SELECT
    IFNULL(ITEM.ITEM_CODE, HIST.ITEM_CODE) AS CODE
,   IFNULL(ITEM.ITEM_NAME, HIST.ITEM_NAME) AS NAME
,   CASE
        WHEN ITEM.ITEM_CODE IS NULL
            THEN "ADDED"
        WHEN HIST.ITEM_CODE IS NULL
            THEN "DELETED"
        WHEN ITEM.USER_UPDATE_DATETIME IS NOT HIST.USER_UPDATE_DATETIME
            THEN "UPDATED"
        ELSE
            NULL
    END AS COMP_RSLT
FROM
    ITEM
FULL OUTER JOIN
    ITEM_HISTORY AS HIST
ON
    ITEM.ITEM_CODE = HIST.ITEM_CODE
GROUP BY
    ITEM.ITEM_CODE
    , HIST.ITEM_CODE
HAVING
    COMP_RSLT IS NOT NULL
ORDER BY
    CODE DESC;