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Copy pathresolve.c
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1902 lines (1814 loc) · 67.3 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"
/*
** 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.
*/
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 */
const char *zType, /* "GROUP" or "ORDER" or "" */
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 );
db = pParse->db;
pDup = sqlite3ExprDup(db, pOrig, 0);
if( pDup!=0 ){
if( zType[0]!='G' ) incrAggFunctionDepth(pDup, nSubquery);
if( pExpr->op==TK_COLLATE ){
pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken);
}
/* Before calling sqlite3ExprDelete(), set the EP_Static flag. This
** prevents ExprDelete() from deleting the Expr structure itself,
** allowing it to be repopulated by the memcpy() on the following line.
** The pExpr->u.zToken might point into memory that will be freed by the
** sqlite3DbFree(db, pDup) on the last line of this block, so be sure to
** make a copy of the token before doing the sqlite3DbFree().
*/
ExprSetProperty(pExpr, EP_Static);
sqlite3ExprDelete(db, pExpr);
memcpy(pExpr, pDup, sizeof(*pExpr));
if( !ExprHasProperty(pExpr, EP_IntValue) && pExpr->u.zToken!=0 ){
assert( (pExpr->flags & (EP_Reduced|EP_TokenOnly))==0 );
pExpr->u.zToken = sqlite3DbStrDup(db, pExpr->u.zToken);
pExpr->flags |= EP_MemToken;
}
if( ExprHasProperty(pExpr, EP_WinFunc) ){
if( pExpr->y.pWin!=0 ){
pExpr->y.pWin->pOwner = pExpr;
}else{
assert( db->mallocFailed );
}
}
sqlite3DbFree(db, pDup);
}
ExprSetProperty(pExpr, EP_Alias);
}
/*
** Return TRUE if the name zCol occurs anywhere in the USING clause.
**
** Return FALSE if the USING clause is NULL or if it does not contain
** zCol.
*/
static int nameInUsingClause(IdList *pUsing, const char *zCol){
if( pUsing ){
int k;
for(k=0; k<pUsing->nId; k++){
if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ) return 1;
}
}
return 0;
}
/*
** 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.
*/
int sqlite3MatchEName(
const struct ExprList_item *pItem,
const char *zCol,
const char *zTab,
const char *zDb
){
int n;
const char *zSpan;
if( NEVER(pItem->eEName!=ENAME_TAB) ) return 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 && sqlite3StrICmp(zSpan, zCol)!=0 ){
return 0;
}
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;
}
}
/*
** 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 char *zCol, /* 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 matching table names */
int nSubquery = 0; /* How many levels of subquery */
sqlite3 *db = pParse->db; /* The database connection */
struct SrcList_item *pItem; /* Use for looping over pSrcList items */
struct SrcList_item *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 hold the row */
Column *pCol; /* A column of pTab */
assert( pNC ); /* the name context cannot be NULL. */
assert( zCol ); /* The Z in X.Y.Z cannot be NULL */
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;
}
}
}
}
/* 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->pTab;
assert( pTab!=0 && pTab->zName!=0 );
assert( pTab->nCol>0 );
if( pItem->pSelect && (pItem->pSelect->selFlags & SF_NestedFrom)!=0 ){
int hit = 0;
pEList = pItem->pSelect->pEList;
for(j=0; j<pEList->nExpr; j++){
if( sqlite3MatchEName(&pEList->a[j], zCol, zTab, zDb) ){
cnt++;
cntTab = 2;
pMatch = pItem;
pExpr->iColumn = j;
hit = 1;
}
}
if( hit || zTab==0 ) continue;
}
if( zDb && pTab->pSchema!=pSchema ){
continue;
}
if( zTab ){
const char *zTabName = pItem->zAlias ? pItem->zAlias : pTab->zName;
assert( zTabName!=0 );
if( sqlite3StrICmp(zTabName, zTab)!=0 ){
continue;
}
if( IN_RENAME_OBJECT && pItem->zAlias ){
sqlite3RenameTokenRemap(pParse, 0, (void*)&pExpr->y.pTab);
}
}
if( 0==(cntTab++) ){
pMatch = pItem;
