On Sunday 01 July 2007 21:16, Michael Fuhr wrote:
> What have you tried and how did the outcome differ from your
> expectations?
The pl/perl trigger function in question generates an exception by
elog(ERROR, "message"). I also tried die(), which didn't make a difference.
When I do something on the table which the trigger function prevents, I get a
message saying ERROR: blablabla. When such an error is generated by a pl/pgsql
trigger function, I can trap the error with WHEN raise_exception. This does
not work for the exception generated by the pl/perl function.
> You could use "WHEN internal_error" or "WHEN others". If that
> doesn't work then please post a simple but complete example that
> shows what you're trying to do.
Trapping "others" works, even though I think it's kind of klunky.
An example:
create table test_table
(
field integer
);
create function test_function() returns trigger as $$
elog(ERROR, "message");
return;
$$ LANGUAGE plperl;
create trigger test_trigger before insert on test_table
for each row execute_procedure test_function();
create function perform_actions() RETURNS VOID as $$
BEGIN
BEGIN
insert into test_table (field) values (1);
EXCEPTION WHEN raise_exception THEN NULL; END;
END:
$$ language plpgsql;
select perform_actions();
The exception generated by the plperl function is not trapped by "WHEN
raise_exception", but it is by "WHEN others".
Is it a bug that postgres doesn't see pl/perl's error as an exception, or is
there a good reason for it?
