Re: How to normalize these 3 tables?

>Hi, I was given 3 tables and am wondering how to normalize or
>restructure them:
>
>table PROJECT:
>project_id integer primary key
>project_name varchar2(20)
>
>table DRUG:
>drug_id integer primary key
>drug_project_id integer foreign key drug_project(drug_project_id)
>
>table DRUG_PROJECT:
>drug_project_id integer primary key
>project_id integer foreign key project(project_id)
>drug_id integer foreign key drug(drug_id)
>
>The reason I have drug_project is because the same drug can associate
>with different projects and I would like to have an unique id for each.
>But it looks like it won't work since I have to foreign keys pointing
>each other on 2nd and 3rd tables.
>
>I appreciate your help. Thanks!
>
>Susana
>
>
>Sent via Deja.com http://www.deja.com/
>Before you buy.
>

Remove the column drug_project_id from the DRUG table. You do not need it; it does not tell you about the DRUG.

Dan Hekimian-Williams Received on Thu Mar 09 2000 - 01:29:19 CET