SELECT
    a AS FIRST_LOGIN
    ,COUNT(MEMBER_CODE) AS MEMBER_CNT
FROM
    --メンバーコード毎に最小のログイン時間を抽出してテーブル化
    ( 
        SELECT
            MEMBER_CODE
            ,MIN(DATE(LOGIN_DATETIME)) AS a
        FROM
            ACCESS_LOG
        GROUP BY
            MEMBER_CODE
            )
WHERE
    a BETWEEN '2023-08-01' AND '2023-08-31'
GROUP BY
    a
ORDER BY
    FIRST_LOGIN DESC;