Mysql事件学习

一、查询数据库事件模式是否开启

SHOW VARIABLES LIKE 'event_scheduler';

 

二、设置开启/关闭事件

SET GLOBAL event_scheduler = ON;//开启
SET GLOBAL event_scheduler = OFF;//关闭

 三、Mysql事件的语法简介

1、创建事件的语法

CREATE
    [DEFINER = { user | CURRENT_USER }]
    EVENT
    [IF NOT EXISTS]
    event_name
    ON SCHEDULE
    [ON COMPLETION [NOT] PRESERVE]
    [ENABLE | DISABLE | DISABLE ON SLAVE]
    [COMMENT 'comment']
    DO event_body;
 
schedule:
    AT timestamp [+ INTERVAL interval] ...
     | EVERY interval
    [STARTS timestamp [+ INTERVAL interval] ...]
    [ENDS timestamp [+ INTERVAL interval] ...]
interval:
  quantity {YEAR | QUARTER | MONTH | DAY | HOUR | MINUTE |
              WEEK | SECOND | YEAR_MONTH | DAY_HOUR |
DAY_MINUTE |DAY_SECOND | HOUR_MINUTE |
HOUR_SECOND | MINUTE_SECOND}

 

2、更改事件的语法 

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

 3、删除事件的语法

DROP EVENT [IF EXISTS] event_name

 

 四、Mysql事件实战 

CREATE TABLE `test` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `t1` datetime DEFAULT NULL,
  `id2` int(11) NOT NULL DEFAULT '0',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=106 DEFAULT CHARSET=utf8

 1、创建一个每隔3秒往test表中插入一条数据的事件

CREATE EVENT IF NOT EXISTS test ON SCHEDULE EVERY 3 SECOND
ON COMPLETION PRESERVE
DO INSERT INTO test(id,t1) VALUES('',NOW());

2、创建一个10分钟后清空test表数据的事件

CREATE EVENT IF NOT EXISTS test
ON SCHEDULE
AT CURRENT_TIMESTAMP + INTERVAL 1 MINUTE
DO TRUNCATE TABLE test.aaa;

 3、创建一个在2012-08-23 00:00:00时刻清空test表数据的事件

CREATE EVENT IF NOT EXISTS test
ON SCHEDULE
AT TIMESTAMP '2012-08-23 00:00:00'
DO TRUNCATE TABLE test;

 4、创建一个从2012年8月22日21点45分开始到10分钟后结束，

运行每隔3秒往test表中插入一条数据的事件

CREATE EVENT IF NOT EXISTS test ON SCHEDULE EVERY 3 SECOND
STARTS '2012-08-22 21:49:00' 
ENDS '2012-08-22 21:49:00'+ INTERVAL  10 MINUTE
ON COMPLETION PRESERVE
DO INSERT INTO test(id,t1) VALUES('',NOW());

 5、6、事件设置2012-08-22 00:00:00时刻开始运行，每隔1调用一次存储过程

CREATE EVENT test ON SCHEDULE EVERY 1 DAY
STARTS '2012-08-22 00:00:00'
ENDS '2012-08-22 00:00:00'+INTERVAL 40 DAY
ON COMPLETION PRESERVE DO
CALL test_add();