title: How to use GroupBy using Dynamic LINQ
body: <p>I am trying to do a GroupBy using Dynamic LINQ but have trouble getting it to work.</p>
  
  <p>This is some sample code illustrating the problem:</p>
  
  <pre><code>List&lt;dtoMyAlbum&gt; listAlbums = new List&lt;dtoMyAlbum&gt;();
  for (int i = 0; i &lt; 5000; i++)
  {
      dtoMyAlbum album = new dtoMyAlbum
      {
          Author = "My Author",
          BookID = i,
          CurrSymbol = "USD",
          Price = 23.23,
          Shop = i % 3 == 0 ? "TESCO" : "HMV"
      };
      listAlbums.Add(album);
  }
  
  IQueryable&lt;dtoMyAlbum&gt; mydata = listAlbums.AsQueryable();
  int count = mydata.Count();
  
  //var mydataGrouped = mydata.GroupBy(a =&gt; a.Shop);      // &lt;-- this works well (but is not dynamic....)
  var mydataGrouped = mydata.GroupBy("Shop");             // &lt;-- does not compile but is kind of what I want...
  
  foreach (var group in mydataGrouped)
  {
      //count = group.Count();
  }
  </code></pre>
  
  <p>I realise that I am missing the 'elementSelector' in the GroupBy overload but all I want to do is to end up with (in this case) two sets of dtoMyAlbum objects so I wish to select ALL elements for all sets...</p>
  
  <p>How would I go about this?</p>