WITH FIRST_LOGIN_TBL AS ( 
   SELECT
        DATE (LOGIN_DATETIME) AS FIRST_LOGIN
      , MEMBER_CODE
      , ROW_NUMBER() OVER (PARTITION BY MEMBER_CODE ORDER BY DATE (LOGIN_DATETIME) ASC)
                              AS NUM 
   FROM
      ACCESS_LOG 
   WHERE
      FIRST_LOGIN BETWEEN '2023-07-31 23:59:59' AND '2023-08-31 23:59:59' 
   ORDER BY
      FIRST_LOGIN
) 
SELECT
     FIRST_LOGIN
   , COUNT(DISTINCT MEMBER_CODE) AS MEMBER_CNT 
FROM
   FIRST_LOGIN_TBL 
WHERE
   NUM = 1 
GROUP BY
   FIRST_LOGIN 
ORDER BY
   FIRST_LOGIN DESC