版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/Evils798/article/details/77478099
测试环境
1.MYSQL版本
+------------+
| version() |
+------------+
| 5.7.18-log |
+------------+
2.建表语句
mysql> show create table M; CREATE TABLE
create table `M` (
`id` int(10) NOT NULL DEFAULT '0',
`domain` varchar(255) DEFAULT NULL,
`ip` int(10) unsigned DEFAULT NULL,
`ipv6` varbinary(16) DEFAULT NULL,
`intime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`id`),
UNIQUE KEY `domain` (`domain`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8
3.表结构
mysql> desc M;
+-----------+------------------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+------------------+------+-----+-------------------+-----------------------------+
| id | int(10) | NO | PRI | 0 | |
| domain | varchar(255) | YES | UNI | NULL | |
| ip | int(10) unsigned | YES | | NULL | |
| ipv6 | varbinary(16) | YES | | NULL | |
| intime | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
+-----------+------------------+------+-----+-------------------+-----------------------------+
测试如下：
在建表的时候没有使用自增ID，这样会引业务后续出现小问题，现在通过数据交换的方式更改M表ID为自增ID
注:生产环境谨慎执行
1.直接更改M表时，是更改不了的，有主键冲突
mysql> alter table M change id id int not null auto_increment;
ERROR 1062 (23000): ALTER TABLE causes auto_increment resequencing, resulting in duplicate entry '1' for key 'PRIMARY'
2.可以用数据交换的方式来进行更改，创建新表M_new
mysql> CREATE TABLE M_new LIKE M;
Query OK, 0 rows affected (0.49 sec)
3.更改新表M_new为自增ID
mysql> ALTER TABLE M_new
-> CHANGE COLUMN `Id` `Id` INT(10) NOT NULL AUTO_INCREMENT;
Query OK, 0 rows affected (0.79 sec)
Records: 0 Duplicates: 0 Warnings: 0
4.将M表数据插入到M_new表中，注意select的列是除了ID列
mysql> insert into M_new (domain,ip,ipv6,intime) select domain,ip,ipv6,intime from M;
5.数据插入完成后，交换表名
mysql>RENAME TABLE M TO M_old, M_new TO M;
Query OK, 0 rows affected (0.34 sec)
6.再次查看M表，现在是自增ID了
mysql> desc M;
+-----------+------------------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+------------------+------+-----+-------------------+-----------------------------+
| Id | int(10) | NO | PRI | NULL | auto_increment |
| domain | varchar(255) | YES | UNI | NULL | |
| ip | int(10) unsigned | YES | | NULL | |
| ipv6 | varbinary(16) | YES | | NULL | |
| intime | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
|+-----------+------------------+------+-----+-------------------+-----------------------------+