/*
    SELECT c.name
    FROM products_categories_map m
    LEFT JOIN products p ON m.product = p.id
    LEFT JOIN companies c ON c.id = p.company
    WHERE m.category = 2
    GROUP BY c.name
    */
		$categories = Doctrine_Query::create() -> select("c.name")
		                                       -> from("ProductsCategories m")
		                                       -> leftJoin("Product p")
		                                       -> leftJoin("Company c ON c.id = p.company")
		                                       -> where("m.category = ?")
		                                       -> groupBy("c.name")
		                                       -> execute(array(1));