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 (
    18516, 51007, 51004, 51005, 51010, 51008, 
    51012, 51011, 51013, 51006, 51015, 
    51016, 51021, 51017, 51018, 51019, 
    51024, 51014, 51022, 51422, 51045, 
    51025, 51440, 51424, 51029, 51442, 
    51429, 51436, 51060, 51020, 51423, 
    51027, 51433, 51430, 51063, 51067, 
    51031, 51062, 51026, 51441, 51035, 
    51435, 51425, 51028, 51431, 51434, 
    51432, 51041, 51033, 51042, 51030, 
    51032, 51037, 51064, 51070, 51426, 
    51038, 51050, 51052, 51059, 51065, 
    51066, 51023, 51055, 51061, 51039, 
    51056, 51069, 51040, 51034, 51036, 
    51009, 51068, 51058, 51071
  ) 
GROUP BY 
  p.product_id