用户在牛客试卷作答区作答记录存储在表exam_record中,内容如下:
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 | 2021-07-02 09:01:01 | 2021-07-02 09:21:01 | 80 |
2 | 1002 | 9001 | 2021-09-05 19:01:01 | 2021-09-05 19:40:01 | 81 |
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 | 2021-07-02 19:01:01 | 2021-07-02 19:30:01 | 82 |
6 | 1002 | 9002 | 2021-07-05 18:01:01 | 2021-07-05 18:59:02 | 90 |
7 | 1003 | 9002 | 2021-07-06 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) |
10 | 1002 | 9003 | 2021-09-01 12:01:01 | 2021-09-01 12:31:01 | 81 |
11 | 1005 | 9001 | 2021-09-01 12:01:01 | 2021-09-01 12:31:01 | 88 |
12 | 1006 | 9002 | 2021-09-02 12:11:01 | 2021-09-02 12:31:01 | 89 |
13 | 1007 | 9002 | 2020-09-02 12:11:01 | 2020-09-02 12:31:01 | 89 |
请计算2021年每个月里试卷作答区用户平均月活跃天数avg_active_days和月度活跃人数mau,上面数据的示例输出如下:
month | avg_active_days | mau |
202107 | 1.50 | 2 |
202109 | 1.25 | 4 |
解释:2021年7月有2人活跃,共活跃了3天(1001活跃1天,1002活跃2天),平均活跃天数1.5;2021年9月有4人活跃,共活跃了5天,平均活跃天数1.25,结果保留2位小数。
注:此处活跃指有交卷行为。
示例1
输入
drop table if exists exam_record; CREATE TABLE exam_record ( id int PRIMARY KEY AUTO_INCREMENT COMMENT '自增ID', uid int NOT NULL COMMENT '用户ID', exam_id int NOT NULL COMMENT '试卷ID', start_time datetime NOT NULL COMMENT '开始时间', submit_time datetime COMMENT '提交时间', score tinyint COMMENT '得分' )CHARACTER SET utf8 COLLATE utf8_general_ci; INSERT INTO exam_record(uid,exam_id,start_time,submit_time,score) VALUES (1001, 9001, '2021-07-02 09:01:01', '2021-07-02 09:21:01', 80), (1002, 9001, '2021-09-05 19:01:01', '2021-09-05 19:40:01', 81), (1002, 9002, '2021-09-02 12:01:01', null, null), (1002, 9003, '2021-09-01 12:01:01', null, null), (1002, 9001, '2021-07-02 19:01:01', '2021-07-02 19:30:01', 82), (1002, 9002, '2021-07-05 18:01:01', '2021-07-05 18:59:02', 90), (1003, 9002, '2021-07-06 12:01:01', null, null), (1003, 9003, '2021-09-07 10:01:01', '2021-09-07 10:31:01', 86), (1004, 9003, '2021-09-06 12:01:01', null, null), (1002, 9003, '2021-09-01 12:01:01', '2021-09-01 12:31:01', 81), (1005, 9001, '2021-09-01 12:01:01', '2021-09-01 12:31:01', 88), (1006, 9002, '2021-09-02 12:11:01', '2021-09-02 12:31:01', 89), (1007, 9002, '2020-09-02 12:11:01', '2020-09-02 12:31:01', 89);
输出
202107|1.50|2 202109|1.25|4