On Fri, Sep 10, 2004 at 17:39:31 -0400,
Kevin Murphy <murphy(at)genome(dot)chop(dot)edu> wrote:
> This is probably a stupid question, but ...
>
> I'd like to be able to take an existing query and modify it to return a
> single row if that's what the base query returns, and 0 rows if the
> base query returns multiple rows. Similarly, I'd like to also modify
> it to return multiple rows if that's what the base query returns, and 0
> rows if the base query return a single row.
>
> What's a good way to do this?
SELECT * FROM whatever HAVING count(*) < 1;