什么时候我们会用到复制表?

例如:我现在对一张表进行操作,但是怕误删数据,所以在同一个数据库中建一个表结构一样,表数据也一样的表,以作备份。

如果用mysqldump比较麻烦,备份.MYD,.MYI这样的文件呢,操作起来也还是麻烦。

一,复制表结构方法1:

    mysql create table a like users; //复制表结构 Query OK, 0 rows affected (0.50 sec) mysql show tables; - | Tables_in_test | - | a | | users | - 2 rows in set (0.00 sec)
mysql create table a like users; //复制表结构Query OK, 0 rows affected (0.50 sec)mysql show tables; ---------------- | Tables_in_test | ---------------- | a || users | ---------------- 2 rows in set (0.00 sec)方法2:
    mysql create table b select * from users limit 0; //复制表结构 Query OK, 0 rows affected (0.00 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql show tables; - | Tables_in_test | - | a | | b | | users | - 3 rows in set (0.00 sec)
mysql create table b select * from users limit 0; //复制表结构Query OK, 0 rows affected (0.00 sec)Records: 0 Duplicates: 0 Warnings: 0mysql show tables; ---------------- | Tables_in_test | ---------------- | a || b || users | ---------------- 3 rows in set (0.00 sec)方法3:
    mysql show create table usersG; //显示创表的sql *************************** 1. row *************************** Table: users Create Table: CREATE TABLE `users` ( //改表名 `ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `user_name` varchar(60) NOT NULL DEFAULT , `user_pass` varchar(64) NOT NULL DEFAULT , PRIMARY KEY (`ID`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 //改auto_increment 1 row in set (0.00 sec)
mysql show create table usersG; //显示创表的sql*************************** 1. row *************************** Table: usersCreate Table: CREATE TABLE `users` ( //改表名 `ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `user_name` varchar(60) NOT NULL DEFAULT '', `user_pass` varchar(64) NOT NULL DEFAULT '', PRIMARY KEY (`ID`)) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 //改auto_increment1 row in set (0.00 sec)把sql语句copy出来,改一下表名和atuo_increment,然后在执行一下。

二,复制表数据,以及表结构方法1:

    mysql create table c select * from users; //复制表的sql Query OK, 4 rows affected (0.00 sec) Records: 4 Duplicates: 0 Warnings: 0
mysql create table c select * from users; //复制表的sqlQuery OK, 4 rows affected (0.00 sec)Records: 4 Duplicates: 0 Warnings: 0方法2:
    mysql create table d select user_name,user_pass from users where id=1; Query OK, 1 row affected (0.00 sec) Records: 1 Duplicates: 0 Warnings: 0
mysql create table d select user_name,user_pass from users where id=1;Query OK, 1 row affected (0.00 sec)Records: 1 Duplicates: 0 Warnings: 0上面的2种方法,方便,快捷,灵活性强。

方法3:先创建一个空表, INSERT INTO 新表 SELECT * FROM 旧表 ,或者INSERT INTO 新表(字段1,字段2,.) SELECT 字段1,字段2, FROM 旧表这种方法不是很方便,也是我以前经常用的。