select
IM110.PORT_CODE AS 港コード,
PORT.PORT_NAME AS 港名,
IM110.AMT AS 入国者数,
IM120.AMT AS 出国者数,
IM110.AMT - IM120.AMT AS 差分
From
PORT
INNER JOIN IMMIGRATION AS IM110
ON IM110.PORT_CODE = PORT.PORT_CODE
AND IM110.KIND_CODE = 110
INNER JOIN IMMIGRATION AS IM120
ON IM120.PORT_CODE = PORT.PORT_CODE
AND IM120.KIND_CODE = 120
WHERE 入国者数 >出国者数
--GROUP BY IM110.PORT_CODE
ORDER BY 差分 DESC ,港コード DESC