SQL Server - 选择时间范围内的频繁记录

Question

我正在寻找一种方法来选择其中一列具有相同记录且日期时间在 5 分钟内的所有记录。我管理一个票务系统，并试图查看在 5 分钟时间内创建的所有类似票证。请参阅下面的示例数据集：

|ID |Subject    |CreatedDateTime    |
-------------------------------------
|1  |A          |2020-09-28 11:01:00|
|2  |A          |2020-09-28 11:02:00|
|3  |A          |2020-09-28 11:03:00|
|4  |A          |2020-09-28 11:03:09|
|5  |A          |2020-09-28 11:04:52|
|6  |A          |2020-09-28 11:15:00|
|7  |B          |2020-09-28 11:20:00|
|8  |B          |2020-09-28 11:20:00|
|9  |B          |2020-09-28 11:20:00|

我的目标是只选择记录 1-5，因为 5 个相同的主题并且它们都是在 5 分钟内创建的。 6-10不应选择，因为Subject数量不够多，或者超出了规定的时间范围。

以下是我到目前为止的一个测试查询，但它没有考虑 5 分钟的范围（我只回顾 1 周，因此该子句）：

SELECT Subject,COUNT(*)
FROM TableName
WHERE CreatedDateTime > DATEADD(day, -7, GETDATE())
GROUP BY Subject
HAVING COUNT(*) > 5 
ORDER BY COUNT(*) DESC;

有没有什么方法可以只在接近的时间范围内看到类似的记录？提前谢谢大家！

Answer 1

您可以为每条记录提前和落后，找出以分钟为单位的时差，然后仅保留在 5 分钟内与至少一条其他记录相连的记录：

WITH cte AS (
    SELECT *,
           DATEDIFF(minute,
               LAG(CreatedDateTime) OVER (PARTITION BY Subject
                                          ORDER BY CreatedDateTime),
               CreatedDateTime) AS LagCreatedDateTime,
           DATEDIFF(minute,
               CreatedDateTime,
               LEAD(CreatedDateTime) OVER (PARTITION BY Subject
                                           ORDER BY CreatedDateTime))
                AS LeadCreatedDateTime
    FROM TableName
)

SELECT *
FROM cte
WHERE LagCreatedDateTime <= 5 OR LeadCreatedDateTime <= 5;

有关使用示例数据运行的示例，请参阅下面的演示链接。

Demo

Answer 2

如果您要对相隔 5 分钟内的记录进行分组，则可以使用递归查询来“分组”日期范围，如下所示

with data
  as (select *,row_number() over(partition by subject order by createddatetime) as rnk
        from t
        )
    ,cte
    as(select id,subject,createddatetime as begin_date, createddatetime,cast(1 as int) as grp
         from data
       where rnk=1  
       union all
       select b.id
             ,b.subject
             ,b.createddatetime
             ,case when datediff(minute,a.createddatetime,b.createddatetime) > 5 then 
                    b.createddatetime
                   else
                    a.createddatetime
               end as createddatetime
             ,case when datediff(minute,a.createddatetime,b.createddatetime) > 5 then 
                    a.grp+1
                   else
                    a.grp
               end as grp  
         from cte a
         join t b
           on a.id+1=b.id
          and a.subject=b.subject 
       )
     select * from cte  order by 1

 +----+---------+-------------------------+-------------------------+-----+
| id | subject |       begin_date        |     createddatetime     | grp |
+----+---------+-------------------------+-------------------------+-----+
|  1 | A       | 2020-09-28 11:01:00.000 | 2020-09-28 11:01:00.000 |   1 |
|  2 | A       | 2020-09-28 11:02:00.000 | 2020-09-28 11:01:00.000 |   1 |
|  3 | A       | 2020-09-28 11:03:00.000 | 2020-09-28 11:01:00.000 |   1 |
|  4 | A       | 2020-09-28 11:03:09.000 | 2020-09-28 11:01:00.000 |   1 |
|  5 | A       | 2020-09-28 11:04:52.000 | 2020-09-28 11:01:00.000 |   1 |
|  6 | A       | 2020-09-28 11:15:00.000 | 2020-09-28 11:15:00.000 |   2 |
|  6 | A       | 2020-09-28 11:17:00.000 | 2020-09-28 11:17:00.000 |   2 |
|  7 | B       | 2020-09-28 11:20:00.000 | 2020-09-28 11:20:00.000 |   1 |
|  8 | B       | 2020-09-28 11:20:00.000 | 2020-09-28 11:20:00.000 |   1 |
|  9 | B       | 2020-09-28 11:20:00.000 | 2020-09-28 11:20:00.000 |   1 |
+----+---------+-------------------------+-------------------------+-----+

db 小提琴链接

https://dbfiddle.uk/?rdbms=sqlserver_2019&fiddle=7fabc2d2753c2ab01bb40f58d82bf222