SELECT 
	 IM.PORT_CODE		AS 港コード
	,MAX(PORT_NAME)		AS 港名
	,SUM(CASE WHEN KIND_CODE = '110' THEN AMT ELSE 0 END) AS 入国者数
	,SUM(CASE WHEN KIND_CODE = '120' THEN AMT ELSE 0 END) AS 出国者数
	,SUM(CASE WHEN KIND_CODE = '110' THEN AMT ELSE 0 END) - SUM(CASE WHEN KIND_CODE = '120' THEN AMT ELSE 0 END) AS 差分
FROM IMMIGRATION AS IM
LEFT JOIN PORT AS PR
ON IM.PORT_CODE = PR.PORT_CODE
WHERE GROUP_CODE = '120'
GROUP BY IM.PORT_CODE
HAVING SUM(CASE WHEN KIND_CODE = '110' THEN AMT ELSE 0 END) - SUM(CASE WHEN KIND_CODE = '120' THEN AMT ELSE 0 END) > 0
ORDER BY
	 SUM(CASE WHEN KIND_CODE = '110' THEN AMT ELSE 0 END) - SUM(CASE WHEN KIND_CODE = '120' THEN AMT ELSE 0 END) DESC
	,IM.PORT_CODE DESC