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