title: Visual C#, Find records in DataTable A which is or not in DataTable B
body: <p>Let's say both DataTable A and B has a column <strong>ID</strong>.</p>
  
  <p>Is there any <strong>concise</strong> way using <strong>Linq</strong> (Not <strong>for loop</strong>) to find records in A which is (or not) in B base on ID!?</p>
  
  <p>For example:</p>
  
  <pre><code>A
  ---
  ID     Value
  2        7
  2        3
  3        5
  5        6
  7        2
  7        5
  7        4
  
  B
  ---
  ID     Value
  1        3
  1        9
  2        4
  4        6
  4        2
  7        4
  9        3
  
  Results from A which is ALSO in B base on ID
  ---
  ID     Value
  2        7
  2        3
  7        2
  7        5
  7        4
  
  Results from A which is NOT in B base on ID
  ---
  ID     Value
  3        5
  5        6
  </code></pre>