行业知识
【牛客】SQL132 每个题目和每份试卷被作答的人数和次数
2026-11-01 20:28:14
来源：互联网转载
描述
���有试卷作答记录表exam_record（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 | 2021-09-01 09:01:01 | 2021-09-01 09:41:01 | 81 |
| 2 | 1002 | 9002 | 2021-09-01 12:01:01 | 2021-09-01 12:31:01 | 70 |
| 3 | 1002 | 9001 | 2021-09-01 19:01:01 | 2021-09-01 19:40:01 | 80 |
| 4 | 1002 | 9002 | 2021-09-01 12:01:01 | 2021-09-01 12:31:01 | 70 |
| 5 | 1004 | 9001 | 2021-09-01 19:01:01 | 2021-09-01 19:40:01 | 85 |
| 6 | 1002 | 9002 | 2021-09-01 12:01:01 | (NULL) | (NULL) |
题目练习表practice_record（uid用户ID, question_id题目ID, submit_time提交时间, score得分）：
| id | uid | question_id | submit_time | score |
| 1 | 1001 | 8001 | 2021-08-02 11:41:01 | 60 |
| 2 | 1002 | 8001 | 2021-09-02 19:30:01 | 50 |
| 3 | 1002 | 8001 | 2021-09-02 19:20:01 | 70 |
| 4 | 1002 | 8002 | 2021-09-02 19:38:01 | 70 |
| 5 | 1003 | 8001 | 2021-08-02 19:38:01 | 70 |
| 6 | 1003 | 8001 | 2021-08-02 19:48:01 | 90 |
| 7 | 1003 | 8002 | 2021-08-01 19:38:01 | 80 |
请统计每个题目和每份试卷被作答的人数和次数，分别按照"试卷"和"题目"的uv & pv降序显示，示例数据结果输出如下：
（）| tid | uv | pv |
| 9001 | 3 | 3 |
| 9002 | 1 | 3 |
| 8001 | 3 | 5 |
| 8002 | 2 | 2 |
解释：“试卷”有3人共练习3次试卷9001，1人作答3次9002；“刷题”有3人刷5次8001，有2人刷2次8002
#在union之前单独排序，需要对表重新命名select * from(selectexam_id as tid,count(distinct uid) as uv,count(start_time) as pvfromexam_recordgroup by exam_idorder by pv desc,uv desc)t1unionselect * from(selectquestion_id as tid,count(distinct uid) as uv,count(submit_time) as pvfrompractice_recordwhere submit_time is not nullgroup by question_idorder by pv desc,uv desc)t2
