SELECT
    I.PORT_CODE AS 港コード
    , P.PORT_NAME AS 港名
    , SUM(
        CASE
            WHEN
                KIND_CODE = '110'
                THEN
                    I.AMT
                ELSE
                    0
        END
    ) AS 入国者数
    , SUM(
        CASE
            WHEN
                KIND_CODE = '120'
                THEN
                    I.AMT
                ELSE
                    0
        END
    ) AS 出国者数
    , SUM(
        CASE
            WHEN
                KIND_CODE = '110'
                THEN
                    I.AMT
                ELSE
                    0
        END
    ) - SUM(
        CASE
            WHEN
                KIND_CODE = '120'
                THEN
                    I.AMT
                ELSE
                    0
        END
    ) AS 差分
FROM
    IMMIGRATION AS I
INNER JOIN
    PORT AS P
    ON 1=1
    AND I.PORT_CODE = P.PORT_CODE
WHERE
    1=1
    AND I.GROUP_CODE = '120'
GROUP BY
    I.PORT_CODE
HAVING
    1=1
    AND (
        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
    , I.PORT_CODE DESC