<enio@pmpf.rs.gov.br> writes:
> I am trying to catch the "UPDATE 0" condition in postgresql.
> I have tried it using triggers, but they are only fired when there
> effectively is an update.
You could try using an AFTER STATEMENT trigger (which will be invoked
even if zero rows are updated), and checking the size of the set of
modified rows ... except that we currently don't provide a way for
per-statement triggers to access the set of modified tuples.
If someone implements that functionality (which is on the TODO list),
that would be a clean solution to your problem.
-Neil