SELECT 
T1.CHECKUP_DATE AS CK_DATE,
T1.MEMBER_CODE AS CODE,
T3.LAST_NAME || T3.FIRST_NAME AS NAME,
ROUND(T1.WEIGHT -T2.WEIGHT,1) AS CHG_WT
FROM 
    HEALTH_CHECKUP T1
INNER JOIN
    HEALTH_CHECKUP T2
ON
    T2.MEMBER_CODE  = T1.MEMBER_CODE
AND T2.CHECKUP_DATE < T1.CHECKUP_DATE
LEFT OUTER JOIN
MEMBER_MST T3
ON
T3.MEMBER_CODE = T1.MEMBER_CODE
WHERE
ABS( ROUND(T1.WEIGHT*10,0) -ROUND(T2.WEIGHT*10,0) ) >= 50 
ORDER BY
CHG_WT DESC,
T1.MEMBER_CODE DESC