title: Query for total should keep on adding with each row of cost Column
body: <p>I have table with columns as</p>
  
  <pre><code>      Operation             Cost
  
       Material Issue         10 
       Material Return        20
       X                      30
       Y                      40
       Z                      50
  </code></pre>
  
  <p>I want want a query where columns are</p>
  
  <pre><code>     Operation             Cost    Total
  
       Material Issue         10      10
       Material Return        20      30
       X                      30      60
       Y                      40      100
       Z                      50      150
  </code></pre>
  
  <p>ie.., the the total should keep on adding with each row of cost Column</p>