基础table为：
mysql> select * from staff; +----+----------+-------+ | id | name | slary | +----+----------+-------+ | 3 | haofugui | 10000 | | 4 | guoming | 3500 | | 5 | haotian | 2900 | +----+----------+-------+ 3 rows in set (0.00 sec) mysql> describe staff; +-------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------+----------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | name | char(20) | YES | | NULL | | | slary | int(11) | YES | | NULL | | +-------+----------+------+-----+---------+----------------+ 3 rows in set (0.00 sec)
INSERT INTO SELECT 语句从一个表复制数据，然后把数据插入到一个已存在的表（目标表）中，目标表中任何已存在的行都不会受影响。
语句1：Insert into Table2(field1,field2,…) select value1,value2,… from Table1 where condition;
语句2：Insert into Table2 select * from Table1;
说明：1）目标表Table2必须存在，MySQL不会自动创建；
2）语句1一般用于两个表结构一致的情况，而语句2用于表结构不一致的情况；
3）语句1中涉及的field1，field2也必须存在；
4）若Table2有主键且不具备自动增长，则 field1， field2…中必须包括主键。
示例：
mysql> create table staff_bak_1 like staff; Query OK, 0 rows affected (0.05 sec) mysql> describe staff_bak_1; +-------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------+----------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | name | char(20) | YES | | NULL | | | slary | int(11) | YES | | NULL | | +-------+----------+------+-----+---------+----------------+ 3 rows in set (0.01 sec) mysql> select * from staff_bak_1; Empty set (0.00 sec) mysql> insert into staff_bak_1 select * from staff; Query OK, 3 rows affected (0.00 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> select * from staff_bak_1; +----+----------+-------+ | id | name | slary | +----+----------+-------+ | 3 | haofugui | 10000 | | 4 | guoming | 3500 | | 5 | haotian | 2900 | +----+----------+-------+ 3 rows in set (0.00 sec)
mysql> create table staff_bak_2 -> (id int auto_increment primary key, -> name char(20)); Query OK, 0 rows affected (0.05 sec) mysql> describe staff_bak_2; +-------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------+----------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | name | char(20) | YES | | NULL | | +-------+----------+------+-----+---------+----------------+ 2 rows in set (0.01 sec) mysql> insert into staff_bak_2(name) select name from staff where id!=5; Query OK, 2 rows affected (0.00 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql> select * from staff_bak_2; +----+----------+ | id | name | +----+----------+ | 1 | haofugui | | 2 | guoming | +----+----------+ 2 rows in set (0.00 sec)
