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Copy pathresolve.c
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2367 lines (2272 loc) · 85.2 KB
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/*
** 2008 August 18
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains routines used for walking the parser tree and
** resolve all identifiers by associating them with a particular
** table and column.
*/
#include "sqliteInt.h"
/*
** Magic table number to mean the EXCLUDED table in an UPSERT statement.
*/
#define EXCLUDED_TABLE_NUMBER 2
/*
** Walk the expression tree pExpr and increase the aggregate function
** depth (the Expr.op2 field) by N on every TK_AGG_FUNCTION node.
** This needs to occur when copying a TK_AGG_FUNCTION node from an
** outer query into an inner subquery.
**
** incrAggFunctionDepth(pExpr,n) is the main routine. incrAggDepth(..)
** is a helper function - a callback for the tree walker.
**
** See also the sqlite3WindowExtraAggFuncDepth() routine in window.c
*/
static int incrAggDepth(Walker *pWalker, Expr *pExpr){
if( pExpr->op==TK_AGG_FUNCTION ) pExpr->op2 += pWalker->u.n;
return WRC_Continue;
}
static void incrAggFunctionDepth(Expr *pExpr, int N){
if( N>0 ){
Walker w;
memset(&w, 0, sizeof(w));
w.xExprCallback = incrAggDepth;
w.u.n = N;
sqlite3WalkExpr(&w, pExpr);
}
}
/*
** Turn the pExpr expression into an alias for the iCol-th column of the
** result set in pEList.
**
** If the reference is followed by a COLLATE operator, then make sure
** the COLLATE operator is preserved. For example:
**
** SELECT a+b, c+d FROM t1 ORDER BY 1 COLLATE nocase;
**
** Should be transformed into:
**
** SELECT a+b, c+d FROM t1 ORDER BY (a+b) COLLATE nocase;
**
** The nSubquery parameter specifies how many levels of subquery the
** alias is removed from the original expression. The usual value is
** zero but it might be more if the alias is contained within a subquery
** of the original expression. The Expr.op2 field of TK_AGG_FUNCTION
** structures must be increased by the nSubquery amount.
*/
static void resolveAlias(
Parse *pParse, /* Parsing context */
ExprList *pEList, /* A result set */
int iCol, /* A column in the result set. 0..pEList->nExpr-1 */
Expr *pExpr, /* Transform this into an alias to the result set */
int nSubquery /* Number of subqueries that the label is moving */
){
Expr *pOrig; /* The iCol-th column of the result set */
Expr *pDup; /* Copy of pOrig */
sqlite3 *db; /* The database connection */
assert( iCol>=0 && iCol<pEList->nExpr );
pOrig = pEList->a[iCol].pExpr;
assert( pOrig!=0 );
assert( !ExprHasProperty(pExpr, EP_Reduced|EP_TokenOnly) );
if( pExpr->pAggInfo ) return;
db = pParse->db;
pDup = sqlite3ExprDup(db, pOrig, 0);
if( db->mallocFailed ){
sqlite3ExprDelete(db, pDup);
pDup = 0;
}else{
Expr temp;
incrAggFunctionDepth(pDup, nSubquery);
if( pExpr->op==TK_COLLATE ){
assert( !ExprHasProperty(pExpr, EP_IntValue) );
pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken);
}
memcpy(&temp, pDup, sizeof(Expr));
memcpy(pDup, pExpr, sizeof(Expr));
memcpy(pExpr, &temp, sizeof(Expr));
if( ExprHasProperty(pExpr, EP_WinFunc) ){
if( ALWAYS(pExpr->y.pWin!=0) ){
pExpr->y.pWin->pOwner = pExpr;
}
}
sqlite3ExprDeferredDelete(pParse, pDup);
}
}
/*
** 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,
int *pbRowid
){
int n;
const char *zSpan;
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) ){
return 0;
}
zSpan += n+1;
for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}
if( zTab && (sqlite3StrNICmp(zSpan, zTab, n)!=0 || zTab[n]!=0) ){
return 0;
}
zSpan += n+1;
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;
