安装mysql数据库
a)下载mysql源安装包:wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
b)安装mysql源:yum localinstall mysql57-community-release-el7-8.noarch.rpm
若结尾出现complete!,则说明MySQL源安装完成
c)检测是否安装完成:yum repolist enabled | grep “mysql.*-comm