1，CentOS 7的yum源中没有正常安装mysql-sever文件
2，官方下载：wget http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm
3，加入安装库：rpm -ivh mysql-community-release-el7-5.noarch.rpm
4，安装：yum install mysql-community-server
5，启动 service mysqld restart
6，初次安装mysql是root账户没有密码
7，设置密码mysql -uroot
set password for ‘root’@‘localhost’ = password('mypasswd');