}
/*
** Return TRUE if the double-quoted string mis-feature should be supported.
*/
static int areDoubleQuotedStringsEnabled(sqlite3 *db, NameContext *pTopNC){
if( db->init.busy ) return 1; /* Always support for legacy schemas */
if( pTopNC->ncFlags & NC_IsDDL ){
/* Currently parsing a DDL statement */
if( sqlite3WritableSchema(db) && (db->flags & SQLITE_DqsDML)!=0 ){
return 1;
}
return (db->flags & SQLITE_DqsDDL)!=0;
}else{
/* Currently parsing a DML statement */
return (db->flags & SQLITE_DqsDML)!=0;
}
}
/*
** The argument is guaranteed to be a non-NULL Expr node of type TK_COLUMN.
** return the appropriate colUsed mask.
*/
Bitmask sqlite3ExprColUsed(Expr *pExpr){
int n;
Table *pExTab;
n = pExpr->iColumn;
assert( ExprUseYTab(pExpr) );
pExTab = pExpr->y.pTab;
assert( pExTab!=0 );
assert( n < pExTab->nCol );
if( (pExTab->tabFlags & TF_HasGenerated)!=0
&& (pExTab->aCol[n].colFlags & COLFLAG_GENERATED)!=0
){
testcase( pExTab->nCol==BMS-1 );
testcase( pExTab->nCol==BMS );
return pExTab->nCol>=BMS ? ALLBITS : MASKBIT(pExTab->nCol)-1;
}else{
testcase( n==BMS-1 );
testcase( n==BMS );
if( n>=BMS ) n = BMS-1;
return ((Bitmask)1)<<n;
}
}
/*
** Create a new expression term for the column specified by pMatch and
** iColumn. Append this new expression term to the FULL JOIN Match set
** in *ppList. Create a new *ppList if this is the first term in the
** set.
*/
static void extendFJMatch(
Parse *pParse, /* Parsing context */
ExprList **ppList, /* ExprList to extend */
SrcItem *pMatch, /* Source table containing the column */
i16 iColumn /* The column number */
){
Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLUMN, 0, 0);
if( pNew ){
pNew->iTable = pMatch->iCursor;
pNew->iColumn = iColumn;
pNew->y.pTab = pMatch->pSTab;
assert( (pMatch->fg.jointype & (JT_LEFT|JT_LTORJ))!=0 );
ExprSetProperty(pNew, EP_CanBeNull);
*ppList = sqlite3ExprListAppend(pParse, *ppList, pNew);
}
}
/*
** Return TRUE (non-zero) if zTab is a valid name for the schema table pTab.
*/
static SQLITE_NOINLINE int isValidSchemaTableName(
const char *zTab, /* Name as it appears in the SQL */
Table *pTab, /* The schema table we are trying to match */
const char *zDb /* non-NULL if a database qualifier is present */
){
const char *zLegacy;
assert( pTab!=0 );
assert( pTab->tnum==1 );
if( sqlite3StrNICmp(zTab, "sqlite_", 7)!=0 ) return 0;
zLegacy = pTab->zName;
if( strcmp(zLegacy+7, &LEGACY_TEMP_SCHEMA_TABLE[7])==0 ){
if( sqlite3StrICmp(zTab+7, &PREFERRED_TEMP_SCHEMA_TABLE[7])==0 ){
return 1;
}
if( zDb==0 ) return 0;
if( sqlite3StrICmp(zTab+7, &LEGACY_SCHEMA_TABLE[7])==0 ) return 1;
if( sqlite3StrICmp(zTab+7, &PREFERRED_SCHEMA_TABLE[7])==0 ) return 1;
}else{
if( sqlite3StrICmp(zTab+7, &PREFERRED_SCHEMA_TABLE[7])==0 ) return 1;
}
return 0;
