title: Group rows in a datatable
body: <p>I am interested in grouping some rows in a datatable after 2 columns and save the results in another datatable. I have the following code for grouping the rows:</p>
  
  <pre><code>var result = from t in newtable.AsEnumerable()
                 group t by new { Col1= t.Field&lt;String&gt;("ID1"), Col2=  t.Field&lt;String&gt;("ID2") } into grp
                   select new
                   {
                       Col1= grp.Key.ID1,
                       Col2= grp.Key.ID2
                   };
  </code></pre>
  
  <p>How can I easily convert <code>result</code> into a datatable?</p>