题解 | #某乎问答最大连续回答问题天数大于等于3天的用户

with t1 as (# 去重
    select 
        distinct answer_date, 
        author_id
    from answer_tb
)
select 
    t2.author_id,
    t3.author_level,
    count(sub) as days_cnt
from (
    select 
        answer_date - row_number()over(partition by author_id order by answer_date) as sub,# 作差
        author_id
    from t1
)t2
left join author_tb t3
on t2.author_id = t3.author_id
group by t2.author_id, author_level
having count(sub) >= 3