>> I know I can setup a FK constraint to make sure Table1.ColA exists in
>> Table2.Key, however what if I want to do the reverse?
>>
>> I want to ensure Table1.ColA does NOT exist in Table2.Key.. Can I do
>> this with any sort of CHECK constraint, trigger, custom function, etc?
>
>
> The most common constraints are provided for, but then after that you
> have to use triggers.
>
> PostgreSQL deliberately doesn't support queries in CHECK constraints
> for this reason.
Thanks! I wrote a Trigger for this and it seems to work fairly well..
I kinda figured that was the obvious way, but thought there might be
some new 9.x feature that made this sort of thing possible.