}
/*
** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
** that name in the set of source tables in pSrcList and make the pExpr
** expression node refer back to that source column. The following changes
** are made to pExpr:
**
** pExpr->iDb Set the index in db->aDb[] of the database X
** (even if X is implied).
** pExpr->iTable Set to the cursor number for the table obtained
** from pSrcList.
** pExpr->y.pTab Points to the Table structure of X.Y (even if
** X and/or Y are implied.)
** pExpr->iColumn Set to the column number within the table.
** pExpr->op Set to TK_COLUMN.
** pExpr->pLeft Any expression this points to is deleted
** pExpr->pRight Any expression this points to is deleted.
**
** The zDb variable is the name of the database (the "X"). This value may be
** NULL meaning that name is of the form Y.Z or Z. Any available database
** can be used. The zTable variable is the name of the table (the "Y"). This
** value can be NULL if zDb is also NULL. If zTable is NULL it
** means that the form of the name is Z and that columns from any table
** can be used.
**
** If the name cannot be resolved unambiguously, leave an error message
** in pParse and return WRC_Abort. Return WRC_Prune on success.
*/
static int lookupName(
Parse *pParse, /* The parsing context */
const char *zDb, /* Name of the database containing table, or NULL */
const char *zTab, /* Name of table containing column, or NULL */
const Expr *pRight, /* Name of the column. */
NameContext *pNC, /* The name context used to resolve the name */
Expr *pExpr /* Make this EXPR node point to the selected column */
){
int i, j; /* Loop counters */
int cnt = 0; /* Number of matching column 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 */
SrcItem *pMatch = 0; /* The matching pSrcList item */
NameContext *pTopNC = pNC; /* First namecontext in the list */
Schema *pSchema = 0; /* Schema of the expression */
int eNewExprOp = TK_COLUMN; /* New value for pExpr->op on success */
Table *pTab = 0; /* Table holding the row */
ExprList *pFJMatch = 0; /* Matches for FULL JOIN .. USING */
const char *zCol = pRight->u.zToken;
assert( pNC ); /* the name context cannot be NULL. */
assert( zCol ); /* The Z in X.Y.Z cannot be NULL */
assert( zDb==0 || zTab!=0 );
assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
/* Initialize the node to no-match */
pExpr->iTable = -1;
ExprSetVVAProperty(pExpr, EP_NoReduce);
/* Translate the schema name in zDb into a pointer to the corresponding
** schema. If not found, pSchema will remain NULL and nothing will match
** resulting in an appropriate error message toward the end of this routine
*/
if( zDb ){
testcase( pNC->ncFlags & NC_PartIdx );
testcase( pNC->ncFlags & NC_IsCheck );
if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){
/* Silently ignore database qualifiers inside CHECK constraints and
** partial indices. Do not raise errors because that might break
** legacy and because it does not hurt anything to just ignore the
** database name. */
zDb = 0;
}else{
for(i=0; i<db->nDb; i++){
assert( db->aDb[i].zDbSName );
if( sqlite3StrICmp(db->aDb[i].zDbSName,zDb)==0 ){
pSchema = db->aDb[i].pSchema;
break;
}
}
if( i==db->nDb && sqlite3StrICmp("main", zDb)==0 ){
/* This branch is taken when the main database has been renamed
** using SQLITE_DBCONFIG_MAINDBNAME. */
pSchema = db->aDb[0].pSchema;
zDb = db->aDb[0].zDbSName;
}
}
}
/* Start at the inner-most context and move outward until a match is found */
assert( pNC && cnt==0 );
do{
ExprList *pEList;
SrcList *pSrcList = pNC->pSrcList;
if( pSrcList ){
for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
pTab = pItem->pSTab;
assert( pTab!=0 && pTab->zName!=0 );
assert( pTab->nCol>0 || pParse->nErr );
assert( (int)pItem->fg.isNestedFrom == IsNestedFrom(pItem));
