如何统计Mysql每天连续发生一个事件的天数？

Question

如何统计MYsql每天连续发生一个事件的天数？

CREATE TABLE MrDataConverter (
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  num INT,
  controller_id INT,
  event_type INT,
  date VARCHAR(255),
  Desired output INT
);
INSERT INTO MrDataConverter 
  (num,controller_id,event_type,date,Desired output) 
VALUES 
  (1,42260,12,'2/27/2023 13:09',8),
  (2,42260,12,'2/26/2023 13:09',7),
  (3,42260,12,'2/25/2023 13:09',6),
  (4,42260,12,'2/24/2023 13:08',5),
  (5,42260,12,'2/23/2023 13:08',4),
  (6,42260,12,'2/22/2023 13:06',3),
  (7,42260,12,'2/21/2023 13:09',2),
  (8,42260,12,'2/20/2023 13:06',1),
  (9,42260,12,'2/19/2023 10:27',0),
  (10,42260,12,'2/19/2023 3:11',0),
  (11,42260,12,'2/17/2023 16:08',0),
  (12,42260,12,'2/17/2023 15:36',0),
  (13,42260,12,'2/17/2023 14:20',0),
  (14,42260,12,'2/17/2023 13:14',9),
  (15,42260,12,'2/16/2023 13:05',8),
  (16,42260,12,'2/15/2023 13:04',7),
  (17,42260,12,'2/14/2023 13:04',6),
  (18,42260,12,'2/13/2023 13:05',5),
  (19,42260,12,'2/12/2023 13:05',4),
  (20,42260,12,'2/11/2023 13:05',3),
  (21,42260,12,'2/10/2023 13:04',2),
  (22,42260,12,'2/9/2023 13:04',1),
  (23,42260,12,'2/8/2023 13:04',0);

我假设我需要做一个 datediff（来自上一行）和 Row_number 函数？

SELECT row_number() over ( PARTITION BY controller_id ORDER BY date DESC) num, controller_id, date
FROM events 
WHERE controller_id = 42260
Order By date desc
LIMIT 200 

Answer 1

将日期字符串转换为日期：

UPDATE MrDataConverter
SET `date` = STR_TO_DATE(`date`, '%m/%d/%Y %H:%i');

这让你到达那里的大部分方式：

SELECT
    num, controller_id, event_type, date,
    COUNT(IF(DATE(`date`) = prev_date, NULL, `date`)) OVER (PARTITION BY controller_id, grp ORDER BY DATE(`date`)) AS `desired output`
FROM (
    SELECT *,
        DATE(`date`) - INTERVAL DENSE_RANK() OVER (PARTITION BY controller_id ORDER BY DATE(`date`)) DAY AS grp,
        LAG(DATE(`date`))  OVER (PARTITION BY controller_id ORDER BY DATE(`date`)) AS prev_date
    FROM MrDataConverter
) t
ORDER BY num ASC;

数	controller_id	事件类型	约会	期望的输出
1	42260	12	2023-02-27 13:09:00	9
2	42260	12	2023-02-26 13:09:00	8
3	42260	12	2023-02-25 13:09:00	7
4	42260	12	2023-02-24 13:08:00	6
5	42260	12	2023-02-23 13:08:00	5
6	42260	12	2023-02-22 13:06:00	4
7	42260	12	2023-02-21 13:09:00	3
8	42260	12	2023-02-20 13:06:00	2
9	42260	12	2023-02-19 10:27:00	1
10	42260	12	2023-02-19 03:11:00	1
11	42260	12	2023-02-17 16:08:00	10
12	42260	12	2023-02-17 15:36:00	10
13	42260	12	2023-02-17 14:20:00	10
14	42260	12	2023-02-17 13:14:00	10
15	42260	12	2023-02-16 13:05:00	9
16	42260	12	2023-02-15 13:04:00	8
17	42260	12	2023-02-14 13:04:00	7
18	42260	12	2023-02-13 13:05:00	6
19	42260	12	2023-02-12 13:05:00	5
20	42260	12	2023-02-11 13:05:00	4
21	42260	12	2023-02-10 13:04:00	3
22	42260	12	2023-02-09 13:04:00	2
23	42260	12	2023-02-08 13:04:00	1