安装MySQL

安装mysql 
vim /etc/yum.repos.d/mysql-community.repo

[mysql57-community]
name=MySQL 5.7 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/7/$basearch/
enabled=1
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql


wget -i -c http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm

yum -y install mysql57-community-release-el7-10.noarch.rpm

systemctl start  mysqld.service

grep "password" /var/log/mysqld.log

mysql -uroot -p

mysql> set global validate_password_policy=0;
mysql> set global validate_password_length=1;
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';

yum -y remove mysql57-community-release-el7-10.noarch