I have installed LAMP on Ubuntu 12.10, and I want to access PhpMyAdmin, but I don't know it's URL.

I tried to access this URL : http://localhost/phpmyadmin

But I got this problem :

Not Found

The requested URL /phpmyadmin was not found on this server.

Apache/2.2.22 (Ubuntu) Server at localhost Port 80

And these are the instructions I followed to install lamp:

http://www.howtoforge.com/ubuntu_lamp_for_newbies

Adding to @thomasrutter answer:

Just in case someone doesn't know this (i didn't for sometime), after running this command to reconfigure phpmyadmin

sudo dpkg-reconfigure -plow phpmyadmin

this screen will appear in your terminal, make sure the * is there inside the brackets [] like this [*] for apache using the Space

Assuming you followed those installation instructions to the letter, phpmyadmin should at least be installed on your computer. However, Apache configuration needs to be added for it to work.

When you installed phpmyadmin, it should have automatically set up its configuration for Apache, making it accessible at http://localhost/phpmyadmin/ (it's possible you may need the trailing slash?).

However, in case it didn't, you can re-run the initial configuration step with the following command:

sudo dpkg-reconfigure -plow phpmyadmin

When changing Apache configuration, it should usually restart Apache automatically, but in case it doesn't, you can always restart Apache with:

sudo service apache2 reload

(Some changes require restart instead of reload).

If you are sure that you do have lamp-stack just open up your terminal and type:

edit /etc/apache2/apache2.conf

or

sudo nano /etc/apache2/apache2.conf

and paste the following at the end of file:

Include /etc/phpmyadmin/apache.conf

Then make sure you restart the server:

sudo service apache2 restart

After installing phpMyAdmin you need to configure it. There is great documentation here: phpMyAdmin @ Community Ubuntu Documentation

Try it out.