title: Node-RED listen PostgreSQL in real-time
body: <p>I need to listen PostgreSQL on changes in real-time with Node-RED.
  How can I do this?</p>
  
  <p>I created trigger on new record in the table and notify this to 'changes' channel.</p>
  
  <pre><code>CREATE FUNCTION notify_trigger() RETURNS trigger AS $$
  DECLARE
  BEGIN
    PERFORM pg_notify('changes', TG_TABLE_NAME || ',id,' || NEW.id );
    RETURN new;
  END;
  $$ LANGUAGE plpgsql;
  
  CREATE TRIGGER watched_table_trigger AFTER INSERT ON users
  FOR EACH ROW EXECUTE PROCEDURE notify_trigger();
  </code></pre>
  
  <p>But I don't know how to listen it from Node-RED. Could you help me please?
  Maybe I can do it differently?</p>