复制表
创建测试表test：mysql> create table test(
-> id int primary key auto_increment,
-> name varchar(32)
-> );
Query OK, 0 rows affected (0.16 sec)
插入几条数据后复制test到test2中mysql> create table test2 select * from test;
Query OK, 2 rows affected (0.08 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql> select * from test2; +----+-------+ | id | name | +----+-------+ | 1 | test1 | | 2 | test2 | +----+-------+ 2 rows in set (0.00 sec)
上面是复制了整张表，我们下面看复制表的一部分字段，相信一这样说就应该想到怎么做了
创建测试表test3mysql> create table test3(
-> id int primary key auto_increment,
-> name varchar(32),
-> age int,
-> birthday timestamp default now()
-> );
Query OK, 0 rows affected (0.06 sec)
插入几条数据后开始复制test3到test4中mysql> create table test4 select id,name,birthday from test3;
Query OK, 7 rows affected (0.06 sec) Records: 7 Duplicates: 0 Warnings: 0 mysql> select * from test4; +----+------+---------------------+ | id | name | birthday | +----+------+---------------------+ | 1 | test | 2010-12-30 23:16:08 | | 2 | test | 2010-12-30 23:16:11 | | 3 | test | 2010-12-30 23:16:12 | | 4 | test | 2010-12-30 23:16:13 | | 5 | test | 2010-12-30 23:16:14 | | 6 | test | 2010-12-30 23:16:16 | | 7 | test | 2010-12-30 23:16:19 | +----+------+---------------------+ 7 rows in set (0.00 sec)
从上面可以看出，如果是只创建含有约束条件的值的表副本就简单了直接where就Ok了mysql> create table test5 select * from test4 where id<3;
Query OK, 2 rows affected (0.11 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql> select * from test5; +----+------+---------------------+ | id | name | birthday | +----+------+---------------------+ | 1 | test | 2010-12-30 23:16:08 | | 2 | test | 2010-12-30 23:16:11 | +----+------+---------------------+ 2 rows in set (0.00 sec)
只复制表结构，不复制表数据
一：(取巧方法)mysql> create table test6 select * from test3 where 0=1;
Query OK, 0 rows affected (0.08 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> select * from test6; Empty set (0.00 sec)
二：(MySQL提供了一个现成的语法)mysql> create table test7 like test6;
Query OK, 0 rows affected (0.06 sec) mysql> select * from test7; Empty set (0.00 sec) mysql> desc test7; +----------+-------------+------+-----+---------------------+-------+ | Field | Type | Null | Key | Default | Extra | +----------+-------------+------+-----+---------------------+-------+ | id | int(11) | NO | | 0 | | | name | varchar(32) | YES | | NULL | | | age | int(11) | YES | | NULL | | | birthday | timestamp | NO | | 0000-00-00 00:00:00 | | +----------+-------------+------+-----+---------------------+-------+ 4 rows in set (0.00 sec)
三：(复制旧表部分结构，同时增加新字段)mysql> create table test8 (location varchar(32),position varchar(32)) select id,name,birthday from test7;
Query OK, 0 rows affected (0.08 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> desc test8; +----------+-------------+------+-----+---------------------+-------+ | Field | Type | Null | Key | Default | Extra | +----------+-------------+------+-----+---------------------+-------+ | location | varchar(32) | YES | | NULL | | | position | varchar(32) | YES | | NULL | | | id | int(11) | NO | | 0 | | | name | varchar(32) | YES | | NULL | | | birthday | timestamp | NO | | 0000-00-00 00:00:00 | | +----------+-------------+------+-----+---------------------+-------+ 5 rows in set (0.00 sec)