Re: limit table to one row

On Tue, 09 Jun 2009 08:24:01 -0700, Brandon Metcalf
<brandon(at)geronimoalloys(dot)com> wrote:
>
> CREATE TABLE foo (
> start DATE,
> length VARCHAR(10),
> );
>
> I need to be able to get one value for each column at any given time.

CREATE UNIQUE INDEX u ON foo ((start IS NOT NULL));

You would just make sure you SELECT FROM foo WHERE start IS NOT NULL;

However, it doesn't prevent you from having 0 rows on the table.