Re: Way to get at parsed trigger 'WHEN' clause expression?

On Thu, Mar 24, 2016 at 4:05 PM, James Robinson <jlrobins(at)socialserve(dot)com>
wrote:

> Folks,
>
> I see that psql's \d displays trigger information of a table by
> making a call to pg_catalog.pg_get_triggerdef(), which abstracts away most
> all need to parse the contents of system catalog pg_trigger. However, we'd
> like to be able to get at a human readable representation of just the WHEN
> clause of the trigger expression. Function pg_get_expr() looked likely, but
> fails when fed a pgqual value from pg_trigger ala:
>
> ERROR: bogus varno: 2
>
> I suspect that it is falling over dead trying to parse the
> representation of NEW and / or OLD. Anything built in, or should we just
> make call to pg_catalog.pg_get_triggerdef() and parse out the WHEN clause
> text?
>
> Thanks!
> ------
> James Robinson
> Socialserve.com by Emphasys Software
>
>

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Your problem description is a bit cloudy. Could you please give just a
little more specific and provide
1. Your PostgreSQL version?
2. Your O./S ?
3. The exact trigger definition?
4. Your exact SQL query for pg_get_triggerdef() ?

Little things like that make it so much easier to provide solutions.

--
*Melvin Davidson*
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.