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 (
    51514, 51520, 51538, 51468, 51476, 51503, 
    51539, 51541, 51491, 51492, 51513, 
    51474, 51522, 51499, 51515, 51502, 
    51509, 51519, 51466, 51465, 51508, 
    51485, 51518, 51543, 51550, 51524, 
    51528, 51504, 51512, 51527, 51482, 
    51542
  ) 
GROUP BY 
  p.product_id