MySQL-mysql定时任务是如何实现的

MySQL-mysql定时任务是如何实现的

浮生未歇 发布于 2017-04-28 字数 136 浏览 994 回复 5

我想实现每隔30秒执行以下下面sql

update userinfo SET endtime = now() WHERE id = '155';

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偏爱自由 2017-11-03 5 楼

Mysql属于中小型数据库系统,它的事件调度器Event Scheduler是在mysql 5.1才开始引入事件调度器是在 MySQL 5.1 中新增的另一个特色功能,可以作为定时任务调度器,取代部分原先只能用操作系统任务调度器才能完成的定时功能。事件调度器是定时触发执行的,在这个角度上也可以称作是"临时的触发器"。触发器只是针对某个表产生的事件执行一些语句,而事件调度器则是在某一个(间隔)时间执行一些语句。事件是由一个特定的线程来管理的,也就是所谓的"事件调度器"。

代码:
/开启event_scheduler,也可以设置为on/
set global event_scheduler =1;
/创建简单的任务,每分钟执行一次,从一个表取数据插入到另一个表,也可以定时取,可以参看下面文档,此处为简单例子/
CREATE EVENT MyEvent
ON SCHEDULE EVERY 1 MINUTE
DO
INSERT INTO list_test (字段1,字段1,字段1,字段1,字段1) select 字段1,字段1,字段1,字段1,字段1 from 表2 where id = 510;
/每天固定时间执行/
CREATE EVENT EVENT_ADD_FOR20_ENOUGH
ON SCHEDULE EVERY 1 DAY
STARTS TIMESTAMP '2009-12-18 02:58:00'/×MYSQL注意时区设置,默认非中国时区×/
DO
SQL语句

事件详细语法事例(EVENT)1>创建事件(CREATE EVENT)

先来看一下它的语法:
CREATE EVENT [IF NOT EXISTS] event_name ON SCHEDULE schedule [ON COMPLETION
[NOT] PRESERVE] [ENABLE | DISABLE] [COMMENT 'comment'] DO sql_statement;

schedule: AT TIMESTAMP [+ INTERVAL INTERVAL] | EVERY INTERVAL [STARTS TIMESTAMP]
[ENDS TIMESTAMP] INTERVAL: quantity {YEAR | QUARTER | MONTH | DAY | HOUR |
MINUTE | WEEK | SECOND | YEAR_MONTH | DAY_HOUR | DAY_MINUTE | DAY_SECOND |
HOUR_MINUTE | HOUR_SECOND | MINUTE_SECOND}

1) 首先来看一个简单的例子来演示每秒插入一条记录到数据表
USE test; CREATE TABLE aaa (timeline TIMESTAMP); CREATE EVENT e_test_insert
ON SCHEDULE EVERY 1 SECOND DO INSERT INTO test.aaa VALUES
(CURRENT_TIMESTAMP);

等待3秒钟后,再执行查询看看:
mysql> SELECT * FROM aaa; +---------------------+ | timeline |
+---------------------+ | 2007-07-18 20:44:26 | | 2007-07-18 20:44:27 | |
2007-07-18 20:44:28 | +---------------------+

2) 5天后清空test表:
CREATE EVENT e_test ON SCHEDULE AT CURRENT_TIMESTAMP + INTERVAL 5 DAY DO
TRUNCATE TABLE test.aaa;

3) 2007年7月20日12点整清空test表:
CREATE EVENT e_test ON SCHEDULE AT TIMESTAMP '2007-07-20 12:00:00' DO
TRUNCATE TABLE test.aaa;

4) 每天定时清空test表:
CREATE EVENT e_test ON SCHEDULE EVERY 1 DAY DO TRUNCATE TABLE
test.aaa;

5) 5天后开启每天定时清空test表:
CREATE EVENT e_test ON SCHEDULE EVERY 1 DAY STARTS CURRENT_TIMESTAMP +
INTERVAL 5 DAY DO TRUNCATE TABLE test.aaa;

6) 每天定时清空test表,5天后停止执行:
CREATE EVENT e_test ON SCHEDULE EVERY 1 DAY ENDS CURRENT_TIMESTAMP +
INTERVAL 5 DAY DO TRUNCATE TABLE test.aaa;

7) 5天后开启每天定时清空test表,一个月后停止执行:
CREATE EVENT e_test ON SCHEDULE EVERY 1 DAY STARTS CURRENT_TIMESTAMP +
INTERVAL 5 DAY ENDS CURRENT_TIMESTAMP + INTERVAL 1 MONTH DO TRUNCATE TABLE
test.aaa;

[ON COMPLETION [NOT] PRESERVE]可以设置这个事件是执行一次还是持久执行,默认为NOT PRESERVE
8)
每天定时清空test表(只执行一次,任务完成后就终止该事件):
CREATE EVENT e_test ON SCHEDULE EVERY 1 DAY ON COMPLETION NOT PRESERVE DO
TRUNCATE TABLE test.aaa;

[ENABLE | DISABLE]可是设置该事件创建后状态是否开启或关闭,默认为ENABLE
[COMMENT
comment]可以给该事件加上注释

2>修改事件(ALTER EVENT)
ALTER EVENT event_name [ON SCHEDULE schedule] [RENAME TO new_event_name]
[ON COMPLETION [NOT] PRESERVE] [COMMENT 'comment'] [ENABLE | DISABLE] [DO
sql_statement]

1) 临时关闭事件
ALTER EVENT e_test DISABLE;

2) 开启事件
ALTER EVENT e_test ENABLE;

