题解 | 筛选限定昵称成就值活跃日期的用户

SELECT
  ui.uid,
  nick_name,
  achievement 
FROM
  (
  SELECT
    uid,
    DATE_FORMAT( start_time, '%Y%m' ) AS active_m 
  FROM
    exam_record 
  WHERE
    submit_time IS NOT NULL UNION ALL
  SELECT
    uid,
    DATE_FORMAT( submit_time, '%Y%m' ) AS active_m 
  FROM
    practice_record 
  ) data_
  JOIN user_info ui ON ui.uid = data_.uid 
  AND ui.nick_name LIKE '牛客%号' 
  AND ( ui.achievement BETWEEN 1200 AND 2500 ) 
GROUP BY
  uid 
HAVING
  MAX( active_m ) = '202109'