基础table为：
mysql> select * from staff;
+----+----------+-------+
| id | name | slary |
+----+----------+-------+
| | haofugui | |
| | guoming | |
| | haotian | |
+----+----------+-------+
rows in set (0.00 sec)mysql> describe staff;
+-------+----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+----------------+
| id | int() | NO | PRI | NULL | auto_increment |
| name | char() | YES | | NULL | |
| slary | int() | YES | | NULL | |
+-------+----------+------+-----+---------+----------------+
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, rows affected (0.05 sec)mysql> describe staff_bak_1; //创建了一个与staff数据结构一致的空数据库，包括主键和自动增长等
+-------+----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+----------------+
| id | int() | NO | PRI | NULL | auto_increment |
| name | char() | YES | | NULL | |
| slary | int() | YES | | NULL | |
+-------+----------+------+-----+---------+----------------+
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;//将staff内的数据全部复制到刚才创建的空数据库
Query OK, rows affected (0.00 sec)
Records: Duplicates: Warnings: mysql> select * from staff_bak_1; //结果
+----+----------+-------+
| id | name | slary |
+----+----------+-------+
| | haofugui | |
| | guoming | |
| | haotian | |
+----+----------+-------+
rows in set (0.00 sec)
mysql> create table staff_bak_2 //创建一个空数据库
-> (id int auto_increment primary key,
-> name char());
Query OK, rows affected (0.05 sec)mysql> describe staff_bak_2;
+-------+----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+----------------+
| id | int() | NO | PRI | NULL | auto_increment |
| name | char() | YES | | NULL | |
+-------+----------+------+-----+---------+----------------+
rows in set (0.01 sec)mysql> insert into staff_bak_2(name) select name from staff where id!=5; //带where子句，将指定的记录复制到新表中。
Query OK, rows affected (0.00 sec)
Records: Duplicates: Warnings: mysql> select * from staff_bak_2; //结果
+----+----------+
| id | name |
+----+----------+
| | haofugui |
| | guoming |
+----+----------+
rows in set (0.00 sec)
