** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
-** $Id: select.c,v 1.205 2004/08/29 16:25:04 drh Exp $
+** $Id: select.c,v 1.206 2004/09/01 03:06:35 drh Exp $
*/
#include "sqliteInt.h"
return -1;
}
+/*
+** Set the value of a token to a '\000'-terminated string.
+*/
+static void setToken(Token *p, const char *z){
+ p->z = z;
+ p->n = strlen(z);
+ p->dyn = 0;
+}
+
+
/*
** Add a term to the WHERE expression in *ppExpr that requires the
** zCol column to be equal in the two tables pTab1 and pTab2.
Expr *pE2a, *pE2b, *pE2c;
Expr *pE;
- dummy.z = zCol;
- dummy.n = strlen(zCol);
- dummy.dyn = 0;
+ setToken(&dummy, zCol);
pE1a = sqlite3Expr(TK_ID, 0, 0, &dummy);
pE2a = sqlite3Expr(TK_ID, 0, 0, &dummy);
- dummy.z = pTab1->zName;
- dummy.n = strlen(dummy.z);
+ setToken(&dummy, pTab1->zName);
pE1b = sqlite3Expr(TK_ID, 0, 0, &dummy);
- dummy.z = pTab2->zName;
- dummy.n = strlen(dummy.z);
+ setToken(&dummy, pTab2->zName);
pE2b = sqlite3Expr(TK_ID, 0, 0, &dummy);
pE1c = sqlite3Expr(TK_DOT, pE1b, pE1a, 0);
pE2c = sqlite3Expr(TK_DOT, pE2b, pE2a, 0);
pE = sqlite3Expr(TK_EQ, pE1c, pE2c, 0);
ExprSetProperty(pE, EP_FromJoin);
- if( *ppExpr ){
- *ppExpr = sqlite3Expr(TK_AND, *ppExpr, pE, 0);
- }else{
- *ppExpr = pE;
- }
+ *ppExpr = sqlite3ExprAnd(*ppExpr, pE);
}
/*
** ON and USING clauses are converted into extra terms of the WHERE clause.
** NATURAL joins also create extra WHERE clause terms.
**
+** The terms of a FROM clause are contained in the Select.pSrc structure.
+** The left most table is the first entry in Select.pSrc. The right-most
+** table is the last entry. The join operator is held in the entry to
+** the left. Thus entry 0 contains the join operator for the join between
+** entries 0 and 1. Any ON or USING clauses associated with the join are
+** also attached to the left entry.
+**
** This routine returns the number of errors encountered.
*/
static int sqliteProcessJoin(Parse *pParse, Select *p){
- SrcList *pSrc;
- int i, j;
+ SrcList *pSrc; /* All tables in the FROM clause */
+ int i, j; /* Loop counters */
+ struct SrcList_item *pLeft; /* Left table being joined */
+ struct SrcList_item *pRight; /* Right table being joined */
+
pSrc = p->pSrc;
- for(i=0; i<pSrc->nSrc-1; i++){
- struct SrcList_item *pTerm = &pSrc->a[i];
- struct SrcList_item *pOther = &pSrc->a[i+1];
+ pLeft = &pSrc->a[0];
+ pRight = &pLeft[1];
+ for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){
+ Table *pLeftTab = pLeft->pTab;
+ Table *pRightTab = pRight->pTab;
- if( pTerm->pTab==0 || pOther->pTab==0 ) continue;
+ if( pLeftTab==0 || pRightTab==0 ) continue;
