select
    PORT_CODE as "港コード"
    , PORT_NAME as "港名"
    , sum(case KIND_CODE when 110 then AMT else 0 end) as "入国者数"
    , sum(case KIND_CODE when 120 then AMT else 0 end) as "出国者数"
    , sum(case KIND_CODE when 110 then AMT else 0 end)-sum(case KIND_CODE when 120 then AMT else 0 end) as "差分"
from
    IMMIGRATION
        inner join PORT using (PORT_CODE)
where
    GROUP_CODE = 120
group by
    PORT_CODE
having
    "差分" >0

order by
    "差分" desc, PORT_CODE desc