题解 | #得分不小于平均分的最低分#

select min(e.score) min_score_over_avg from exam_record e 
join examination_info e1
on e.exam_id = e1.exam_id
where   e1.tag='SQL'

and e.score >= (select avg(e.score) from exam_record e 
                    join examination_info e1
                    on e.exam_id = e1.exam_id
                    where   e1.tag='SQL')