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