title: how to write sql query for calculate time different
body: <pre><code>I have table structure like this
  
  EnrollNo,Date,Time
  
  1, 8-10-2011 12:00:32 , 13:12 
  1, 8-10-2011 12:00:32 , 23:14 
  2, 8-10-2011 12:00:32 , 11:12 
  2, 8-10-2011 12:00:32 , 20:14 
  3, 8-10-2011 12:00:32 , 12:12 
  3, 8-10-2011 12:00:32 , 23:14 
  4, 8-10-2011 12:00:32 , 17:12 
  4, 8-10-2011 12:00:32 , 23:14
  
  
  Data Type for EnrollNo is int, Date is Datetime, Time is text
  
  I want out put like below
  
  EnrollNo, Date, TimeDiff, Timein, Timeout
  
  1, 8-10-2011 12:00:32, 10:02 , 13:12, 23:14
  2, 8-10-2011 12:00:32, 09:02 , 11:12, 20:14 
  3, 8-10-2011 12:00:32, 11:02 , 12:12, 23:14 
  4, 8-10-2011 12:00:32, 06:02 , 17:12, 23:14
  </code></pre>