SELECT 
A.max_date as CK_DATE,
A.m_code as CODE,
MEM.LAST_NAME || MEM.FIRST_NAME as NAME,
(A.weight * 10 - B.weight * 10) / 10 as CHG_WT
FROM 
(SELECT MEMBER_CODE as m_code,
        MAX(CHECKUP_DATE) as max_date,
        WEIGHT as weight
    FROM HEALTH_CHECKUP 
    GROUP BY MEMBER_CODE)
A INNER JOIN
(SELECT MEMBER_CODE as m_code,
        MIN(CHECKUP_DATE) as min_date,
        WEIGHT as weight
    FROM HEALTH_CHECKUP
    GROUP BY MEMBER_CODE)
B ON A.m_code = B.m_code
INNER JOIN MEMBER_MST MEM
ON A.m_code = MEM.MEMBER_CODE
WHERE ABS((A.weight * 10 - B.weight * 10) / 10) >= 5
ORDER BY CHG_WT DESC,CODE DESC