title: Updating a date format in MySQL
body: <p>I am working on a table that has two formats of dates stored in a field some are in <code>mm/dd/yy</code> and the newer entries are in <code>yyyy/mm/dd</code> like they should be.</p>
  <p>I want to run an query like this</p>
  <pre><code>UPDATE table
     SET date_field = DATE_FORMAT(date_field, '%Y/%m/%d') 
  WHERE date_field = DATE_FORMAT(date_field, '%m/%d/%y')
  </code></pre>
  <p>But it is just not working out. One result that I got was that it was just taking the <code>%m</code> data and turning it into the <code>%Y</code> and really messing up the data.</p>
  <p>Any thoughts?</p>