mysql-Mysql中index与key的区别
来源:动视网
责编:小采
时间:2020-11-09 16:33:47
mysql-Mysql中index与key的区别
mysql-Mysql中index与key的区别:mysqlindexkey -------------------------+| user | CREATE TABLE user (id int(11) NOT NULL,name varchar(50) default NULL,companyId int(11) default NULL, PRIMARY KEY (id), KEY company_user_id (companyId)) ENGINE=InnoDB DEFAULT CHARSET=gbk |上面
导读mysql-Mysql中index与key的区别:mysqlindexkey -------------------------+| user | CREATE TABLE user (id int(11) NOT NULL,name varchar(50) default NULL,companyId int(11) default NULL, PRIMARY KEY (id), KEY company_user_id (companyId)) ENGINE=InnoDB DEFAULT CHARSET=gbk |上面

mysqlindexkey
-------------------------+
| user | CREATE TABLE user
(
id
int(11) NOT NULL,
name
varchar(50) default NULL,
companyId
int(11) default NULL,
PRIMARY KEY (id
),
KEY company_user_id
(companyId
)
) ENGINE=InnoDB DEFAULT CHARSET=gbk |
上面的建表语句中,KEY company_user_id
(companyId
),这句话起什么作用?
和 index company_user_id
(companyId
)有什么区别?
mysql-Mysql中index与key的区别
mysql-Mysql中index与key的区别:mysqlindexkey -------------------------+| user | CREATE TABLE user (id int(11) NOT NULL,name varchar(50) default NULL,companyId int(11) default NULL, PRIMARY KEY (id), KEY company_user_id (companyId)) ENGINE=InnoDB DEFAULT CHARSET=gbk |上面