WITH additem as(
select i.item_code as CODE,
i.item_name as NAME,
case
when h.USER_UPDATE_DATETIME is null then "ADDED"
when h.USER_UPDATE_DATETIME = i.USER_UPDATE_DATETIME then "hoge"
when h.USER_UPDATE_DATETIME < i.USER_UPDATE_DATETIME then "UPDATED"
end as COMP_RSLT
from ITEM i left outer join ITEM_HISTORY h on i.item_name = h.item_name
),
delitem as(
select h.item_code as CODE,
h.item_name as NAME,
case
when i.USER_UPDATE_DATETIME is null then "DELETED"
else "hoge"
end as COMP_RSLT
from ITEM i right outer join ITEM_HISTORY h on i.item_name = h.item_name
)
select * from additem where COMP_RSLT != "hoge"
union select * from delitem where COMP_RSLT != "hoge"
order by CODE