/* When the NATURAL keyword is present, add WHERE clause terms for
** every column that the two tables have in common.
*/
- if( pTerm->jointype & JT_NATURAL ){
- Table *pTab;
- if( pTerm->pOn || pTerm->pUsing ){
+ if( pLeft->jointype & JT_NATURAL ){
+ if( pLeft->pOn || pLeft->pUsing ){
sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
"an ON or USING clause", 0);
return 1;
}
- pTab = pTerm->pTab;
- for(j=0; j<pTab->nCol; j++){
- if( columnIndex(pOther->pTab, pTab->aCol[j].zName)>=0 ){
- addWhereTerm(pTab->aCol[j].zName, pTab, pOther->pTab, &p->pWhere);
+ for(j=0; j<pLeftTab->nCol; j++){
+ char *zName = pLeftTab->aCol[j].zName;
+ if( columnIndex(pRightTab, zName)>=0 ){
+ addWhereTerm(zName, pLeftTab, pRightTab, &p->pWhere);
}
}
}
/* Disallow both ON and USING clauses in the same join
*/
- if( pTerm->pOn && pTerm->pUsing ){
+ if( pLeft->pOn && pLeft->pUsing ){
sqlite3ErrorMsg(pParse, "cannot have both ON and USING "
"clauses in the same join");
return 1;
}
/* Add the ON clause to the end of the WHERE clause, connected by
- ** and AND operator.
+ ** an AND operator.
*/
- if( pTerm->pOn ){
- setJoinExpr(pTerm->pOn);
- if( p->pWhere==0 ){
- p->pWhere = pTerm->pOn;
- }else{
- p->pWhere = sqlite3Expr(TK_AND, p->pWhere, pTerm->pOn, 0);
- }
- pTerm->pOn = 0;
+ if( pLeft->pOn ){
+ setJoinExpr(pLeft->pOn);
+ p->pWhere = sqlite3ExprAnd(p->pWhere, pLeft->pOn);
+ pLeft->pOn = 0;
}
/* Create extra terms on the WHERE clause for each column named
** Report an error if any column mentioned in the USING clause is
** not contained in both tables to be joined.
*/
- if( pTerm->pUsing ){
- IdList *pList;
- int j;
- assert( i<pSrc->nSrc-1 );
- pList = pTerm->pUsing;
+ if( pLeft->pUsing ){
+ IdList *pList = pLeft->pUsing;
for(j=0; j<pList->nId; j++){
- if( columnIndex(pTerm->pTab, pList->a[j].zName)<0 ||
- columnIndex(pOther->pTab, pList->a[j].zName)<0 ){
+ char *zName = pList->a[j].zName;
+ if( columnIndex(pLeftTab, zName)<0 || columnIndex(pRightTab, zName)<0 ){
sqlite3ErrorMsg(pParse, "cannot join using column %s - column "
- "not present in both tables", pList->a[j].zName);
+ "not present in both tables", zName);
return 1;
}
- addWhereTerm(pList->a[j].zName, pTerm->pTab, pOther->pTab, &p->pWhere);
+ addWhereTerm(zName, pLeftTab, pRightTab, &p->pWhere);
}
}
}
for(i=0, pCol=aCol; i<pTab->nCol; i++, pCol++){
Expr *pR;
char *zType;
+ char *zName;
Expr *p = pEList->a[i].pExpr;
assert( p->pRight==0 || p->pRight->token.z==0 || p->pRight->token.z[0]!=0 );
- if( pEList->a[i].zName ){
- pCol->zName = sqliteStrDup(pEList->a[i].zName);
+ if( (zName = pEList->a[i].zName)!=0 ){
+ zName = sqliteStrDup(zName);
}else if( p->op==TK_DOT
&& (pR=p->pRight)!=0 && pR->token.z && pR->token.z[0] ){
int cnt;
- sqlite3SetNString(&pCol->zName, pR->token.z, pR->token.n, 0);
+ zName = sqlite3MPrintf("%T", &pR->token);
for(j=cnt=0; j<i; j++){
- if( sqlite3StrICmp(aCol[j].zName, pCol->zName)==0 ){