}
for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
/* If there has been exactly one prior match and this match
** is for the right-hand table of a NATURAL JOIN or is in a
** USING clause, then skip this match.
*/
if( cnt==1 ){
if( pItem->fg.jointype & JT_NATURAL ) continue;
if( nameInUsingClause(pItem->pUsing, zCol) ) continue;
}
cnt++;
pMatch = pItem;
/* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
break;
}
}
}
if( pMatch ){
pExpr->iTable = pMatch->iCursor;
pExpr->y.pTab = pMatch->pTab;
/* RIGHT JOIN not (yet) supported */
assert( (pMatch->fg.jointype & JT_RIGHT)==0 );
if( (pMatch->fg.jointype & JT_LEFT)!=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.
*/
if( zDb==0 && zTab!=0 && cntTab==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( op!=TK_DELETE && sqlite3StrICmp("new",zTab) == 0 ){
pExpr->iTable = 1;
pTab = pParse->pTriggerTab;
}else if( op!=TK_INSERT && sqlite3StrICmp("old",zTab)==0 ){
pExpr->iTable = 0;
pTab = pParse->pTriggerTab;
}
}
#endif /* SQLITE_OMIT_TRIGGER */
#ifndef SQLITE_OMIT_UPSERT
if( (pNC->ncFlags & NC_UUpsert)!=0 ){
Upsert *pUpsert = pNC->uNC.pUpsert;
if( pUpsert && sqlite3StrICmp("excluded",zTab)==0 ){
pTab = pUpsert->pUpsertSrc->a[0].pTab;
pExpr->iTable = 2;
}
}
#endif /* SQLITE_OMIT_UPSERT */
if( pTab ){
int iCol;
pSchema = pTab->pSchema;
cntTab++;
for(iCol=0, pCol=pTab->aCol; iCol<pTab->nCol; iCol++, pCol++){
if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
if( iCol==pTab->iPKey ){
iCol = -1;
}
break;
}
}
if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && VisibleRowid(pTab) ){
/* IMP: R-51414-32910 */
iCol = -1;
}
if( iCol<pTab->nCol ){
cnt++;
#ifndef SQLITE_OMIT_UPSERT
if( pExpr->iTable==2 ){
testcase( iCol==(-1) );
if( IN_RENAME_OBJECT ){
pExpr->iColumn = iCol;
pExpr->y.pTab = pTab;
eNewExprOp = TK_COLUMN;
}else{
pExpr->iTable = pNC->uNC.pUpsert->regData + iCol;
eNewExprOp = TK_REGISTER;
ExprSetProperty(pExpr, EP_Alias);
}
}else
#endif /* SQLITE_OMIT_UPSERT */
{
#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));
}
pExpr->y.pTab = pTab;
pExpr->iColumn = (i16)iCol;
eNewExprOp = TK_TRIGGER;
#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)
&& VisibleRowid(pMatch->pTab)
){
cnt = 1;
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( (pNC->ncFlags & NC_UEList)!=0
&& cnt==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].eEName==ENAME_NAME
&& sqlite3_stricmp(zAs, zCol)==0
){
Expr *pOrig;
assert( pExpr->pLeft==0 && pExpr->pRight==0 );
assert( pExpr->x.pList==0 );
assert( 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;
pExpr->y.pTab = 0;
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. Either way, we have an error.
