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|
+---------------------+
| -07-18 20:44:26 |
| -07-18 20:44:27 |
| -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) 7月20日12点整清空test表：
CREATE EVENT e_test
ON SCHEDULE AT TIMESTAMP '-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。
三、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;
四、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;
附:如需规定每天几点执行mysql 请见下例
CREATE EVENT myevent
-> ON SCHEDULE EVERY 1 DAY STARTS '-10-24 02:00:00'
-> DO
-> delete from t where ptime
五、查询事件(SHOW EVENTS)
'gooder', 'tt', 'root@localhost', 'SYSTEM', 'RECURRING', '', '1', 'SECOND', '-09-23 16:31:26', '', 'ENABLED', 0, 'utf8', 'utf8_general_ci', 'gbk_chinese_ci'
/*创建定时处理的事件--用户每天将gps上报数据 通过存储过程autogpsinfo_TurnStore 记录到相应的数据表*/
CREATE event gpsinfo_TurnStore
ON SCHEDULE EVERY 1 DAY STARTS '-01-10 04:00:00'
DO
CALL autogpsinfo_TurnStore;
还有个地方需要注意的，如果是第一次用的话，可能出现不执行的情况，不是代码写错了。是因为需要先打开事件调度器
/*使用系统变量event_scheduler来打开事件调度器，true为打开，false为关闭*/
SET GLOBAL event_scheduler=TRUE
执行了这句代码之后就OK了
