SELECT 
    CASE 
        WHEN I.ITEM_CODE IS NULL THEN H.ITEM_CODE 
        ELSE I.ITEM_CODE 
    END AS CODE,
    CASE 
        WHEN I.ITEM_CODE IS NULL THEN H.ITEM_NAME 
        ELSE I.ITEM_NAME 
    END AS NAME,
    CASE 
        WHEN I.ITEM_CODE IS NULL AND H.ITEM_CODE IS NOT NULL THEN 'DELETED'
        WHEN I.ITEM_CODE IS NOT NULL AND H.ITEM_CODE IS NULL THEN 'ADDED'
        WHEN I.USER_UPDATE_DATETIME != H.USER_UPDATE_DATETIME THEN 'UPDATED'
    END AS COMP_RSLT
FROM 
    ITEM I
FULL OUTER JOIN 
    ITEM_HISTORY H 
ON 
    I.ITEM_CODE = H.ITEM_CODE
WHERE 
    (I.ITEM_CODE IS NULL AND H.ITEM_CODE IS NOT NULL) 
    OR (I.ITEM_CODE IS NOT NULL AND H.ITEM_CODE IS NULL) 
    OR (I.USER_UPDATE_DATETIME != H.USER_UPDATE_DATETIME)
ORDER BY 
    CODE DESC;