Re: Multiple parent design
Date: Fri, 16 Apr 2004 08:26:24 -0400
Some people may object to my previous suggestion, because it relies on NULLS. Here's an alternative:
Take the parent_id out of the phone table.
Create two new tables:
create table PERSONAL_PHONE
PERSON_ID); create table COMPANY_PHONE
COMPANY_ID); Put in the appropriate constraints for referential integrity, and relationships. A PHONE_ID must exist in one and only one of these two tables.
"Laconic2" <laconic2_at_comcast.net> wrote in message
> Create two columns in the phone table, Person_id and Company_id. Enforce
> referential integrity on each one separately. Allow each one to be NULL.
> If necessary, enforce a constraint that either Person_id or Company_id
> be null.
Received on Fri Apr 16 2004 - 14:26:24 CEST