with foreign_in as (

    select
        i.PORT_CODE, 
        p.PORT_NAME, 
        i.AMT
    from 
        IMMIGRATION i
        inner join PORT p
        on i.PORT_CODE = p.PORT_CODE
    where
        GROUP_CODE = '120' and KIND_CODE = '110'
    
),
foreign_out as (
    
    select
        i.PORT_CODE, 
        p.PORT_NAME, 
        i.AMT
    from 
        IMMIGRATION i
        inner join PORT p
        on i.PORT_CODE = p.PORT_CODE
    where
        GROUP_CODE = '120' and KIND_CODE = '120'
)

select
    n.PORT_CODE as '港コード',
    n.PORT_NAME as '港名',
    n.AMT as '入国者数',
    out.AMT as '出国者数',
    (n.AMT - out.AMT) as '差分'
from 
    foreign_in n
    inner join foreign_out out
    on n.PORT_CODE = out.PORT_CODE
where
    (n.AMT - out.AMT) > 0
order by 
    差分 desc,
    港コード desc