Re: Wrong result with constant quals

Vik Fearing <vik(at)postgresfriends(dot)org> writes:
> The following query returns a wrong result, in my opinion.

> postgres=# select 1 where false having true;
> ?column?
> ----------
> 1
> (1 row)

> The correct result should be zero rows.

No, I don't think so. The presence of HAVING without GROUP BY makes
this act like a query with an aggregate function and no GROUP BY: you
get a single grouped row, regardless of what the input is. There's a
reasonably clear specification of that in SQL92 7.8 <having clause>:

1) Let T be the result of the preceding <from clause>, <where
clause>, or <group by clause>. If that clause is not a <group
by clause>, then T consists of a single group and does not have
a grouping column.

"A single group" is not "no groups".

Later SQL versions define this by reference to "GROUP BY ()", but
I think the effect is the same.

regards, tom lane