select 
  P.PORT_CODE as "港コード",
  P.PORT_NAME as "港名",
  SUM(CASE WHEN I.KIND_CODE = "110" THEN AMT END) as "入国者数",
  SUM(CASE WHEN I.KIND_CODE = "120" THEN AMT END) as "出国者数",
  SUM(CASE WHEN I.KIND_CODE = "110" THEN AMT END) - SUM(CASE WHEN I.KIND_CODE = "120" THEN AMT END) as "差分"
from
  PORT P
join
  IMMIGRATION I
join
  GRP G
on
  P.PORT_CODE = I.PORT_CODE
and
  I.GROUP_CODE = G.GROUP_CODE
where
  G.GROUP_CODE = "120"
group by
  P.PORT_CODE
having
  SUM(CASE WHEN I.KIND_CODE = "110" THEN AMT END) > SUM(CASE WHEN I.KIND_CODE = "120" THEN AMT END)
order by
  5 DESC, 1 DESC;