SELECT
IN_TBL.PORT_CODE AS '港コード',
PORT.PORT_NAME AS '港名',
IN_TBL.AMT AS '入国者数',
OUT_TBL.AMT AS '出国者数',
(IN_TBL.AMT - OUT_TBL.AMT) AS '差分'
FROM (SELECT PORT_CODE, AMT FROM IMMIGRATION WHERE KIND_CODE = '110' AND GRP_CODE = '120') AS IN_TBL
JOIN (SELECT PORT_CODE, AMT FROM IMMIGRATION WHERE KIND_CODE = '120' AND GRP_CODE = '120') AS OUT_TBL ON OUT_TBL.PORT_CODE = IN_TBL.PORT_CODE
JOIN PORT ON PORT.PORT_CODE = IN_TBL.PORT_CODE
WHERE IN_TBL.AMT > OUT_TBL.AMT
ORDER BY (IN_TBL.AMT - OUT_TBL.AMT) DESC, IN_TBL.PORT_CODE DESC
;