/*
** Expression pExpr is one operand of a comparison operator that might
** be useful for indexing. This routine checks to see if pExpr appears
** in any index. Return TRUE (1) if pExpr is an indexed term and return
** FALSE (0) if not. If TRUE is returned, also set *piCur to the cursor
** number of the table that is indexed and *piColumn to the column number
** of the column that is indexed, or -2 if an expression is being indexed.
**
** If pExpr is a TK_COLUMN column reference, then this routine always returns
** true even if that particular column is not indexed, because the column
** might be added to an automatic index later.
*/
static int exprMightBeIndexed(
SrcList *pFrom, /* The FROM clause */
Bitmask mPrereq, /* Bitmask of FROM clause terms referenced by pExpr */
Expr *pExpr, /* An operand of a comparison operator */
int *piCur, /* Write the referenced table cursor number here */
int *piColumn /* Write the referenced table column number here */
){
Index *pIdx;
int i;
int iCur;
if( pExpr->op==TK_COLUMN ){
*piCur = pExpr->iTable;
*piColumn = pExpr->iColumn;
return 1;
}
if( mPrereq==0 ) return 0; /* No table references */
if( (mPrereq&(mPrereq-1))!=0 ) return 0; /* Refs more than one table */
for(i=0; mPrereq>1; i++, mPrereq>>=1){}
iCur = pFrom->a[i].iCursor;
for(pIdx=pFrom->a[i].pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( pIdx->aColExpr==0 ) continue;
for(i=0; i<pIdx->nKeyCol; i++){
if( pIdx->aiColumn[i]!=(-2) ) continue;
if( sqlite3ExprCompare(pExpr, pIdx->aColExpr->a[i].pExpr, iCur)==0 ){
*piCur = iCur;
*piColumn = -2;
return 1;
}
}
}
return 0;
}
/*
** pOrderBy is an ORDER BY or GROUP BY clause in SELECT statement pSelect.
** The Name context of the SELECT statement is pNC. zType is either
** "ORDER" or "GROUP" depending on which type of clause pOrderBy is.
**
** This routine resolves each term of the clause into an expression.
** If the order-by term is an integer I between 1 and N (where N is the
** number of columns in the result set of the SELECT) then the expression
** in the resolution is a copy of the I-th result-set expression. If
** the order-by term is an identifier that corresponds to the AS-name of
** a result-set expression, then the term resolves to a copy of the
** result-set expression. Otherwise, the expression is resolved in
** the usual way - using sqlite3ResolveExprNames().
**
** This routine returns the number of errors. If errors occur, then
** an appropriate error message might be left in pParse. (OOM errors
** excepted.)
*/
static int resolveOrderGroupBy(
NameContext *pNC, /* The name context of the SELECT statement */
Select *pSelect, /* The SELECT statement holding pOrderBy */
ExprList *pOrderBy, /* An ORDER BY or GROUP BY clause to resolve */
const char *zType /* Either "ORDER" or "GROUP", as appropriate */
){
int i, j; /* Loop counters */
int iCol; /* Column number */
struct ExprList_item *pItem; /* A term of the ORDER BY clause */
Parse *pParse; /* Parsing context */
int nResult; /* Number of terms in the result set */
if( pOrderBy==0 ) return 0;
nResult = pSelect->pEList->nExpr;
pParse = pNC->pParse;
for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
Expr *pE = pItem->pExpr;
Expr *pE2 = sqlite3ExprSkipCollate(pE);
if( zType[0]!='G' ){
iCol = resolveAsName(pParse, pSelect->pEList, pE2);
if( iCol>0 ){
/* If an AS-name match is found, mark this ORDER BY column as being
** a copy of the iCol-th result-set column. The subsequent call to
** sqlite3ResolveOrderGroupBy() will convert the expression to a
** copy of the iCol-th result-set expression. */
pItem->u.x.iOrderByCol = (u16)iCol;
continue;
}
}
if( sqlite3ExprIsInteger(pE2, &iCol) ){
/* The ORDER BY term is an integer constant. Again, set the column
** number so that sqlite3ResolveOrderGroupBy() will convert the
** order-by term to a copy of the result-set expression */
if( iCol<1 || iCol>0xffff ){
resolveOutOfRangeError(pParse, zType, i+1, nResult);
return 1;
}
pItem->u.x.iOrderByCol = (u16)iCol;
continue;
}
/* Otherwise, treat the ORDER BY term as an ordinary expression */
pItem->u.x.iOrderByCol = 0;
if( sqlite3ResolveExprNames(pNC, pE) ){
return 1;
}
for(j=0; j<pSelect->pEList->nExpr; j++){
if( sqlite3ExprCompare(pE, pSelect->pEList->a[j].pExpr, -1)==0 ){
pItem->u.x.iOrderByCol = j+1;
}
}
}
return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType);
