Re: foreign key constraint versus referential integrity constraint
From: paul c <toledobythesea_at_oohay.ac>
Date: Thu, 29 Oct 2009 03:04:11 GMT
Message-ID: <LC7Gm.49742$Db2.7559_at_edtnps83>
Date: Thu, 29 Oct 2009 03:04:11 GMT
Message-ID: <LC7Gm.49742$Db2.7559_at_edtnps83>
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.) Received on Thu Oct 29 2009 - 04:04:11 CET