首先要確保之前安裝的mysql被卸載干凈
[root@localhost ~]# rpm -qa|grep -i mysql
mysql-community-release-el7-5.noarch
[root@localhost ~]# rpm -e mysql-community-release-el7-5.noarch --nodeps
或者
[root@localhost ~]# yum -y remove mysql-libs*
然后登陸mysql官網，找到對應版本的yum源地址：
登陸官網：http://dev.mysql.com/downloads/repo/yum/
點擊對應版本后面的Download按鈕，進入到下面這個頁面：
通過鼠標右鍵，選擇：復制鏈接地址，就可以獲得對應版本的yum源地址，例如：
http://dev.mysql.com/get/mysql57-community-release-el6-9.noarch.rpm
通過以下步驟進行安裝：
[root@localhost ~]# rpm -Uvh http://dev.mysql.com/get/mysql57-community-release-el6-9.noarch.rpm
Retrieving http://dev.mysql.com/get/mysql57-community-release-el6-9.noarch.rpm
warning: /var/tmp/rpm-tmp.q1TNuY: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing... ########################################### [100%]
1:mysql57-community-relea########################################### [100%]
[root@localhost ~]# yum repolist enabled | grep mysql
Failed to set locale, defaulting to C
mysql-connectors-community MySQL Connectors Community 21
mysql-tools-community MySQL Tools Community 38
mysql57-community MySQL 5.7 Community Server 114
[root@localhost ~]# yum install mysql-community-server
查看mysql root缺省密碼
[root@localhost ~]# sudo grep 'temporary password' /var/log/mysqld.log
2016-08-11T10:16:43.180993Z 1 [Note] A temporary password is generated for root@localhost: 4k#Xq3h4Q7kR