题解 | 某乎问答高质量的回答中用户属于各级别的数量

select (case when author_level between 1 and 2 then '1-2级'
 when author_level between 3 and 4 then '3-4级'
 else '5-6级'
 end
 ) as level_cut,
 count(an.issue_id) as num

 from author_tb au
 join(
select * from answer_tb where char_len>=100) an
on au.author_id = an.author_id
group by level_cut
order by num desc

简单