3) 将每天清空test表改为5天清空一次:
ALTER EVENT e_test ON SCHEDULE EVERY 5 DAY;

3>删除事件(DROP
EVENT)

语法很简单,如下所示:
DROP EVENT [IF EXISTS] event_name

例如删除前面创建的e_test事件
DROP EVENT e_test;

当然前提是这个事件存在,否则会产生ERROR 1513 (HY000): Unknown event错误,因此最好加上IF EXISTS
DROP EVENT IF EXISTS e_test;

夜无邪 2017-09-15 4 楼

MySQL Limit版本无法执行定时任务,可以通过Linux的Crontab来实现
1、建立一个cronmysql执行的脚本文件,增加如下内容

mysql -u username -p密码 databasename -e "update userinfo SET endtime = now() WHERE id = '155'"

或者把很多sql语句写在一个文件里面bat.sql

 mysql -u username -p密码 databasename < bat.sql

2、增加cronmysql的执行权限

 chmod +x /data/shell/cronmysql

3、通过修改 /etc/crontab 添加要执行的SQL调用的脚本文件
*/30 * * * * /data/shell/cronmysql
其他版本的mysql
先看看event 事件是否开启

 show variables like ‘%sche%’;

如没开启,则开启。需要数据库超级权限

 set global event_scheduler =1;

创建存储过程 abc

 CREATE PROCEDURE abc ()
BEGIN
update userinfo SET endtime = now() WHERE id = '155'; //执行的sql语句
….
END;

创建event e_abc

 create event if not exists e_abc
on schedule every 1800 second //执行的sql语句 注:当数据库比较繁忙时候会出现不运行定时任务的情况出现
on completion preserve
do call abc();

关闭事件任务

 alter event e_abc ON
COMPLETION PRESERVE DISABLE;

开户事件任务

 alter event e_abc ON
COMPLETION PRESERVE ENABLE;

完整的写法是

 delimiter //
create procedure 过程名()
BEGIN
SQL语句;
END;
//

注意://必须要加。

想挽留 2017-08-06 3 楼

如果是MySQL 5.1以上版本可以用MySQL的事件调度器Event Scheduler,这样就可以定时执行。如果或MySQL5.1以下版本可以用Cron来执行
方法一:利用MySQL的事件调试器

/开启event_scheduler,也可以设置为on/

set global event_scheduler =1; /创建事件,每30分钟执行一次,执行更新用户表信息/

CREATE EVENT MyEvent ON SCHEDULE EVERY 30 MINUTE

DO

update userinfo SET endtime = now() WHERE id = '155';

方法二:利用Linux Cron定时执行
(1)、在Crontab中添加

 30 * * * * root /usr/sbin/bakmysql

(2)、mysql -u username -p密码 databasename < update userinfo SET endtime = now() WHERE id = '155';

浮生未歇 2017-07-03 2 楼

一、查看event是否开启

show variables like '%sche%';

开启event_scheduler
set global event_scheduler =1;

二、创建存储过程test

CREATE PROCEDURE test ()
BEGIN
update userinfo SET endtime = now() WHERE id = '155';
END;

三、创建event e_test

create event if not exists e_test
on schedule every 30 second
on completion preserve
do call test();
每隔30秒将执行存储过程test

关闭事件任务
alter event e_test ON COMPLETION PRESERVE DISABLE;

开户事件任务
alter event e_test ON COMPLETION PRESERVE ENABLE;

想挽留 2017-05-10 1 楼

MySQL定时任务代码

 DELIMITER $$
DROP PROCEDURE IF EXISTS `mystock`.`TEST_KKK`$$
CREATE PROCEDURE `mystock`.`TEST_KKK`()
/*LANGUAGE SQL
| [NOT] DETERMINISTIC
| { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA }
| SQL SECURITY { DEFINER | INVOKER }
| COMMENT 'string'*/
BEGIN
DECLARE NUM INTEGER DEFAULT 0;
DECLARE $A INT;
SELECT (20-COUNT(STOCK_CODE)) as number into NUM FROM get_stock_list WHERE FLAG = 0 AND STIME = curdate();
IF NUM>0 THEN
PREPARE STMP FROM 'INSERT INTO get_stock_list
(stock_code,stock_name,close,raises,stime) select stock_code,
stock_name,close,result1,selectd from choice_stock where stock_code
not in (select stock_code from get_stock_list where stime = curdate() and flag = 0)
and selectd = curdate() and selectd = curdate() order by id limit ?' ;
SET @A = NUM;
EXECUTE STMP USING @A;
END IF;
END$$
DELIMITER ;
代码

DELIMITER $$
DROP FUNCTION IF EXISTS `mystock`.`FUNCTION_ADD_STOCK_FOR20`$$
CREATE DEFINER=`root`@`localhost` FUNCTION `FUNCTION_ADD_STOCK_FOR20`() RETURNS int(11)
BEGIN
DECLARE NUM,ANOTHER INTEGER;
SELECT COUNT(STOCK_CODE) as number into NUM FROM get_stock_list WHERE FLAG = 0 AND STIME = curdate();
if(NUM<20)
THEN
SET ANOTHER = 20 - NUM;
INSERT INTO get_stock_list (stock_code,stock_name,close,raises,stime) s
elect stock_code,stock_name,close,result1,selectd from choice_stock
where stock_code not in (select stock_code from get_stock_list where stime = curdate() and flag = 0) order by id LIMIT 10;
END IF;
RETURN NUM;
END$$

DELIMITER ;

以上的相关内容就是对MySQL定时任务(定时执行操作) 的介绍,望你能有所收获。