select t1.PORT_CODE as 港コード,
PORT.PORT_NAME as 港名,
t1.AMT as 入国者数,
t2.AMT as 出国者数,
t1.AMT - t2.AMT as 差分
from GRP,IMMIGRATION as t1,IMMIGRATION as t2,PORT
where GRP.GROUP_CODE=t1.GROUP_CODE
and t1.PORT_CODE=PORT.PORT_CODE
and t1.PORT_CODE=t2.PORT_CODE
and t1.KIND_CODE="110"
and t2.KIND_CODE="120"
and t1.AMT>t2.AMT
order by 差分 DESC,t1.PORT_CODE DESC