Re: Default value if query returns 0 rows? - Mailing list pgsql-general

On Fri, 17 Sep 2004, Bruno Wolff III wrote:

> >
> >   if exists (select 1 from map where name = 'foo') then
> >     select id from map where name = 'foo'
> >   else
> >     select -1
> >   end if
> >
>
> If there can be at most one match you can use a subselect and coalesce.
>

Bruno,

Thanks for the suggestion.  I've come up with the following that appears to
work:

  SELECT
    COALESCE((SELECT id FROM map WHERE name = $1), -1)
    FROM map_level
    LIMIT 1

-- Lars

--
Lars Kellogg-Stedman <lars@oddbit.com>