MYSQL event operation step record

Mainly record the creation process of mysql events, enable, delete, view and other statements

1. Take the 82 server waf_data_copy1 table as an example, create a stored procedure, delete the time (datetime) field of the table, and delete the data 60 days ago

use cloud;
DROP PROCEDURE IF EXISTS pro_clean_data;
CREATE PROCEDURE pro_clean_data()
    BEGIN
      DELETE FROM WAF_data_copy1 WHERE DATE(TIME) <= DATE(DATE_SUB(NOW(),INTERVAL 60 DAY));
    END 

Among them, TIME is the time basis for judgment.
​ Here is to delete data older than 60 days. If you need to delete data older than a few months, (take three months as an example) it is INTERVAL 3 MONTH.

注意一个问题，是关于mysql中BEGIN和END的坑，这个问题是查询定界符没更改导致的。如果是直接操作后台mysql进行语句编写时， 
你在建立触发器之前，先执行这个语句 DELIMITER $$ ；
(这一句把原来默认的查询结尾定界符--分号 改为 $$，然后，你就可以在begin ....end 中
间 的每一句加 分号，最后在end的 后面，以$$ 作结束。 因为新的语句定界符已经是$$ 。
触发器建立后，你可以根据情况，把查询定界符$$ 改为原来的分号 ， 使用 delimiter ;

mysql> DELIMITER $$
mysql>  CREATE PROCEDURE pro_clean_data()
    ->     BEGIN
    ->        DELETE FROM WAF_data_copy1 WHERE DATE(TIME) <= DATE(DATE_SUB(NOW(),INTERVAL 60 DAY));
    ->      END$$
Query OK, 0 rows affected (0.05 sec)

mysql> DELIMITER ;
 

2. create event

CREATE EVENT IF NOT EXISTS event_time_cleaner
ON SCHEDULE EVERY 1 DAY STARTS '2021-10-13 14:16:00'
ON COMPLETION PRESERVE
DO CALL pro_clean_data()

3. Check if the event is enabled

show VARIABLES like 'event_scheduler';

4. start event

set global event_scheduler=on;

建议配置文件添加相关参数，确保当数据库重启后，事件依然生效
在my.cnf中的[mysqld]部分添加，
event_scheduler=on
然后重启mysql

5. 2 ways to view created events

show events;
select * from information_schema.events;

6. delete event

drop event event_time_cleaner;

7. View the execution results through the query statement, see