PostgresQL trigger for updated_at

trigger.sql

-- create function 
CREATE OR REPLACE FUNCTION trigger_set_update_timestamp()
RETURNS TRIGGER AS $$
BEGIN
  NEW.updated_at = NOW();
  RETURN NEW;
END;
$$ LANGUAGE plpgsql;

-- create trigger
CREATE TRIGGER set_timestamp
BEFORE UPDATE ON thd_columns
FOR EACH ROW
EXECUTE PROCEDURE trigger_set_update_timestamp();

-- rename trigger 
ALTER TRIGGER set_timestamp ON thd_columns
RENAME TO set_update_timestamp;

-- disable trigger
ALTER TABLE employees
DISABLE TRIGGER log_last_name_changes;

-- disable all triggers
ALTER TABLE employees
DISABLE TRIGGER ALL;

-- drop trigger
DROP TRIGGER IF EXISTS set_update_timestamp ON thd_columns;