParse->nTab++;
ds@1952	3106	pKeyInfo = keyInfoFromExprList(pParse, p->pEList);
ds@1952	3107	sqlite3VdbeOp3(v, OP_OpenEphemeral, distinct, 0,
ds@1952	3108	(char*)pKeyInfo, P3_KEYINFO_HANDOFF);
ds@1952	3109	}else{
ds@1952	3110	distinct = -1;
ds@1952	3111	}
ds@1952	3112
ds@1952	3113	/* Aggregate and non-aggregate queries are handled differently */
ds@1952	3114	if( !isAgg && pGroupBy==0 ){
ds@1952	3115	/* This case is for non-aggregate queries
ds@1952	3116	** Begin the database scan
ds@1952	3117	*/
ds@1952	3118	pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pOrderBy);
ds@1952	3119	if( pWInfo==0 ) goto select_end;
ds@1952	3120
ds@1952	3121	/* If sorting index that was created by a prior OP_OpenEphemeral
ds@1952	3122	** instruction ended up not being needed, then change the OP_OpenEphemeral
ds@1952	3123	** into an OP_Noop.
ds@1952	3124	*/
ds@1952	3125	if( addrSortIndex>=0 && pOrderBy==0 ){
ds@1952	3126	sqlite3VdbeChangeToNoop(v, addrSortIndex, 1);
ds@1952	3127	p->addrOpenEphm[2] = -1;
ds@1952	3128	}
ds@1952	3129
ds@1952	3130	/* Use the standard inner loop
ds@1952	3131	*/
ds@1952	3132	if( selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, eDest,
ds@1952	3133	iParm, pWInfo->iContinue, pWInfo->iBreak, aff) ){
ds@1952	3134	goto select_end;
ds@1952	3135	}
ds@1952	3136
ds@1952	3137	/* End the database scan loop.
ds@1952	3138	*/
ds@1952	3139	sqlite3WhereEnd(pWInfo);
ds@1952	3140	}else{
ds@1952	3141	/* This is the processing for aggregate queries */
ds@1952	3142	NameContext sNC; /* Name context for processing aggregate information */
ds@1952	3143	int iAMem; /* First Mem address for storing current GROUP BY */
ds@1952	3144	int iBMem; /* First Mem address for previous GROUP BY */
ds@1952	3145	int iUseFlag; /* Mem address holding flag indicating that at least
ds@1952	3146	** one row of the input to the aggregator has been
ds@1952	3147	** processed */
ds@1952	3148	int iAbortFlag; /* Mem address which causes query abort if positive */
ds@1952	3149	int groupBySort; /* Rows come from source in GROUP BY order */
ds@1952	3150
ds@1952	3151
ds@1952	3152	/* The following variables hold addresses or labels for parts of the
ds@1952	3153	** virtual machine program we are putting together */
ds@1952	3154	int addrOutputRow; /* Start of subroutine that outputs a result row */
ds@1952	3155	int addrSetAbort; /* Set the abort flag and return */
ds@1952	3156	int addrInitializeLoop; /* Start of code that initializes the input loop */
ds@1952	3157	int addrTopOfLoop; /* Top of the input loop */
ds@1952	3158	int addrGroupByChange; /* Code that runs when any GROUP BY term changes */
ds@1952	3159	int addrProcessRow; /* Code to process a single input row */
ds@1952	3160	int addrEnd; /* End of all processing */
ds@1952	3161	int addrSortingIdx; /* The OP_OpenEphemeral for the sorting index */
ds@1952	3162	int addrReset; /* Subroutine for resetting the accumulator */
ds@1952	3163
ds@1952	3164	addrEnd = sqlite3VdbeMakeLabel(v);
ds@1952	3165
ds@1952	3166	/* Convert TK_COLUMN nodes into TK_AGG_COLUMN and make entries in
ds@1952	3167	** sAggInfo for all TK_AGG_FUNCTION nodes in expressions of the
ds@1952	3168	** SELECT statement.