if( pItem->fg.isNestedFrom ){
/* In this case, pItem is a subquery that has been formed from a
** parenthesized subset of the FROM clause terms. Example:
** .... FROM t1 LEFT JOIN (t2 RIGHT JOIN t3 USING(x)) USING(y) ...
** \_________________________/
** This pItem -------------^
*/
int hit = 0;
Select *pSel;
assert( pItem->fg.isSubquery );
assert( pItem->u4.pSubq!=0 );
pSel = pItem->u4.pSubq->pSelect;
assert( pSel!=0 );
pEList = pSel->pEList;
assert( pEList!=0 );
assert( pEList->nExpr==pTab->nCol );
for(j=0; j<pEList->nExpr; j++){
int bRowid = 0; /* True if possible rowid match */
if( !sqlite3MatchEName(&pEList->a[j], zCol, zTab, zDb, &bRowid) ){
continue;
}
if( bRowid==0 ){
if( cnt>0 ){
if( pItem->fg.isUsing==0
|| sqlite3IdListIndex(pItem->u3.pUsing, zCol)<0
|| pMatch==pItem
){
/* Two or more tables have the same column name which is
** not joined by USING. Or, a single table has two columns
** that match a USING term (if pMatch==pItem). These are both
** "ambiguous column name" errors. 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;
}
cntTab++;
pMatch = pItem;
pExpr->iColumn = j;
pEList->a[j].fg.bUsed = 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;
}
assert( zDb==0 || zTab!=0 );
if( zTab ){
if( zDb ){
if( pTab->pSchema!=pSchema ) continue;
if( pSchema==0 && strcmp(zDb,"*")!=0 ) continue;
}
if( pItem->zAlias!=0 ){
if( sqlite3StrICmp(zTab, pItem->zAlias)!=0 ){
continue;
}
}else if( sqlite3StrICmp(zTab, pTab->zName)!=0 ){
if( pTab->tnum!=1 ) continue;
if( !isValidSchemaTableName(zTab, pTab, zDb) ) continue;
}
assert( ExprUseYTab(pExpr) );
if( IN_RENAME_OBJECT && pItem->zAlias ){
sqlite3RenameTokenRemap(pParse, 0, (void*)&pExpr->y.pTab);
}
}
j = sqlite3ColumnIndex(pTab, zCol);
if( j>=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++;
pMatch = pItem;
/* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
if( pItem->fg.isNestedFrom ){
sqlite3SrcItemColumnUsed(pItem, j);
}
}
if( 0==cnt && VisibleRowid(pTab) ){
/* pTab is a potential ROWID match. Keep track of it and match
** the ROWID later if that seems appropriate. (Search for "cntTab"
** to find related code.) Only allow a ROWID match if there is
** a single ROWID match candidate.
*/
#ifdef SQLITE_ALLOW_ROWID_IN_VIEW
/* In SQLITE_ALLOW_ROWID_IN_VIEW mode, allow a ROWID match
** if there is a single VIEW candidate or if there is a single
** non-VIEW candidate plus multiple VIEW candidates. In other
** words non-VIEW candidate terms take precedence over VIEWs.
*/
if( cntTab==0
|| (cntTab==1
&& pMatch!=0
&& ALWAYS(pMatch->pSTab!=0)
&& (pMatch->pSTab->tabFlags & TF_Ephemeral)!=0
&& (pTab->tabFlags & TF_Ephemeral)==0)
){
cntTab = 1;
pMatch = pItem;
}else{
cntTab++;
}
#else
/* The (much more common) non-SQLITE_ALLOW_ROWID_IN_VIEW case is
** simpler since we require exactly one candidate, which will
** always be a non-VIEW
*/
cntTab++;
pMatch = pItem;
#endif
}
}
if( pMatch ){
pExpr->iTable = pMatch->iCursor;
assert( ExprUseYTab(pExpr) );
pExpr->y.pTab = pMatch->pSTab;
if( (pMatch->fg.jointype & (JT_LEFT|JT_LTORJ))!=0 ){
ExprSetProperty(pExpr, EP_CanBeNull);
}
pSchema = pExpr->y.pTab->pSchema;
}
} /* if( pSrcList ) */
#if !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT)