*/
if( cnt!=1 ){
const char *zErr;
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{
sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol);
}
pParse->checkSchema = 1;
pTopNC->nErr++;
}
/* 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( pExpr->iColumn>=0 && pMatch!=0 ){
int n = pExpr->iColumn;
Table *pExTab = pExpr->y.pTab;
assert( pExTab!=0 );
assert( pMatch->iCursor==pExpr->iTable );
if( (pExTab->tabFlags & TF_HasGenerated)!=0
&& (pExTab->aCol[n].colFlags & COLFLAG_GENERATED)!=0
){
testcase( pExTab->nCol==BMS-1 );
testcase( pExTab->nCol==BMS );
pMatch->colUsed = pExTab->nCol>=BMS ? ALLBITS : MASKBIT(pExTab->nCol)-1;
}else{
testcase( n==BMS-1 );
testcase( n==BMS );
if( n>=BMS ) n = BMS-1;
pMatch->colUsed |= ((Bitmask)1)<<n;
}
}
/* Clean up and return
*/
sqlite3ExprDelete(db, pExpr->pLeft);
pExpr->pLeft = 0;
sqlite3ExprDelete(db, pExpr->pRight);
pExpr->pRight = 0;
pExpr->op = eNewExprOp;
ExprSetProperty(pExpr, EP_Leaf);
lookupname_end:
if( cnt==1 ){
assert( pNC!=0 );
if( !ExprHasProperty(pExpr, EP_Alias) ){
sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
}
/* 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 ){
struct SrcList_item *pItem = &pSrc->a[iSrc];
Table *pTab = p->y.pTab = pItem->pTab;
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 */
){
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;
}
#define sqlite3ResolveNotValid(P,N,M,X,E) \
assert( ((X)&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr|NC_GenCol))==0 ); \
if( ((N)->ncFlags & (X))!=0 ) notValidImpl(P,N,M,E);
/*
** Expression p should encode a floating point value between 1.0 and 0.0.
** Return 1024 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;
sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8);
assert( r>=0.0 );
if( r>1.0 ) return -1;
return (int)(r*134217728.0);
}
/*
** 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 );
pParse = pNC->pParse;
assert( pParse==pWalker->pParse );
#ifndef NDEBUG
if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){
SrcList *pSrcList = pNC->pSrcList;
int i;
for(i=0; i<pNC->pSrcList->nSrc; i++){
assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab);
}
}
#endif
switch( pExpr->op ){
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
/* The special operator TK_ROW means use the rowid for the first
** column in the FROM clause. This is used by the LIMIT and ORDER BY
** clause processing on UPDATE and DELETE statements.
*/
case TK_ROW: {
SrcList *pSrcList = pNC->pSrcList;
struct SrcList_item *pItem;
assert( pSrcList && pSrcList->nSrc==1 );
pItem = pSrcList->a;
assert( HasRowid(pItem->pTab) && pItem->pTab->pSelect==0 );
pExpr->op = TK_COLUMN;
pExpr->y.pTab = pItem->pTab;
pExpr->iTable = pItem->iCursor;
pExpr->iColumn = -1;
pExpr->affExpr = SQLITE_AFF_INTEGER;
break;
}
#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT)