}
/*
** Subterms pOne and pTwo are contained within WHERE clause pWC. The
** two subterms are in disjunction - they are OR-ed together.
**
** If these two terms are both of the form: "A op B" with the same
** A and B values but different operators and if the operators are
** compatible (if one is = and the other is <, for example) then
** add a new virtual AND term to pWC that is the combination of the
** two.
**
** Some examples:
**
** x<y OR x=y --> x<=y
** x=y OR x=y --> x=y
** x<=y OR x<y --> x<=y
**
** The following is NOT generated:
**
** x<y OR x>y --> x!=y
*/
static void whereCombineDisjuncts(
SrcList *pSrc, /* the FROM clause */
WhereClause *pWC, /* The complete WHERE clause */
WhereTerm *pOne, /* First disjunct */
WhereTerm *pTwo /* Second disjunct */
){
u16 eOp = pOne->eOperator | pTwo->eOperator;
sqlite3 *db; /* Database connection (for malloc) */
Expr *pNew; /* New virtual expression */
int op; /* Operator for the combined expression */
int idxNew; /* Index in pWC of the next virtual term */
if( (pOne->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
if( (pTwo->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
if( (eOp & (WO_EQ|WO_LT|WO_LE))!=eOp
&& (eOp & (WO_EQ|WO_GT|WO_GE))!=eOp ) return;
assert( pOne->pExpr->pLeft!=0 && pOne->pExpr->pRight!=0 );
assert( pTwo->pExpr->pLeft!=0 && pTwo->pExpr->pRight!=0 );
if( sqlite3ExprCompare(pOne->pExpr->pLeft, pTwo->pExpr->pLeft, -1) ) return;
if( sqlite3ExprCompare(pOne->pExpr->pRight, pTwo->pExpr->pRight, -1) )return;
/* If we reach this point, it means the two subterms can be combined */
if( (eOp & (eOp-1))!=0 ){
if( eOp & (WO_LT|WO_LE) ){
eOp = WO_LE;
}else{
assert( eOp & (WO_GT|WO_GE) );
eOp = WO_GE;
}
}
db = pWC->pWInfo->pParse->db;
pNew = sqlite3ExprDup(db, pOne->pExpr, 0);
if( pNew==0 ) return;
for(op=TK_EQ; eOp!=(WO_EQ<<(op-TK_EQ)); op++){ assert( op<TK_GE ); }
pNew->op = op;
idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
exprAnalyze(pSrc, pWC, idxNew);
