var result = new List<FactOnlineSalesCsv>();
            string orderKey = "";
            int orderKeyIndex = 1;

            foreach(var item in order)
            {
                result.Add(new FactOnlineSalesCsv
                {
                    OrderKey = item.OrderKey,
                    PaymentMethodKey = item.PaymentMethodKey,
                    ProductKey = item.ProductKey,
                    ChannelKey = item.ChannelKey,
                    CustomerKey = item.CustomerKey,
                    DeliveryMethodKey = item.DeliveryMethodKey,
                    OrderDateKey = dimDateCsv.FirstOrDefault(t => t.FullDate == item.OrderDate).DateKey,
                    ShipDateKey = dimDateCsv.FirstOrDefault(t => t.FullDate == item.DeliveryDate).DateKey,
                    ProductCost = 0.0475 * (double)item.TransactionPrice,
                    DeliveryCost = Math.Round(item.DeliveryCost / item.Quantity, 2),
                    DiscountPctg = item.DiscountPctg,
                    DiscountAmount = item.DiscountAmount,
                    CatalogPrice = item.CatalogPrice,
                    OrderLineNumber = orderKey == item.OrderKey ? orderKeyIndex + 1 : 1,
                    Quantity = item.Quantity,
                    SalesTerritoryKey = dimSalesTerritoryCsv.FirstOrDefault(t => t.CountryKey == item.CountryKey).SalesTerritoryKey,
                    TransactionPrice = item.TransactionPrice
                });

                if(orderKey == item.OrderKey)
                {
                    orderKeyIndex += 1;
                } 
                else
                {
                    orderKeyIndex = 1;
                }

                orderKey = item.OrderKey;