title: Most recent record within 3 months if one exists
body: <p>I am working with a report writer (DataInsights). In this particular report some clients have a "Special Rate" and some don't. For those that do, there is an expiration date. Currently, the report is yielding several lines per client that has a Special Rate because each spell of a special rate is generating it's own line. We would like a simple SQL statement that will maintain all the records that do not have  a "Special Rate" and only returns a line for the most  recent "Special Rate" "Expiration Date" if it falls within the last 3 months . (if there is no way to limit it to the last 3 months, then that's okay, we just need the most recent line)</p>
  
  <p>Example:</p>
  
  <p>(current) </p>
  
  <pre><code>Name        Client #        Rate        Exp. Date  
  John Doe        12345       Special     01/12/2014  
  John Doe        12345       Special     01/12/2015  
  John Doe        12345       Special     01/12/2016  
  Jane White      78965  
  Dixie Brown     45879       Exceptional 07/30/2011  
  Dixie Brown     45879       Exceptional 07/30/2012  
  Dixie Brown     45879       Exceptional 07/30/2013  
  </code></pre>
  
  <p>(should be)</p>
  
  <pre><code>John Doe        12345       Special     01/12/2016  
  Jane White      78965   
  Dixie Brown     45879
  </code></pre>