/* If we have not already resolved the name, then maybe
** it is a new.* or old.* trigger argument reference. Or
** maybe it is an excluded.* from an upsert. Or maybe it is
** a reference in the RETURNING clause to a table being modified.
*/
if( cnt==0 && zDb==0 ){
pTab = 0;
#ifndef SQLITE_OMIT_TRIGGER
if( pParse->pTriggerTab!=0 ){
int op = pParse->eTriggerOp;
assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT );
if( pParse->bReturning ){
if( (pNC->ncFlags & NC_UBaseReg)!=0
&& ALWAYS(zTab==0
|| sqlite3StrICmp(zTab,pParse->pTriggerTab->zName)==0
|| isValidSchemaTableName(zTab, pParse->pTriggerTab, 0))
){
pExpr->iTable = op!=TK_DELETE;
pTab = pParse->pTriggerTab;
}
}else if( op!=TK_DELETE && zTab && sqlite3StrICmp("new",zTab) == 0 ){
pExpr->iTable = 1;
pTab = pParse->pTriggerTab;
}else if( op!=TK_INSERT && zTab && sqlite3StrICmp("old",zTab)==0 ){
pExpr->iTable = 0;
pTab = pParse->pTriggerTab;
}
}
#endif /* SQLITE_OMIT_TRIGGER */
#ifndef SQLITE_OMIT_UPSERT
if( (pNC->ncFlags & NC_UUpsert)!=0 && zTab!=0 ){
Upsert *pUpsert = pNC->uNC.pUpsert;
if( pUpsert && sqlite3StrICmp("excluded",zTab)==0 ){
pTab = pUpsert->pUpsertSrc->a[0].pSTab;
pExpr->iTable = EXCLUDED_TABLE_NUMBER;
}
}
#endif /* SQLITE_OMIT_UPSERT */
if( pTab ){
int iCol;
pSchema = pTab->pSchema;
cntTab++;
iCol = sqlite3ColumnIndex(pTab, zCol);
if( iCol>=0 ){
if( pTab->iPKey==iCol ) iCol = -1;
}else{
if( sqlite3IsRowid(zCol) && VisibleRowid(pTab) ){
iCol = -1;
}else{
iCol = pTab->nCol;
}
}
if( iCol<pTab->nCol ){
cnt++;
pMatch = 0;
#ifndef SQLITE_OMIT_UPSERT
if( pExpr->iTable==EXCLUDED_TABLE_NUMBER ){
testcase( iCol==(-1) );
assert( ExprUseYTab(pExpr) );
if( IN_RENAME_OBJECT ){
pExpr->iColumn = iCol;
pExpr->y.pTab = pTab;
eNewExprOp = TK_COLUMN;
}else{
pExpr->iTable = pNC->uNC.pUpsert->regData +
sqlite3TableColumnToStorage(pTab, iCol);
eNewExprOp = TK_REGISTER;
}
}else
#endif /* SQLITE_OMIT_UPSERT */
{
assert( ExprUseYTab(pExpr) );
pExpr->y.pTab = pTab;
if( pParse->bReturning ){
eNewExprOp = TK_REGISTER;
pExpr->op2 = TK_COLUMN;
pExpr->iColumn = iCol;
pExpr->iTable = pNC->uNC.iBaseReg + (pTab->nCol+1)*pExpr->iTable +
sqlite3TableColumnToStorage(pTab, iCol) + 1;
}else{
pExpr->iColumn = (i16)iCol;
eNewExprOp = TK_TRIGGER;
#ifndef SQLITE_OMIT_TRIGGER
if( iCol<0 ){
pExpr->affExpr = SQLITE_AFF_INTEGER;
}else if( pExpr->iTable==0 ){
testcase( iCol==31 );
testcase( iCol==32 );
pParse->oldmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol));
}else{
testcase( iCol==31 );
testcase( iCol==32 );
pParse->newmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol));
}
#endif /* SQLITE_OMIT_TRIGGER */
}
}
}
}
}
#endif /* !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) */
/*
** Perhaps the name is a reference to the ROWID
*/
if( cnt==0
&& cntTab>=1
&& pMatch
&& (pNC->ncFlags & (NC_IdxExpr|NC_GenCol))==0
&& sqlite3IsRowid(zCol)
&& ALWAYS(VisibleRowid(pMatch->pSTab) || pMatch->fg.isNestedFrom)
){
cnt = cntTab;
#if SQLITE_ALLOW_ROWID_IN_VIEW+0==2
if( pMatch->pSTab!=0 && IsView(pMatch->pSTab) ){
eNewExprOp = TK_NULL;
}
#endif
if( pMatch->fg.isNestedFrom==0 ) pExpr->iColumn = -1;
pExpr->affExpr = SQLITE_AFF_INTEGER;
