Detailed explanation of MySQL database Event scheduled execution tasks

#1. Create a stored procedure for events to call 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. Enable event (for the timing to work, the MySQL constant GLOBAL event_scheduler must be on or 1)
show variables like 'event_scheduler'
set global event_scheduler='on'

#3、Create Evnet event 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、Open Event alter event middle_event on completion preserve enable;

#5. Close Event event alter event middle_event on completion preserve disable;