Relating two databases in Datamapper ORM

[eluser]elmystica[/eluser]
hi,

I'm having two tables: products and brands.

Products:

Code:

id
name
brand_id
...

Brands

Code:

id
label
url

Every product belongs to only one brand ofcourse, but brands have many products.
I don't want to use a join-table (I use them on a lot of other relations).

I have two models:

Products

Code:

<?php

class Product extends DataMapper {

var $table  = 'products';

var $has_one = array(
      'brand'  => array(),
      'category' => array(),
      'gender'  => array(),
      'material' => array(),
      'shape'  => array(),
      'structure' => array()
      );
      
var $has_many = array(
      'color'   => array(),
      'list_item'  => array()
      );

function __construct($id = NULL)
{
  parent::__construct($id);
}
}

Brands

Code:

<?php

class Brand extends DataMapper {

var $has_many = array(
      'product' => array(
        'class'   => 'product',
        'other_field' => 'product',
        'join_table' => ''
       )
      );

function __construct($id = NULL)
{
  parent::__construct($id);
}
}

I made this part in a controller:

Code:

$p = new Product();
$p->get_by_id($this->uri->segment(3));
$p->brand->get();
  
echo $this->db->last_query() . "<br />";
  
foreach($p->brand as $b)
{
echo $b->brand_label;
}

The goal is to detect the brand on a product.

However, this doesn't work as I hoped it would ...
I noticed the query was like this:

Code:

SELECT brands.* FROM brands LEFT OUTER JOIN brands_products brands_products ON brands.id = brands_products.product_id WHERE brands_products.product_id = 5

it relies on join-table, which I don't want to use.

What is the right way to do this kind of operations?