[thelist] Constraint/trigger help
Bill Moseley
moseley at hank.org
Fri May 18 01:17:23 CDT 2007
Say I have a mail reader application where people can create their own
mailboxes (folders). So I have a table:
create table mailbox (
id integer,
name text,
owner int references user(id)
);
So, now the user table should store their default mailbox
(ignoring that I've referenced user above before defining it)
create table user (
id integer,
name text,
email text,
default_mailbox integer references mailbox(id)
);
How can I ensure (in the database) that default_mailbox references a
mailbox that has its owner set to the same user? Obviously, don't
want one user's default mailbox to reference another user's mailbox.
I'm not thrilled by the circular references there.
--
Bill Moseley
moseley at hank.org
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