Thread: [GENERAL] Event Trigger question
Hi All;
we are creating an event trigger on ddl_command_end and I want the function to know the TABLE and COMMAND run, for example if the ddl command was an "ALTER TABLE ADD COLUMN X" then I want to pull the table and the actual alter command. We're running version 9.4 so the pg_event_trigger_ddl_commands function is not available.
I see in the 9.4 docs that the variable tg_tag is used, and I see some references to tg_event
I assume we can pass ALTER TABLE as the filter value like so:
CREATE OR REPLACE FUNCTION trap_alter_statements() RETURNS event_triggerLANGUAGE plpgsql AS $$ BEGIN RAISE EXCEPTION 'command %', tg_tag; END; $$; CREATE EVENT TRIGGER abort_ddl ON ddl_command_start WHEN TAG IN 'ALTER TABLE' EXECUTE PROCEDURE trap_alter_statements(); Questions: 1) is the above "WHEN TAG IN 'ALTER TABLE'" correct? 2) where can I find a complete list of the tg_ variables? I see this list: https://www.postgresql.org/docs/9.4/static/plpgsql-trigger.html which includes TG_NAME. OLD, NEW, etc but tg_tag and tg_event are not in the list. Are there other variables I can reference? 3) which specific variable will show me (a) the full command run and (b) the table name? Thanks in advance
On Thursday, July 13, 2017, ProPAAS DBA <dba@propaas.com> wrote:
2) where can I find a complete list of the tg_ variables? I see this list: https://www.postgresql.org/docs/9.4/static/plpgsql- trigger.html which includes TG_NAME. OLD, NEW, etc but tg_tag and tg_event are not in the list. Are there other variables I can reference?
They are listed at the bottom of the page you linked to.
David J.
Oh duh, I'm blind... Thanks!
On 07/13/2017 07:29 PM, David G. Johnston wrote:
On Thursday, July 13, 2017, ProPAAS DBA <dba@propaas.com> wrote:
2) where can I find a complete list of the tg_ variables? I see this list: https://www.postgresql.org/docs/9.4/static/plpgsql- trigger.html which includes TG_NAME. OLD, NEW, etc but tg_tag and tg_event are not in the list. Are there other variables I can reference? They are listed at the bottom of the page you linked to.David J.