title: Aggregation replacement
body: <p>I have to aggregate (sum) a metric and round the result to 2 decimals. If the result of rounding is 0 the expectation is not to show anything, I mean result should be null.</p>
  
  <p>eg:</p>
  
  <pre><code>round(sum(report.QTY),2)
  </code></pre>
  
  <p>some rows of report.QTY are very low values such as 0.0005 etc, and the rounding results to 0.
  How will I show the result as null.</p>
  
  <p>I can think of the following, </p>
  
  <pre><code>case when round(sum(dl.QTY),2)=0 then null else round(sum(dl.QTY),2) end
  </code></pre>
  
  <p>which I think may not be the best way or the only way. Appreciate any help.</p>