There doesn't seem to be much documentation on foreign keys and how to
use them properly.
I am setting up a DB with two tables: users, and a table of objects
where are always owned by users. I want to make sure that there's no
way to have an object which isn't owned. Let's say these are the
tables:
CREATE TABLE user (
number INT4,
name VARCHAR(400)
);
and
CREATE TABLE object (
owner INT4,
description VARCHAR(200)
);
The constraint is that there should never be a row in the object table
where the owner column has a number which doesn't have a corresponding
owner in the user table.
I'm sure I can do something with foreign keys to implement this
constraint, but I can't figure it out.
Thanks
