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Teach grammar and parser about aggregate(DISTINCT ...). No implementation

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yet, but at least we can give a better error message:
regression=> select count(distinct f1) from int4_tbl;
ERROR:  aggregate(DISTINCT ...) is not implemented yet
instead of 'parser: parse error at or near distinct'.
This commit is contained in:
Tom Lane
1999-12-10 07:37:35 +00:00
parent ecba5d308c
commit 18c3000286
11 changed files with 220 additions and 114 deletions
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174
src/backend/parser/parse_func.c
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@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.63 1999/12/07 04:09:39 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.64 1999/12/10 07:37:35 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -87,6 +87,7 @@ ParseNestedFuncOrColumn(ParseState *pstate, Attr *attr, int *curr_resno, int pre
retval = ParseFuncOrColumn(pstate, strVal(lfirst(attr->attrs)),
lcons(param, NIL),
false, false,
curr_resno,
precedence);
}
@ -98,6 +99,7 @@ ParseNestedFuncOrColumn(ParseState *pstate, Attr *attr, int *curr_resno, int pre
ident->isRel = TRUE;
retval = ParseFuncOrColumn(pstate, strVal(lfirst(attr->attrs)),
lcons(ident, NIL),
false, false,
curr_resno,
precedence);
}
@ -107,6 +109,7 @@ ParseNestedFuncOrColumn(ParseState *pstate, Attr *attr, int *curr_resno, int pre
{
retval = ParseFuncOrColumn(pstate, strVal(lfirst(mutator_iter)),
lcons(retval, NIL),
false, false,
curr_resno,
precedence);
}
@ -219,6 +222,7 @@ agg_select_candidate(Oid typeid, CandidateList candidates)
*/
Node *
ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
bool agg_star, bool agg_distinct,
int *curr_resno, int precedence)
{
Oid rettype = InvalidOid;
@ -230,12 +234,13 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
char *refname = NULL;
Relation rd;
Oid relid;
int nargs;
int nargs = length(fargs);
Func *funcnode;
Oid oid_array[MAXFARGS];
Oid *true_oid_array;
Node *retval;
bool retset;
bool must_be_agg = agg_star || agg_distinct;
bool attisset = false;
Oid toid = InvalidOid;
Expr *expr;
@ -252,11 +257,11 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
* that argument is a relation, param, or PQ function returning a
* complex * type, then the function could be a projection.
*/
/* We only have one parameter */
if (length(fargs) == 1)
/* We only have one parameter, and it's not got aggregate decoration */
if (nargs == 1 && !must_be_agg)
{
/* Is is a plain Relation name from the parser? */
if (nodeTag(first_arg) == T_Ident && ((Ident *) first_arg)->isRel)
/* Is it a plain Relation name from the parser? */
if (IsA(first_arg, Ident) && ((Ident *) first_arg)->isRel)
{
RangeTblEntry *rte;
Ident *ident = (Ident *) first_arg;
@ -292,15 +297,10 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
refname,
funcname);
}
else
{
/* drop through - attr is a set */
;
}
/* else drop through - attr is a set */
}
else if (ISCOMPLEX(exprType(first_arg)))
{
/*
* Attempt to handle projection of a complex argument. If
* ParseComplexProjection can't handle the projection, we have
@ -325,8 +325,7 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
argrelid = typeidTypeRelid(toid);
/*
* A projection contains either an attribute name or the
* "*".
* A projection contains either an attribute name or "*".
*/
if ((get_attnum(argrelid, funcname) == InvalidAttrNumber)
&& strcmp(funcname, "*"))
@ -336,76 +335,99 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
if (retval)
return retval;
}
}
if (nargs == 1 || must_be_agg)
{
/*
* See if it's an aggregate.
*/
Oid basetype;
int ncandidates;
CandidateList candidates;
/* We don't presently cope with, eg, foo(DISTINCT x,y) */
if (nargs != 1)
elog(ERROR, "Aggregate functions may only have one parameter");
/*
* the aggregate COUNT is a special case, ignore its base
* type. Treat it as zero. XXX mighty ugly --- FIXME
*/
if (strcmp(funcname, "count") == 0)
basetype = 0;
else
basetype = exprType(lfirst(fargs));
/* try for exact match first... */
if (SearchSysCacheTuple(AGGNAME,
PointerGetDatum(funcname),
ObjectIdGetDatum(basetype),
0, 0))
return (Node *) ParseAgg(pstate, funcname, basetype,
fargs, agg_star, agg_distinct,
precedence);
/*
* No exact match yet, so see if there is another entry in the
* aggregate table which is compatible. - thomas 1998-12-05
*/
ncandidates = agg_get_candidates(funcname, basetype, &candidates);
if (ncandidates > 0)
{
Oid type;
/*
* Parsing aggregates.
