Re: So what's null then if it's not nothing?

From: David Cressey <dcressey_at_verizon.net>
Date: Tue, 13 Dec 2005 11:58:13 GMT
Message-ID: <pHynf.1925$pF.1163@trndny08>

"Jon Heggland" <heggland_at_idi.ntnu.no> wrote in message news:MPG.1e07ca1b45bb3a9f989744_at_news.ntnu.no...

> I don't see why '<' is something to get worked up about. Why is it bad
> to define some (arbitrary) order for truth values? As for defining a
> strange '=', they do so for the other domains (and I think Codd does it
> too), and Codd's article doesn't mention Kleene either. It seems strange
> if Codd didn't bother to correct the SQL committee if it got things so
> very wrong.

Strongly agreed.

In Pascal, where FALSE < TRUE, you can use all the comparison operators as Boolean operators.
In particular, <= can be used in place of "implies". In other words, if A implies B then A<=B will be true.

People get worked up about order in this forum, because they think that the next point you are going to make is that lists are more expressive than sets. Received on Tue Dec 13 2005 - 05:58:13 CST