MySQL数据库定时任务举例讲解

SHOW VARIABLES LIKE 'event_scheduler';
SELECT @@event_scheduler;
SHOW PROCESSLIST;

-- 开启事件调度器
SET GLOBAL event_scheduler = ON;
-- 关闭事件调度器
SET GLOBAL event_scheduler = OFF;
-- 查看事件调度器状态
SHOW VARIABLES LIKE 'event_scheduler';

 事件调度器启动状态
event_scheduler = on

-- 创建用户信息表
CREATE TABLE IF NOT EXISTS tb_user
(
	id INT AUTO_INCREMENT PRIMARY KEY COMMENT '用户编号',
	name VARCHAR(30) NOT NULL COMMENT '用户姓名',
	create_time TIMESTAMP COMMENT '创建时间'
) COMMENT = '用户信息表';

CREATE EVENT IF NOT EXISTS event_user
ON SCHEDULE EVERY 5 SECOND
ON COMPLETION PRESERVE
COMMENT '新增用户信息定时任务'
DO INSERT INTO tb_user(name,create_time) VALUES('pan_junbiao的博客',NOW());

CREATE PROCEDURE p_total()
BEGIN
	DECLARE n_total INT default 0;
	SELECT COUNT(*) INTO n_total FROM db_database11.tb_user;
	INSERT INTO tb_total (userNumber,createtime) VALUES(n_total,NOW());
END;

CREATE EVENT IF NOT EXISTS e_autoTotal
ON SCHEDULE EVERY 1 MONTH STARTS DATE_ADD(DATE_ADD(DATE_SUB(CURDATE(),INTERVAL DAY(CURDATE())-1 DAY),INTERVAL 1 MONTH),INTERVAL 1 HOUR)
ON COMPLETION PRESERVE ENABLE
DO CALL p_total();

SELECT * FROM information_schema.events; 

ALTER
	[DEFINER={user | CURRENT_USER}]
	EVENT [IF NOT EXISTS] event_name
	ON SCHEDULE schedule
	[ON COMPLETION [NOT] PRESERVE]
	[ENABLE | DISABLE | DISABLE ON SLAVE]
	[COMMENT 'comment']
	DO event_body;

--启动名称为event_user的事件。
ALTER EVENT event_user ENABLE;
--关闭名称为event_user的事件。
ALTER EVENT event_user DISABLE;

--删除名称为event_user的事件。
DROP EVENT IF EXISTS event_user;

-- 单位有：SECOND,MINUTE,HOUR,DAY,WEEK(周),QUARTER(季度),MONTH,YEAR
-- 每秒执行1次
ON SCHEDULE EVERY 1 SECOND
-- 每两分钟执行1次
ON SCHEDULE EVERY 2 MINUTE
-- 每3天执行1次
ON SCHEDULE EVERY 3 DAY
-- 5天后执行
ON SCHEDULE AT CURRENT_TIMESTAMP()+INTERVAL 5 DAY
-- 10分钟后执行
ON SCHEDULE AT CURRENT_TIMESTAMP()+INTERVAL 10 MINUTE
-- 在2016年10月1日，晚上9点50执行
ON SCHEDULE AT '2021-12-01 1:50:00'
-- 5天后开始每天都执行执行到下个月底
ON SCHEDULE EVERY 1 DAY STARTS CURRENT_TIMESTAMP()+INTERVAL 5 DAY ENDS CURRENT_TIMESTAMP()+INTERVAL 1 MONTH
-- 从现在起每天执行，执行5天
ON SCHEDULE EVERY 1 DAY ENDS CURRENT_TIMESTAMP()+INTERVAL 5 DAY
-- 每天凌晨一点执行
ON SCHEDULE EVERY 1 DAY STARTS DATE_ADD(DATE_ADD(CURDATE(), INTERVAL 1 DAY), INTERVAL 1 HOUR)
-- 每个月的五号一点执行一次
ON SCHEDULE EVERY 5 MONTH STARTS DATE_ADD(DATE_ADD(DATE_SUB(CURDATE(),INTERVAL DAY(CURDATE())-1 DAY), INTERVAL 1 MONTH),INTERVAL 1 HOUR)
-- 每年一月一号凌晨三点执行一次
ON SCHEDULE  EVERY 1 YEAR STARTS DATE_ADD(DATE(CONCAT(YEAR(CURDATE()) + 1,'-',1,'-',1)),INTERVAL 3 HOUR)

-- 查看定时策略是否开启
show variables like 'event_scheduler';
-- 开启定时策略（ON是开启状态）
set global event_scheduler=1;
-- 创建procedure(存储过程)
use 123;
delimiter //
create procedure updateTime()
begin
-- (begin后end//前放要定时处理的sql用;结尾，可以放多个sql)
update demo_table set demo_time = DATE_ADD(NOW(),  INTERVAL  FLOOR(1 + (RAND() * 10800))   SECOND );
end//
delimiter ;
-- 创建定时任务
create event updateTime_LY
ON SCHEDULE EVERY 1 DAY STARTS DATE_ADD(DATE_ADD(CURDATE(), INTERVAL 1 DAY), INTERVAL 1 HOUR)
on completion preserve disable
do call updateTime();
-- 查看定时任务事件
SELECT event_name,event_definition,interval_value,interval_field,status FROM information_schema.EVENTS;
-- 开启和关闭创建好的事件
alter event updateTime_LY on completion preserve enable;//开启定时任务
alter event updateTime_LY on completion preserve disable;//关闭定时任务
-- 删除
drop event updateTime_LY;