rpm -qa | grep mysql

rpm -e mysql　　// 普通删除模式

rpm -e --nodeps mysql　　// 强力删除模式，如果使用上面命令删除时，提示有依赖的其它文件，则用该命令可以对其进行强力删除

wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm

rpm -ivh mysql-community-release-el7-5.noarch.rpm

yum update

yum install mysql-server

chown -R mysql:mysql /var/lib/mysql/

mysqld --initialize

systemctl start mysqld

systemctl status mysqld

mysqladmin --version

mysqladmin -u root password "new_password";

mysql -u root -p