CREATE OR REPLACE FUNCTION public.fn_admin_add_course_admin(p_course_id integer, p_professor_id integer)
 RETURNS jsonb
 LANGUAGE plpgsql
AS $function$
DECLARE v_id int;
BEGIN
  INSERT INTO public.course_admins (course_id, professor_id)
  VALUES (p_course_id, p_professor_id)
  ON CONFLICT ON CONSTRAINT course_admins_uq DO NOTHING
  RETURNING id INTO v_id;

  IF v_id IS NULL THEN
    RETURN jsonb_build_object('error', 'Ya es administrador de este curso.');
  END IF;
  RETURN jsonb_build_object('success', true, 'id', v_id);
END;
$function$
;