题解 | #某乎问答高质量的回答中用户属于各级别的数量#
某乎问答高质量的回答中用户属于各级别的数量
https://www.nowcoder.com/practice/69c85db3e59245efb7cee51996fe2273
select level_cnt, count(*) num from (select case author_level when 5 then '5-6级' when 6 then '5-6级' when 3 then '3-4级' when 4 then '3-4级' else '1-2级' end level_cnt from author_tb join answer_tb using(author_id) where char_len>= 100) t group by level_cnt order by num desc;