lambda expression in c#

how can this query turn in a lambda expression?

var query = from Lending in lend
            join book in Book on lend.BookId equals book.Id
            select new {lend.Id, book.Id};

var query = context.Lending.Join ();

 i don't know what to write in the parenthesis

Your post makes no sense. I'm just guessing but it looks like you're trying to use LINQ in some way.

http://msdn.microsoft.com/en-us/vcsharp/aa336746.aspx

You should use [code] these[/code] around your sample or no one will read it. Not that it matters, because your post has no discernible point or goal.