ds@1952	3169	*/
ds@1952	3170	memset(&sNC, 0, sizeof(sNC));
ds@1952	3171	sNC.pParse = pParse;
ds@1952	3172	sNC.pSrcList = pTabList;
ds@1952	3173	sNC.pAggInfo = &sAggInfo;
ds@1952	3174	sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr+1 : 0;
ds@1952	3175	sAggInfo.pGroupBy = pGroupBy;
ds@1952	3176	if( sqlite3ExprAnalyzeAggList(&sNC, pEList) ){
ds@1952	3177	goto select_end;
ds@1952	3178	}
ds@1952	3179	if( sqlite3ExprAnalyzeAggList(&sNC, pOrderBy) ){
ds@1952	3180	goto select_end;
ds@1952	3181	}
ds@1952	3182	if( pHaving && sqlite3ExprAnalyzeAggregates(&sNC, pHaving) ){
ds@1952	3183	goto select_end;
ds@1952	3184	}
ds@1952	3185	sAggInfo.nAccumulator = sAggInfo.nColumn;
ds@1952	3186	for(i=0; i<sAggInfo.nFunc; i++){
ds@1952	3187	if( sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->pList) ){
ds@1952	3188	goto select_end;
ds@1952	3189	}
ds@1952	3190	}
ds@1952	3191	if( db->mallocFailed ) goto select_end;
ds@1952	3192
ds@1952	3193	/* Processing for aggregates with GROUP BY is very different and
ds@1952	3194	** much more complex tha aggregates without a GROUP BY.
ds@1952	3195	*/
ds@1952	3196	if( pGroupBy ){
ds@1952	3197	KeyInfo pKeyInfo; / Keying information for the group by clause */
ds@1952	3198
ds@1952	3199	/* Create labels that we will be needing
ds@1952	3200	*/
ds@1952	3201
ds@1952	3202	addrInitializeLoop = sqlite3VdbeMakeLabel(v);
ds@1952	3203	addrGroupByChange = sqlite3VdbeMakeLabel(v);
ds@1952	3204	addrProcessRow = sqlite3VdbeMakeLabel(v);
ds@1952	3205
ds@1952	3206	/* If there is a GROUP BY clause we might need a sorting index to
ds@1952	3207	** implement it. Allocate that sorting index now. If it turns out
ds@1952	3208	** that we do not need it after all, the OpenEphemeral instruction
ds@1952	3209	** will be converted into a Noop.
ds@1952	3210	*/
ds@1952	3211	sAggInfo.sortingIdx = pParse->nTab++;
ds@1952	3212	pKeyInfo = keyInfoFromExprList(pParse, pGroupBy);
ds@1952	3213	addrSortingIdx =
ds@1952	3214	sqlite3VdbeOp3(v, OP_OpenEphemeral, sAggInfo.sortingIdx,
ds@1952	3215	sAggInfo.nSortingColumn,
ds@1952	3216	(char*)pKeyInfo, P3_KEYINFO_HANDOFF);
ds@1952	3217
ds@1952	3218	/* Initialize memory locations used by GROUP BY aggregate processing
ds@1952	3219	*/
ds@1952	3220	iUseFlag = pParse->nMem++;
ds@1952	3221	iAbortFlag = pParse->nMem++;
ds@1952	3222	iAMem = pParse->nMem;
ds@1952	3223	pParse->nMem += pGroupBy->nExpr;
ds@1952	3224	iBMem = pParse->nMem;
ds@1952	3225	pParse->nMem += pGroupBy->nExpr;
ds@1952	3226	sqlite3VdbeAddOp(v, OP_MemInt, 0, iAbortFlag);
ds@1952	3227	VdbeComment((v, "# clear abort flag"));
ds@1952	3228	sqlite3VdbeAddOp(v, OP_MemInt, 0, iUseFlag);
ds@1952	3229	VdbeComment((v, "# indicate accumulator empty"));
ds@1952	3230	sqlite3VdbeAddOp(v, OP_Goto, 0, addrInitializeLoop);
ds@1952	3231
ds@1952	3232	/* Generate a subroutine that outputs a single row of the result
ds@1952	3233	** set. This subroutine first looks at the iUseFlag. If iUseFlag
ds@1952	3234	** is less than or equal to zero, the subroutine is a no-op. If
ds@1952	3235	** the processing calls for the query to abort, this subroutine
ds@1952	3236	** increments the iAbortFlag memory location before returning in
ds@1952	3237	** order to signal the caller to abort.
