select
    i.PORT_CODE 港コード,
    PORT_NAME 港名,
    inband 入国者数,
    outband 出国者数,
    inband - outband 差分
from
    (
        (
            select
                PORT_CODE,
                GROUP_CODE,
                AMT inband
            from
                IMMIGRATION
            where
                KIND_CODE = 110
        ) i1
        left outer join (
            select
                PORT_CODE,
                GROUP_CODE,
                AMT outband
            from
                IMMIGRATION
            where
                KIND_CODE = 120
        ) i2 on i1.PORT_CODE = i2.PORT_CODE
        and i1.GROUP_CODE = i2.GROUP_CODE
    ) i
    left outer join PORT p on i.PORT_CODE = p.PORT_CODE
    left outer join GRP g on i.GROUP_CODE = g.GROUP_CODE
where
    inband > outband
order by
    差分 desc,
    港コード desc