Re: Storing "deleted" data
Date: Tue, 1 Nov 2005 10:30:18 +0200
Message-ID: <dk792u$2bs$1_at_domitilla.aioe.org>
You forgot zombies.
<zeldorblat_at_gmail.com> wrote in message
news:1130769897.026173.216650_at_g49g2000cwa.googlegroups.com...
> >b)You can try to declare a foreign key reference to one table AND
another.
>
> That doesn't help, though. Consider the following:
>
> create table livePeople (
> personID int not null,
> ...
> )
>
> create table deadPeople (
> personID int not null,
> ...
> )
>
> create table personComment (
> personID int not null,
> commentID int not null
> )
>
> So what primary key does personComment.personID refer to? As far as I
> know, while it can refer to livePerson.personID AND
> deadPerson.personID, it can't refer to livePerson.personID OR
> deadPerson.personID. Furthermore, there's no way to indicate that
> livePerson.personID and deadPerson.personID have to be unique when
> combined.
>
Received on Tue Nov 01 2005 - 09:30:18 CET