Bill <pg(at)dbginc(dot)com> writes:
> Is it possible to create a type and use that instead of the domain or
> will I have the same problem with a type?
You'd have the same problem. By the time the trigger sees it, the row
has already been converted to the table's column datatype(s), so any
exception associated with a datatype or domain would be thrown already.
A lot of people seem to have trouble with this concept; I dunno what
data representation they think the trigger is working on...
If you want to enforce constraints for a table in the trigger, you can
do that, but it's not going to work to try to mix and match
trigger-based and datatype-based restrictions.
regards, tom lane