Re: RM VERY STRONG SUGGESTION 4: TRANSITION CONSTRAINTS
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Sat, 04 Sep 2010 01:03:44 -0300
Message-ID: <4c81c52b$0$11815$9a566e8b_at_news.aliant.net>
>
> I disagree. At the logical level of discourse, both assignments are the
> same.
Date: Sat, 04 Sep 2010 01:03:44 -0300
Message-ID: <4c81c52b$0$11815$9a566e8b_at_news.aliant.net>
Bob Badour wrote:
> Brian wrote:
>
>> On Sep 3, 2:29 pm, Erwin <e.sm..._at_myonline.be> wrote: >> >>> On 3 sep, 17:35, Brian <br..._at_selzer-software.com> wrote: >> >> <snip> >> >>>> UPDATE is not the same as a combination of DELETE-then-INSERT, but not >>>> because of some objectid. >>> >>> It is the same. Always. Before some update, relvar R has value >>> {t1}. After that update, relvar R has the value {t2}. >>> >>> Please explain what the difference is between this update and a >>> multiple assignment consisting of the delete of t1 and the insert of >>> t2. >> >> In the update, the referent of t1 is the referent of t2, but in the >> multiple assignment, the referent of t1 ceased to exist and the >> referent of t2 came into existence. The "meaning" of the fact "t2" is >> therefore different. For example,
>
> I disagree. At the logical level of discourse, both assignments are the
> same.
WTF? How did Selzer get out of my filter? Received on Sat Sep 04 2010 - 06:03:44 CEST