select -- 不去重,也可以通过 level, count(score) as level_cnt from user_info d1,exam_record d2,examination_info d3 where d1.uid=d2.uid and d2.exam_id=d3.exam_id and tag='SQL' and score > 80 group by level order by level_cnt desc;
点赞

相关推荐

牛客网
牛客网在线编程
牛客网题解
牛客企业服务