title: Finding max in mysql when column is varchar
body: <p>I have a varchar field that is code of letters and is auto incremented (manualy), so after A is B until after Z becomes AA and so on.</p>
  
  <p>My issue is when I hit AA and I try to select MAX of this field:</p>
  
  <pre><code>SELECT MAX(letter) from jobs
  </code></pre>
  
  <p>Returns Z instead of AA. This is correct if you are ordering names, but I have a code. There's a way to get this right?</p>