http://dev.mysql.com/tech-resources/articles/event-feature.html

给个示例：

SQL code

如果你是5.1后的版本的话，可以用event功能，示例如下：

检查event功能： 
mysql> show variables like '%sche%';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| event_scheduler | OFF   |
+-----------------+-------+
1 row in set (0.01 sec)

启动event功能：
mysql> set global event_scheduler =1;
Query OK, 0 rows affected (0.00 sec)

确定起用event功能后，执行下面的建立event：(每24小时执行一次，任务的操作主体是update那部分）
delimiter //
create EVENT my_stat_event
    ON SCHEDULE
    EVERY 24 HOUR
    STARTS concat(date_format(now(),'%Y-%m-%d'),' 23:00:00')
    on completion preserve ENABLE
    do
    begin
     update order_total a inner join (select company_id, sum(goods_number) as total_count from order_goods group by company_id) b on a.company_id=b.company_id
       set a.total=b.total_count;
    end;
    //

执行上面的建立作业后，查看作业的信息：
mysql> select * from information_schema.events where event_name='my_stat_event';