title: get zero value in sql
body: <p>how to get zero value in group by ? I have a query like this</p>
  <pre><code>SELECT cb.pk_id
         , cb.name
         , date_format(sa.reg_date,'%M %Y') as bulan
         , COUNT(sa.qty) AS count 
  FROM tbl_pic cb 
           LEFT JOIN tbl_asset sa ON cb.pk_id = sa.pic 
  GROUP BY cb.pk_id
           , cb.name
           , cb.identity
           , year(reg_date)
           , month(reg_date)
  </code></pre>
  <p>with result like this</p>
  <p><a href="https://i.stack.imgur.com/YtkA8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YtkA8.png" alt="Image of actual result" /></a></p>
  <p>i want to get zero value on non-existent month result like this</p>
  <p><a href="https://i.stack.imgur.com/kN3rC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kN3rC.png" alt="Image of Expected Result" /></a></p>
  <p>is it possible ? Thank you</p>