Em Thursday 06 March 2008 22:10:14 Jamie Tufnell escreveu: > > I already have site_id in the users table and I can determine the > site_group_id from that. So it seems redundant to me, to store > site_group_id for each user as well. Also, I'm not sure how I would > enforce that the site_group_id added to the users table would > correspond correctly with the site_id (as per the sites table). > Perhaps I would make a composite foreign key?
Or you manage site_group_id from a trigger. When the user creates / chooses a site_id and updates/inserts this information then you fill site_group_id with a trigger. This way you guarantee the correctness of this parameter. > I've never come up against this situation before, and because of the > reasons above, I'm getting the feeling there might be a better way to > design this. Again, a trigger can do that. Slower than denormalizing the database, but it can be done. -- Jorge Godoy <[EMAIL PROTECTED]> -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
