MySQL的計劃任務創建

MySQL的計劃任務創建     實際項目中只想將最近7天的記錄保存在MySQL數據庫中，使用程序通過SQL指令的方式刪除比較麻煩且效率低，用Mysql 提供的事件調度器（event scheduler)可輕松實現。  www.2cto.com   具體步驟如下： 1：超級用戶方式登陸MySQL console # mysql　-uroot   2：打開event_scheduler(默認是關掉的） mysql> set global event_scheduler = ON;   3：創建我們的事件（本例中命名為delete_old_record)  www.2cto.com   mysql> CREATE EVENT delete_old_record 　　　ON SCHEDULE EVERY 1 DAY STARTS NOW() 　　　DO 　　　　-- delete the old records of demo_1_table 　　　　DELETE FROM demo_1_table WHERE datediff(NOW(),log_timestamp)>=7; 　　　　-- delete the old records of puma_2_table 　　　　DELETE FROM demo_2_table WHERE datediff(NOW(),log_timestamp)>=7; 　　　　-- delete the old records of puma_3_table 　　　　DELETE FROM demo_3_table WHERE datediff(NOW(),log_timestamp)>=7; 　　　　-- delete the old records of puma_4_table 　　　　DELETE FROM demo_4_table WHERE datediff(NOW(),log_timestamp)>=7;   4：啟動創建的事件 mysql> ALTER EVENT delete_old_record ENABLE;   這樣以後，數據庫就會每天執行DO後面的作業，刪除各個table中7天之前的記錄。   附錄：CREATE EVENT的格式如下： CREATE     [DEFINER = { user | CURRENT_USER }]     EVENT     [IF NOT EXISTS]     event_name     ON SCHEDULE 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}