select a.PORT_CODE as 港コード
      ,b.PORT_NAME as 港名
      ,a.amt_in as 入国者数
      ,a.amt_out as 出国者数
      ,a.amt_in - a.amt_out AS 差分
from (
select a.PORT_CODE
      ,sum(case when KIND_CODE = '110' THEN a.AMT ELSE 0 END) as amt_in
      ,sum(case when KIND_CODE = '120' THEN a.AMT ELSE 0 END) as amt_out
from IMMIGRATION a
group by a.PORT_CODE
)a
left join PORT b
on a.PORT_CODE = b.PORT_CODE
where a.amt_in > a.amt_out
order by a.amt_in - a.amt_out desc,a.PORT_CODE desc