sql累计求和-贡献度

• 计算各个用户的消费金额综合
• 对用户消费金额进行累加，并计算累计占比，就是贡献度

select 
t.*
from
    (select 
    user_id 
    ,round(amount,2) amount
    ,round(sum(amount)over(order by amount desc) ,2) cum_amount
    ,round(sum(amount)over(order by amount desc)/(select sum(pur_amount) from cd_now),4) as cum_rate
    from 
        (select 
        user_id 
        ,sum(pur_amount) amount
        from 
        cd_now 
        where pur_amount >0
        group by 
        user_id ) user_table
    ) t
where t.cum_rate<0.8