从MySQL表中删除索引
要从MySQL表中删除索引，语法如下-
alter table yourTableName drop index `yourIndexName`;
让我们首先创建一个表-
Mysql> create table DemoTable1469 -> ( -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentName varchar(40), -> StudentAge int -> );
以下是在列名上添加索引的查询-
mysql> create index `Student Name_Index` on DemoTable1469(StudentName); Records: 0 Duplicates: 0 Warnings: 0
让我们检查表说明-
mysql> desc DemoTable1469;
这将产生以下输出-
+-------------+-------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+-------------+------+-----+---------+----------------+ | StudentId | int(11) | NO | PRI | NULL | auto_increment | | StudentName | varchar(40) | YES | MUL | NULL | | | StudentAge | int(11) | YES | | NULL | | +-------------+-------------+------+-----+---------+----------------+ 3 rows in set (0.00 sec)
以下是删除索引的查询-
mysql> alter table DemoTable1469 drop index `Student Name_Index`; Records: 0 Duplicates: 0 Warnings: 0
让我们再次检查表描述-
mysql> desc DemoTable1469;
这将产生以下输出-
+-------------+-------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+-------------+------+-----+---------+----------------+ | StudentId | int(11) | NO | PRI | NULL | auto_increment | | StudentName | varchar(40) | YES | | NULL | | | StudentAge | int(11) | YES | | NULL | | +-------------+-------------+------+-----+---------+----------------+ 3 rows in set (0.00 sec)