SELECT
    SUBSTRING(LOGIN_DATETIME, 1, INSTR(LOGIN_DATETIME, " ")-1) AS FIRST_LOGIN,
    COUNT(DISTINCT MEMBER_CODE) AS MEMBER_CNT
FROM
    ACCESS_LOG
WHERE
    FIRST_LOGIN BETWEEN '2023-08-01' AND '2023-08-31'
GROUP BY
    FIRST_LOGIN
HAVING
    MEMBER_CODE NOT IN(
        SELECT 
            MEMBER_CODE
        FROM
            ACCESS_LOG
        WHERE
            LOGIN_DATETIME < FIRST_LOGIN
        )
ORDER BY
    FIRST_LOGIN DESC;