题解 | #得分不小于平均分的最低分#

select
    min(score) as min_score_over_avg
from
    exam_record er  join examination_info ei on er.exam_id=ei.exam_id
where
    tag = 'SQL' and score >=(
        select
            avg(score)
        from
            (select
                    er.*,
                    ei.tag,
                    ei.difficulty
                from
                    exam_record er
                    join examination_info ei on er.exam_id = ei.exam_id
            )t1
       where
            tag = 'SQL'           
    );
	这个题目还是有点难度的，先要找出平均值，然后再作为筛选条件