SELECT
	 I.PORT_CODE AS 港コード
	,P.PORT_NAME AS 港名
	,SUM(CASE WHEN I.KIND_CODE = '110' THEN I.AMT ELSE 0 END) AS 入国者数
	,SUM(CASE WHEN I.KIND_CODE = '120' THEN I.AMT ELSE 0 END) AS 出国者数
	,SUM(CASE WHEN I.KIND_CODE = '110' THEN I.AMT ELSE 0 END) - SUM(CASE WHEN I.KIND_CODE = '120' THEN I.AMT ELSE 0 END) AS 差分
FROM IMMIGRATION AS I
INNER JOIN [PORT] AS P
ON  I.PORT_CODE  = P.PORT_CODE 
INNER JOIN GRP AS G
ON  I.GROUP_CODE = G.GROUP_CODE
WHERE G.GROUP_NAME = '外国人'
GROUP BY I.PORT_CODE, P.PORT_NAME
HAVING (SUM(CASE WHEN I.KIND_CODE = '110' THEN I.AMT ELSE 0 END) - SUM(CASE WHEN I.KIND_CODE = '120' THEN I.AMT ELSE 0 END)) > 0
ORDER BY 差分 DESC, 港コード DESC