题解 | 应该是对的吧
筛选限定昵称成就值活跃日期的用户
http://www.nowcoder.com/practice/2ed07ff8f67a474d90523b88402e401b
SELECT
uid,
nick_name,
achievement
FROM user_info
WHERE nick_name LIKE '牛客%号'
AND achievement BETWEEN 1200 AND 2500
AND uid IN (
SELECT uid
FROM (
SELECT uid, start_time AS act_time
FROM exam_record
UNION ALL
SELECT uid, submit_time AS act_time
FROM practice_record
) temp
GROUP BY uid
HAVING DATE_FORMAT(MAX(act_time), '%Y%m') = 202109
)