这题没有写出来 参考大佬的

select min(er.score) as min_score_over_avg
from exam_record er join examination_info ei
on er.exam_id = ei.exam_id
where ei.tag = 'SQL' 
and score >= (select avg(er2.score) 
              from exam_record er2 
              join examination_info ei2
              on er2.exam_id = ei2.exam_id
              where tag = 'SQL'
                                  )