MySQL普通表转换为分区表实战指南

mysqldump -u [username] -p[password] [database_name] new_table > new_table_backup.sql

CREATE TABLE backup_table_name AS SELECT * FROM original_table_name;

ALTER TABLE original_table_name DROP PRIMARY KEY
add  original_table_name ADD PRIMARY KEY (id, create_time);

ALTER TABLE original_table_name 
PARTITION BY RANGE (YEAR(create_time)) (
    PARTITION p0 VALUES LESS THAN (2022),
    PARTITION p1 VALUES LESS THAN (2023),
    PARTITION p2 VALUES LESS THAN (2024),
    ...
    PARTITION pn VALUES LESS THAN MAXVALUE
);

CREATE TABLE new_partitioned_table (
  id INT NOT NULL,
  name VARCHAR(50),
  create_time TIMESTAMP NOT NULL,
  PRIMARY KEY (id, create_time)
) ENGINE=InnoDB
PARTITION BY RANGE COLUMNS(create_time) (
    PARTITION p0 VALUES LESS THAN ('2023-01-01'),
    PARTITION p1 VALUES LESS THAN ('2023-02-01'),
    PARTITION p2 VALUES LESS THAN ('2023-03-01'),
    PARTITION future VALUES LESS THAN MAXVALUE
);

INSERT INTO new_partitioned_table (id, name, create_time) SELECT * FROM original_table_name ;

SELECT COUNT(*) FROM original_table_name ; -- 记下这个数量
SELECT COUNT(*) FROM new_partitioned_table; -- 应该与前一个查询的结果相同

DROP TABLE original_table_name ;
RENAME TABLE new_partitioned_table TO original_table_name ;

DELIMITER //
CREATE PROCEDURE CreateNextMonthPartition()
BEGIN
    DECLARE v_next_month DATE;
    DECLARE v_partition_name VARCHAR(255);
    DECLARE v_alter_sql TEXT;
    DECLARE v_last_partition_name VARCHAR(255);
    DECLARE v_last_partition_values VARCHAR(255);
    
    -- 获取下个月的第一天
    SET v_next_month = DATE_FORMAT(DATE_ADD(NOW(), INTERVAL 1 MONTH), '%Y-%m-01');
    
    -- 生成新分区的名称
    SET v_partition_name = CONCAT('p', DATE_FORMAT(v_next_month, '%Y%m'));
    
    -- 获取最后一个分区的名称和值，以便在ALTER TABLE语句中使用
    SELECT 
        PARTITION_NAME, 
        PARTITION_DESCRIPTION 
    INTO 
        v_last_partition_name, 
        v_last_partition_values 
    FROM 
        INFORMATION_SCHEMA.PARTITIONS 
    WHERE 
        TABLE_NAME = 'new_table' AND 
        TABLE_SCHEMA = DATABASE() 
    ORDER BY 
        PARTITION_ORDINAL_POSITION DESC 
    LIMIT 1;
    
    -- 构建ALTER TABLE语句来添加新分区
    SET v_alter_sql = CONCAT(
        'ALTER TABLE new_partitioned_table  REORGANIZE PARTITION ', v_last_partition_name, 
        ' INTO (',
        'PARTITION ', v_last_partition_name, ' VALUES LESS THAN (', v_last_partition_values, '),',
        'PARTITION ', v_partition_name, ' VALUES LESS THAN (', 
        QUOTE(DATE_FORMAT(DATE_ADD(v_next_month, INTERVAL 1 MONTH), '%Y-%m-01')), ')',
        'PARTITION future VALUES LESS THAN MAXVALUE)',
        ';'
    );
    
    -- 执行ALTER TABLE语句
    PREPARE stmt FROM v_alter_sql;
    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;
END //
DELIMITER ;