}
/*
** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z
** might refer to an result-set alias. This happens, for example, when
** we are resolving names in the WHERE clause of the following command:
**
** SELECT a+b AS x FROM table WHERE x<10;
**
** In cases like this, replace pExpr with a copy of the expression that
** forms the result set entry ("a+b" in the example) and return immediately.
** Note that the expression in the result set should have already been
** resolved by the time the WHERE clause is resolved.
**
** The ability to use an output result-set column in the WHERE, GROUP BY,
** or HAVING clauses, or as part of a larger expression in the ORDER BY
** clause is not standard SQL. This is a (goofy) SQLite extension, that
** is supported for backwards compatibility only. Hence, we issue a warning
** on sqlite3_log() whenever the capability is used.
*/
if( cnt==0
&& (pNC->ncFlags & NC_UEList)!=0
&& zTab==0
){
pEList = pNC->uNC.pEList;
assert( pEList!=0 );
for(j=0; j<pEList->nExpr; j++){
char *zAs = pEList->a[j].zEName;
if( pEList->a[j].fg.eEName==ENAME_NAME
&& sqlite3_stricmp(zAs, zCol)==0
){
Expr *pOrig;
assert( pExpr->pLeft==0 && pExpr->pRight==0 );
assert( ExprUseXList(pExpr)==0 || pExpr->x.pList==0 );
assert( ExprUseXSelect(pExpr)==0 || pExpr->x.pSelect==0 );
pOrig = pEList->a[j].pExpr;
if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){
sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
return WRC_Abort;
}
if( ExprHasProperty(pOrig, EP_Win)
&& ((pNC->ncFlags&NC_AllowWin)==0 || pNC!=pTopNC )
){
sqlite3ErrorMsg(pParse, "misuse of aliased window function %s",zAs);
return WRC_Abort;
}
if( sqlite3ExprVectorSize(pOrig)!=1 ){
sqlite3ErrorMsg(pParse, "row value misused");
return WRC_Abort;
}
resolveAlias(pParse, pEList, j, pExpr, nSubquery);
cnt = 1;
pMatch = 0;
assert( zTab==0 && zDb==0 );
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenRemap(pParse, 0, (void*)pExpr);
}
goto lookupname_end;
}
}
}
/* Advance to the next name context. The loop will exit when either
** we have a match (cnt>0) or when we run out of name contexts.
*/
if( cnt ) break;
pNC = pNC->pNext;
nSubquery++;
}while( pNC );
/*
** If X and Y are NULL (in other words if only the column name Z is
** supplied) and the value of Z is enclosed in double-quotes, then
** Z is a string literal if it doesn't match any column names. In that
** case, we need to return right away and not make any changes to
** pExpr.
**
** Because no reference was made to outer contexts, the pNC->nRef
** fields are not changed in any context.
*/
if( cnt==0 && zTab==0 ){
assert( pExpr->op==TK_ID );
if( ExprHasProperty(pExpr,EP_DblQuoted)
&& areDoubleQuotedStringsEnabled(db, pTopNC)
){
/* If a double-quoted identifier does not match any known column name,
** then treat it as a string.
**
** This hack was added in the early days of SQLite in a misguided attempt
** to be compatible with MySQL 3.x, which used double-quotes for strings.
** I now sorely regret putting in this hack. The effect of this hack is
** that misspelled identifier names are silently converted into strings
** rather than causing an error, to the frustration of countless
** programmers. To all those frustrated programmers, my apologies.
**
** Someday, I hope to get rid of this hack. Unfortunately there is
** a huge amount of legacy SQL that uses it. So for now, we just
** issue a warning.
*/
sqlite3_log(SQLITE_WARNING,
"double-quoted string literal: \"%w\"", zCol);
#ifdef SQLITE_ENABLE_NORMALIZE
sqlite3VdbeAddDblquoteStr(db, pParse->pVdbe, zCol);
#endif
pExpr->op = TK_STRING;
memset(&pExpr->y, 0, sizeof(pExpr->y));
return WRC_Prune;
}
if( sqlite3ExprIdToTrueFalse(pExpr) ){
return WRC_Prune;
