title: how to subtract two datatables with linq
body: <p>Is there any way to subtract two datatables in order to have rows of the first datatable that are not in the second one?</p>
  
  <p>I have tried .Except() method like below but it does not work for me.</p>
  
  <pre><code>dt1.AsEnumerable().Except(dt2.AsEnumerable()).CopyToDataTable();
  </code></pre>
  
  <p>I think i have mistake in using this method but i could not find that?</p>