uname -a
cat /etc/redhat-release 

CentOS Linux release 7.6.1810 (Core) 


https://dev.mysql.com/downloads/mysql/5.7.html#downloads
下载  mysql-5.7.26-1.el7.x86_64.rpm-bundle.tar 

解压可看到多个 rpm包

依次安装

rpm -ivh mysql-community-common-5.7.26-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-5.7.26-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-5.7.26-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-5.7.26-1.el7.x86_64.rpm


sudo  systemctl start mysqld.service

启动服务 
daemon命令
service mysqld start

systemctl 命令
systemctl start mysqld.service

使用 mysqld 脚本启动
/etc/inint.d/mysqld stop

/var/log/mysqld.log
A temporary password is generated for root@localhost: d5+IAwkpQhyZ

登录mysql并修改root密码

mysql -u root -p 

set password = password('YOUR-NEW-PASSWORD');

根据需要开启防火墙端口
#开启3306端口
firewall-cmd --zone=public --add-port=3306/tcp --permanent  
#刷新防火墙
firewall-cmd --reload