MySQL SELECT INTO 等效语句是什么?
mysqlmysqli database
SELECT INTO 等效语句是 CREATE TABLE AS SELECT 语句。语法如下 −
CREATE TABLE yourNewTableName AS SELECT *FROM yourTableName;
为了理解上述概念，让我们创建一个表。创建表的查询如下 −
mysql> create table selectIntoEquivalentDemo -> ( -> ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> ClientName varchar(20), -> ClientAge int -> ); Query OK, 0 rows affected (0.71 sec)
使用 insert 命令在表中插入一些记录。 查询语句如下 −
mysql> insert into selectIntoEquivalentDemo(ClientName,ClientAge) values('Larry',34);
Query OK, 1 row affected (0.13 sec)
mysql> insert into selectIntoEquivalentDemo(ClientName,ClientAge) values('Maxwell',44);
Query OK, 1 row affected (0.06 sec)
mysql> insert into selectIntoEquivalentDemo(ClientName,ClientAge) values('Bob',38);
Query OK, 1 row affected (0.07 sec)
mysql> insert into selectIntoEquivalentDemo(ClientName,ClientAge) values('David',39);
Query OK, 1 row affected (0.09 sec)
使用 select 语句显示表中的所有记录。查询如下 −
mysql> select *from selectIntoEquivalentDemo
这是输出 −
+----------+------------+-----------+ | ClientId | ClientName | ClientAge | +----------+------------+-----------+ | 1 | Larry | 34 | | 2 | Maxwell | 44 | | 3 | Bob | 38 | | 4 | David | 39 | +----------+------------+-----------+ 4 rows in set (0.00 sec)
以下是 MySQL 中 SELECT INTO 等效查询 −
mysql> create table Client_information AS select *from selectIntoEquivalentDemo; Query OK, 4 rows impacted (0.57 sec) Records: 4 Duplicates: 0 Warnings: 0
现在让我们从新表中检查表记录。查询如下 −
mysql> select *from Client_information;
这是输出 −
+----------+------------+-----------+ | ClientId | ClientName | ClientAge | +----------+------------+-----------+ | 1 | Larry | 34 | | 2 | Maxwell | 44 | | 3 | Bob | 38 | | 4 | David | 39 | +----------+------------+-----------+ 4 rows in set (0.00 sec)
