Linq where in clause

Question

I have hierarchy wherein a Department contains Teams and Teams contain Delegates. What I'm trying to do is get a list of Delegates that exist under a given Department. I tried doing it this way:

var teams = from tms in db.Teams
            where tms.DepartmentID == DepartmentID
            select tms;

var TeamDelegates = from tds in db.J_TeamDelegates
                    where tds.TeamID in teams.TeamID //error here
                    select tds;

But the teams collection doesn't allow you to refer to a particular property as if it were a collection. What I'm trying to say is "Select all the Delegates with TeamIDs in the teams collection."

Answer 1

var TeamDelegates = from tds in db.J_TeamDelegates
                    where teams.Any(x => x.TeamID == tds.TeamID)
                    select tds;

Answer 2

I think you can use a join here.

var TeamDelegates = from tms in db.Teams
                    where tms.DepartmentID == DepartmentID
                    join tds in db.J_TeamDelegates on tms.TeamID equals tds.TeamID
                    select tds;