SELECT
IM1.PORT_CODE AS 港コード,
PORT.PORT_NAME AS 港名,
IM1.AMT AS 入国者数,
IM2.AMT AS 出国者数,
IM1.AMT - IM2.AMT AS 差分
FROM IMMIGRATION AS IM1
INNER JOIN IMMIGRATION AS IM2
ON IM1.PORT_CODE = IM2.PORT_CODE
AND IM1.GROUP_CODE = '120'
AND IM2.GROUP_CODE = '120'
AND IM1.KIND_CODE = '110'
AND IM2.KIND_CODE = '120'
INNER JOIN PORT
ON IM1.PORT_CODE = PORT.PORT_CODE
WHERE IM1.AMT > IM2.AMT
ORDER BY 差分 DESC, 港コード DESC;