select
po.PORT_CODE as "港コード",
po.PORT_NAME as "港名",
sum((select AMT
from IMMIGRATION
where KIND_CODE = 110 and GROUP_CODE = 120)) as "入国者数",
sum((select AMT
from IMMIGRATION
where KIND_CODE = 120 and GROUP_CODE = 120)) as "出国者数",
sum((select AMT
from IMMIGRATION
where KIND_CODE = 110 and GROUP_CODE = 120)) - 
sum((select AMT
from IMMIGRATION
where KIND_CODE = 120 and GROUP_CODE = 120)) as "差分"
from IMMIGRATION im join  PORT po
on im.PORT_CODE = po.PORT_CODE
group by po.port_code
order by "差分" desc ,po.port_code desc