[SQL]confirmation-rate

https://leetcode.com/problems/confirmation-rate

Confirmation Rate - LeetCode

with base as (
select
    user_id
    , count(distinct if(action = 'confirmed', time_stamp, null))/count(distinct time_stamp) confirmation_rate
from Confirmations
group by 1
)
select
    distinct c.user_id
    , if(b.confirmation_rate is null, 0, round(b.confirmation_rate,2)) confirmation_rate
from Signups c
left join base b on c.user_id = b.user_id