请从试卷作答记录表中找到SQL试卷得分不小于该类试卷平均得分的用户最低得分。
示例数据 exam_record表(uid用户ID, exam_id试卷ID, start_time开始作答时间, submit_time交卷时间, score得分):
id | uid | exam_id | start_time | submit_time | score |
1 | 1001 | 9001 | 2020-01-02 09:01:01 | 2020-01-02 09:21:01 | 80 |
2 | 1002 | 9001 | 2021-09-05 19:01:01 | 2021-09-05 19:40:01 | 89 |
3 | 1002 | 9002 | 2021-09-02 12:01:01 | (NULL) | (NULL) |
4 | 1002 | 9003 | 2021-09-01 12:01:01 | (NULL) | (NULL) |
5 | 1002 | 9001 | 2021-02-02 19:01:01 | 2021-02-02 19:30:01 | 87 |
6 | 1002 | 9002 | 2021-05-05 18:01:01 | 2021-05-05 18:59:02 | 90 |
7 | 1003 | 9002 | 2021-02-06 12:01:01 | (NULL) | (NULL) |
8 | 1003 | 9003 | 2021-09-07 10:01:01 | 2021-09-07 10:31:01 | 86 |
9 | 1004 | 9003 | 2021-09-06 12:01:01 | (NULL) | (NULL) |
examination_info表(exam_id试卷ID, tag试卷类别, difficulty试卷难度, duration考试时长, release_time发布时间)
id | exam_id | tag | difficulty | duration | release_time |
1 | 9001 | SQL | hard | 60 | 2020-01-01 10:00:00 |
2 | 9002 | SQL | easy | 60 | 2020-02-01 10:00:00 |
3 | 9003 | 算法 | medium | 80 | 2020-08-02 10:00:00 |
示例输出数据:
min_score_over_avg |
87 |
解释:试卷9001和9002为SQL类别,作答这两份试卷的得分有[80,89,87,90],平均分为86.5,不小于平均分的最小分数为87
- select min(score) from
- exam_record left join examination_info using(exam_id)
- where tag='SQL' and score is not null and
- score>= (
- select avg(score) as avg_score from
- exam_record left join examination_info using(exam_id)
- where tag='SQL' and score is not null)