ds@1952	3238	*/
ds@1952	3239	addrSetAbort = sqlite3VdbeCurrentAddr(v);
ds@1952	3240	sqlite3VdbeAddOp(v, OP_MemInt, 1, iAbortFlag);
ds@1952	3241	VdbeComment((v, "# set abort flag"));
ds@1952	3242	sqlite3VdbeAddOp(v, OP_Return, 0, 0);
ds@1952	3243	addrOutputRow = sqlite3VdbeCurrentAddr(v);
ds@1952	3244	sqlite3VdbeAddOp(v, OP_IfMemPos, iUseFlag, addrOutputRow+2);
ds@1952	3245	VdbeComment((v, "# Groupby result generator entry point"));
ds@1952	3246	sqlite3VdbeAddOp(v, OP_Return, 0, 0);
ds@1952	3247	finalizeAggFunctions(pParse, &sAggInfo);
ds@1952	3248	if( pHaving ){
ds@1952	3249	sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, 1);
ds@1952	3250	}
ds@1952	3251	rc = selectInnerLoop(pParse, p, p->pEList, 0, 0, pOrderBy,
ds@1952	3252	distinct, eDest, iParm,
ds@1952	3253	addrOutputRow+1, addrSetAbort, aff);
ds@1952	3254	if( rc ){
ds@1952	3255	goto select_end;
ds@1952	3256	}
ds@1952	3257	sqlite3VdbeAddOp(v, OP_Return, 0, 0);
ds@1952	3258	VdbeComment((v, "# end groupby result generator"));
ds@1952	3259
ds@1952	3260	/* Generate a subroutine that will reset the group-by accumulator
ds@1952	3261	*/
ds@1952	3262	addrReset = sqlite3VdbeCurrentAddr(v);
ds@1952	3263	resetAccumulator(pParse, &sAggInfo);
ds@1952	3264	sqlite3VdbeAddOp(v, OP_Return, 0, 0);
ds@1952	3265
ds@1952	3266	/* Begin a loop that will extract all source rows in GROUP BY order.
ds@1952	3267	** This might involve two separate loops with an OP_Sort in between, or
ds@1952	3268	** it might be a single loop that uses an index to extract information
ds@1952	3269	** in the right order to begin with.