*/
Type tp;
Oid basetype;
int ncandidates;
CandidateList candidates;
/*
* the aggregate COUNT is a special case, ignore its base
* type. Treat it as zero
*/
if (strcmp(funcname, "count") == 0)
basetype = 0;
else
basetype = exprType(lfirst(fargs));
/* try for exact match first... */
if (SearchSysCacheTuple(AGGNAME,
PointerGetDatum(funcname),
ObjectIdGetDatum(basetype),
0, 0))
return (Node *) ParseAgg(pstate, funcname, basetype,
fargs, precedence);
/*
* No exact match yet, so see if there is another entry in the
* aggregate table which is compatible. - thomas 1998-12-05
*/
ncandidates = agg_get_candidates(funcname, basetype, &candidates);
if (ncandidates > 0)
type = agg_select_candidate(basetype, candidates);
if (OidIsValid(type))
{
Oid type;
type = agg_select_candidate(basetype, candidates);
if (OidIsValid(type))
{
lfirst(fargs) = coerce_type(pstate, lfirst(fargs),
basetype, type, -1);
basetype = type;
return (Node *) ParseAgg(pstate, funcname, basetype,
fargs, precedence);
}
else
{
elog(ERROR, "Unable to select an aggregate function %s(%s)",
funcname, typeidTypeName(basetype));
}
lfirst(fargs) = coerce_type(pstate, lfirst(fargs),
basetype, type, -1);
basetype = type;
return (Node *) ParseAgg(pstate, funcname, basetype,
fargs, agg_star, agg_distinct,
precedence);
}
else
{
/* Multiple possible matches --- give up */
elog(ERROR, "Unable to select an aggregate function %s(%s)",
funcname, typeidTypeName(basetype));
}
}
if (must_be_agg)
{
/*
* See if this is a single argument function with the function
* name also a type name and the input argument and type name
* binary compatible... This means that you are trying for a
* type conversion which does not need to take place, so we'll
* just pass through the argument itself. (make this clearer
* with some extra brackets - thomas 1998-12-05)
* No matching agg, but we had '*' or DISTINCT, so a plain
* function could not have been meant.
*/
if ((HeapTupleIsValid(tp = SearchSysCacheTuple(TYPENAME,
PointerGetDatum(funcname),
0, 0, 0)))
&& IS_BINARY_COMPATIBLE(typeTypeId(tp), basetype))
return ((Node *) lfirst(fargs));
elog(ERROR, "There is no aggregate function %s(%s)",
funcname, typeidTypeName(basetype));
}
}
/*
* See if this is a single argument function with the function
* name also a type name and the input argument and type name
* binary compatible... This means that you are trying for a
* type conversion which does not need to take place, so we'll
* just pass through the argument itself. (make this clearer
* with some extra brackets - thomas 1998-12-05)
*/
if (nargs == 1)
{
Type tp;
tp = SearchSysCacheTuple(TYPENAME,
PointerGetDatum(funcname),
0, 0, 0);
if (HeapTupleIsValid(tp) &&
IS_BINARY_COMPATIBLE(typeTypeId(tp), exprType(lfirst(fargs))))
{
/* XXX FIXME: probably need to change expression's marked type? */
return (Node *) lfirst(fargs);
}
}
/*
* If we dropped through to here it's really a function (or a set,
@ -461,14 +483,14 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
{ /* set functions don't have parameters */
/*
* any functiona args which are typed "unknown", but aren't
* any function args which are typed "unknown", but aren't
* constants, we don't know what to do with, because we can't
* cast them - jolly
*/
if (exprType(pair) == UNKNOWNOID && !IsA(pair, Const))
elog(ERROR, "There is no function '%s'"
" with argument #%d of type UNKNOWN",
funcname, nargs);
funcname, nargs+1);
else
toid = exprType(pair);
}
@ -572,7 +594,7 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
text *seqname;
int32 aclcheck_result = -1;
Assert(length(fargs) == ((funcid == F_SETVAL) ? 2 : 1));
Assert(nargs == ((funcid == F_SETVAL) ? 2 : 1));
seq = (Const *) lfirst(fargs);
if (!IsA((Node *) seq, Const))
elog(ERROR, "Only constant sequence names are acceptable for function '%s'", funcname);