/*
** 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);
}
/*
** 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 ORDER BY clause in a compound SELECT statement. Modify
** each term of the ORDER BY clause is a constant integer between 1
** and N where N is the number of columns in the compound SELECT.
**
** ORDER BY terms that are already an integer between 1 and N are
** unmodified. ORDER BY terms that are integers outside the range of
** 1 through N generate an error. ORDER BY terms that are expressions
** are matched against result set expressions of compound SELECT
** beginning with the left-most SELECT and working toward the right.
** At the first match, the ORDER BY expression is transformed into
** the integer column number.
**
** Return the number of errors seen.
*/
static int resolveCompoundOrderBy(
Parse *pParse, /* Parsing context. Leave error messages here */
Select *pSelect /* The SELECT statement containing the ORDER BY */
){
int i;
ExprList *pOrderBy;
ExprList *pEList;
sqlite3 *db;
int moreToDo = 1;
pOrderBy = pSelect->pOrderBy;
if( pOrderBy==0 ) return 0;
db = pParse->db;
#if SQLITE_MAX_COLUMN
if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause");
return 1;
}
#endif
for(i=0; i<pOrderBy->nExpr; i++){
pOrderBy->a[i].done = 0;
}
pSelect->pNext = 0;
while( pSelect->pPrior ){
pSelect->pPrior->pNext = pSelect;
pSelect = pSelect->pPrior;
}
while( pSelect && moreToDo ){
struct ExprList_item *pItem;
moreToDo = 0;
pEList = pSelect->pEList;
assert( pEList!=0 );
for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
int iCol = -1;
Expr *pE, *pDup;
if( pItem->done ) continue;
pE = pItem->pExpr;
if( sqlite3ExprIsInteger(pE, &iCol) ){
if( iCol<=0 || iCol>pEList->nExpr ){
resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr);
return 1;
}
}else{
iCol = resolveAsName(pParse, pEList, pE);
if( iCol==0 ){
pDup = sqlite3ExprDup(db, pE, 0);
if( !db->mallocFailed ){
assert(pDup);
iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup);
}
sqlite3ExprDelete(db, pDup);
}
}
if( iCol>0 ){
CollSeq *pColl = pE->pColl;
int flags = pE->flags & EP_ExpCollate;
sqlite3ExprDelete(db, pE);
pItem->pExpr = pE = sqlite3Expr(db, TK_INTEGER, 0);
if( pE==0 ) return 1;
pE->pColl = pColl;
pE->flags |= EP_IntValue | flags;
pE->u.iValue = iCol;
pItem->iCol = (u16)iCol;
pItem->done = 1;
}else{
moreToDo = 1;
}
}
pSelect = pSelect->pNext;
}
for(i=0; i<pOrderBy->nExpr; i++){
if( pOrderBy->a[i].done==0 ){
sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any "
"column in the result set", i+1);
return 1;
}
}
return 0;
}
/*
** This procedure generates VDBE code for a single invocation of either the
** sqlite_detach() or sqlite_attach() SQL user functions.
*/
static void codeAttach(
Parse *pParse, /* The parser context */
int type, /* Either SQLITE_ATTACH or SQLITE_DETACH */
FuncDef *pFunc, /* FuncDef wrapper for detachFunc() or attachFunc() */
Expr *pAuthArg, /* Expression to pass to authorization callback */
Expr *pFilename, /* Name of database file */
Expr *pDbname, /* Name of the database to use internally */
Expr *pKey /* Database key for encryption extension */
){
int rc;
NameContext sName;
Vdbe *v;
sqlite3* db = pParse->db;
int regArgs;
memset(&sName, 0, sizeof(NameContext));
sName.pParse = pParse;
if(
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pFilename)) ||
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) ||
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey))
){
pParse->nErr++;
goto attach_end;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
if( pAuthArg ){
char *zAuthArg = pAuthArg->u.zToken;
int i;
char iBuf[32];
if( sqlite3ExprIsInteger(pAuthArg, &i) ){
sqlite3_snprintf(sizeof(iBuf), iBuf, "%d", pAuthArg->u.iValue);
zAuthArg = iBuf;
}
if( NEVER(zAuthArg==0) ){
goto attach_end;
}
rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0);
if(rc!=SQLITE_OK ){
goto attach_end;
}
}
#endif /* SQLITE_OMIT_AUTHORIZATION */
v = sqlite3GetVdbe(pParse);
regArgs = sqlite3GetTempRange(pParse, 4);
sqlite3ExprCode(pParse, pFilename, regArgs);
sqlite3ExprCode(pParse, pDbname, regArgs+1);
sqlite3ExprCode(pParse, pKey, regArgs+2);
assert( v || db->mallocFailed );
if( v ){
sqlite3VdbeAddOp3(v, OP_Function, 0, regArgs+3-pFunc->nArg, regArgs+3);
assert( pFunc->nArg==-1 || (pFunc->nArg&0xff)==pFunc->nArg );
sqlite3VdbeChangeP5(v, (u8)(pFunc->nArg));
sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF);
/* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
** statement only). For DETACH, set it to false (expire all existing
** statements).
*/
sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH));
}
attach_end:
sqlite3ExprDelete(db, pFilename);
sqlite3ExprDelete(db, pDbname);
sqlite3ExprDelete(db, pKey);
}