ds@1952	3270	*/
ds@1952	3271	sqlite3VdbeResolveLabel(v, addrInitializeLoop);
ds@1952	3272	sqlite3VdbeAddOp(v, OP_Gosub, 0, addrReset);
ds@1952	3273	pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pGroupBy);
ds@1952	3274	if( pWInfo==0 ) goto select_end;
ds@1952	3275	if( pGroupBy==0 ){
ds@1952	3276	/* The optimizer is able to deliver rows in group by order so
ds@1952	3277	** we do not have to sort. The OP_OpenEphemeral table will be
ds@1952	3278	** cancelled later because we still need to use the pKeyInfo
ds@1952	3279	*/
ds@1952	3280	pGroupBy = p->pGroupBy;
ds@1952	3281	groupBySort = 0;
ds@1952	3282	}else{
ds@1952	3283	/* Rows are coming out in undetermined order. We have to push
ds@1952	3284	** each row into a sorting index, terminate the first loop,
ds@1952	3285	** then loop over the sorting index in order to get the output
ds@1952	3286	** in sorted order
ds@1952	3287	*/
ds@1952	3288	groupBySort = 1;
ds@1952	3289	sqlite3ExprCodeExprList(pParse, pGroupBy);
ds@1952	3290	sqlite3VdbeAddOp(v, OP_Sequence, sAggInfo.sortingIdx, 0);
ds@1952	3291	j = pGroupBy->nExpr+1;
ds@1952	3292	for(i=0; i<sAggInfo.nColumn; i++){
ds@1952	3293	struct AggInfo_col *pCol = &sAggInfo.aCol[i];
ds@1952	3294	if( pCol->iSorterColumn<j ) continue;
ds@1952	3295	sqlite3ExprCodeGetColumn(v, pCol->pTab, pCol->iColumn, pCol->iTable);
ds@1952	3296	j++;
ds@1952	3297	}
ds@1952	3298	sqlite3VdbeAddOp(v, OP_MakeRecord, j, 0);
ds@1952	3299	sqlite3VdbeAddOp(v, OP_IdxInsert, sAggInfo.sortingIdx, 0);
ds@1952	3300	sqlite3WhereEnd(pWInfo);
ds@1952	3301	sqlite3VdbeAddOp(v, OP_Sort, sAggInfo.sortingIdx, addrEnd);
ds@1952	3302	VdbeComment((v, "# GROUP BY sort"));
ds@1952	3303	sAggInfo.useSortingIdx = 1;
ds@1952	3304	}
ds@1952	3305
ds@1952	3306	/* Evaluate the current GROUP BY terms and store in b0, b1, b2...
ds@1952	3307	** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
ds@1952	3308	** Then compare the current GROUP BY terms against the GROUP BY terms
ds@1952	3309	** from the previous row currently stored in a0, a1, a2...
ds@1952	3310	*/
ds@1952	3311	addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
ds@1952	3312	for(j=0; j<pGroupBy->nExpr; j++){
ds@1952	3313	if( groupBySort ){
ds@1952	3314	sqlite3VdbeAddOp(v, OP_Column, sAggInfo.sortingIdx, j);
ds@1952	3315	}else{
ds@1952	3316	sAggInfo.directMode = 1;
ds@1952	3317	sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr);
ds@1952	3318	}
ds@1952	3319	sqlite3VdbeAddOp(v, OP_MemStore, iBMem+j, j<pGroupBy->nExpr-1);
ds@1952	3320	}
ds@1952	3321	for(j=pGroupBy->nExpr-1; j>=0; j--){
ds@1952	3322	if( j<pGroupBy->nExpr-1 ){
ds@1952	3323	sqlite3VdbeAddOp(v, OP_MemLoad, iBMem+j, 0);
ds@1952	3324	}
ds@1952	3325	sqlite3VdbeAddOp(v, OP_MemLoad, iAMem+j, 0);
ds@1952	3326	if( j==0 ){
ds@1952	3327	sqlite3VdbeAddOp(v, OP_Eq, 0x200, addrProcessRow);
ds@1952	3328	}else{
ds@1952	3329	sqlite3VdbeAddOp(v, OP_Ne, 0x200, addrGroupByChange);
ds@1952	3330	}
ds@1952	3331	sqlite3VdbeChangeP3(v, -1, (void*)pKeyInfo->aColl[j], P3_COLLSEQ);
ds@1952	3332	}
ds@1952	3333
ds@1952	3334	/* Generate code that runs whenever the GROUP BY changes.
ds@1952	3335	** Change in the GROUP BY are detected by the previous code
ds@1952	3336	** block. If there were no changes, this block is skipped.
ds@1952	3337	**
ds@1952	3338	** This code copies current group by terms in b0,b1,b2,...
ds@1952	3339	** over to a0,a1,a2. It then calls the output subroutine
ds@1952	3340	** and resets the aggregate accumulator registers in preparation
ds@1952	3341	** for the next GROUP BY batch.
