Re: design question

From: stu <smcgouga_at_nospam.co.uk>
Date: Wed, 22 Jan 2003 08:57:06 -0000
Message-ID: <b0lmfe$27$1$8302bc10@news.demon.co.uk>

"Heinz Huber" <XhhuberX_at_no-racon-linz.at-no> wrote in message news:3e2e4b3f$0$20418$91cee783_at_newsreader02.highway.telekom.at...
> As soon as you have a supertype, you don't have to create new surrogate
> keys for the subtypes. If teacher/student ID are generated values, you
> can simply use Users.ID since that value is unique anyway.
>
> Heinz
>

But think about what happens if a student also teaches a class. The User ID on its own is no longer unique.

Stu Received on Wed Jan 22 2003 - 02:57:06 CST