> --> I have a table with an UNIQUE constraint. Is it possible to have
> --> something like a trigger (or error handler) which is called every time
> --> a insert statement would break this constraint? Or in some simple cases
> --> that this record is just dropped silently, without reporting an error?
> I believe that a UNIQUE constraint will stop the insert before any trigger
> ever fires. Maybe someone else knows for sure.
I do not know if there is an specific error handler built in postgresql (besides error-codes).
If you break the unique constraint an error will be thrown. A
workaround may be to launch a trigger BEFORE the insertion and do whatever is necessary within the trigger.
http://www.postgresql.org/docs/8.1/static/sql-createtrigger.html
--
Oscar