title: How to sum of two column into third column for all rows
body: <p>How to sum of two column into third column or in output  for all rows</p>
  
  <pre><code>order_id  english maths grand_total 
     1         10      10         20
     2         20      5          25
     3         10      10         20
  </code></pre>
  
  <p>I run this query     "select sum(english+maths)as grand_total from table"<br>
   and the result is   </p>
  
  <pre><code>grand_total
     20 
  </code></pre>
  
  <p>I get only first row not all rows how to get sum of all row in one column </p>