如何在 MySQL 中从一个结构不同的表向另一个表插入数据?
为此,使用 INSERT INTO SELECT 语句。我们先创建一个表 −
mysql> create table DemoTable1 -> ( -> PersonId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> PersonName varchar(20), -> PersonAge int, -> PersonCountryName varchar(20) -> ); Query OK, 0 rows affected (0.55 sec)
使用 insert 命令在表中插入一些记录 −
mysql> insert into DemoTable1(PersonName,PersonAge,PersonCountryName) values('Chris Brown',24,'US'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1(PersonName,PersonAge,PersonCountryName) values('John Doe',26,'UK'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable1(PersonName,PersonAge,PersonCountryName) values('David Miller',23,'AUS'); Query OK, 1 row affected (0.10 sec)
使用 select 语句显示表中的所有记录 −
mysql> select * from DemoTable1;
这会产生以下输出 −
+----------+--------------+-----------+-------------------+ | PersonId | PersonName | PersonAge | PersonCountryName | +----------+--------------+-----------+-------------------+ | 1 | Chris Brown | 24 | US | | 2 | John Doe | 26 | UK | | 3 | David Miller | 23 | AUS | +----------+--------------+-----------+-------------------+ 3 rows in set (0.00 sec)
下面是创建第二个表的查询 −
mysql> create table DemoTable2 -> ( -> EmployeeId int, -> EmployeeFullName varchar(30), -> EmployeeAge int, -> EmployeeCountryName varchar(20), -> EmployeeSalary int default 20000 -> ); Query OK, 0 rows affected (0.52 sec)
下面是查询用于从一个带有不同结构的表向另一个表中插入数据 −
mysql> insert into DemoTable2(EmployeeId,EmployeeFullName,EmployeeAge,EmployeeCountryName) select PersonId,PersonName,PersonAge,PersonCountryName from DemoTable1; Query OK, 3 rows affected (0.26 sec) Records: 3 Duplicates: 0 Warnings: 0
使用 select 语句显示表中的所有记录 −
mysql> select * from DemoTable1;
这会产生以下输出 −
+------------+------------------+-------------+---------------------+----------------+ | EmployeeId | EmployeeFullName | EmployeeAge | EmployeeCountryName | EmployeeSalary | +------------+------------------+-------------+---------------------+----------------+ | 1 | Chris Brown | 24 | US | 20000 | | 2 | John Doe | 26 | UK | 20000 | | 3 | David Miller | 23 | AUS | 20000 | +------------+------------------+-------------+---------------------+----------------+ 3 rows in set (0.00 sec)
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