After installing phpmyadmin by using the command:
sudo apt-get install phpmyadmin
you may face the problem that cannot access phpmyadmin.
Not Found
The requested URL /phpmyadmin was not found on this server.
Apache/2.2.22 (Ubuntu) Server at localhost Port 80
Let's check apache2 config file:
sudo nano /etc/apache2/apache2.conf 
and search insert:
Include /etc/phpmyadmin/apache.conf 
at the bottom of file. and restart apache2
sudo /etc/init.d/apache2 restart