1. 下载rpm文件，用于yum安装

• 浏览器打开MySQL Yum Repository下载页
  MySQL Yum Repository.png
• 点击Red Hat Enterprise Linux 7 / Oracle Linux 7 (Architecture Independent), RPM Package 右侧的【Download】下载按钮
  MySQL Community Downloads.png
• 点击左下方链接【No thanks, just start my download】，开始下载

2. 安装mysql8

• 将下载好的rpm包上传到CentOS7的/tmp目录
  yum -y install /tmp/mysql80-community-release-el7-3.noarch.rpm
• yum安装MySQL服务器
  yum -y install mysql-community-server
• 启动MySQL服务
  systemctl start mysqld.service
• 查看服务启动之后的状态
  systemctl status mysqld.service
  mysql service status.png
• 找出root用户的密码
  grep "password" /var/log/mysqld.log
  mysql temporary password.png
• 用查出来的初始密码连接数据库
  mysql -uroot -p
  enter mysql.png
• 修改初始密码
  ALTER USER 'root'@'localhost' IDENTIFIED BY 'Root_12root';
SHOW VARIABLES LIKE 'validate_password%';
  validate_password.png
  set global validate_password.policy=0;
set global validate_password.length=1;
ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
• 设置mysql远程连接

mysql> use mysql;
mysql> update user set host="%" where user='root';
mysql> grant all privileges on test.* to root@'%';
mysql> GRANT ALL ON *.* TO 'root'@'%';
mysql> flush privileges;

• 客户端连接mysql弹窗报错：
  客户端连接报错.png
• 原因是mysql8的加密方式规则不一样，是caching_sha2_password。需要将加密方式改成mysql_native_password

mysql> ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY '123456';