SELECT 
            	 P.port_code AS 港コード
            	,P.port_name AS 港名
            	,SUM(
            		CASE I.kind_code
            			WHEN '110' THEN I.AMT
            		END
            	) AS 入国者数
            	,SUM(
            		CASE I.kind_code
            			WHEN '120' THEN I.AMT
            		END
            	) AS 出国者数
            	,SUM(   CASE I.kind_code WHEN '110' THEN I.AMT END) 
            	-
            	 SUM( CASE I.kind_code WHEN '120' THEN I.AMT END) 差分
            FROM
            	Port P
            INNER JOIN
            	IMMIGRATION I	
            ON
            	P.port_code = I.port_code
            GROUP BY
            	 P.port_code	
            	,P.port_name
            HAVING
                差分 > 0
            ORDER BY
                差分 DESC 
               ,港コード DESC