Re: Adding UNIQUE constraint on NULL column - Mailing list pgsql-general

Yes
On Thu, 2005-01-13 at 10:12, Doug McNaught wrote:
> Dave Smith <dave.smith@candata.com> writes:
>
> > I am trying to add a unique constraint on a column that can be null. The
> > documentation states that null is treated as non equal values but I want
> > them to be equal. Is there another way of doing this other than writing
> > a before insert trigger?
>
> UNIQUE constraints on NULLable columns work fine.  It's not clear from
> the above what you're looking for.
>
> Are you really saying that you want 'NULL = NULL' to return 't'?
>
> -Doug
--
Dave Smith
CANdata Systems Ltd
416-493-9020