Re: Constraints and Functional Dependencies
From: paul c <toledobythesea_at_oohay.ac>
Date: Sun, 25 Feb 2007 00:26:21 GMT
Message-ID: <NI4Eh.1119605$1T2.260816_at_pd7urf2no>
Date: Sun, 25 Feb 2007 00:26:21 GMT
Message-ID: <NI4Eh.1119605$1T2.260816_at_pd7urf2no>
mAsterdam wrote:
...
> Yes, a reference (I like the term) is what the (i) defines ...
...
Not to tout SQL of which I know very little but I believe it or at least some implementations, uses the keyword "REFERENCES". For all I know, the same implementations also support "FOREIGN KEY" phrase. If that's so, I'd be curious to know from SQL experts whether the typical implementations require the latter to reference a "primary key" and if the former doesn't. If that's so I'd be really curious to hear of examples where REFERENCES is superior in practice to "FOREIGN KEY".
p Received on Sun Feb 25 2007 - 01:26:21 CET