&& !defined(SQLITE_OMIT_SUBQUERY) */
/* A column name: ID
** Or table name and column name: ID.ID
** Or a database, table and column: ID.ID.ID
**
** The TK_ID and TK_OUT cases are combined so that there will only
** be one call to lookupName(). Then the compiler will in-line
** lookupName() for a size reduction and performance increase.
*/
case TK_ID:
case TK_DOT: {
const char *zColumn;
const char *zTable;
const char *zDb;
Expr *pRight;
if( pExpr->op==TK_ID ){
zDb = 0;
zTable = 0;
zColumn = pExpr->u.zToken;
}else{
Expr *pLeft = pExpr->pLeft;
testcase( pNC->ncFlags & NC_IdxExpr );
testcase( pNC->ncFlags & NC_GenCol );
sqlite3ResolveNotValid(pParse, pNC, "the \".\" operator",
NC_IdxExpr|NC_GenCol, 0);
pRight = pExpr->pRight;
if( pRight->op==TK_ID ){
zDb = 0;
}else{
assert( pRight->op==TK_DOT );
zDb = pLeft->u.zToken;
pLeft = pRight->pLeft;
pRight = pRight->pRight;
}
zTable = pLeft->u.zToken;
zColumn = pRight->u.zToken;
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenRemap(pParse, (void*)pExpr, (void*)pRight);
sqlite3RenameTokenRemap(pParse, (void*)&pExpr->y.pTab, (void*)pLeft);
}
}
return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr);
}
/* Resolve function names
*/
case TK_FUNCTION: {
ExprList *pList = pExpr->x.pList; /* The argument list */
int n = pList ? pList->nExpr : 0; /* Number of arguments */
int no_such_func = 0; /* True if no such function exists */
int wrong_num_args = 0; /* True if wrong number of arguments */
int is_agg = 0; /* True if is an aggregate function */
int nId; /* Number of characters in function name */
const char *zId; /* The function name. */
FuncDef *pDef; /* Information about the function */
u8 enc = ENC(pParse->db); /* The database encoding */
int savedAllowFlags = (pNC->ncFlags & (NC_AllowAgg | NC_AllowWin));
#ifndef SQLITE_OMIT_WINDOWFUNC
Window *pWin = (IsWindowFunc(pExpr) ? pExpr->y.pWin : 0);
#endif
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
zId = pExpr->u.zToken;
nId = sqlite3Strlen30(zId);
pDef = sqlite3FindFunction(pParse->db, zId, n, enc, 0);
if( pDef==0 ){
pDef = sqlite3FindFunction(pParse->db, zId, -2, enc, 0);
if( pDef==0 ){
no_such_func = 1;
}else{
wrong_num_args = 1;
}
}else{
is_agg = pDef->xFinalize!=0;
if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
ExprSetProperty(pExpr, EP_Unlikely);
if( n==2 ){
pExpr->iTable = exprProbability(pList->a[1].pExpr);
if( pExpr->iTable<0 ){
sqlite3ErrorMsg(pParse,
"second argument to likelihood() must be a "
"constant between 0.0 and 1.0");
pNC->nErr++;
}
}else{
/* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is
** equivalent to likelihood(X, 0.0625).
** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is
** short-hand for likelihood(X,0.0625).
** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand
** for likelihood(X,0.9375).
** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent
** to likelihood(X,0.9375). */
/* TUNING: unlikely() probability is 0.0625. likely() is 0.9375 */
pExpr->iTable = pDef->zName[0]=='u' ? 8388608 : 125829120;
}
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0,pDef->zName,0);
if( auth!=SQLITE_OK ){
if( auth==SQLITE_DENY ){
sqlite3ErrorMsg(pParse, "not authorized to use function: %s",
pDef->zName);
pNC->nErr++;
}
pExpr->op = TK_NULL;
return WRC_Prune;
}
}
#endif
if( pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG) ){
/* For the purposes of the EP_ConstFunc flag, date and time
** functions and other functions that change slowly are considered
** constant because they are constant for the duration of one query.
** This allows them to be factored out of inner loops. */
ExprSetProperty(pExpr,EP_ConstFunc);
}
if( (pDef->funcFlags & SQLITE_FUNC_CONSTANT)==0 ){
/* Clearly non-deterministic functions like random(), but also
