title: Linq-to-SQL select many columns
body: <p>I'm using Linq-to-SQL and I just started to learn some of the basics. I have problem with select command many columns in many tables. I give songs which selected into session (contain songid) and display songname, artistname, genrename in datagrid. </p>
  
  <p>But it's not working.</p>
  
  <pre><code>ArrayList SelectedSongs = (ArrayList)Session["SelectedSongs"];
  
  string songIds = "";
  
  foreach (int id in SelectedSongs)
              songIds += id + ", ";
  
  var query = from s in sa.Songs
              from ar in sa.Artists
              from g in sa.Genres
              where s.SongID in (songIds)
              select new { s.SongID, s.SongName, ar.ArtistName, g.GenreName };
  
  dgSongs.DataSource = query;
  </code></pre>
  
  <p>Can anyone help me solve this problem.
  Thanks.</p>