How can i pass a parameter (that is a returned value of another model function) to a function of a model class.

here's my model class functions

```
public function get_products_categories()
{
$query = $this->db->query('SELECT DISTINCT category 
                           FROM products');
return $query->result_array();
}   

public function get_products_names($category)
{
$query = $this->db->query('SELECT name 
                           FROM products
                           WHERE category=$category');
return $query->result_array();
}   

```

and here's how I am doing in the controller class

```
$this->load->model('products_model');
    $data['products_categories'] = $this->products_model->get_products_categories();
    $data['products_names'] = $this->products_model->get_products_names();

```

Now what I want is to pass `$products_categories` to the function `$this->products_model->get_products_names();` but this is not possible `$products_categories` is not variable here in the controller class but in the view file, it can be used as a variable

Any Ideas ?