- int n;
- char zBuf[30];
- sprintf(zBuf,"_%d",++cnt);
- n = strlen(zBuf);
- sqlite3SetNString(&pCol->zName, pR->token.z, pR->token.n, zBuf,n,0);
+ if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){
+ sqliteFree(zName);
+ zName = sqlite3MPrintf("%T_%d", &pR->token, ++cnt);
j = -1;
}
}
}else if( p->span.z && p->span.z[0] ){
- sqlite3SetNString(&pCol->zName, p->span.z, p->span.n, 0);
+ zName = sqlite3MPrintf("%T", &p->span);
}else{
- char zBuf[30];
- sprintf(zBuf, "column%d", i+1);
- pCol->zName = sqliteStrDup(zBuf);
+ zName = sqlite3MPrintf("column%d", i+1);
}
- sqlite3Dequote(pCol->zName);
+ sqlite3Dequote(zName);
+ pCol->zName = zName;
zType = sqliteStrDup(columnType(pParse, pSelect->pSrc ,p));
pCol->zType = zType;
/* A sub-query in the FROM clause of a SELECT */
assert( pFrom->pSelect!=0 );
if( pFrom->zAlias==0 ){
- char zFakeName[60];
- sprintf(zFakeName, "sqlite_subquery_%p_", (void*)pFrom->pSelect);
- sqlite3SetString(&pFrom->zAlias, zFakeName, 0);
+ pFrom->zAlias =
+ sqlite3MPrintf("sqlite_subquery_%p_", (void*)pFrom->pSelect);
}
pFrom->pTab = pTab =
sqlite3ResultSetOfSelect(pParse, pFrom->zAlias, pFrom->pSelect);
Expr *pExpr, *pLeft, *pRight;
char *zName = pTab->aCol[j].zName;
- if( i>0 && (pTabList->a[i-1].jointype & JT_NATURAL)!=0 &&
- columnIndex(pTabList->a[i-1].pTab, zName)>=0 ){
- /* In a NATURAL join, omit the join columns from the
- ** table on the right */
- continue;
- }
- if( i>0 && sqlite3IdListIndex(pTabList->a[i-1].pUsing, zName)>=0 ){
- /* In a join with a USING clause, omit columns in the
- ** using clause from the table on the right. */
- continue;
+ if( i>0 ){
+ struct SrcList_item *pLeft = &pTabList->a[i-1];
+ if( (pLeft->jointype & JT_NATURAL)!=0 &&
+ columnIndex(pLeft->pTab, zName)>=0 ){
+ /* In a NATURAL join, omit the join columns from the
+ ** table on the right */
+ continue;
+ }
+ if( sqlite3IdListIndex(pLeft->pUsing, zName)>=0 ){
+ /* In a join with a USING clause, omit columns in the
+ ** using clause from the table on the right. */
+ continue;
+ }
}
pRight = sqlite3Expr(TK_ID, 0, 0, 0);
if( pRight==0 ) break;
- pRight->token.z = zName;
- pRight->token.n = strlen(zName);
- pRight->token.dyn = 0;
+ setToken(&pRight->token, zName);
if( zTabName && pTabList->nSrc>1 ){
pLeft = sqlite3Expr(TK_ID, 0, 0, 0);
pExpr = sqlite3Expr(TK_DOT, pLeft, pRight, 0);
if( pExpr==0 ) break;
- pLeft->token.z = zTabName;
- pLeft->token.n = strlen(zTabName);
- pLeft->token.dyn = 0;
- sqlite3SetString((char**)&pExpr->span.z, zTabName, ".", zName, 0);
- pExpr->span.n = strlen(pExpr->span.z);
+ setToken(&pLeft->token, zTabName);
+ setToken(&pExpr->span, sqlite3MPrintf("%s.%s", zTabName, zName));
pExpr->span.dyn = 1;
pExpr->token.z = 0;
pExpr->token.n = 0;
void sqlite3SelectUnbind(Select *p){
int i;
SrcList *pSrc = p->pSrc;
+ struct SrcList_item *pItem;
Table *pTab;
if( p==0 ) return;
- for(i=0; i<pSrc->nSrc; i++){
- if( (pTab = pSrc->a[i].pTab)!=0 ){
