SELECT
	port.port_code AS "港コード",
	port.port_name AS "港名",
	sum(
		CASE immigration.kind_code
		WHEN 110 THEN
			immigration.amt
		ELSE
			0
		END) AS "入国者数",
	sum(
		CASE immigration.kind_code
		WHEN 120 THEN
			immigration.amt
		ELSE
			0
		END) AS "出国者数",
	sum(
		CASE immigration.kind_code
		WHEN 110 THEN
			immigration.amt
		ELSE
			0
		END) - sum(
		CASE immigration.kind_code
		WHEN 120 THEN
			immigration.amt
		ELSE
			0
		END) AS "差分"
FROM
	immigration
	JOIN port ON immigration.port_code = port.port_code
	JOIN grp ON immigration.group_code = grp.group_code
WHERE
	grp.group_code = 120
GROUP BY
	port.port_code
HAVING
	"差分" > 0
ORDER BY
	"差分" DESC,
	"港コード" DESC