Re: Constraints and Functional Dependencies
Date: Mon, 26 Feb 2007 20:57:28 GMT
Message-ID: <YQHEh.28795$kr6.19665_at_trndny09>
"paul c" <toledobythesea_at_oohay.ac> wrote in message
news: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".
>
I would be very hesitant to draw deep philosophical inferences from the
choices that the designers of SQL made regarding keywords. The same goes
for any other computer language.
And I say htis as someone who likes SQL a bit more than the purists of this