Re: a union is always a join!
From: rpost <rpost_at_pcwin518.campus.tue.nl>
Date: Tue, 7 Apr 2009 19:52:34 +0000 (UTC)
Message-ID: <grgau2$2gal$1_at_mud.stack.nl>
>is superfluous. Makes sense, doesn't it.
Date: Tue, 7 Apr 2009 19:52:34 +0000 (UTC)
Message-ID: <grgau2$2gal$1_at_mud.stack.nl>
I just wrote
>[...] if you can point out which entity
>has changed, there must be some property or properties in the real
>world by which you made that identification, and those properties
>must be key attributes in your database model, so we should express the
>change in terms of changes to key attribute values and the identifier
xxx
>is superfluous. Makes sense, doesn't it.
Not much. I meant to say changes to other attributes.
-- ReinierReceived on Tue Apr 07 2009 - 21:52:34 CEST