select min(score) from exam_record r, examination_info i where r.exam_id = i.exam_id and i.tag = 'SQL' and r.score >= ( select avg(er.score) from exam_record er join examination_info ei on er.exam_id = ei.exam_id where ei.tag = 'SQL' and er.score is not null ) 这题没有写出来，查看了下题解区才知道自己哪里错了 看来自己还是子查询这块不会，思考问题不是很全面