SELECT 
    IFNULL([I].[ITEM_CODE],[IH].[ITEM_CODE]) AS [CODE]
    ,IFNULL([I].[ITEM_NAME],[IH].[ITEM_NAME]) AS [NAME]
    ,CASE 
        WHEN [IH].[USER_UPDATE_DATETIME] IS NULL
            THEN 'ADDED'
        WHEN [I].[USER_UPDATE_DATETIME] > [IH].[USER_UPDATE_DATETIME]
            THEN 'UPDATED'
        ELSE 'DELETED'
    END AS [COMP_RSLT]
FROM [ITEM] AS [I]
LEFT OUTER JOIN [ITEM_HISTORY] AS [IH]
ON [I].[ITEM_CODE] = [IH].[ITEM_CODE]
ORDER BY [CODE]