SELECT
    FIRST_LOGIN_DATE AS FIRST_LOGIN
    , COUNT(MEMBER_CODE) AS MEMBER_CNT 
FROM
    ( 
        -- 会員毎に初めにログインした日を取得
        SELECT
            MEMBER_CODE
              -- DATE関数で日付のみに編集
            , MIN(DATE (LOGIN_DATETIME)) AS FIRST_LOGIN_DATE 
        FROM
            ACCESS_LOG 
        GROUP BY
            MEMBER_CODE
    ) AS SUB
WHERE
    FIRST_LOGIN_DATE BETWEEN '2023-08-01' AND '2023-08-31' 
GROUP BY
    FIRST_LOGIN_DATE 
ORDER BY
    FIRST_LOGIN_DATE DESC;