添加索引的几种方法
1.添加PRIMARY KEY(主键索引):
ALTER TABLE table_name
ADD PRIMARY KEY ( column
)
‘table_name’ 表名
column 字段
将table_name表的column字段设置为主键
2.添加UNIQUE(唯一索引) :
ALTER TABLE table_name
ADD UNIQUE ( column
)
3.添加INDEX(普通索引) :
写法一:ALTER TABLE table_name
ADD INDEX index_name ( column
)
写法二:CREATE INDEX index_name ON table_name
(column1
,column2
,column3
)
4.添加FULLTEXT(全文索引) :
ALTER TABLE table_name
ADD FULLTEXT ( column
)
5.添加多列索引(联合索引):
写法一:ALTER TABLE table_name
ADD INDEX index_name ( column1
, column2
, column3
)
写法二:CREATE INDEX index_name ON table_name
(column1
,column2
,column3
)
6. 查询表索引
SHOW INDEX FROM table_name
;
7. 删除索引
DROP INDEX index_name ON table_name
;
最后附上索引详解地址:https://www.cnblogs.com/sheseido/p/5825441.html
https://www.cnblogs.com/nickchen121/p/11155947.html