Re: Question about relationship and composite pk

From: JRStern <JRStern_at_gte.net>
Date: Tue, 20 Mar 2001 01:19:45 GMT
Message-ID: <3ab6b01c.38516864@news.gte.net>

On Mon, 19 Mar 2001 21:36:48 GMT, "For example: John Smith" <f_at_r.c> wrote:
>Is it possible for a 1 to many relationship to have (1,1) Cardinality on
>both sides of the relationship?
>
>Are composite primary keys a bad thing? The table I have consists of only
>the two attributes which ocur many times, but only together once.

It sounds like you're describing an association table.

Student Table, pk=name

---

Smith
Jones

Association Table, pk=name+class

---

Smith, Geography
Smith, Math
Jones, Geography

Class Table, pk=class

---

Geography
Math

J. Received on Mon Mar 19 2001 - 19:19:45 CST