Joining By Anonymous Types

Just found this out yesterday so I thought I would post and pass on to all two of you reading this. Suppose you have a User table and a Contacts table and you wanted to find all the users that match up with the contacts table. Now suppose there is no direct correlation. What to do? You could do something really brilliant by joining the tables together on FirstName and LastName, because we all know that there will always only be one John Smith in either table. Screw you, I couldn't think of a better example at the time.

public static List<User> GetAllUsersWithMatchingContactInformationUsingJoin()
{
  List<User> foundUsers;
          
  var query = from user in dataContext.Users
              join contact in dataContext.Contacts on new {user.FirstName, user.LastName } equals new { contact.FirstName, contact.LastName }
              select user;
          
              foundUsers = query.ToList();
          
  return foundUsers;
}

As you can see here:

join contact in dataContext.Contacts on new {user.FirstName, user.LastName } equals new { contact.FirstName, contact.LastName }

You can create a type on the fly and then compare it to another. I thought that was interesting.