Re: So what's null then if it's not nothing?
Date: 29 Nov 2005 05:53:30 -0800
Jon Heggland wrote:
> SQL is confused, and breeds confusion. For one thing, NULL is not a
> value. If it were, it would be equal to itself.
With respect to nulls, SQL is no more confused that Codd's original
work on which SQL's null treatment is based. There is no need to
attack SQL whose deficiencies are well known if all one wants to
discuss is the notion of null..
> > null = null comparison.
> By SQL fiat, perhaps. But *should* it be? What gives SQL the right to
> redefine notions of equality and "distinctness" in this manner? Or never
> mind the right; does it make *sense*? Is it worth the price?
null=null evaluates to unknown according to the 3vl logic rules.
> By the way, is NULL = NULL a valid SQL expression now?
Received on Tue Nov 29 2005 - 14:53:30 CET