Totally uninstall MySQL Server Ubuntu

When you uninstall MySQL for any purpose and reinstall the MySQL Server, perhaps you want to fresh install for all the configuration, but you found that the configuration still remains.

Try this lists accordingly:

sudo service mysql stop  #or mysqld
sudo killall -9 mysql
sudo killall -9 mysqld
sudo apt-get remove --purge mysql-server mysql-client mysql-common

sudo deluser -f mysql
sudo rm -rf /var/lib/mysql
sudo apt-get purge mysql-server-core-5.7
sudo apt-get purge mysql-client-core-5.7
sudo rm -rf /var/log/mysql
sudo rm -rf /etc/mysql

sudo apt-get autoremove
sudo apt-get autoclean