基于MYSQL数据库实现自动创建分区

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概述

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，今天主要分享一下在MYSQL数据库应如何实现自动创建分区。

1、准备测试表及数据

CREATE TABLE `t1` ( `id` bigint(20) NOT NULL COMMENT 'id', `insert_user` varchar(128) CHARACTER SET utf8 COLLATE utf8_bin DEFAULT NULL COMMENT 'Insert User', `insert_date` datetime NOT NULL COMMENT 'Insert Date', PRIMARY KEY (`id`,insert_date) USING BTREE, KEY `fsl_idx_order_release_insert_date` (`insert_date`) USING BTREE ) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC COMMENT='test' /*!50500 PARTITION BY RANGE COLUMNS(insert_date) ( PARTITION p VALUES LESS THAN ('2020-08-01') ENGINE = InnoDB, PARTITION p VALUES LESS THAN ('2020-09-01') ENGINE = InnoDB) */ insert into t1 values (1,'hwb',now()),(1,'hwb2',now()+1),(1,'hwb3',now()+2);

2、相关存储过程

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 `ycdb` // DROP PROCEDURE IF EXISTS `create_partition_by_month` // CREATE PROCEDURE `create_partition_by_month` ( IN_SCHEMANAME VARCHAR ( 64 ), IN_TABLENAME VARCHAR ( 64 ) ) BEGIN DECLARE ROWS_CNT INT UNSIGNED; DECLARE BEGINTIME TIMESTAMP; DECLARE ENDTIME INT UNSIGNED; DECLARE PARTITIONNAME VARCHAR ( 16 ); DECLARE ENDTIME_DATETIME VARCHAR ( 30 ); SET BEGINTIME = DATE( NOW( ) - INTERVAL DAY ( NOW( ) ) DAY + INTERVAL 1 DAY + INTERVAL 1 MONTH ); select BEGINTIME; SET PARTITIONNAME = DATE_FORMAT( BEGINTIME, 'p%Y%m' ); select PARTITIONNAME; SET ENDTIME = UNIX_TIMESTAMP( BEGINTIME + INTERVAL 1 MONTH ); select endtime; SET ENDTIME_DATETIME = FROM_UNIXTIME( ENDTIME ); select ENDTIME_DATETIME; 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 ('", ENDTIME_DATETIME, "') 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; --手动测试 call create_partition_by_month("ycdb", "t1");

3、数据库定时任务(每小时执行一次)

每小时执行一次，检查下个月的表分区是否已经创建，如果没有创建，则调用上面的存储过程创建。

DELIMITER $ #该表所在的数据库名称 USE `ycdb`$ CREATE EVENT IF NOT EXISTS `Month_partition_t1` ON SCHEDULE EVERY 1 hour #执行周期，还有天、月等等 STARTS '2020-08-10 17:00:00' ON COMPLETION PRESERVE ENABLE COMMENT 'Creating partitions By month' 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 ycdb.create_partition_by_month("ycdb", "t1"); END$ DELIMITER ;

如果没有执行，请检查Mysql是否开启了event(默认是关闭的)

 [mysqld] event_scheduler=ON

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