[PATCH] Add pg_get_event_trigger_ddl() function - Mailing list pgsql-hackers

Hi

Attached is a patch implementing a function to generate the DDL for a CREATE
EVENT TRIGGER statement. This complements existing similar functions
(pg_get_database_ddl(), pg_get_role_ddl() etc.).

Patch includes regression test and documentation.

Example:

  CREATE OR REPLACE FUNCTION forbid_table_rewrites()
    RETURNS event_trigger
    LANGUAGE plpgsql
  AS $$
    BEGIN
      RAISE EXCEPTION 'command % prohibited', tg_tag;
    END;
   $$;

  CREATE EVENT TRIGGER forbid_rewrites
    ON table_rewrite
    WHEN tag IN ('ALTER TABLE', 'ALTER MATERIALIZED VIEW')
      EXECUTE FUNCTION forbid_table_rewrites();

SELECT pg_get_event_trigger_ddl('forbid_rewrites');

postgres=# SELECT pg_get_event_trigger_ddl('forbid_rewrites',true);
                  pg_get_event_trigger_ddl
------------------------------------------------------------
 CREATE EVENT TRIGGER forbid_rewrites                      +
     ON table_rewrite                                      +
     WHEN TAG IN ('ALTER TABLE', 'ALTER MATERIALIZED VIEW')+
     EXECUTE FUNCTION public.forbid_table_rewrites();
(1 row)


Regards

Ian Barwick