CREATE_EVENT_TRIGGER(7pg17)

okay bestie, welcome to the CREATE EVENT TRIGGER(7) page from the PostgreSQL 17.11 docs 💖 this one's giving "make a trigger that fires on events" and it's honestly iconic ✨

🌸 NAME 🌸

CREATE_EVENT_TRIGGER — defines a brand-new event trigger, periodt 💅

🦋 SYNOPSIS 🦋

CREATE EVENT TRIGGER name
    ON event
    [ WHEN filter_variable IN (filter_value [, ... ]) [ AND ... ] ]
    EXECUTE { FUNCTION | PROCEDURE } function_name()

✨ DESCRIPTION ✨

CREATE EVENT TRIGGER creates a new event trigger, no cap. Whenever the designated event happens, and the WHEN condition associated with the trigger — if there is one — is satisfied, the trigger function gets executed 🔥

For a general introduction to event triggers, see Chapter 38. And listen: the user who creates an event trigger becomes its owner 👑

🎀 PARAMETERS 🎀

• name — the name you're giving the new trigger. This name must be unique within the database, so no duplicate-name drama 🙈
• event — the name of the event that triggers a call to the given function. See Section 38.1 for more info on event names 📖
• filter_variable — the name of a variable used to filter events. This makes it possible to restrict the firing of the trigger to a subset of the cases in which it is supported. Currently the only supported filter_variable is TAG 🏷️
• filter_value — a list of values for the associated filter_variable for which the trigger should fire. For TAG, this means a list of command tags (e.g., 'DROP FUNCTION') 💬
• function_name — a user-supplied function that is declared as taking no argument and returning type event_trigger.

In the syntax of CREATE EVENT TRIGGER, the keywords FUNCTION and PROCEDURE are equivalent, but the referenced function must in any case be a function, not a procedure. The use of the keyword PROCEDURE here is historical and deprecated — so yeah, it's giving old-school, not main character energy 😭

💀 NOTES 💀

Only superusers can create event triggers. That's the rule, bestie 🚨

Event triggers are disabled in single-user mode (see postgres(1)) as well as when event_triggers is set to false. If an erroneous event trigger disables the database so much that you can't even drop the trigger, restart with event_triggers set to false to temporarily disable event triggers, or in single-user mode, and you'll be able to do that 🫶

okay but fr fr, if your trigger nuked the vibe that hard, this is the emergency exit 😭 use it.

🌈 EXAMPLES 🌈

Forbid the execution of any DDL command:

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

CREATE EVENT TRIGGER abort_ddl ON ddl_command_start
   EXECUTE FUNCTION abort_any_command();

🧚 COMPATIBILITY 🧚

There is no CREATE EVENT TRIGGER statement in the SQL standard. It's simply not on the standard's radar, bestie 💅

👑 SEE ALSO 👑

• ALTER EVENT TRIGGER (ALTER_EVENT_TRIGGER(7))
• DROP EVENT TRIGGER (DROP_EVENT_TRIGGER(7))
• CREATE FUNCTION (CREATE_FUNCTION(7))

---

byeee bestie 💖 this page is from PostgreSQL 17.11, dated 2026 — CREATE EVENT TRIGGER(7) out 🫶✨