题解 | 考试分数(四)

with grade_num as (
    select 
        job,
        count(job) as cnt
    from 
        grade
    group by 
        job
)

select 
    job,
    case 
        when mod(cnt,2) = 1 then round((cnt + 1) / 2,0)
        when mod(cnt,2) = 0 then round(cnt / 2,0)
    end as start,
    case
        when mod(cnt,2) = 1 then round((cnt + 1) / 2,0)
        when mod(cnt,2) = 0 then round((cnt / 2) + 1,0)
    end as end
from 
    grade_num
order by 
    job