title: I need help writing a complex SQL statement
body: <pre><code>**PLEDGE TABLE**
  PledgeID  PledgeAmount  PledgeDate   DonorID   
  ---------|-------------|------------|---------
  1        | 100         | 04/03/2014 | 1
  2        | 200         | 04/03/2013 | 1
  3        | 100         | 04/03/2009 | 2
  4        | 2,000       | 01/01/2012 | 3
  5        | 1,000       | 01/01/2012 | 4
  6        | 500         | 01/01/2009 | 4
  
  **DONOR TABLE**
  DonorID   Name           SpouseID    
  ---------|-------------|-------------
  1        | John Smith  | 3
  2        | Jack Johnson| NULL
  3        | Jane Smith  | 1
  4        | John Adams  | NULL
  </code></pre>
  
  <p>I have 2 tables: a Donor table and a Pledge table. I want to run a query that returns only one record per couple (specifically the max or most recent pledge date) who have given in previous years but not this year. This is very important for our non-profit since the best people to solicit donations to are past donors. However, in our database sometimes the wife gives and the next year the husband gives so it is under both. Some are not married.</p>
  
  <p>So in the above table, only John Adam's pledge in 2012 and Jack Johnson's pledge in 2009 should be returned. Jane Smith should not be returned even though she has not given since 2012 because her husband gave this year. </p>