SELECT
	 P.PORT_CODE AS 港コード
	,P.PORT_NAME AS 港名
	,SUM(I_N.AMT) AS 入国者数
	,SUM(I_S.AMT) AS 出国者数
	,SUM(I_N.AMT) - SUM(I_S.AMT) AS 差分
FROM
	(
		SELECT
			*
		FROM
			IMMIGRATION
		WHERE
			KIND_CODE = '110'
			AND GROUP_CODE = '120'
	)AS I_N
INNER JOIN
	(
		SELECT
			*
		FROM
			IMMIGRATION
		WHERE
			KIND_CODE = '120'
			AND GROUP_CODE = '120'
	)AS I_S
ON I_N.PORT_CODE = I_S.PORT_CODE
AND I_N.GROUP_CODE = I_S.GROUP_CODE
INNER JOIN
	GRP AS G
ON G.GROUP_CODE = I_N.GROUP_CODE
INNER JOIN
	PORT AS P
ON P.PORT_CODE = I_N.PORT_CODE
GROUP BY
	 P.PORT_CODE
	,P.PORT_NAME
HAVING
	SUM(I_N.AMT) > SUM(I_S.AMT)
ORDER BY
	 差分 DESC
	,港コード DESC