Question

I have two classes, basically one holds Members and the other Sessions.

They are joined together with a common field called "name". There is one member but can be many Sessions.

So if I do a standard join I get back 1 member and many sessions. I just want to get back the first row of sessions.

The session has field called SessioEndTime. So I need to order by DESC on this to pick out the first record.

This is my linq; I have returns too many. I think I need a subquery but I am a little confused.

  var sessions = from m in this.members 
                   join s in this.sessions
                   on m.Name equals s.Name
                   select new { MemberName = m.Name, SessionTime = s.SessioEndTime};

Edit

To make it clear, imagine I have five members, each member has NUMEROUS sessions. I just wish to receive my five members but with only one session each, that session is the LATEST session which can be got from the SessioEndTime.

Answer 1

Try this:

var sessions =  
    from m in this.members                     
    join s in 
    (
        from se in this.sessions
        group se by se.Name into g
        select new {Name = g.Key, SessioEndTime = g.Max(a=>a.SessioEndTime)}
    )   
    on m.Name equals s.Name                    
    select new { MemberName = m.Name, SessionTime = s.SessioEndTime}