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