[root@master1 ~]# rpm -qa|grep mariadb [root@master1 ~]# rpm -e --nodeps libs-5.5.68-1.el7.x86_64（这个就是上面查出来的包名）
wget http://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm
yum -y insatall wget
[root@master1 ~]# rpm -ivh mysql57-community-release-el7-11.noarch.rpm
[root@master1 ~]# yum install mysql-community-server
root@master1 ~]# service mysqld restart
[root@master1 ~]# grep "password" /var/log/mysqld.log
[root@master1 ~]# mysql -uroot -p
mysql> SET passworld=PASSWORD("123456ABCDabcd.")
mysql> set global validate_password_policy=low;
mysql> set global validate_password_length=6;（设置成几长度就是几）
mysql> ALTER USER ‘root‘@‘localhost‘ IDENTIFIED BY ‘654321‘;
mysql> grant all privileges on *.* to username@‘%‘ identified by ‘654321‘;
原文：https://www.cnblogs.com/Xinyi-bigdata/p/15208085.html