}
}
/*
** cnt==0 means there was not match.
** cnt>1 means there were two or more matches.
**
** cnt==0 is always an error. cnt>1 is often an error, but might
** be multiple matches for a NATURAL OUTER JOIN or a OUTER JOIN USING.
*/
assert( pFJMatch==0 || cnt>0 );
assert( !ExprHasProperty(pExpr, EP_xIsSelect|EP_IntValue) );
if( cnt!=1 ){
const char *zErr;
if( pFJMatch ){
if( pFJMatch->nExpr==cnt-1 ){
if( ExprHasProperty(pExpr,EP_Leaf) ){
ExprClearProperty(pExpr,EP_Leaf);
}else{
sqlite3ExprDelete(db, pExpr->pLeft);
pExpr->pLeft = 0;
sqlite3ExprDelete(db, pExpr->pRight);
pExpr->pRight = 0;
}
extendFJMatch(pParse, &pFJMatch, pMatch, pExpr->iColumn);
pExpr->op = TK_FUNCTION;
pExpr->u.zToken = "coalesce";
pExpr->x.pList = pFJMatch;
pExpr->affExpr = SQLITE_AFF_DEFER;
cnt = 1;
goto lookupname_end;
}else{
sqlite3ExprListDelete(db, pFJMatch);
pFJMatch = 0;
}
}
zErr = cnt==0 ? "no such column" : "ambiguous column name";
if( zDb ){
sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol);
}else if( zTab ){
sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol);
}else if( cnt==0 && ExprHasProperty(pRight,EP_DblQuoted) ){
sqlite3ErrorMsg(pParse, "%s: \"%s\" - should this be a"
" string literal in single-quotes?",
zErr, zCol);
}else{
sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol);
}
sqlite3RecordErrorOffsetOfExpr(pParse->db, pExpr);
pParse->checkSchema = 1;
pTopNC->nNcErr++;
eNewExprOp = TK_NULL;
}
assert( pFJMatch==0 );
/* Remove all substructure from pExpr */
if( !ExprHasProperty(pExpr,(EP_TokenOnly|EP_Leaf)) ){
sqlite3ExprDelete(db, pExpr->pLeft);
pExpr->pLeft = 0;
sqlite3ExprDelete(db, pExpr->pRight);
pExpr->pRight = 0;
ExprSetProperty(pExpr, EP_Leaf);
}
/* If a column from a table in pSrcList is referenced, then record
** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes
** bit 0 to be set. Column 1 sets bit 1. And so forth. Bit 63 is
** set if the 63rd or any subsequent column is used.
**
** The colUsed mask is an optimization used to help determine if an
** index is a covering index. The correct answer is still obtained
** if the mask contains extra set bits. However, it is important to
** avoid setting bits beyond the maximum column number of the table.
** (See ticket [b92e5e8ec2cdbaa1]).
**
** If a generated column is referenced, set bits for every column
** of the table.
*/
if( pMatch ){
if( pExpr->iColumn>=0 ){
pMatch->colUsed |= sqlite3ExprColUsed(pExpr);
}else{
pMatch->fg.rowidUsed = 1;
}
}
pExpr->op = eNewExprOp;
lookupname_end:
if( cnt==1 ){
assert( pNC!=0 );
#ifndef SQLITE_OMIT_AUTHORIZATION
if( db->xAuth ){
if( pFJMatch ){
assert( pExpr->op==TK_FUNCTION );
assert( sqlite3_stricmp(pExpr->u.zToken,"coalesce")==0 );
assert( pExpr->x.pList==pFJMatch );
assert( pFJMatch->nExpr>0 );
for(i=0; i<pFJMatch->nExpr; i++){
assert( pFJMatch->a[i].pExpr->op==TK_COLUMN );
sqlite3AuthRead(pParse,pFJMatch->a[i].pExpr,pSchema,pNC->pSrcList);
}
}else if( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER ){
sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
}
}
#endif
/* Increment the nRef value on all name contexts from TopNC up to
** the point where the name matched. */
for(;;){
assert( pTopNC!=0 );
pTopNC->nRef++;
if( pTopNC==pNC ) break;
pTopNC = pTopNC->pNext;
}
return WRC_Prune;
} else {
return WRC_Abort;
