SELECT
    SUB.CHECKUP_DATE AS CK_DATE,
    SUB.MEMBER_CODE AS CODE,
    SUB.LAST_NAME || SUB.FIRST_NAME AS NAME,
    ROUND(SUB.PRE - SUB.WEIGHT, 1) AS CHG_WT
FROM
    (
        SELECT
            *,
            MAX(WEIGHT) OVER(
                PARTITION BY H.MEMBER_CODE
                ORDER BY
                    CHECKUP_DATE DESC ROWS BETWEEN 1 FOLLOWING
                    AND 1 FOLLOWING
            ) AS PRE
        FROM
            HEALTH_CHECKUP AS H
            INNER JOIN MEMBER_MST AS M ON H.MEMBER_CODE = M.MEMBER_CODE
    ) AS SUB
WHERE
    CHG_WT IS NOT NULL
ORDER BY
    CHG_WT DESC,
    CODE DESC