Question

I have two tables that I have joined in a query like this

IQueryable<Auction> closed =
                (from a in CurrentDataSource.Auctions
                 join p in CurrentDataSource.Payments
                     on a.Id equals p.AuctionId
                 where <some condition>
                 select a);

What I want really is to say give me all auctions where there IS NO join with the Payments table or some condition is true. I can do this with T-SQL but not sure how to do it with Linq. Can you help?

Answer 1

You can use a left outer join and check for payments being null, just like you can in T-SQL.

IQueryable<Auction> closed =
                (from a in CurrentDataSource.Auctions
                 join p in CurrentDataSource.Payments
                     on a.Id equals p.AuctionId into temp
                 from t in temp.DefaultIfEmpty()
                 where t == null && <some condition>
                 select a);