SELECT
	P.PORT_CODE AS 港コード,
	MAX(P.PORT_NAME) AS 港名,
	SUM(CASE WHEN I.KIND_CODE = 110 THEN AMT ELSE 0 END) AS 入国者数,
	SUM(CASE WHEN I.KIND_CODE = 120 THEN AMT ELSE 0 END) AS 出国者数,
	SUM(CASE WHEN I.KIND_CODE = 110 THEN AMT ELSE 0 END) - SUM(CASE WHEN I.KIND_CODE = 120 THEN AMT ELSE 0 END) AS 差分
FROM
	IMMIGRATION I
INNER JOIN
    PORT P
ON
    I.PORT_CODE = P.PORT_CODE
    AND I.GROUP_CODE = 120
GROUP BY
	P.PORT_CODE, P.PORT_NAME
HAVING
    差分 > 0
ORDER BY
    差分 desc,
    港コード desc