title: Get Unique rows based on values and sort by Time
body: <p>I have the following table. I want to get 1 of each source order by Time (asc). Source is not fixed - it could be anything </p>
  
  <pre><code>Time                    |Source
  ------------------------------------
  2012-08-18 05:00:03.000 | A
  2012-08-19 06:00:03.000 | B
  2012-08-18 06:00:03.000 | B
  2012-08-20 06:00:03.000 | C
  2012-08-21 06:00:03.000 | A
  </code></pre>
  
  <p>So based on the above table ill get the below result  </p>
  
  <pre><code>Time                    |Source
  ------------------------------------
  2012-08-18 05:00:03.000 | A
  2012-08-18 06:00:03.000 | B
  2012-08-20 06:00:03.000 | C
  </code></pre>