On Mon, May 15, 2017 at 7:00 AM, Ashutosh Bapat <ashutosh.ba...@enterprisedb.com> wrote: > On Sat, May 13, 2017 at 2:45 AM, Paul Jungwirth > <p...@illuminatedcomputing.com> wrote: >> Here is a patch to amend the docs here: >> >> https://www.postgresql.org/docs/devel/static/plpgsql-trigger.html >> >> In the example for an AFTER trigger, you see this code: >> >> -- >> -- Create a row in emp_audit to reflect the operation performed on emp, >> -- make use of the special variable TG_OP to work out the operation. >> -- >> IF (TG_OP = 'DELETE') THEN >> INSERT INTO emp_audit SELECT 'D', now(), user, OLD.*; >> RETURN OLD; >> ELSIF (TG_OP = 'UPDATE') THEN >> INSERT INTO emp_audit SELECT 'U', now(), user, NEW.*; >> RETURN NEW; >> ELSIF (TG_OP = 'INSERT') THEN >> INSERT INTO emp_audit SELECT 'I', now(), user, NEW.*; >> RETURN NEW; >> END IF; >> RETURN NULL; -- result is ignored since this is an AFTER trigger >> >> What are all those RETURNs doing in there? The comment on the final RETURN >> is correct, so returning NEW or OLD above seems confusing, and likely a >> copy/paste error. >> >> This patch just removes those three lines from the example code. > > https://www.postgresql.org/docs/devel/static/trigger-definition.html says > "The return value is ignored for row-level triggers fired after an > operation, and so they can return NULL.". There's nothing wrong with > the example, returning OLD or NEW, but as you have pointed out it's > confusing. So, +1 for this change.
Committed. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
