> Now, looking at your Customer row that looks up control
> tables to get descriptions of things like Country,
> Payment Terms, Currency, etc. If we place a foreign key
> constraint on those lookup columns, we are forcing our
> "true master" to be dependent on the existence of the
> lookup row. This is conceptually incorrect.

But it is correct. I cannot create a customer for Australia until
Australia is defined to the system. If Australia sinks into the ocean
then when I delete that country I will need to delete all the
customers - except the good swimmers.

Geoff Worboys
Telesis Computing