WITH tmp_add AS (
SELECT
    ITEM.ITEM_CODE AS CODE
    ,ITEM.ITEM_NAME AS NAME
    ,'ADDED' AS COMP_RSLT
FROM
    ITEM
LEFT JOIN
    ITEM_HISTORY
ON
    ITEM.ITEM_CODE = ITEM_HISTORY.ITEM_CODE
WHERE
    ITEM_HISTORY.ITEM_CODE IS NULL
), tmp_del AS (
SELECT
    ITEM_HISTORY.ITEM_CODE AS CODE
    ,ITEM_HISTORY.ITEM_NAME AS NAME
    ,'DELETED' AS COMP_RSLT
FROM
    ITEM_HISTORY
LEFT JOIN
    ITEM
ON
    ITEM.ITEM_CODE = ITEM_HISTORY.ITEM_CODE
WHERE
    ITEM.ITEM_CODE IS NULL
), tmp_diff AS (
SELECT
    ITEM.ITEM_CODE AS CODE
    ,ITEM.ITEM_NAME AS NAME
    ,'UPDATED' AS COMP_RSLT
FROM
    ITEM
INNER JOIN
    ITEM_HISTORY
ON
    ITEM.ITEM_CODE = ITEM_HISTORY.ITEM_CODE
WHERE
    ITEM_HISTORY.USER_UPDATE_DATETIME <> ITEM.USER_UPDATE_DATETIME
)

SELECT * FROM tmp_add
UNION ALL
SELECT * FROM tmp_del
UNION ALL
SELECT * FROM tmp_diff
ORDER BY CODE DESC