在MySQL中将列名从StudentName更改为FirstName？
使用带有ALTER语句的CHANGE。让我们首先创建一个表-
mysql> create table DemoTable -> ( -> StudentName varchar(100), -> Age int -> );
现在检查表的描述-
mysql> desc DemoTable;
输出结果
这将产生以下输出-
+----------------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +----------------+--------------+------+-----+---------+-------+ | StudentName | varchar(100) | YES | | NULL | | | Age | int(11) | YES | | NULL | | +----------------+--------------+------+-----+---------+-------+ 2 rows in set (0.25 sec)
这是使用ALTER的查询-
mysql> alter table DemoTable -> add column Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> add column CountryName varchar(100) after Age, -> change column StudentName FirstName varchar(200); Records: 0 Duplicates: 0 Warnings: 0
现在再次检查表的描述-
mysql> desc DemoTable;
输出结果
这将产生以下输出-
+-------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+--------------+------+-----+---------+----------------+ | FirstName | varchar(200) | YES | | NULL | | | Age | int(11) | YES | | NULL | | | CountryName | varchar(100) | YES | | NULL | | | Id | int(11) | NO | PRI | NULL | auto_increment | +-------------+--------------+------+-----+---------+----------------+ 4 rows in set (0.00 sec)