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