题解 | #出现三次以上相同积分的情况#

/*
with t as(
    select number,
    count(id) cnt
from grade
group by number
)

select number from t
where cnt>=3
order by number */

with t as(
    select distinct number,
    count(id) over(partition by number) cnt  --使用窗口函数，number必须去重，否则报错。
from grade

)

select number from t
where cnt>=3
order by number