Re: v9.1, DROP TRIGGER IF EXISTS behaving oddly

On 01/13/2016 02:51 PM, David Rowley wrote:

On 14 January 2016 at 11:32, Adrian Klaver <adrian.klaver@aklaver.com
<mailto:adrian.klaver@aklaver.com>> wrote:

    On 01/13/2016 02:24 PM, Tom Lane wrote:

        "Williamson, Michael" <Michael.Williamson@tamucc.edu

        <mailto:Michael.Williamson@tamucc.edu>> 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=b152c6cd0de1827ba58756e24e18110cf902182a

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