}
}
/*
** Allocate and return a pointer to an expression to load the column iCol
** from datasource iSrc in SrcList pSrc.
*/
Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){
Expr *p = sqlite3ExprAlloc(db, TK_COLUMN, 0, 0);
if( p ){
SrcItem *pItem = &pSrc->a[iSrc];
Table *pTab;
assert( ExprUseYTab(p) );
pTab = p->y.pTab = pItem->pSTab;
p->iTable = pItem->iCursor;
if( p->y.pTab->iPKey==iCol ){
p->iColumn = -1;
}else{
p->iColumn = (ynVar)iCol;
if( (pTab->tabFlags & TF_HasGenerated)!=0
&& (pTab->aCol[iCol].colFlags & COLFLAG_GENERATED)!=0
){
testcase( pTab->nCol==63 );
testcase( pTab->nCol==64 );
pItem->colUsed = pTab->nCol>=64 ? ALLBITS : MASKBIT(pTab->nCol)-1;
}else{
testcase( iCol==BMS );
testcase( iCol==BMS-1 );
pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol);
}
}
}
return p;
}
/*
** Report an error that an expression is not valid for some set of
** pNC->ncFlags values determined by validMask.
**
** static void notValid(
** Parse *pParse, // Leave error message here
** NameContext *pNC, // The name context
** const char *zMsg, // Type of error
** int validMask, // Set of contexts for which prohibited
** Expr *pExpr // Invalidate this expression on error
** ){...}
**
** As an optimization, since the conditional is almost always false
** (because errors are rare), the conditional is moved outside of the
** function call using a macro.
*/
static void notValidImpl(
Parse *pParse, /* Leave error message here */
NameContext *pNC, /* The name context */
const char *zMsg, /* Type of error */
Expr *pExpr, /* Invalidate this expression on error */
Expr *pError /* Associate error with this expression */
){
const char *zIn = "partial index WHERE clauses";
if( pNC->ncFlags & NC_IdxExpr ) zIn = "index expressions";
#ifndef SQLITE_OMIT_CHECK
else if( pNC->ncFlags & NC_IsCheck ) zIn = "CHECK constraints";
#endif
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
else if( pNC->ncFlags & NC_GenCol ) zIn = "generated columns";
#endif
sqlite3ErrorMsg(pParse, "%s prohibited in %s", zMsg, zIn);
if( pExpr ) pExpr->op = TK_NULL;
sqlite3RecordErrorOffsetOfExpr(pParse->db, pError);
}
#define sqlite3ResolveNotValid(P,N,M,X,E,R) \
assert( ((X)&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol))==0 ); \
if( ((N)->ncFlags & (X))!=0 ) notValidImpl(P,N,M,E,R);
/*
** Expression p should encode a floating point value between 1.0 and 0.0.
** Return 134,217,728 (2^27) times this value. Or return -1 if p is not
** a floating point value between 1.0 and 0.0.
*/
static int exprProbability(Expr *p){
double r = -1.0;
if( p->op!=TK_FLOAT ) return -1;
assert( !ExprHasProperty(p, EP_IntValue) );
sqlite3AtoF(p->u.zToken, &r);
assert( r>=0.0 );
if( r>1.0 ) return -1;
return (int)(r*134217728.0);
}
/*
** Set the EP_SubtArg property on every expression inside of
** pList. If any subexpression is actually a subquery, then
** also set the EP_SubtArg property on the first result-set
** column of that subquery.
*/
static SQLITE_NOINLINE void resolveSetExprSubtypeArg(ExprList *pList){
int nn, ii;
nn = pList ? pList->nExpr : 0;
for(ii=0; ii<nn; ii++){
Expr *pExpr = pList->a[ii].pExpr;
while( 1 /*exit-by-break*/ ){
ExprSetProperty(pExpr, EP_SubtArg);
if( pExpr->op==TK_SELECT ){
assert( ExprUseXSelect(pExpr) );
assert( pExpr->x.pSelect!=0 );
resolveSetExprSubtypeArg(pExpr->x.pSelect->pEList);
break;
}
if( pExpr->op==TK_UPLUS ){
pExpr = pExpr->pLeft;
assert( pExpr!=0 );
}else{
break;
}
}
}
}
/*
** This routine is callback for sqlite3WalkExpr().
**
** Resolve symbolic names into TK_COLUMN operators for the current
** node in the expression tree. Return 0 to continue the search down
** the tree or 2 to abort the tree walk.
**
** This routine also does error checking and name resolution for
** function names. The operator for aggregate functions is changed
** to TK_AGG_FUNCTION.
*/
static int resolveExprStep(Walker *pWalker, Expr *pExpr){
NameContext *pNC;
Parse *pParse;
pNC = pWalker->u.pNC;
assert( pNC!=0 );