title: How to get the difference in years from two different dates?
body: <p>I want to get the difference in years from two different dates using MySQL database. </p>
  
  <p>for example:</p>
  
  <ul>
  <li>2011-07-20 - 2011-07-18 => 0 year</li>
  <li>2011-07-20 - 2010-07-20 => 1 year</li>
  <li>2011-06-15 - 2008-04-11 => <strike>2</strike> 3 years</li>
  <li>2011-06-11 - 2001-10-11 => 9 years</li>
  </ul>
  
  <p>How about the SQL syntax? Is there any built in function from MySQL to produce the result?</p>