}
/*
** pE is a pointer to an expression which is a single term in the
** ORDER BY of a compound SELECT. The expression has not been
** name resolved.
**
** At the point this routine is called, we already know that the
** ORDER BY term is not an integer index into the result set. That
** case is handled by the calling routine.
**
** Attempt to match pE against result set columns in the left-most
** SELECT statement. Return the index i of the matching column,
** as an indication to the caller that it should sort by the i-th column.
** The left-most column is 1. In other words, the value returned is the
** same integer value that would be used in the SQL statement to indicate
** the column.
**
** If there is no match, return 0. Return -1 if an error occurs.
*/
static int resolveOrderByTermToExprList(
Parse *pParse, /* Parsing context for error messages */
Select *pSelect, /* The SELECT statement with the ORDER BY clause */
Expr *pE /* The specific ORDER BY term */
){
int i; /* Loop counter */
ExprList *pEList; /* The columns of the result set */
NameContext nc; /* Name context for resolving pE */
sqlite3 *db; /* Database connection */
int rc; /* Return code from subprocedures */
u8 savedSuppErr; /* Saved value of db->suppressErr */
assert( sqlite3ExprIsInteger(pE, &i)==0 );
pEList = pSelect->pEList;
/* Resolve all names in the ORDER BY term expression
*/
memset(&nc, 0, sizeof(nc));
nc.pParse = pParse;
nc.pSrcList = pSelect->pSrc;
nc.pEList = pEList;
nc.allowAgg = 1;
nc.nErr = 0;
db = pParse->db;
savedSuppErr = db->suppressErr;
db->suppressErr = 1;
rc = sqlite3ResolveExprNames(&nc, pE);
db->suppressErr = savedSuppErr;
if( rc ) return 0;
/* Try to match the ORDER BY expression against an expression
** in the result set. Return an 1-based index of the matching
** result-set entry.
*/
for(i=0; i<pEList->nExpr; i++){
if( sqlite3ExprCompare(pEList->a[i].pExpr, pE)<2 ){
return i+1;
}
}
/* If no match, return 0. */
return 0;
}
/*
** pE is a pointer to an expression which is a single term in the
** ORDER BY of a compound SELECT. The expression has not been
** name resolved.
**
** At the point this routine is called, we already know that the
** ORDER BY term is not an integer index into the result set. That
** case is handled by the calling routine.
**
** Attempt to match pE against result set columns in the left-most
** SELECT statement. Return the index i of the matching column,
** as an indication to the caller that it should sort by the i-th column.
** The left-most column is 1. In other words, the value returned is the
** same integer value that would be used in the SQL statement to indicate
** the column.
**
** If there is no match, return 0. Return -1 if an error occurs.
*/
static int resolveOrderByTermToExprList(
Parse *pParse, /* Parsing context for error messages */
Select *pSelect, /* The SELECT statement with the ORDER BY clause */
Expr *pE /* The specific ORDER BY term */
){
int i; /* Loop counter */
ExprList *pEList; /* The columns of the result set */
NameContext nc; /* Name context for resolving pE */
assert( sqlite3ExprIsInteger(pE, &i)==0 );
pEList = pSelect->pEList;
/* Resolve all names in the ORDER BY term expression
*/
memset(&nc, 0, sizeof(nc));
nc.pParse = pParse;
nc.pSrcList = pSelect->pSrc;
nc.pEList = pEList;
nc.allowAgg = 1;
nc.nErr = 0;
if( sqlite3ResolveExprNames(&nc, pE) ){
sqlite3ErrorClear(pParse);
return 0;
}
/* Try to match the ORDER BY expression against an expression
** in the result set. Return an 1-based index of the matching
** result-set entry.
*/
for(i=0; i<pEList->nExpr; i++){
if( sqlite3ExprCompare(pEList->a[i].pExpr, pE) ){
return i+1;
}
}
/* If no match, return 0. */
return 0;
