Re: modeling either/or relationship...

From: JOG <jog_at_cs.nott.ac.uk>
Date: 2 Feb 2006 15:35:15 -0800
Message-ID: <1138923315.824865.313960@g47g2000cwa.googlegroups.com>

-CELKO- wrote:
> >> Still, I get this strange feeling thinking about NULLs in UNIQUE. <<
>
> We did, too. I can only vaguely remember the arguements in X3H2 now.
>
> Basically, we said that there is equality and there is grouping, as in
> GROUP BY. NULLs fail equality, but get grouped together. The
> REFERENCES clause uses grouping and not equality.
>
> As we used to say about OS/JCL, it makes perfect sense after you work
> with it for decade :)

"All roads lead to rome"...

do "all threads on comp.theory.database lead to nulls?" Received on Thu Feb 02 2006 - 17:35:15 CST