1.卸载已有mysql服务

①查找已有MySQL服务：

rpm -qa | grep postfix

rpm -qa | grep mariadb

②卸载

rpm -e postfix-2.10.1-6.el7.x86_64

rpm -e mariadb-libs-5.5.44-2.el7.x86_64

2.从官网下载Mysql5.7

http://mirrors.sohu.com/mysql/MySQL-5.7/

上传到/home/test/mysql文件夹

3.（需要按照下面的顺序进行安装）

mysql-community-common-5.7.23-1.el7.x86_64.rpm

mysql-community-libs-5.7.23-1.el7.x86_64.rpm

mysql-community-client-5.7.23-1.el7.x86_64.rpm

mysql-community-server-5.7.23-1.el7.x86_64.rpm

mysql-community-devel-5.7.23-1.el7.x86_64.rpm

mysql-community-libs-compat-5.7.23-1.el7.x86_64.rpm

安装过程举例：

rpm -ivh mysql-community-common-5.7.23-1.el7.x86_64.rpm