title: Operand data type varchar is invalid for sum operator
body: <p>I have this SQL view query.</p>
  
  <pre><code>SUM('ValueFC') AS VALUEFC_0 .....
  
  ........
   SUM(g.AMTCUR_0 * g.SNS_0 * - 1) AS 'ValueFC', 
  </code></pre>
  
  <p>Whenever I run it it says " Operand data type varchar is invalid for sum operator"</p>