Re: Way to get at parsed trigger 'WHEN' clause expression? - Mailing list pgsql-general

From Melvin Davidson
Subject Re: Way to get at parsed trigger 'WHEN' clause expression?
Date
Msg-id CANu8FixfeX0Fg=soWeo4qH_P4WzT7TA=ztoYVUkvODTM-ws6cA@mail.gmail.com
Whole thread Raw
In response to Way to get at parsed trigger 'WHEN' clause expression?  (James Robinson <jlrobins@socialserve.com>)
Responses Re: Way to get at parsed trigger 'WHEN' clause expression?
List pgsql-general


On Thu, Mar 24, 2016 at 4:05 PM, James Robinson <jlrobins@socialserve.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
 

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general


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.

pgsql-general by date:

Previous
From: "Jernigan, Kevin"
Date:
Subject: Re: PostgreSQL advocacy
Next
From: "Pavlov, Vladimir"
Date:
Subject: Re: Multixacts wraparound monitoring