+ for(i=0, pItem=pSrc->a; i<pSrc->nSrc; i++, pItem++){
+ if( (pTab = pItem->pTab)!=0 ){
if( pTab->isTransient ){
sqlite3DeleteTable(0, pTab);
}
- pSrc->a[i].pTab = 0;
- if( pSrc->a[i].pSelect ){
- sqlite3SelectUnbind(pSrc->a[i].pSelect);
+ pItem->pTab = 0;
+ if( pItem->pSelect ){
+ sqlite3SelectUnbind(pItem->pSelect);
}
}
}
nColumn = p->pEList->nExpr;
pKeyInfo = sqliteMalloc( sizeof(*pKeyInfo)+nColumn*sizeof(CollSeq*) );
if( pKeyInfo==0 ) return 0;
- pKeyInfo->enc = pParse->db->enc;
+ pKeyInfo->enc = db->enc;
pKeyInfo->nField = nColumn;
for(i=0; i<nColumn; i++){
pKeyInfo->aColl[i] = sqlite3ExprCollSeq(pParse, p->pEList->a[i].pExpr);
SrcList *pSubSrc; /* The FROM clause of the subquery */
ExprList *pList; /* The result set of the outer query */
int iParent; /* VDBE cursor number of the pSub result set temp table */
- int i;
- Expr *pWhere;
+ int i; /* Loop counter */
+ Expr *pWhere; /* The WHERE clause */
+ struct SrcList_item *pSubitem; /* The subquery */
/* Check to see if flattening is permitted. Return 0 if not.
*/
if( p==0 ) return 0;
pSrc = p->pSrc;
assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
- pSub = pSrc->a[iFrom].pSelect;
+ pSubitem = &pSrc->a[iFrom];
+ pSub = pSubitem->pSelect;
assert( pSub!=0 );
if( isAgg && subqueryIsAgg ) return 0;
if( subqueryIsAgg && pSrc->nSrc>1 ) return 0;
** those references with expressions that resolve to the subquery FROM
** elements we are now copying in.
*/
- iParent = pSrc->a[iFrom].iCursor;
+ iParent = pSubitem->iCursor;
{
int nSubSrc = pSubSrc->nSrc;
- int jointype = pSrc->a[iFrom].jointype;
+ int jointype = pSubitem->jointype;
+ Table *pTab = pSubitem->pTab;
- if( pSrc->a[iFrom].pTab && pSrc->a[iFrom].pTab->isTransient ){
- sqlite3DeleteTable(0, pSrc->a[iFrom].pTab);
+ if( pTab && pTab->isTransient ){
+ sqlite3DeleteTable(0, pSubitem->pTab);
}
- sqliteFree(pSrc->a[iFrom].zDatabase);
- sqliteFree(pSrc->a[iFrom].zName);
- sqliteFree(pSrc->a[iFrom].zAlias);
+ sqliteFree(pSubitem->zDatabase);
+ sqliteFree(pSubitem->zName);
+ sqliteFree(pSubitem->zAlias);
if( nSubSrc>1 ){
int extra = nSubSrc - 1;
for(i=1; i<nSubSrc; i++){
p->pHaving = p->pWhere;
p->pWhere = pWhere;
substExpr(p->pHaving, iParent, pSub->pEList);
- if( pSub->pHaving ){
- Expr *pHaving = sqlite3ExprDup(pSub->pHaving);
- if( p->pHaving ){
- p->pHaving = sqlite3Expr(TK_AND, p->pHaving, pHaving, 0);
- }else{
- p->pHaving = pHaving;
- }
- }
+ p->pHaving = sqlite3ExprAnd(p->pHaving, sqlite3ExprDup(pSub->pHaving));
assert( p->pGroupBy==0 );
p->pGroupBy = sqlite3ExprListDup(pSub->pGroupBy);
- }else if( p->pWhere==0 ){
- p->pWhere = pWhere;
}else{
substExpr(p->pWhere, iParent, pSub->pEList);
- if( pWhere ){
- p->pWhere = sqlite3Expr(TK_AND, p->pWhere, pWhere, 0);
- }
+ p->pWhere = sqlite3ExprAnd(p->pWhere, pWhere);
}
/* The flattened query is distinct if either the inner or the
projects / thirdparty / sqlite.git / commitdiff
