Re: User defined exceptions

On Wed, Jul 15, 2015 at 10:10 AM, Alex Ignatov <a(dot)ignatov(at)postgrespro(dot)ru>
wrote:

> Hello all!
> Trying to emulate "named" user defined exception with:
> CREATE OR REPLACE FUNCTION exception_aaa () RETURNS text AS $body$
> BEGIN
> return 31234;
> END;
> $body$
> LANGUAGE PLPGSQL
> SECURITY DEFINER
> ;
>
> do $$
> begin
> raise exception using errcode=exception_aaa();
> exception
> when sqlstate exception_aaa()
> then
> raise notice 'got exception %',sqlstate;
> end;
> $$
>
> Got:
>
> ERROR: syntax error at or near "exception_aaa"
> LINE 20: sqlstate exception_aaa()
>
> I looks like "when sqlstate exception_aaa()" doesn't work.
>
> How can I catch exception in this case?
>

​I'm doubtful that it can be done presently.

If it were possible your exception_aaa function would have to be declared
IMMUTABLE. It also seems pointless to declare it security definer.

​There is nothing in the documentation that suggests that (or, to be fair,
prohibits) the "condition" can be anything other than a pre-defined name or
a constant string. When plpgsql get a function body it doesn't go looking
for random functions to execute.

David J.