recordSeq 为自增主键，missionID为可能重复键

DELETE
FROM
  t_cmp_record
WHERE
  recordSeq NOT IN (
    SELECT
      t_temp.minSeq
    FROM
      (
        SELECT
          MIN(recordSeq) AS minSeq
        FROM
          t_cmp_record
        GROUP BY
          missionID
      ) t_temp
  )