Question

I have this query

List<int> AuctionIds = 
   (from a in _auctionContext.Auctions
    where a.AuctionEventId == auction.AuctionEventId
    select new { a.Id }).ToList();

But I receive a compile error

Cannot implicitly convert type 'System.Collections.Generic.List<AnonymousType#1>' to 'System.Collections.Generic.List<int>'

What type should AuctionIds be?

EDIT

The AuctionIds field is in fact in another class (a model class) so I can’t just use var. I can’t believe Jon Skeet hasn’t answered this.

Answer 1

You are adding an anonymous object to a List<int>..
If you were to do it the way you had it.. I would use the var keyword..

var AuctionIds = 
       (from a in _auctionContext.Auctions
        where a.AuctionEventId == auction.AuctionEventId
        select new{Id = a.Id}).ToList();

Reason is I don’t know what type an anonymous object is.. but the compiler should be able to handle it.

EDIT:

Eh, about creating a AuctionIDModel class?

 public class AuctionIDModel
    {
       int Id{get;set;}
    }

    List<AuctionIDModel> AuctionIds = 
           (from a in _auctionContext.Auctions
            where a.AuctionEventId == auction.AuctionEventId
            select new AuctionIDModel{Id = a.Id}).ToList();