Please excuse my mistake. We were dropping a view that had the trigger on it beforehand, then in trying to re-build the entire schema had scripts that attempted to drop trigger if they existed before re-creating the view and triggers. I over-sanitized the example I posted and made it unclear. I did some more testing and DROP TRIGGER IF EXISTS indeed works as expected if the table/view is there and the trigger is not there. As a follow-up, it would be nice if "IF EXISTS" could apply to either the trigger or the relation it is applied to, as I don't think a trigger can't exist without a relation to apply it to. Michael On Wed, 2016-01-13 at 15:08 -0800, Adrian Klaver wrote: > On 01/13/2016 02:51 PM, David Rowley wrote: > > On 14 January 2016 at 11:32, Adrian Klaver <adrian.klaver@aklaver.c > om > > <mailto:adrian.klaver@xxxxxxxxxxx>> wrote: > > > > On 01/13/2016 02:24 PM, Tom Lane wrote: > > > > "Williamson, Michael" <Michael.Williamson@xxxxxxxxxx > > <mailto:Michael.Williamson@xxxxxxxxxx>> writes: > > > > I'm attempting to drop a trigger that may or may not > exist, > > so am using > > the "IF EXISTS" clause. Â This works fine for tables, > views, > > functions, > > domains, and types, but for some reason seems to be > ignored for > > triggers. Â I'd expect to see more about this online if > it > > were a bug, > > so I'm thinking I may be missing something obvious. > > > > > > Example: > > DROP TRIGGER IF EXISTS udf_customer_update_trigger ON > customer; > > > > > > Expected Output: > > NOTICE:Â Â trigger "udf_customer_update_trigger" does > not > > exist, skipping > > > > > > Observed Output: > > ERROR:Â Â relation "udf_customer_update_trigger" does > not exist > > > > > > Environment: > > CentOS 6.6 > > postgresql91-server-9.1.14-1PGDG.rhel6.x86_64 > > > > > > This has worked the way you're imagining since (I think) > 9.4. > > Before > > that the "if exists" semantics only applied to the trigger > itself, > > not to the relation. > > > > > > Alright now I am confused. Other then changing table to > table_name I > > am not seeing where the below changed. In both cases a NOTICE > is > > supposed to be raised. > > > > http://www.postgresql.org/docs/9.1/interactive/sql-droptrigger. > html > > > > http://www.postgresql.org/docs/9.4/interactive/sql-droptrigger. > html > > > > > > Seems to have been changed in > > http://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=b152c > 6cd0de1827ba58756e24e18110cf902182a > > I will take a look at this at some point. The part that has me > confused > from the original post is this: > > ERROR: relation "udf_customer_update_trigger" does not exist > > If the ERROR is because the table does not exist, why not?: > > ERROR: relation "customer" does not exist > > > > > Perhaps that commit should have also made changes to the documents > to > > change things such as: > > > > Do not throw an error if the trigger does not exist. A notice is > issued > > in this case. > > > > To > > > > Do not throw an error if the trigger or table does not exist. A > notice > > is issued in this case. > > > > -- > > David Rowley http://www.2ndQuadrant.com/ > > PostgreSQL Development, 24x7 Support, Training & Services > > -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
