Re: Relation Schemata vs. Relation Variables
From: Erwin <e.smout_at_myonline.be>
Date: 21 Aug 2006 01:57:05 -0700
Message-ID: <1156150625.141893.273410_at_b28g2000cwb.googlegroups.com>
Date: 21 Aug 2006 01:57:05 -0700
Message-ID: <1156150625.141893.273410_at_b28g2000cwb.googlegroups.com>
>
> I think a transition constraint must be defined as a relational
> expression in the general form of some join between t and t'.
>
"Suppliers with status 20 cannot be deleted."
I think this is indeed an example of a transition constraint. Can this be expressed using just JOIN ? Received on Mon Aug 21 2006 - 10:57:05 CEST