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
        INNER JOIN
        	GRP G
        ON
        	G.group_code = I.group_code
        GROUP BY
        	 P.port_code	
        	,P.port_name
        HAVING
            差分 > 0
        ORDER BY
            差分 DESC 
           ,港コード DESC