SELECT 
  p.product_id, 
  ifnull(
    count(dp.post_id), 
    0
  ) as discussion_amount_posts 
FROM 
  cscart_discussion 
  INNER JOIN cscart_products as p ON (
    cscart_discussion.object_id = p.product_id
  ) 
  INNER JOIN cscart_discussion_posts as dp ON (
    cscart_discussion.thread_id = dp.thread_id 
    AND cscart_discussion.object_type = 'P' 
    AND cscart_discussion.company_id = 1
  ) 
WHERE 
  dp.status = 'A' 
  and p.product_id in (
    51480, 51479, 132, 3, 2, 66, 133, 51471, 
    51472, 51470, 51529, 51459, 51457, 
    51460, 51501, 51464, 51478, 51469, 
    51486, 51467, 51461, 51475, 51477, 
    51473, 51458, 51463, 51516, 51532, 
    51492, 51514, 51468, 51476, 51491, 
    51513, 51474, 51462, 51502, 51465, 
    51515, 51466, 51485, 51518, 51528, 
    51527, 51482, 51512, 51493, 51511, 
    51505, 51535
  ) 
GROUP BY 
  p.product_id