I thought I have my MySQL server installed by Synaptic Package Manager but in fact I haven’t. I was trying to log into the sever via phpmyadmin but couldn’t. Tried again via command line using
but failed. Decided to install it again by command line
apt-get install mysql-server mysql-client php5-mysql
Bingo, I got it finally I could login by username = ‘root’ and password = ‘nothing’.