创建定时程序出错。求巨牛解答

SQL code

CREATE PROCEDURE update_a() UPDATE ecs_users SET user_name = '123';

CREATE event update_aa;
ON SCHEDULE EVERY 30 SECOND;
ON SCHEDULE AT DATE_ADD(NOW(),INTERVAL 1 MINUTE);
ON COMPLETION PRESERVE;
DO CALL update_a();

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1

------解决方案--------------------
delimiter $
CREATE PROCEDURE update_a() 
begin
UPDATE ecs_users SET user_name = '123';
end
$
delimiter ;
------解决方案--------------------
错误提示是什么？