title: How to sum two columns which already created using sum in Redshift
body: <p>I tried adding two numbers that are present in two different columns but it's not adding up when there are no numbers present in the second column(B). Please find the screenshot of the table and the query I was using to achieve this.</p>
  <p><a href="https://i.stack.imgur.com/EuSkh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EuSkh.png" alt="enter image description here" /></a></p>
  <p>Not getting the value present in COLUMN A in total sales.</p>
  <p><a href="https://i.stack.imgur.com/HHPEO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HHPEO.png" alt="enter image description here" /></a></p>
  <p>The query which I ran but wasn't successful.</p>
  <pre><code>SELECT Date,
         SUM(sales a) as &quot;total_a&quot;,
         SUM(sales b) as &quot;total_b&quot;,
         (&quot;total_a&quot;+&quot;total_b&quot;) as &quot;total_sales&quot;
  FROM data_table
  GROUP BY Date;
  </code></pre>