WITH BEF_WEIGHT AS (
SELECT MIN(HC.CHECKUP_DATE), HC.MEMBER_CODE AS BEF_CODE, HC.WEIGHT AS BEF_WT, MM.LAST_NAME || MM.FIRST_NAME AS FULLNAME
FROM HEALTH_CHECKUP HC
INNER JOIN MEMBER_MST MM
ON HC.MEMBER_CODE = MM.MEMBER_CODE
GROUP BY HC.MEMBER_CODE)

SELECT MAX(HC.CHECKUP_DATE) AS CK_DATE, HC.MEMBER_CODE AS CODE, MM.LAST_NAME || MM.FIRST_NAME AS NAME, ROUND((HC.WEIGHT - (SELECT BEF_WT FROM BEF_WEIGHT WHERE HC.MEMBER_CODE = BEF_CODE )), 2) AS CHG_WT
FROM HEALTH_CHECKUP HC
INNER JOIN MEMBER_MST MM
ON HC.MEMBER_CODE = MM.MEMBER_CODE
GROUP BY HC.MEMBER_CODE

HAVING CHG_WT < -5 OR CHG_WT > 5