title: Join two tables and display records only if 2nd table does not have a matching date
body: <p>I have two tables that I'm trying to join. I want to be able to join on ClientID, and only display those records where DateA does not match DateB. This is the structure of my tables</p>
  
  <pre><code>tbl1
  CLientID             DateA
  17                   08/01/2016
  19                   06/27/2016
  21                   12/1/2015
  
  
  tbl2
  RcrNo            ClientID           DateB
  1                17                 08/01/2016
  2                19                 06/27/2016
  3                21                 12/22/2015
  </code></pre>
  
  <p>Desired Result:</p>
  
  <pre><code>ClientID             Date
  21                   12/22/2015
  </code></pre>
  
  <p>SO as can be seen ClientID 21 is the only client out of the 3 whose DateA does not match DateB. How would I be able to join them like this?</p>