1、首先，根据自己的机子到MySQL官网下载对应的数据库https://dev.mysql.com/downloads/mysql/

 2、卸载mariadb，并解压Mysql

 3、安装

rpm -ivh mysql-community-common-8.0.26-1.el7.x86_64.rpm --nodeps 
rpm -ivh mysql-community-libs-8.0.26-1.el7.x86_64.rpm --nodeps 
rpm -ivh mysql-community-client-8.0.26-1.el7.x86_64.rpm --nodeps 
rpm -ivh mysql-community-server-8.0.26-1.el7.x86_64.rpm  --nodeps 

查看 

 4、初始化

CentOS7安装MySQL 8.0.26的过程 - 编程教程

又报错了