with en as(
    select 
        PORT_CODE,
        sum(AMT) as inamt
    from IMMIGRATION
    where
        KIND_CODE = '110'
    group by
        PORT_CODE
), de as(
    select 
        PORT_CODE,
        sum(AMT) as outamt
    from IMMIGRATION
    where
        KIND_CODE = '120'
    group by
        PORT_CODE
)
select 
    pt.PORT_CODE as 港コード,
    pt.PORT_NAME as 港名,
    inamt as 入国者数,
    outamt as 出国者数,
    inamt - outamt as 差分
from PORT as pt
inner join en on pt.PORT_CODE = en.PORT_CODE
inner join de on pt.PORT_CODE = de.PORT_CODE
where 
    inamt - outamt > 0
order by
    pt.PORT_CODE desc;