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)
以上是 从MySQL表中删除索引 的全部内容, 来源链接: utcz.com/z/345393.html