title: LINQ on datatable, group, sum and get comma delimited string C#
body: <p>I have a datatable that is currently of the structure</p>
  
  <pre><code>Index | Player | Score
  a     |  abby  |   1
  z     |  bob   |   5
  f     |  abby  |   4
  p     |  bob   |   3
  </code></pre>
  
  <p>I want to group the datatable by player in Linq such that it will provide the index column as a comma-separated string, and sum the score column for that player returning the result as a datatable.</p>
  
  <p>For example the above should end up like.</p>
  
  <pre><code>Index | Player | Score
  a,f   |  abby  |   5   
  z,p   |  bob   |   8
  </code></pre>
  
  <p>I have unfortunately no clue how to do this, I can only find examples on how to do the sum component, but some of these only seem to work on a <code>datatable</code> with two columns and not three.</p>
  
  <p>Thanks in advance</p>