SELECT
AVG (dr.rating_value)
FROM
cscart_discussion_rating AS dr
LEFT JOIN cscart_discussion_posts AS dp ON dp.post_id = dr.post_id
LEFT JOIN cscart_discussion AS d ON d.thread_id = dp.thread_id
WHERE
d.object_id = 682
AND d.object_type = 'P'
AND type IN ('B', 'R')
AND dp.status = 'A'
AND dr.rating_value > 0