Mysql事件调度器
show variables like '%event_scheduler%';
set global event_scheduler=1;
/*每天凌晨1点对数据库group表内数据项进行检查,若start_time小于当天日期,则置状态为0,表示旅游团已关闭*/
CREATE EVENT IF NOT EXISTS update_group_activated
ON SCHEDULE EVERY 1 DAY STARTS DATE_ADD(DATE_ADD(CURDATE(), INTERVAL 1 DAY), INTERVAL 1 HOUR)
ON COMPLETION PRESERVE ENABLE
DO UPDATE `group` SET `activate`='0' WHERE `activated`='1' AND DATE_ADD(CURDATE(), INTERVAL 1 DAY) > `start_time`;
/*例如start_time为2018-12-15 08:00,要求当天及之后不能再访问旅行团,curdate()是2018-12-15,date_add之后就大于start_time,但是会小于2018-12-16的日期*/
/*此处的start_time为带时间的date,不能只是日期*/