title: calculate/sum timestamp in sql
body: <p>I am stucking by calculating the timestamp,how can i calculate/sum on different timestamp, example as below</p>
  
  <pre><code>Time (Timestamp in one column)
  ***********************
  0:00:01
  0:00:08
  0:00:12
  0:00:38
  0:01:04
  2:04:49
  15:48:38
  23:30:59
  7:05:52
  8:17:29
  </code></pre>
  
  <p>I want to show the sum(timestamp) in <code>hh:mi</code>.Any help?</p>