SELECT
ITEM.ITEM_CODE AS CODE,
ITEM.ITEM_NAME AS NAME,
CASE 
WHEN ITEM.ITEM_CODE = TEM_HISTORY.ITEM_CODE
AND ITEM.USER_UPDATE_DATETIME > TEM_HISTORY.USER_UPDATE_DATETIME 
then "UPDATED" 
ELSE NULL
end AS level
FROM ITEM LEFT JOIN ITEM_HISTORY ON ITEM.ITEM_CODE = ITEM_HISTORY.ITEM_CODE