SELECT
COALESCE(ITEM.ITEM_CODE,IH.ITEM_CODE) "CODE",
COALESCE(ITEM.ITEM_NAME,IH.ITEM_NAME) 'NAME',
CASE WHEN ITEM.USER_UPDATE_DATETIME IS NULL THEN 'DELETED'
WHEN IH.USER_UPDATE_DATETIME IS NULL THEN 'ADDED'
ELSE 'UPDATED' END
AS COMP_RSLT

FROM ITEM_HISTORY IH FULL OUTER JOIN ITEM
ON ITEM.ITEM_CODE = IH.ITEM_CODE
WHERE IH.USER_UPDATE_DATETIME != ITEM.USER_UPDATE_DATETIME
OR  IH.USER_UPDATE_DATETIME IS NULL
OR  ITEM.USER_UPDATE_DATETIME IS NULL
ORDER BY CODE DESC;