SELECT
ifnull(i.ITEM_CODE, h.ITEM_CODE) AS CODE,
ifnull(i.ITEM_NAME, h.ITEM_NAME) AS NAME,
CASE 
    WHEN i.ITEM_CODE is null THEN 'DELETED'
    WHEN h.ITEM_CODE is null THEN 'ADDED'
    WHEN i.USER_UPDATE_DATETIME <> h.USER_UPDATE_DATETIME THEN 'UPDATED'
    ELSE null
END
AS COMP_RSLT
FROM 
 ITEM AS i
 FULL OUTER JOIN ITEM_HISTORY AS h
 ON i.ITEM_CODE = h.ITEM_CODE
WHERE COMP_RSLT is not null
ORDER BY CODE DESC;