From: David Cressey <>
Date: Sun, 30 Dec 2007 22:42:12 GMT
Message-ID: <89Vdj.7299$cq5.3693_at_trndny06>

"Brian Selzer" <> wrote in message news:JeSdj.2231$
> "stevedtrm" <> wrote in message
> >> > If everyone is clear NULLS shouldn't be used, why the debate as to
> >> > to do about them ?
> >>
> >> Because SQL allows NULL and even promotes the idea that NULL solves
> >> problem instead of introducing many.
> >
> > So everyone is agreed that NULLs shouldn't appear anywhere, and its
> > just a matter of time before NULLS become a legacy problem and a
> > relational language supercedes SQL?
> >
> No, Steve, not everyone is agreed.
> > Are the two solutions I suggested before the widely accepted as
> > resolutions to the two problems NULLs were introduced to eradicate?
> >
> >>Missing information? Then surely there should just be no tuple?
> >
> A row may contain a lot more information that would otherwise be useful.
> Would you tell a potential customer that you won't serve them because you
> don't know everything about them? I think not! Haven't you been asked
> your e-mail address at a retailer? What would you think if the cashier
> you to get lost for refusing to supply it?
> >>To indicate that there can be no value? Why not a seperate table with
> >>a boolean value in the non-key column?
> In my opinion, null should only ever be used to indicate "There should be
> value here, but it hasn't been supplied."

A quibble.

I would say that it indicates that there is space for a value here, but no value has been place in the space.

As for the rest of it, we've had this discussion in c.d.t. before, at least a dozen times. Received on Sun Dec 30 2007 - 23:42:12 CET

Original text of this message