I tried mysql in my command line :

I get :

The program 'mysql' is currently not installed.  You can install it by typing:
sudo apt-get install mysql-client-core-5.5

But when I do:

sudo apt-get install mysql-client-core-5.5

But I get:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
mysql-client-core-5.5 is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 47 not upgraded.

I'm very much confused!

Thanks in advance.