Re: NULLs ;-)

On Nov 28, 2006, at 9:37 , Scott Ribe wrote:

>> (Can we talk about NULL next? :P)
>
> Seriously though, there is one thing I've been meaning to bring up. I
> understand why NULLs compare the way they do in queries, and that's
> fine.
> But there are times when I need to query what would be described in
> relational terms as "not known to be equal", and
>
> where a <> b or (a is null and b is not null) or (a is not null
> and b is
> null)

> So, first, have I missed some way to express that more easily in
> PG? And if
> not, is there any reason not to request a new operator? (Perhaps "a
> nktbe
> b"? The C guy in me prefers "a != b" but that would be *FAR* too
> prone to
> confusion with <>.)

Check out IS DISTINCT FROM

http://www.postgresql.org/docs/current/interactive/functions-
comparison.html

I think that will help you.

Michael Glaesemann
grzm seespotcode net