题解 | #得分不小于平均分的最低分#

select min(score) 
from exam_record left join (
    select exam_record.exam_id,avg(score) as avg_score
    from exam_record left join examination_info on exam_record.exam_id=examination_info.exam_id 
    where score is not null and tag='SQL'
    group by exam_record.exam_id
    
) as a on exam_record.exam_id =a.exam_id
where score >= avg_score