如何在magento2产品列表中按“折扣”排序？

Question

$invoices_total = DB::table('invoices')
        ->join('products', 'invoices.id', '=', 'commodities.invoice_id')
        ->join('commodities', 'products.id', '=', 'commodities.product_id')
        ->sum('products.price * commodities.number')
        ->groupBy('invoices.id')
        ->get();