--追加リスト
WITH ADDED AS
(SELECT *,'ADDED' AS COMP_RSLT FROM
(SELECT ITEM_CODE FROM ITEM
EXCEPT
SELECT ITEM_CODE FROM ITEM_HISTORY)),

--更新リスト
UPDATED AS
(SELECT *,'UPDATED' AS COMP_RSLT FROM
(SELECT ITEM_CODE FROM
(SELECT * FROM ITEM
EXCEPT
SELECT * FROM ITEM_HISTORY)
EXCEPT
SELECT ITEM_CODE FROM ADDED)),

--削除リスト
DELETED AS 
(SELECT *,'DELETED' AS COMP_RSLT FROM
(SELECT ITEM_CODE FROM ITEM_HISTORY
EXCEPT
SELECT ITEM_CODE FROM ITEM))

--まとめ
SELECT * FROM ADDED
UNION
SELECT * FROM UPDATED
UNION
SELECT * FROM DELETED
ORDER BY ITEM_CODE DESC;