MySQL複製表-INSERT INTO SELECT

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基礎table為：

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 語句從一個表複製資料，然後把資料插入到一個已存在的表（目標表）中，目標表中任何已存在的行都不會受影響。

語句1：Insert into Table2(field1,field2,…) select value1,value2,… from Table1 where condition;

語句2：Insert into Table2 select * from Table1;

 

說明：1）目標表Table2必須存在，MySQL不會自動建立；

             2）語句1一般用於兩個表結構一致的情況，而語句2用於表結構不一致的情況；

             3）語句1中涉及的field1，field2也必須存在；

             4）若Table2有主鍵且不具備自動成長，則 field1， field2…中必須包括主鍵。

樣本：

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: 0mysql> 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: 0mysql> select * from staff_bak_2;+----+----------+| id | name     |+----+----------+|  1 | haofugui ||  2 | guoming  |+----+----------+2 rows in set (0.00 sec)

 

MySQL複製表-INSERT INTO SELECT