codeigniter get category and subcategory

You will need a route in application/config/routes.php. E.g.:

PHP Code:

$route['category/(:any)'] = 'category/view/$1'; 


Create a controller named Category.php
Create a method inside it named view, which accepts the category_id as parameter:

PHP Code:

public function view($category)
{
  //collect category and subcategories from your database, see documentation about the Query Builder.
  //display the data in a view you load, see documentation about loading views
} 


The tutorial about the News section could give you a good start.