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