求出每个team粉丝数最多的3个国家

有这么个表

fans(team,nationality,fanCount)

'Barcelona','Germany',12000
'Barcelona','Spain',18000
'Barcelona','China',13000
'Barcelona','USA',15000
'Barcelona','Italy',11000
'Real Madrid','France',19000
'Real Madrid','Germany',13000
'Real Madrid','USA',17000
'Real Madrid','Korea',16000
'Real Madrid','UK',12000

现在分别要求出每个team粉丝数最多的3个国家

select *

from fans t1

where

(

  select count(*)

  from fans t2

  where t1.team=t2.team

  and t2.fanCount>=t1.fanCount

) <=3