title: DataTable linq query to group by a column
body: <p>I have developed a Windows application using C#. Used a DataTable to list all information. That Data-Table has duplicate values.</p>
  
  <p>My result: </p>
  
  <pre><code>Lead Owners             &lt;2Days  &lt;5Days  &lt;10Days &lt;20Days &gt;20Days Grand-Total
  Dan Mahoney                                1                
  Richard James Whitaker            1             
  Richard James Whitaker            1             
  Richard James Whitaker            1             
  Richard James Whitaker            1             
  Wayne Dunne              1              
  Wayne Dunne              1              
  Richard James Whitaker            1             
  Wayne Dunne              1              
  Richard James Whitaker            1             
  Richard James Whitaker            1             
  </code></pre>
  
  <p>Expected Result:</p>
  
  <pre><code>Lead Owners             &lt;2Days  &lt;5Days  &lt;10Days &lt;20Days &gt;20Days Grand-Total
  Dan Mahoney                                1                
  Richard James Whitaker            7             
  Wayne Dunne              3              
  </code></pre>
  
  <p>I need a linq query to achieve the expected result.</p>
  
  <p>Kindly help me to get this.
  Thanks in advance.</p>