由于項目的業務是不斷往前跑的，所以難免數據庫的表的量會越來越龐大，不斷的擠占硬盤空間。即使再大的空間也支撐不起業務的增長，所以定期刪除不必要的數據是很有必要的。在我們項目中由于不清理數據，一個表占的空間竟然達到了4G之多。想想有多可怕...
#1、建立存儲過程供事件調用
delimiter//
drop procedure if exists middle_proce//
create procedure middle_proce()
begin
DELETE FROM jg_bj_comit_log WHERE comit_time SUBDATE(NOW(),INTERVAL 2 MONTH);
optimize table jg_bj_comit_log;
DELETE FROM jg_bj_order_create WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_order_create;
DELETE FROM jg_bj_order_match WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_order_match;
DELETE FROM jg_bj_order_cancel WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_order_cancel;
DELETE FROM jg_bj_operate_arrive WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_operate_arrive;
DELETE FROM jg_bj_operate_depart WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_operate_depart;
DELETE FROM jg_bj_operate_login WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_operate_login;
DELETE FROM jg_bj_operate_logout WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_operate_logout;
DELETE FROM jg_bj_operate_pay WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_operate_pay;
DELETE FROM jg_bj_position_driver WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_position_driver;
DELETE FROM jg_bj_position_vehicle WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_position_vehicle;
DELETE FROM jg_bj_rated_passenger WHERE created_on SUBDATE(NOW(),INTERVAL 3 MONTH);
optimize table jg_bj_rated_passenger;
end//
delimiter;
#2、開啟event(要使定時起作用，MySQL的常量GlOBAL event_schduleer 必須為on 或者1)
show variables like 'event_scheduler'
set global event_scheduler='on'
#3、創建Evnet事件
drop event if exists middle_event;
create event middle_event
on schedule every 1 DAY STARTS '2017-12-05 00:00:01'
on completion preserve ENABLE
do call middle_proce();
#4、開啟Event 事件
alter event middle_event on completion preserve enable;
#5、關閉Event 事件
alter event middle_event on completion preserve disable;
