Re: foreign key constraint versus referential integrity constraint
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Thu, 29 Oct 2009 00:09:30 -0300
Message-ID: <4ae9076a$0$26483$9a566e8b_at_news.aliant.net>
>
> I thought constraints constrain, ie., limit. (I've often thought that
> isn't enough in practice, eg., I've never seen a default defined
> algebraically and beyond that I wouldn't mind a variation on constraints
> that lets me force an assertion, eg., some tuple that is always present,
> whether the user has thought to include it or not, probably CJ Date
> would disagree with that.)
Date: Thu, 29 Oct 2009 00:09:30 -0300
Message-ID: <4ae9076a$0$26483$9a566e8b_at_news.aliant.net>
paul c wrote:
> Mr. Scott wrote:
> ...
>
>> Constraints specify what can be true, not what is supposed to be true. >> ...
>
> I thought constraints constrain, ie., limit. (I've often thought that
> isn't enough in practice, eg., I've never seen a default defined
> algebraically and beyond that I wouldn't mind a variation on constraints
> that lets me force an assertion, eg., some tuple that is always present,
> whether the user has thought to include it or not, probably CJ Date
> would disagree with that.)
I cannot make sense of what you wrote. I suspect you have omitted much context, internal dialogue and assumptions. Received on Thu Oct 29 2009 - 04:09:30 CET