官网下载压缩包解压，依次安装下来rpm
rpm -ivh mysql-community-common-8.0.31-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-plugins-8.0.31-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-8.0.31-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-compat-8.0.31-1.el7.x86_64.rpm
yum install openssl-devel
rpm -ivh mysql-community-devel-8.0.31-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-8.0.31-1.el7.x86_64.rpm
rpm -ivh mysql-community-icu-data-files-8.0.31-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-8.0.31-1.el7.x86_64.rpm
启动：systemctl start mysqld
查看系统默认生成的密码：cat /var/log/mysqld.log
2022-11-08T07:22:48.651856Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: dh<8bj6t(j9E
初始化密码：alter user ‘root’@’localhost’ identified by ‘dh<8bj6t(j9’;
设置密码的安全等级：set global validate_password.policy = 0;
set global validate_password.length = 4;
创建一个任何用户都可以链接的用户：
create user ‘root’@’%’ identified by ‘123456’;
并给root用户分配权限; grant all on *.* to ‘root’@’%’;