ds@1952	3342	*/
ds@1952	3343	sqlite3VdbeResolveLabel(v, addrGroupByChange);
ds@1952	3344	for(j=0; j<pGroupBy->nExpr; j++){
ds@1952	3345	sqlite3VdbeAddOp(v, OP_MemMove, iAMem+j, iBMem+j);
ds@1952	3346	}
ds@1952	3347	sqlite3VdbeAddOp(v, OP_Gosub, 0, addrOutputRow);
ds@1952	3348	VdbeComment((v, "# output one row"));
ds@1952	3349	sqlite3VdbeAddOp(v, OP_IfMemPos, iAbortFlag, addrEnd);
ds@1952	3350	VdbeComment((v, "# check abort flag"));
ds@1952	3351	sqlite3VdbeAddOp(v, OP_Gosub, 0, addrReset);
ds@1952	3352	VdbeComment((v, "# reset accumulator"));
ds@1952	3353
ds@1952	3354	/* Update the aggregate accumulators based on the content of
ds@1952	3355	** the current row
ds@1952	3356	*/
ds@1952	3357	sqlite3VdbeResolveLabel(v, addrProcessRow);
ds@1952	3358	updateAccumulator(pParse, &sAggInfo);
ds@1952	3359	sqlite3VdbeAddOp(v, OP_MemInt, 1, iUseFlag);
ds@1952	3360	VdbeComment((v, "# indicate data in accumulator"));
ds@1952	3361
ds@1952	3362	/* End of the loop
ds@1952	3363	*/
ds@1952	3364	if( groupBySort ){
ds@1952	3365	sqlite3VdbeAddOp(v, OP_Next, sAggInfo.sortingIdx, addrTopOfLoop);
ds@1952	3366	}else{
ds@1952	3367	sqlite3WhereEnd(pWInfo);
ds@1952	3368	sqlite3VdbeChangeToNoop(v, addrSortingIdx, 1);
ds@1952	3369	}
ds@1952	3370
ds@1952	3371	/* Output the final row of result
ds@1952	3372	*/
ds@1952	3373	sqlite3VdbeAddOp(v, OP_Gosub, 0, addrOutputRow);
ds@1952	3374	VdbeComment((v, "# output final row"));
ds@1952	3375
ds@1952	3376	} /* endif pGroupBy */
ds@1952	3377	else {
ds@1952	3378	/* This case runs if the aggregate has no GROUP BY clause. The
ds@1952	3379	** processing is much simpler since there is only a single row
ds@1952	3380	** of output.
ds@1952	3381	*/
ds@1952	3382	resetAccumulator(pParse, &sAggInfo);
ds@1952	3383	pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0);
ds@1952	3384	if( pWInfo==0 ) goto select_end;
ds@1952	3385	updateAccumulator(pParse, &sAggInfo);
ds@1952	3386	sqlite3WhereEnd(pWInfo);
ds@1952	3387	finalizeAggFunctions(pParse, &sAggInfo);
ds@1952	3388	pOrderBy = 0;
ds@1952	3389	if( pHaving ){
ds@1952	3390	sqlite3ExprIfFalse(pParse, pHaving, addrEnd, 1);
ds@1952	3391	}
ds@1952	3392	selectInnerLoop(pParse, p, p->pEList, 0, 0, 0, -1,
ds@1952	3393	eDest, iParm, addrEnd, addrEnd, aff);
ds@1952	3394	}
ds@1952	3395	sqlite3VdbeResolveLabel(v, addrEnd);
ds@1952	3396
ds@1952	3397	} /* endif aggregate query */
ds@1952	3398
ds@1952	3399	/* If there is an ORDER BY clause, then we need to sort the results
ds@1952	3400	** and send them to the callback one by one.
ds@1952	3401	*/
ds@1952	3402	if( pOrderBy ){
ds@1952	3403	generateSortTail(pParse, p, v, pEList->nExpr, eDest, iParm);
ds@1952	3404	}
ds@1952	3405
ds@1952	3406	#ifndef SQLITE_OMIT_SUBQUERY
ds@1952	3407	/* If this was a subquery, we have now converted the subquery into a
ds@1952	3408	** temporary table. So set the SrcList_item.isPopulated flag to prevent
ds@1952	3409	** this subquery from being evaluated again and to force the use of
ds@1952	3410	** the temporary table.
