I need to install Mysql-server
in an Ubuntu 18
machine which do not have any internet access. There are plethora of instruction material exist on this this subject but all they require Ubuntu machine to be online.
One such documentation can be available here (quite comprehensive though)
https://www.digitalocean.com/community/tutorials/how-to-install-mysql-on-ubuntu-18-04
You can visit https://dev.mysql.com/downloads/mysql/ from a computer that can go online.
Then, select your OS and version
Download DEB Bundle on a computer that can go online. Move the downloaded file internally to your system that cannot hit the Internet.
Your downloaded file will be a .tar. Use command tar -xvf filename.tar
(See https://www.cyberciti.biz/faq/tar-extract-linux/ for command).
You will get a new directory. cd that-directory
will get you in that directory. You will see a bunch of .deb files.
Install the deb files one by one using sudo apt-get install filename.deb
depending on what you want to install. Other commands to install deb files can be found in this discussion https://unix.stackexchange.com/questions/159094/how-to-install-a-deb-file-by-dpkg-i-or-by-apt.