title: MySQL: how to select the record with the most recent update date
body: <p>How do I select the records with the most recent update dates?  Sample data:</p>
  
  <pre><code>id, update_date, data_point
  1, 2013-03-01, AAA
  1, 2013-03-02, AAB
  1, 2013-03-03, AAC
  2, 2013-04-02, BAS
  2, 2013-04-05, SOR
  3, 2013-01-01, AAW
  3, 2013-02-02, AJS
  </code></pre>
  
  <p>What query can I write to select rows 3, 5, and 7- the latest record for each id?</p>