laravel子查询怎么用orm实现下面的sql呢，

select
case when t.c=1 then 1
when t.c=2 then 2
when t.c=3 then 3
when t.c=4 then 4
else 5 end as renshu,count(t.id)
from (
select count(uid) c,id from userinfo where reason2='送站' group by id)t group by renshu;

大神帮忙看看:joy: