MySQL 自动增加分区

ALTER TABLE tb_3a_huandan_detail PARTITION BY RANGE (TO_DAYS(ServiceStartTime))
(
    PARTITION p20160523 VALUES LESS THAN (TO_DAYS('2016-05-23')),
    PARTITION p20160524 VALUES LESS THAN (TO_DAYS('2016-05-24')),
    PARTITION p20160525 VALUES LESS THAN (TO_DAYS('2016-05-25')),
    PARTITION p20160526 VALUES LESS THAN (TO_DAYS('2016-05-26')),
    PARTITION p20160527 VALUES LESS THAN (TO_DAYS('2016-05-27'))
)

DELIMITER $$

USE `nres`$$

DROP PROCEDURE IF EXISTS `create_Partition_3Ahuadan`$$

CREATE DEFINER=`nres`@`%` PROCEDURE `create_Partition_3Ahuadan`()
BEGIN
/* 事务回滚，其实放这里没什么作用，ALTER TABLE是隐式提交，回滚不了的。*/
    DECLARE EXIT HANDLER FOR SQLEXCEPTION ROLLBACK;
    START TRANSACTION;

/* 到系统表查出这个表的最大分区，得到最大分区的日期。在创建分区的时候，名称就以日期格式存放，方便后面维护 */
    SELECT REPLACE(partition_name,'p','') INTO @P12_Name FROM INFORMATION_SCHEMA.PARTITIONS
    WHERE table_name='tb_3a_huandan_detail' ORDER BY partition_ordinal_position DESC LIMIT 1;
     SET @Max_date= DATE(DATE_ADD(@P12_Name+0, INTERVAL 1 DAY))+0;
/* 修改表，在最大分区的后面增加一个分区，时间范围加1天 */
    SET @s1=CONCAT('ALTER TABLE tb_3a_huandan_detail ADD PARTITION (PARTITION p',@Max_date,' VALUES LESS THAN (TO_DAYS (''',DATE(@Max_date),''')))');
    /* 输出查看增加分区语句*/
    SELECT @s1;
    PREPARE stmt2 FROM @s1;
    EXECUTE stmt2;
    DEALLOCATE PREPARE stmt2;
/* 取出最小的分区的名称，并删除掉 。
    注意：删除分区会同时删除分区内的数据，慎重 */
    /*select partition_name into @P0_Name from INFORMATION_SCHEMA.PARTITIONS
    where table_name='tb_3a_huandan_detail' order by partition_ordinal_position limit 1;
    SET @s=concat('ALTER TABLE tb_3a_huandan_detail DROP PARTITION ',@P0_Name);
    PREPARE stmt1 FROM @s;
    EXECUTE stmt1;
    DEALLOCATE PREPARE stmt1; */
/* 提交 */
    COMMIT ;
 END$$

DELIMITER ;

DELIMITER ||
CREATE EVENT Partition_3Ahuadan_event
          ON SCHEDULE
          EVERY 1 day STARTS '2016-05-27 23:59:59'
          DO
      BEGIN

          CALL nres.`create_Partition_3Ahuadan`;

 END ||
DELIMITER ;