On Mon, May 18, 2009 at 3:13 PM, Joshua Berry <yoberi@gmail.com> wrote:
> Hello all,
>
> Is there an easy and efficient way to return a boolean false for a query
> that returns no result, and true for one that does return a result?
>
Probably the best general approach is to:
select count(*) = 1 from
(
<query> limit 1
)q;
the point being that in some cases (not all obviously) the limit 1 can
be a huge win, as you only care if there are rows or not. with little
work (you have to be aware of if/when you can tack 'limit 1 onto a
query) you could generalize it into a pl/pgsql dynamic sql function
taking a query string.
merlin
