SELECT 
p.PORT_CODE AS 港コード
, p.PORT_NAME AS 港名
, i1.AMT AS 入国者数
, i2.AMT AS 出国者数
, i1.AMT-i2.AMT AS 差分
FROM PORT p
INNER JOIN IMMIGRATION i1 on p.PORT_CODE = i1.PORT_CODE AND i1.KIND_CODE = '110'
INNER JOIN IMMIGRATION i2 on p.PORT_CODE = i2.PORT_CODE AND i2.KIND_CODE = '120'
WHERE i1.AMT-i2.AMT > 0
ORDER BY 差分 DESC, p.PORT_CODE DESC
;