public function getProductPositions($categoryId, $storeId)
    {
        $select = $this->getBaseSelect()
            ->where('category_id = ?', (int) $categoryId)
            ->where('store_id = ?', (int) $storeId)
            ->where('position IS NOT NULL')
            ->columns(['product_id', 'position']);

        return $this->getConnection()->fetchPairs($select);
    }