CREATE EVENT e_test
 ON SCHEDULE EVERY 1 DAY
 DO TRUNCATE TABLE test.aaa;

CREATE EVENT tj_groupon.`e_t_GrossProfit_ins`
  ON SCHEDULE
  EVERY 4 HOUR
  STARTS concat(date_format(now(),'%Y-%m-%d'),' 01:50:00')
  ON completion preserve ENABLE
  DO call tj_groupon.p_t_GrossProfit_ins();
//

DELIMITER ;

ALTER EVENT tj_groupon.`e_t_GrossProfit_ins` ON   
COMPLETION PRESERVE ENABLE;  

要使定时起作用 MySQL的常量GLOBAL event_scheduler必须为on或者是1
-- 查看是否开启定时器
SHOW VARIABLES LIKE '%sche%'; 

-- 开启定时器 0：off 1：on
SET GLOBAL event_scheduler = 1;  

-- 开启事件

ALTER EVENT tj_groupon.e_insert_t_Groupon_order2 ON   
COMPLETION PRESERVE ENABLE;  

ALTER EVENT tj_groupon.e_insert_t_Groupon_order_lastmonths ON   
COMPLETION PRESERVE ENABLE;  

ALTER EVENT groupon.summary_event ON   
COMPLETION PRESERVE ENABLE;  

ALTER EVENT tj_groupon.e_city_sale_ins ON   
COMPLETION PRESERVE ENABLE;  

-- 关闭事件
ALTER EVENT event_test ON   
COMPLETION PRESERVE DISABLE;

------解决方案--------------------
写到crontab里面


------解决方案--------------------
http://topic.csdn.net/u/20091020/22/c51bb709-6dbc-4fd1-b874-077714ed547e.html
另征集定时执行mysql数据库任务方案。