public function findAllByBudgetId($budgetId)
    {
        $budgetId = (int) $budgetId;

        $this->addWhere('budget_id', $budgetId);
        $list = $this->select();

        $collection = array();
        foreach ($list as $item) {
            $collection[$item->getCategoryId()] = $item;
        }

        return $collection;
    }