WITH WEIGHT_CHANGE AS (
  SELECT 
    HC1.MEMBER_CODE,
    HC1.CHECKUP_DATE AS CK_DATE,
    ROUND(HC1.WEIGHT - HC2.WEIGHT, 2) AS CHG_WT
  FROM 
    HEALTH_CHECKUP HC1
  JOIN 
    HEALTH_CHECKUP HC2
  ON 
    HC1.MEMBER_CODE = HC2.MEMBER_CODE
  WHERE 
    HC1.CHECKUP_DATE > HC2.CHECKUP_DATE
),
RANKED_WEIGHT_CHANGE AS (
  SELECT 
    WC.*,
    RANK() OVER (PARTITION BY MEMBER_CODE ORDER BY CK_DATE DESC) AS RNK
  FROM 
    WEIGHT_CHANGE WC
)
SELECT 
  RWC.CK_DATE,
  RWC.MEMBER_CODE AS CODE,
  MM.LAST_NAME || MM.FIRST_NAME AS NAME,
  CASE
    WHEN ROUND(RWC.CHG_WT, 1) = ROUND(RWC.CHG_WT) THEN CAST(ROUND(RWC.CHG_WT) AS INTEGER)
    ELSE ROUND(RWC.CHG_WT, 1)
  END AS CHG_WT
FROM 
  RANKED_WEIGHT_CHANGE RWC
JOIN 
  MEMBER_MST MM
ON 
  RWC.MEMBER_CODE = MM.MEMBER_CODE
WHERE 
  RWC.RNK <= 2 AND
  ABS(RWC.CHG_WT) >= 5
ORDER BY 
  CHG_WT DESC,
  CODE DESC;