ds@1952	3411	*/
ds@1952	3412	if( pParent ){
ds@1952	3413	assert( pParent->pSrc->nSrc>parentTab );
ds@1952	3414	assert( pParent->pSrc->a[parentTab].pSelect==p );
ds@1952	3415	pParent->pSrc->a[parentTab].isPopulated = 1;
ds@1952	3416	}
ds@1952	3417	#endif
ds@1952	3418
ds@1952	3419	/* Jump here to skip this query
ds@1952	3420	*/
ds@1952	3421	sqlite3VdbeResolveLabel(v, iEnd);
ds@1952	3422
ds@1952	3423	/* The SELECT was successfully coded. Set the return code to 0
ds@1952	3424	** to indicate no errors.
ds@1952	3425	*/
ds@1952	3426	rc = 0;
ds@1952	3427
ds@1952	3428	/* Control jumps to here if an error is encountered above, or upon
ds@1952	3429	** successful coding of the SELECT.
ds@1952	3430	*/
ds@1952	3431	select_end:
ds@1952	3432
ds@1952	3433	/* Identify column names if we will be using them in a callback. This
ds@1952	3434	** step is skipped if the output is going to some other destination.
ds@1952	3435	*/
ds@1952	3436	if( rc==SQLITE_OK && eDest==SRT_Callback ){
ds@1952	3437	generateColumnNames(pParse, pTabList, pEList);
ds@1952	3438	}
ds@1952	3439
ds@1952	3440	sqlite3_free(sAggInfo.aCol);
ds@1952	3441	sqlite3_free(sAggInfo.aFunc);
ds@1952	3442	return rc;
ds@1952	3443	}
ds@1952	3444
ds@1952	3445	#if defined(SQLITE_DEBUG)
ds@1952	3446	/*
ds@1952	3447	*******************************************************************************
ds@1952	3448	** The following code is used for testing and debugging only. The code
ds@1952	3449	** that follows does not appear in normal builds.
ds@1952	3450	**
ds@1952	3451	** These routines are used to print out the content of all or part of a
ds@1952	3452	** parse structures such as Select or Expr. Such printouts are useful
ds@1952	3453	** for helping to understand what is happening inside the code generator
ds@1952	3454	** during the execution of complex SELECT statements.
ds@1952	3455	**
ds@1952	3456	** These routine are not called anywhere from within the normal
ds@1952	3457	** code base. Then are intended to be called from within the debugger
ds@1952	3458	** or from temporary "printf" statements inserted for debugging.
