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
            ELSE 0
        END
    ) AS '入国者数',
    SUM(CASE I.KIND_CODE
            WHEN 120 THEN I.AMT
            ELSE 0
        END
    ) AS '出国者数',
    SUM(CASE I.KIND_CODE
            WHEN 110 THEN I.AMT
            ELSE 0
        END
    ) -
    SUM(CASE I.KIND_CODE
            WHEN 120 THEN I.AMT
            ELSE 0
        END
    ) AS '差分'
FROM
    IMMIGRATION I
INNER JOIN
    PORT P
ON
    I.PORT_CODE = P.PORT_CODE
GROUP BY
    P.PORT_CODE, P.PORT_NAME
HAVING SUM(CASE I.KIND_CODE
            WHEN 110 THEN I.AMT
            ELSE 0
        END
    ) > 
    SUM(CASE I.KIND_CODE
            WHEN 120 THEN I.AMT
            ELSE 0
        END
    )
ORDER BY SUM(CASE I.KIND_CODE
            WHEN 110 THEN I.AMT
            ELSE 0
        END
    ) -
    SUM(CASE I.KIND_CODE
            WHEN 120 THEN I.AMT
            ELSE 0
        END
    ) DESC,
    '港コード' DESC
;