Do following steps:
- sudo apt-get remove --purge mysql*
- sudo apt-get purge mysql*
- sudo apt-get autoremove.
- sudo apt-get autoclean.
- sudo apt-get remove dbconfig-mysql.
- sudo apt-get dist-upgrade. >> optional, it would consume a lot of bandwith
- sudo apt-get install mysql-server.
input root password and do not forget
run your mysql-server (service mysql restart)
log into your mysql (mysql -u root -p) input your root password