Distinct در Linq

[alibabaei2]

سلام
چندتا جدول باهم طبق کد زیر با هم join شده اند حالا می خوام از دستور distinct استفاده کنم اما جوابی که می گیرم جواب دلخواه نیست
var n = (from od in DataContext.Context.OrderDetails
join i in DataContext.Context.Ingredients
on od.IngID equals i.IngID
join ad in DataContext.Context.OrderAmountDetails
on od.OrderDetailID equals ad.OrderDetailID
join inv in DataContext.Context.Inventories
on ad.OrderAmountDetailID equals inv.OrderAmountDetailID
join c in DataContext.Context.Companies
on ad.CompanyID equals c.CompanyID
where
ad.OrderDetailID == OrderDetailID &&
inv.DeliveryDate != null && inv.IsQuarantine == true
&& inv.IsMainInventory == true
orderby inv.InventoryID
select new
{
OrderAmountDetailID = ad.OrderAmountDetailID,
OrderDetailID = od.OrderDetailID,
// OrderID = od.OrderID,
IngName = i.IngName,
RecieveAmount = inv.RecieveAmount,
// PredictedDeliveryDate = od.PredictedDeliveryDate,
CompanyName = c.CompanyName,

DeliveryDate = inv.DeliveryDate,
IsQualityControl = inv.IsQualityControl,
DateOfQualityControl = inv.DateOfQualityControl,
DateOfMainInventory = inv.DateOfMainInventory,

DateOfQCResult = inv.DateOfQCResult,
DateOfQuarantine = inv.DateOfQuarantine,
TotalIngName = (from ii in DataContext.Context.Ingredients
join odd in DataContext.Context.OrderDetails
on i.IngID equals od.IngID
select odd.Amount).Sum()

}).Distinct();