}
/*
** Analyze the ON CONFLICT clause described by pUpsert. Resolve all
** symbols in the conflict-target.
**
** Return SQLITE_OK if everything works, or an error code is something
** is wrong.
*/
int sqlite3UpsertAnalyzeTarget(
Parse *pParse, /* The parsing context */
SrcList *pTabList, /* Table into which we are inserting */
Upsert *pUpsert /* The ON CONFLICT clauses */
){
Table *pTab; /* That table into which we are inserting */
int rc; /* Result code */
int iCursor; /* Cursor used by pTab */
Index *pIdx; /* One of the indexes of pTab */
ExprList *pTarget; /* The conflict-target clause */
Expr *pTerm; /* One term of the conflict-target clause */
NameContext sNC; /* Context for resolving symbolic names */
Expr sCol[2]; /* Index column converted into an Expr */
assert( pTabList->nSrc==1 );
assert( pTabList->a[0].pTab!=0 );
assert( pUpsert!=0 );
assert( pUpsert->pUpsertTarget!=0 );
/* Resolve all symbolic names in the conflict-target clause, which
** includes both the list of columns and the optional partial-index
** WHERE clause.
*/
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
rc = sqlite3ResolveExprListNames(&sNC, pUpsert->pUpsertTarget);
if( rc ) return rc;
rc = sqlite3ResolveExprNames(&sNC, pUpsert->pUpsertTargetWhere);
if( rc ) return rc;
/* Check to see if the conflict target matches the rowid. */
pTab = pTabList->a[0].pTab;
pTarget = pUpsert->pUpsertTarget;
iCursor = pTabList->a[0].iCursor;
if( HasRowid(pTab)
&& pTarget->nExpr==1
&& (pTerm = pTarget->a[0].pExpr)->op==TK_COLUMN
&& pTerm->iColumn==XN_ROWID
){
/* The conflict-target is the rowid of the primary table */
assert( pUpsert->pUpsertIdx==0 );
return SQLITE_OK;
}
/* Initialize sCol[0..1] to be an expression parse tree for a
** single column of an index. The sCol[0] node will be the TK_COLLATE
** operator and sCol[1] will be the TK_COLUMN operator. Code below
** will populate the specific collation and column number values
** prior to comparing against the conflict-target expression.
*/
memset(sCol, 0, sizeof(sCol));
sCol[0].op = TK_COLLATE;
sCol[0].pLeft = &sCol[1];
sCol[1].op = TK_COLUMN;
sCol[1].iTable = pTabList->a[0].iCursor;
/* Check for matches against other indexes */
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int ii, jj, nn;
if( !IsUniqueIndex(pIdx) ) continue;
if( pTarget->nExpr!=pIdx->nKeyCol ) continue;
if( pIdx->pPartIdxWhere ){
if( pUpsert->pUpsertTargetWhere==0 ) continue;
if( sqlite3ExprCompare(pParse, pUpsert->pUpsertTargetWhere,
pIdx->pPartIdxWhere, iCursor)!=0 ){
continue;
}
}
nn = pIdx->nKeyCol;
for(ii=0; ii<nn; ii++){
Expr *pExpr;
sCol[0].u.zToken = (char*)pIdx->azColl[ii];
if( pIdx->aiColumn[ii]==XN_EXPR ){
assert( pIdx->aColExpr!=0 );
assert( pIdx->aColExpr->nExpr>ii );
pExpr = pIdx->aColExpr->a[ii].pExpr;
if( pExpr->op!=TK_COLLATE ){
sCol[0].pLeft = pExpr;
pExpr = &sCol[0];
}
}else{
sCol[0].pLeft = &sCol[1];
sCol[1].iColumn = pIdx->aiColumn[ii];
pExpr = &sCol[0];
}
for(jj=0; jj<nn; jj++){
if( sqlite3ExprCompare(pParse, pTarget->a[jj].pExpr, pExpr,iCursor)<2 ){
break; /* Column ii of the index matches column jj of target */
}
}
if( jj>=nn ){
/* The target contains no match for column jj of the index */
break;
}
}
if( ii<nn ){
/* Column ii of the index did not match any term of the conflict target.
** Continue the search with the next index. */
continue;
}
pUpsert->pUpsertIdx = pIdx;
return SQLITE_OK;
}
sqlite3ErrorMsg(pParse, "ON CONFLICT clause does not match any "
"PRIMARY KEY or UNIQUE constraint");
return SQLITE_ERROR;
}
