rpm -qa | grep mysql如下图,没有显示任何结果,则代表之前系统没有装过mysql

wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm如果报错: -bash: wget: 未找到命令,则安装插件
yum -y install wgetsudo rpm -ivh mysql-community-release-el7-5.noarch.rpm
sudo yum install mysql-server下载的快的话,基本半分钟内就能安装完

mysql -u root可能会如下报错: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) 原因:原因是/var/lib/mysql的访问权限问题。
chown root /var/lib/mysql/service mysqld restartmysql -u root
use mysql;
update user set password=password('123456') where user='root';
exit;接着继续重启MySQL服务
service mysqld restart mysql -u root -p
GRANT ALL PRIVILEGES ON *.* TO root@"%" IDENTIFIED BY "root";service mysqld restartsystemctl stop firewalld.service