title: MySQL get last date records from multiple
body: <p>I have the following in my db:</p>
  
  <pre><code>ID      datetime             type   value
  1094    2013-09-25 09:11:18  HDD      89%
  1094    2013-09-25 09:11:18  CPU      55%
  1093    2013-09-25 09:11:18  HDD      77%
  1093    2013-09-25 09:11:18  CPU      55%
  1094    2013-09-25 08:21:28  HDD      85%
  1094    2013-09-25 08:21:28  CPU      11%
  1093    2013-09-25 07:04:00  HDD      76%
  </code></pre>
  
  <p>I want to get the last date for every ID and type record:</p>
  
  <pre><code>1094    2013-09-25 09:11:18  HDD      89%
  1094    2013-09-25 09:11:18  CPU      55%
  1093    2013-09-25 09:11:18  HDD      77%
  1093    2013-09-25 09:11:18  CPU      55%
  </code></pre>