Re: does a table always need a PK?

"Lauri Pietarinen" <lauri.pietarinen_at_atbusiness.com> wrote in message news:3F5442BC.8000500_at_atbusiness.com...
> Paul G. Brown wrote:
>
> >Lauri Pietarinen <lauri.pietarinen_at_atbusiness.com> wrote in message
news:<bj0da9$ue8$1_at_nyytiset.pp.htv.fi>...
> >
> >
> [snip]
>
> > Trouble is, you can't build systems for the most of the time. If
you're
> > going to implement something it has to cater to the nasty corner cases:
the
> > ones where it isn't clear where to add the duplicate discard operations
but
> > where it is clear you're going to need a lot of 'em. (Queries sans
keys).
> >
> >
> You could also argue that current SQL-implementations miss lot's of
> corner cases as the now stand. So you would
> perhaps be trading some corner cases for other ones, i.e. we would gain
> some things and perhaps lose
> others...

Queries without keys? All relations have at least one key. Received on Tue Sep 02 2003 - 14:50:37 CEST