安装MySQL 8.0版本
系统环境：
CentOS Linux release 8.1.1911 (Core)
添加源
rpm -Uvh https://repo.mysql.com//mysql80-community-release-el8-1.noarch.rpm
dnf clean all
安装
dnf install mysql mysql-server mysql-devel
启动并设置开机自启
systemctl enable mysqld
systemctl start mysqld
修改root密码
[root@centos8 ~]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 8
Server version: 8.0.17 Source distribution
Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
mysql> ALTER user 'root'@'localhost' IDENTIFIED BY 'PASSWORD';
Query OK, 0 rows affected (0.00 sec)
mysql> exit
Bye
Tips：密码必须包含大写字母、数字、特殊符号，不需要
flush privileges来刷新权限。