WITH PARTITION AS (
    SELECT
        CHECKUP_DATE
        , MEMBER_CODE
        , WEIGHT
        , ROW_NUMBER() OVER(
            PARTITION BY
                MEMBER_CODE
            ORDER BY
                MEMBER_CODE ASC
                , CHECKUP_DATE ASC
        ) AS ROW
    FROM
        HEALTH_CHECKUP
)
, TWO_WEIGHT AS (
    SELECT
        MAX(CHECKUP_DATE) AS CK_DATE
        , MEMBER_CODE AS CODE
        , MAX(CASE WHEN ROW = 1 THEN WEIGHT ELSE NULL END) AS FIRST
        , MAX(CASE WHEN ROW = 2 THEN WEIGHT ELSE NULL END) AS SECOND
    FROM
        PARTITION
    GROUP BY
        MEMBER_CODE
)
SELECT
    TWO_WEIGHT.CK_DATE AS CK_DATE
    , TWO_WEIGHT.CODE AS CODE
    , MEMBER_MST.LAST_NAME || FIRST_NAME AS NAME
    , ROUND(TWO_WEIGHT.SECOND - TWO_WEIGHT.FIRST, 1) AS CHG_WT
FROM
    TWO_WEIGHT
INNER JOIN
    MEMBER_MST ON TWO_WEIGHT.CODE = MEMBER_MST.MEMBER_CODE
WHERE
    ABS(ROUND(TWO_WEIGHT.SECOND - TWO_WEIGHT.FIRST, 1)) >= 5
ORDER BY
    CHG_WT DESC
    , CODE DESC
;