title: How to find difference between two columns data?
body: <p>I have a temp table with two columns of integer data i want to find the difference between two columns in 3rd column.</p>
  
  <pre><code>#TEMP1
  
  Present   previous
  59           88
  75           75
  45           45
  77           88
  09           08
  
  #temp2
  
  Difference
   29
   0
   0
   11 
   -1
  </code></pre>
  
  <p>Is this possible ??</p>