> >In cases where the userid - accountid pairs are always unique, the > >additional PK is redundant (although 99% of the time it's there anyway > >due to lazy design). A "lookup" table whose sole purpose is to create > >relationships between the two other tables should not have duplicate > >userid-accountid pairs. > > > >In another case, let's say you have a table containing logon > >information which stores userid and accountid along with other data in > >each row. In this case you'd have multiple instances of the same > >userid-accountid pairs, and you'd need a separate PK to uniquely > >reference specific instances of that pair in the table. > > > >Kristina > > > I think I said I agreed with that. > > Cheers, > > tedd > > -- > ------- > http://sperling.com http://ancientstones.com http://earthstones.com > >
Tedd, Absolutely, you did, but what I was trying to say (poorly I guess) was that a lot of what Dan put out there (which was fantastic stuff) related (at least insofar as my understanding of it) only to the first case where there aren't any duplicate userid-accountid pairs. Kristina _______________________________________________ New York PHP Users Group Community Talk Mailing List http://lists.nyphp.org/mailman/listinfo/talk http://www.nyphp.org/Show-Participation
