一、下载安装包https://downloads.mysql.com/archives/community/使用wget命令下载tar包wgethttps://downloads.mysql.com/archives/get/p/23/file/mysql-server_5.7.42-1ubuntu18.04_amd64.deb-bundle.tarsudotar-xvfmysql-server_5.7.42-1ubuntu18.04_amd64.deb-bu