题解 | #得分不小于平均分的最低分#

select min(er.score) min_score_over_avg 
from examination_info ei join exam_record er 
on 
ei.exam_id=er.exam_id and ei.tag='SQL' 
where er.score>=(select avg(er.score) from examination_info ei join exam_record er on ei.exam_id=er.exam_id and ei.tag='SQL');