ds@1952	3459	*/
ds@1952	3460	void sqlite3PrintExpr(Expr *p){
ds@1952	3461	if( p->token.z && p->token.n>0 ){
ds@1952	3462	sqlite3DebugPrintf("(%.*s", p->token.n, p->token.z);
ds@1952	3463	}else{
ds@1952	3464	sqlite3DebugPrintf("(%d", p->op);
ds@1952	3465	}
ds@1952	3466	if( p->pLeft ){
ds@1952	3467	sqlite3DebugPrintf(" ");
ds@1952	3468	sqlite3PrintExpr(p->pLeft);
ds@1952	3469	}
ds@1952	3470	if( p->pRight ){
ds@1952	3471	sqlite3DebugPrintf(" ");
ds@1952	3472	sqlite3PrintExpr(p->pRight);
ds@1952	3473	}
ds@1952	3474	sqlite3DebugPrintf(")");
ds@1952	3475	}
ds@1952	3476	void sqlite3PrintExprList(ExprList *pList){
ds@1952	3477	int i;
ds@1952	3478	for(i=0; i<pList->nExpr; i++){
ds@1952	3479	sqlite3PrintExpr(pList->a[i].pExpr);
ds@1952	3480	if( i<pList->nExpr-1 ){
ds@1952	3481	sqlite3DebugPrintf(", ");
ds@1952	3482	}
ds@1952	3483	}
ds@1952	3484	}
ds@1952	3485	void sqlite3PrintSelect(Select *p, int indent){
ds@1952	3486	sqlite3DebugPrintf("%*sSELECT(%p) ", indent, "", p);
ds@1952	3487	sqlite3PrintExprList(p->pEList);
ds@1952	3488	sqlite3DebugPrintf("\n");
ds@1952	3489	if( p->pSrc ){
ds@1952	3490	char *zPrefix;
ds@1952	3491	int i;
ds@1952	3492	zPrefix = "FROM";
ds@1952	3493	for(i=0; i<p->pSrc->nSrc; i++){
ds@1952	3494	struct SrcList_item *pItem = &p->pSrc->a[i];
ds@1952	3495	sqlite3DebugPrintf("%*s ", indent+6, zPrefix);
ds@1952	3496	zPrefix = "";
ds@1952	3497	if( pItem->pSelect ){
ds@1952	3498	sqlite3DebugPrintf("(\n");
ds@1952	3499	sqlite3PrintSelect(pItem->pSelect, indent+10);
ds@1952	3500	sqlite3DebugPrintf("%*s)", indent+8, "");
ds@1952	3501	}else if( pItem->zName ){
ds@1952	3502	sqlite3DebugPrintf("%s", pItem->zName);
ds@1952	3503	}
ds@1952	3504	if( pItem->pTab ){
ds@1952	3505	sqlite3DebugPrintf("(table: %s)", pItem->pTab->zName);
ds@1952	3506	}
ds@1952	3507	if( pItem->zAlias ){
ds@1952	3508	sqlite3DebugPrintf(" AS %s", pItem->zAlias);
ds@1952	3509	}
ds@1952	3510	if( i<p->pSrc->nSrc-1 ){
ds@1952	3511	sqlite3DebugPrintf(",");
ds@1952	3512	}
ds@1952	3513	sqlite3DebugPrintf("\n");
ds@1952	3514	}
ds@1952	3515	}
ds@1952	3516	if( p->pWhere ){
ds@1952	3517	sqlite3DebugPrintf("%*s WHERE ", indent, "");
ds@1952	3518	sqlite3PrintExpr(p->pWhere);
ds@1952	3519	sqlite3DebugPrintf("\n");
ds@1952	3520	}
ds@1952	3521	if( p->pGroupBy ){
ds@1952	3522	sqlite3DebugPrintf("%*s GROUP BY ", indent, "");
ds@1952	3523	sqlite3PrintExprList(p->pGroupBy);
ds@1952	3524	sqlite3DebugPrintf("\n");
ds@1952	3525	}
ds@1952	3526	if( p->pHaving ){
ds@1952	3527	sqlite3DebugPrintf("%*s HAVING ", indent, "");
ds@1952	3528	sqlite3PrintExpr(p->pHaving);
ds@1952	3529	sqlite3DebugPrintf("\n");
ds@1952	3530	}
ds@1952	3531	if( p->pOrderBy ){
ds@1952	3532	sqlite3DebugPrintf("%*s ORDER BY ", indent, "");
ds@1952	3533	sqlite3PrintExprList(p->pOrderBy);
ds@1952	3534	sqlite3DebugPrintf("\n");
ds@1952	3535	}
ds@1952	3536	}
ds@1952	3537	/* End of the structure debug printing code
ds@1952	3538	*****************************************************************************/
ds@1952	3539	#endif /* defined(SQLITE_TEST) \|\| defined(SQLITE_DEBUG) */

author	Scott Ehlert <ds@alliedmods.net>
	Sun Mar 30 07:00:22 2008 +0000 (2008-03-30)
changeset 1952	b7aa2b626807
permissions	-rw-r--r--