徒手写一个,就这个思路,没跑sql: select s.name as name, s.id as id from student s left join mark m on s.id=m.sid where m.score < 60 group by s.id having count(*) >= 3;
徒手写一个,就这个思路,没跑sql:
select s.name as name, s.id as id from student s left join mark m on s.id=m.sid where m.score < 60 group by s.id having count(*) >= 3;