with tmp as(
select 
PORT_CODE,
sum(
case when KIND_CODE = 110 then AMT
else 0 end
) as pin,
sum(
case when KIND_CODE = 120 then AMT
else 0 end
) as pout
from IMMIGRATION
where GROUP_CODE = 120
group by 1
)
select 
t.PORT_CODE as "港コード",
p.PORT_NAME as "港名",
t.pin as "入国者数",
t.pout as "出国者数",
t.pin-t.pout "差分"
from tmp t left join PORT p on t.PORT_CODE = p.PORT_CODE
where t.pin-t.pout > 0
order by 5 desc, 1 desc