一、上传或下载安装包（注意内存）
下载地址：https://downloads.mysql.com/archives/community/
wget https://downloads.mysql.com/archives/get/p/23/file/mysql-8.0.18-1.el7.x86_64.rpm-bundle.tar
二、解压
tar -xvf mysql-8.1.0-1.el7.x86_64.rpm-bundle.tar -C path(解压目录)
注：解压文件没有外面的mysql文件夹，需要自己建 mkdir mysql，移动多个文件，可用通配符，例：mv *.rpm path(目的路径)
三、安装插件
yum install openssl-devel
yum -y install perl
yum -y install perl-Data-Dumper
yum -y install perl-JSON
yum -y install net-tools
四、干掉mariadb
yum remove mariadb
yum list installed|grep mariadb
yum remove mariadb-libs
五、进入解压目录安装mysql
yum install libcrypto*
rpm -ivh mysql-community-common-8.0.18-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-8.0.18-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-compat-8.0.18-1.el7.x86_64.rpm
rpm -ivh mysql-community-devel-8.0.18-1.el7.x86_64.rpm
rpm -ivh mysql-community-embedded-compat-8.0.18-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-8.0.18-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-8.0.18-1.el7.x86_64.rpm
rpm -ivh mysql-community-test-8.0.18-1.el7.x86_64.rpm
六、卸载
查看安装的
rpm -qa|grep mysql
rpm -ev 查出来的