Add a new attribute to products

[Nuvish]

How to add a new attribute in admin products page?
for example,add a new column 'favorite' between the other attributes.

Iv added a new field in the database of prestashop,table:ps_category_product,iv added favorite(tinyint).

By adding this line in adminproducts.php:
---> 'favorite' => array('title' => $this->l('Favorite'),'active' => 'favorite', 'width' => 30, 'align' => 'center','type' => 'bool','orderby' => false),

This makes favorite appear in the admin catalog page.

Then iv added cp.`favorite` like this in the codes :

$this->_select = 'cp.`position`,cp.`favorite`, i.`id_image`,(a.`price` * ((100 + (t.`rate`))/100)) AS price_final';

This makes the small red crosses appear in the page,in the favorite column.
But then,how to make all this work?
like when i click on a cross,it updates the database(favorite field) and actually make the product become a favorite one.

[BWT]

=) Have a good day my friends!

[Nuvish]

i've got it to work..
But this is not the proper way to do it,as core has to be changed.
Now,this override thing bugs me.

[Nuvish]

I think this can be done by creating a module to override the adminproducts.
like here - http://www.ebizness-services.com/white_papers/prestashop/admin_override

But iv been unable to get this to work..