** date/time functions that use 'now', and other functions like
** sqlite_version() that might change over time cannot be used
** in an index or generated column. Curiously, they can be used
** in a CHECK constraint. SQLServer, MySQL, and PostgreSQL all
** all this. */
sqlite3ResolveNotValid(pParse, pNC, "non-deterministic functions",
NC_IdxExpr|NC_PartIdx|NC_GenCol, 0);
}else{
assert( (NC_SelfRef & 0xff)==NC_SelfRef ); /* Must fit in 8 bits */
pExpr->op2 = pNC->ncFlags & NC_SelfRef;
if( pNC->ncFlags & NC_FromDDL ) ExprSetProperty(pExpr, EP_FromDDL);
}
if( (pDef->funcFlags & SQLITE_FUNC_INTERNAL)!=0
&& pParse->nested==0
&& (pParse->db->mDbFlags & DBFLAG_InternalFunc)==0
){
/* Internal-use-only functions are disallowed unless the
** SQL is being compiled using sqlite3NestedParse() or
** the SQLITE_TESTCTRL_INTERNAL_FUNCTIONS test-control has be
** used to activate internal functionsn for testing purposes */
no_such_func = 1;
pDef = 0;
}else
if( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0
&& !IN_RENAME_OBJECT
){
sqlite3ExprFunctionUsable(pParse, pExpr, pDef);
}
}
if( 0==IN_RENAME_OBJECT ){
#ifndef SQLITE_OMIT_WINDOWFUNC
assert( is_agg==0 || (pDef->funcFlags & SQLITE_FUNC_MINMAX)
|| (pDef->xValue==0 && pDef->xInverse==0)
|| (pDef->xValue && pDef->xInverse && pDef->xSFunc && pDef->xFinalize)
);
if( pDef && pDef->xValue==0 && pWin ){
sqlite3ErrorMsg(pParse,
"%.*s() may not be used as a window function", nId, zId
);
pNC->nErr++;
}else if(
(is_agg && (pNC->ncFlags & NC_AllowAgg)==0)
|| (is_agg && (pDef->funcFlags&SQLITE_FUNC_WINDOW) && !pWin)
|| (is_agg && pWin && (pNC->ncFlags & NC_AllowWin)==0)
){
const char *zType;
if( (pDef->funcFlags & SQLITE_FUNC_WINDOW) || pWin ){
zType = "window";
}else{
zType = "aggregate";
}
sqlite3ErrorMsg(pParse, "misuse of %s function %.*s()",zType,nId,zId);
pNC->nErr++;
is_agg = 0;
}
#else
if( (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) ){
sqlite3ErrorMsg(pParse,"misuse of aggregate function %.*s()",nId,zId);
pNC->nErr++;
is_agg = 0;
}
#endif
else if( no_such_func && pParse->db->init.busy==0
#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
&& pParse->explain==0
#endif
){
sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
pNC->nErr++;
}else if( wrong_num_args ){
sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",
nId, zId);
pNC->nErr++;
}
#ifndef SQLITE_OMIT_WINDOWFUNC
else if( is_agg==0 && ExprHasProperty(pExpr, EP_WinFunc) ){
sqlite3ErrorMsg(pParse,
"FILTER may not be used with non-aggregate %.*s()",
nId, zId
);
pNC->nErr++;
}
#endif
if( is_agg ){
/* Window functions may not be arguments of aggregate functions.
** Or arguments of other window functions. But aggregate functions
** may be arguments for window functions. */
#ifndef SQLITE_OMIT_WINDOWFUNC
pNC->ncFlags &= ~(NC_AllowWin | (!pWin ? NC_AllowAgg : 0));
#else
pNC->ncFlags &= ~NC_AllowAgg;
#endif
}
}
#ifndef SQLITE_OMIT_WINDOWFUNC
else if( ExprHasProperty(pExpr, EP_WinFunc) ){
is_agg = 1;
}
#endif
sqlite3WalkExprList(pWalker, pList);
if( is_agg ){
#ifndef SQLITE_OMIT_WINDOWFUNC
if( pWin ){
Select *pSel = pNC->pWinSelect;
assert( pWin==pExpr->y.pWin );
if( IN_RENAME_OBJECT==0 ){
sqlite3WindowUpdate(pParse, pSel ? pSel->pWinDefn : 0, pWin, pDef);
}
sqlite3WalkExprList(pWalker, pWin->pPartition);
sqlite3WalkExprList(pWalker, pWin->pOrderBy);
sqlite3WalkExpr(pWalker, pWin->pFilter);
sqlite3WindowLink(pSel, pWin);
pNC->ncFlags |= NC_HasWin;
}else
#endif /* SQLITE_OMIT_WINDOWFUNC */
{
NameContext *pNC2 = pNC;
pExpr->op = TK_AGG_FUNCTION;
pExpr->op2 = 0;
#ifndef SQLITE_OMIT_WINDOWFUNC
if( ExprHasProperty(pExpr, EP_WinFunc) ){
sqlite3WalkExpr(pWalker, pExpr->y.pWin->pFilter);
}
#endif
while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){
pExpr->op2++;
pNC2 = pNC2->pNext;
}