특정 주제를 '해결됨'으로 표시한 사람은 누구인가요?

[JammyDodger]

To look up who has marked a particular topic as Solved:

-- [params]
-- topic_id :topic_id 

SELECT 
   target_topic_id, 
   acting_user_id, 
   created_at::date
FROM user_actions
WHERE target_topic_id = :topic_id
AND action_type = 15
ORDER BY created_at DESC