mysql 创建分区表_Mysql分区表及自动创建分区Partition

Range分区表建表语句如下，其中分区键必须和id构成主键和唯一键

CREATE TABLE `test1` (

`id` char(32) COLLATE utf8mb4_unicode_ci NOT NULL COMMENT ‘自增主键(guid)‘,

`create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT ‘创建时间‘,

`partition_key` int(8) NOT NULL COMMENT ‘分区键(格式:yyyyMMdd)‘,

PRIMARY KEY (`id`,`partition_key`),

UNIQUE KEY `id_UNIQUE` (`id`,`partition_key`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

PARTITION BY RANGE (partition_key)

(PARTITION p0 VALUES LESS THAN (20180619) ENGINE = InnoDB,

PARTITION p20180619 VALUES LESS THAN (20180620) ENGINE = InnoDB,

PARTITION p20180621 VALUES LESS THAN (20180622) ENGINE = InnoDB,

PARTITION p20180622 VALUES LESS THAN (20180623) ENGINE = InnoDB,

PARTITION p20180623 VALUES LESS THAN (20180624) ENGINE = InnoDB);

新增分区

alter TABLE `test1` add PARTITION(

PARTITION p20180629 VALUES LESS THAN (20180630) ENGINE = InnoDB

);

删除分区

alter table `test1` drop PARTITION p20180629;

Mysql不能自动创建分区，需要使用mysql event事件的方式自动创建分区

1.创建分区的存储过程如下(每次执行先校验当前分区是否存在，如果存在则不处理；不存在则创建)：

DELIMITER $$

#该表所在数据库名称

USE `demo`$$

DROP PROCEDURE IF EXISTS `create_partition_by_day`$$

CREATE PROCEDURE `create_partition_by_day`(IN_SCHEMANAME VARCHAR(64), IN_TABLENAME VARCHAR(64))

BEGIN

#当前日期存在的分区的个数

DECLARE ROWS_CNT INT UNSIGNED;

#目前日期，为当前日期的后一天

DECLARE TARGET_DATE TIMESTAMP;

#分区的名称，格式为p20180620

DECLARE PARTITIONNAME VARCHAR(9);

#当前分区名称的分区值上限，即为 PARTITIONNAME + 1

DECLARE PARTITION_ADD_DAY VARCHAR(9);

SET TARGET_DATE = NOW() + INTERVAL 1 DAY;

SET PARTITIONNAME = DATE_FORMAT( TARGET_DATE, ‘p%Y%m%d‘ );

SET TARGET_DATE = TARGET_DATE + INTERVAL 1 DAY;

SET PARTITION_ADD_DAY = DATE_FORMAT( TARGET_DATE, ‘%Y%m%d‘ );

SELECT COUNT(*) INTO ROWS_CNT FROM information_schema.partitions

WHERE table_schema = IN_SCHEMANAME AND table_name = IN_TABLENAME AND partition_name = PARTITIONNAME;

IF ROWS_CNT = 0 THEN

SET @SQL = CONCAT( ‘ALTER TABLE `‘, IN_SCHEMANAME, ‘`.`‘, IN_TABLENAME, ‘`‘,

‘ ADD PARTITION (PARTITION ‘, PARTITIONNAME, " VALUES LESS THAN (",

PARTITION_ADD_DAY ,") ENGINE = InnoDB);" );

PREPARE STMT FROM @SQL;

EXECUTE STMT;

DEALLOCATE PREPARE STMT;

ELSE

SELECT CONCAT("partition `", PARTITIONNAME, "` for table `",IN_SCHEMANAME, ".", IN_TABLENAME, "` already exists") AS result;

END IF;

END$$

DELIMITER ;

2.数据库定时任务(每小时执行一次)

DELIMITER $$

#该表所在的数据库名称

USE `demo`$$

CREATE EVENT IF NOT EXISTS `daily_generate_partition`

ON SCHEDULE EVERY 1 hour #执行周期，还有天、月等等

STARTS ‘2018-06-20 00:00:00‘

ON COMPLETION PRESERVE

ENABLE

COMMENT ‘Creating partitions‘

DO BEGIN

#调用刚才创建的存储过程，第一个参数是数据库名称，第二个参数是表名称

CALL datacollectcenter.create_partition_by_day(‘demo‘,‘test1‘);

END$$

DELIMITER ;