INSERT INTO dev.contest_registration (contest_id, user_id) VALUES (#{contestId}, #{userId}) ON CONFLICT (contest_id, user_id) DO UPDATE SET delete_flag = 0 SELECT r.id, r.user_id AS userId, u.username, r.created_at AS createdAt FROM dev.contest_registration r JOIN dev.user u ON u.id = r.user_id AND u.delete_flag = 0 WHERE r.contest_id = #{contestId} AND r.delete_flag = 0 ORDER BY r.created_at