定时执行mysql数据库任务方案

命题： 每日 02:00 am 定时删除 表 t (id int primary key,ptime TIMESTAMP DEFAULT CURRENT_TIMESTAMP) 中三天之前的记录。

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方法一：操做系统
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(Windows)

在WINDOWS 操做系统中 的计划任务中定时操做,  
进入WINDOWS的命令行， (开始->运行-> 输入 cmd 回车)

C:\>at 02:00 /every:M,T,W,Th,F,S,Su "C:\Program Files\MySQL\MySQL Server 5.1\bin\mysql.exe" -u root -p123 csdn -e "delete from t where ptime <date_sub(curdate(),interval 3 day)"
Added a new job with job ID = 1


C:\>at
Status ID   Day           Time      Command Line
-------------------------------------------------------------------------------
    1   Each Monday...      上午 02:00  "C:\Program Files\MySQL\MySQL
Server 5.1\bin\mysql.exe" -u root -p123 csdn -e "delete from t where ptime <date_
sub(curdate(),interval 3 day)"

C:\>

linux

一、建立backup.sh文件


#!/bin/sh


export MYSQLBAKDATE=`date +%Y%m%d`
# echo $MYSQLBAKDATE
export OUTFILE=$MYSQLBAKDATE'.TestDB.dbf'
# echo $OUTFILE
rm -f /bak/$OUTFILE
/usr/local/mysql/bin/mysqldump -uroot -p****** -R TestDB > /bak/$OUTFILE
gzip /bak/$OUTFILE


#END




若是考虑得再周全点，能够考虑删除一个星期或一个月以前的备份文件。


二、使用crontab -e命令编辑计划任务，加入如下一条记录




30 02 * * * sh /usr/local/mysql/backup.sh




表示在凌晨2点30分作备份

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方法二：MySQL事件 Event
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MySQL 5.1.6 以后，你能够直接使用相似于oralce job的mysql event

首先，检查一下你的MYSQL是否打开了这项功能。

mysql> show variables like '%sc%';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| event_scheduler | OFF   |
+-----------------+-------+
1 row in set (0.00 sec)

默认下是未打开的，你能够到 my.ini (windows)/ my.cnf (linux/unix) 参数文件中定义后重启mysqld
或者直接 set global event_scheduler=on;

mysql> show variables like '%sc%';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| event_scheduler | ON    |
+-----------------+-------+
1 row in set (0.00 sec)

建立这个event


mysql> CREATE EVENT myevent
    -> ON SCHEDULE EVERY 1 DAY STARTS '2009-10-24 02:00:00'
    -> DO
    ->  delete from t where ptime <date_sub(curdate(),interval 3 day);
Query OK, 0 rows affected (0.09 sec)


mysql> show events;
+------+---------+----------------+-----------+-----------+------------+----------------+----------------+---------------------+------+---------+--
| Db   | Name    | Definer        | Time zone | Type      | Execute at | Interval value | Interval field | Starts              | Ends | Status  | O
+------+---------+----------------+-----------+-----------+------------+----------------+----------------+---------------------+------+---------+--
| csdn | myevent | root@localhost  | SYSTEM    | RECURRING | NULL       | 1              | DAY            | 2009-10-24 02:00:00 | NULL | ENABLED |  
+------+---------+----------------+-----------+-----------+------------+----------------+----------------+---------------------+------+---------+--
1 row in set (0.00 sec)


mysql>

关于EVENT的介绍（很遗憾，没有中文版的）

http://dev.mysql.com/doc/refman/5.1/en/events.html
19.4. Using the Event Scheduler
19.4.1. Event Scheduler Overview  
19.4.2. Event Scheduler Configuration  
19.4.3. Event Syntax  
19.4.4. Event Metadata  
19.4.5. Event Scheduler Status  
19.4.6. The Event Scheduler and MySQL Privileges  

关于create event 的语法和例子。
http://dev.mysql.com/doc/refman/5.1/en/create-event.html
12.1.11. CREATE EVENT Syntax