select
    t1.PORT_CODE as '港コード'
    , t2.PORT_NAME   as '港名'
    , sum(case when t1.KIND_CODE = '110' THEN t1.AMT ELSE 0 end) as '入国者数'
    , sum(case when t1.KIND_CODE = '120' THEN t1.AMT ELSE 0 end) as '出国者数'
    , sum(case when t1.KIND_CODE = '110' THEN t1.AMT ELSE 0 end) - sum(case when t1.KIND_CODE = '120' THEN t1.AMT ELSE 0 end) as '差分'
from IMMIGRATION t1
left join PORT t2
on t1.PORT_CODE = t2.PORT_CODE 
left join GRP t3
on t1.GROUP_CODE = t3.GROUP_CODE 
where t1.GROUP_CODE = '120'
group by t1.PORT_CODE
having sum(case when t1.KIND_CODE = '110' THEN t1.AMT ELSE 0 end) > sum(case when t1.KIND_CODE = '120' THEN t1.AMT ELSE 0 end)
order by '差分' desc, '港コード' desc