diff options
Diffstat (limited to 'src/resolve.c')
| -rw-r--r-- | src/resolve.c | 103 |
1 files changed, 65 insertions, 38 deletions
diff --git a/src/resolve.c b/src/resolve.c index 7fc0151ad..bd890c9f8 100644 --- a/src/resolve.c +++ b/src/resolve.c @@ -104,21 +104,36 @@ static void resolveAlias( } /* -** Subqueries stores the original database, table and column names for their -** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN". -** Check to see if the zSpan given to this routine matches the zDb, zTab, -** and zCol. If any of zDb, zTab, and zCol are NULL then those fields will -** match anything. +** Subqueries store the original database, table and column names for their +** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN", +** and mark the expression-list item by setting ExprList.a[].fg.eEName +** to ENAME_TAB. +** +** Check to see if the zSpan/eEName of the expression-list item passed to this +** routine matches the zDb, zTab, and zCol. If any of zDb, zTab, and zCol are +** NULL then those fields will match anything. Return true if there is a match, +** or false otherwise. +** +** SF_NestedFrom subqueries also store an entry for the implicit rowid (or +** _rowid_, or oid) column by setting ExprList.a[].fg.eEName to ENAME_ROWID, +** and setting zSpan to "DATABASE.TABLE.<rowid-alias>". This type of pItem +** argument matches if zCol is a rowid alias. If it is not NULL, (*pbRowid) +** is set to 1 if there is this kind of match. */ int sqlite3MatchEName( const struct ExprList_item *pItem, const char *zCol, const char *zTab, - const char *zDb + const char *zDb, + int *pbRowid ){ int n; const char *zSpan; - if( pItem->fg.eEName!=ENAME_TAB ) return 0; + int eEName = pItem->fg.eEName; + if( eEName!=ENAME_TAB && (eEName!=ENAME_ROWID || NEVER(pbRowid==0)) ){ + return 0; + } + assert( pbRowid==0 || *pbRowid==0 ); zSpan = pItem->zEName; for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){} if( zDb && (sqlite3StrNICmp(zSpan, zDb, n)!=0 || zDb[n]!=0) ){ @@ -130,9 +145,11 @@ int sqlite3MatchEName( return 0; } zSpan += n+1; - if( zCol && sqlite3StrICmp(zSpan, zCol)!=0 ){ - return 0; + if( zCol ){ + if( eEName==ENAME_TAB && sqlite3StrICmp(zSpan, zCol)!=0 ) return 0; + if( eEName==ENAME_ROWID && sqlite3IsRowid(zCol)==0 ) return 0; } + if( eEName==ENAME_ROWID ) *pbRowid = 1; return 1; } @@ -265,7 +282,7 @@ static int lookupName( ){ int i, j; /* Loop counters */ int cnt = 0; /* Number of matching column names */ - int cntTab = 0; /* Number of matching table names */ + int cntTab = 0; /* Number of potential "rowid" matches */ int nSubquery = 0; /* How many levels of subquery */ sqlite3 *db = pParse->db; /* The database connection */ SrcItem *pItem; /* Use for looping over pSrcList items */ @@ -342,39 +359,49 @@ static int lookupName( assert( pEList!=0 ); assert( pEList->nExpr==pTab->nCol ); for(j=0; j<pEList->nExpr; j++){ - if( !sqlite3MatchEName(&pEList->a[j], zCol, zTab, zDb) ){ + int bRowid = 0; /* True if possible rowid match */ + if( !sqlite3MatchEName(&pEList->a[j], zCol, zTab, zDb, &bRowid) ){ continue; } - if( cnt>0 ){ - if( pItem->fg.isUsing==0 - || sqlite3IdListIndex(pItem->u3.pUsing, zCol)<0 - ){ - /* Two or more tables have the same column name which is - ** not joined by USING. This is an error. Signal as much - ** by clearing pFJMatch and letting cnt go above 1. */ - sqlite3ExprListDelete(db, pFJMatch); - pFJMatch = 0; - }else - if( (pItem->fg.jointype & JT_RIGHT)==0 ){ - /* An INNER or LEFT JOIN. Use the left-most table */ - continue; - }else - if( (pItem->fg.jointype & JT_LEFT)==0 ){ - /* A RIGHT JOIN. Use the right-most table */ - cnt = 0; - sqlite3ExprListDelete(db, pFJMatch); - pFJMatch = 0; - }else{ - /* For a FULL JOIN, we must construct a coalesce() func */ - extendFJMatch(pParse, &pFJMatch, pMatch, pExpr->iColumn); + if( bRowid==0 ){ + if( cnt>0 ){ + if( pItem->fg.isUsing==0 + || sqlite3IdListIndex(pItem->u3.pUsing, zCol)<0 + ){ + /* Two or more tables have the same column name which is + ** not joined by USING. This is an error. Signal as much + ** by clearing pFJMatch and letting cnt go above 1. */ + sqlite3ExprListDelete(db, pFJMatch); + pFJMatch = 0; + }else + if( (pItem->fg.jointype & JT_RIGHT)==0 ){ + /* An INNER or LEFT JOIN. Use the left-most table */ + continue; + }else + if( (pItem->fg.jointype & JT_LEFT)==0 ){ + /* A RIGHT JOIN. Use the right-most table */ + cnt = 0; + sqlite3ExprListDelete(db, pFJMatch); + pFJMatch = 0; + }else{ + /* For a FULL JOIN, we must construct a coalesce() func */ + extendFJMatch(pParse, &pFJMatch, pMatch, pExpr->iColumn); + } } + cnt++; + hit = 1; + }else if( cnt>0 ){ + /* This is a potential rowid match, but there has already been + ** a real match found. So this can be ignored. */ + continue; } - cnt++; - cntTab = 2; + cntTab++; pMatch = pItem; pExpr->iColumn = j; pEList->a[j].fg.bUsed = 1; - hit = 1; + + /* rowid cannot be part of a USING clause - assert() this. */ + assert( bRowid==0 || pEList->a[j].fg.bUsingTerm==0 ); if( pEList->a[j].fg.bUsingTerm ) break; } if( hit || zTab==0 ) continue; @@ -569,10 +596,10 @@ static int lookupName( && pMatch && (pNC->ncFlags & (NC_IdxExpr|NC_GenCol))==0 && sqlite3IsRowid(zCol) - && ALWAYS(VisibleRowid(pMatch->pTab)) + && ALWAYS(VisibleRowid(pMatch->pTab) || pMatch->fg.isNestedFrom) ){ cnt = 1; - pExpr->iColumn = -1; + if( pMatch->fg.isNestedFrom==0 ) pExpr->iColumn = -1; pExpr->affExpr = SQLITE_AFF_INTEGER; } |