获取每 5 分钟时间间隔的总和

Question

问题描述

我有一个表格 (

#tmstmp

)，有 2 列

dt

(

DATETIME

) 和

payload

(

INT

)。最终我想对每 5 分钟间隔的

payload

求和。

代码

设置

DECLARE @start DATETIME = N'2024-1-1 12:00:00';
DROP TABLE IF EXISTS #tmstmp
                     , #numbers;
CREATE TABLE #tmstmp (
  dt DATETIME PRIMARY KEY
  , payload INT NOT NULL
);

CREATE TABLE #numbers (
  n INT PRIMARY KEY
);
WITH numbers (n) AS (
  SELECT 0 AS n
  UNION ALL
  SELECT n + 1 AS n
    FROM numbers
   WHERE n < 100
)
INSERT
  INTO #numbers
SELECT n
  FROM numbers;

WITH rnd (mins, secs) AS (
  SELECT n2.n AS mins
         , CAST(ABS(CHECKSUM(NEWID())) % 60 AS INT) AS mins
   FROM #numbers AS n1
        , #numbers as n2
  WHERE n1.n < 5
    AND n2.n < 15
), tmstmp (dt) AS (
  SELECT DATEADD(SECOND, secs, DATEADD(MINUTE, mins, @start)) AS dt
    FROM rnd
) 
INSERT  
  INTO #tmstmp
SELECT DISTINCT dt
       , -1 AS payload
  FROM tmstmp
 ORDER BY dt;

UPDATE #tmstmp
   SET payload = CAST(ABS(CHECKSUM(NEWID())) % 10 AS INT);
GO

不重叠的时间段很容易

DECLARE @start DATETIME = N'2024-1-1 12:00:00';
DECLARE @slotDuration INT = 5;

WITH agg (slot, sum_payload) AS (
  SELECT DATEDIFF(MINUTE, @start, dt) / @slotDuration AS slot
         , SUM(payload) AS sum_payload
    FROM #tmstmp
   GROUP BY DATEDIFF(MINUTE, @start, dt) / @slotDuration
)
SELECT DATEADD(MINUTE, slot * @slotDuration, @start) AS [from]
       , DATEADD(MINUTE, (slot + 1) * @slotDuration, @start) AS [to]
       , sum_payload
  FROM agg;

来自	到	总有效负载
2024-01-01 12:00:00	2024-01-01 12:05:00	124
2024-01-01 12:05:00	2024-01-01 12:10:00	106
2024-01-01 12:10:00	2024-01-01 12:15:00	95

最终目标：获得跑步时间

但是，我希望在范围内输入每个间隔，即从

12:00-12:05

、

12:01-12:06

、

12:02-12:07

等直到最后一个时间段。

我可以之前构建整个范围内的限制，并在

JOIN

中使用它，如下所示：

DECLARE @start DATETIME = N'2024-1-1 12:00:00';
DECLARE @slotDuration INT = 5;
DECLARE @intervals INT = (SELECT DATEDIFF(MINUTE, @start, MAX(dt)) FROM #tmstmp);

WITH ranges ([from], [to], slot) AS (
  SELECT DATEADD(MINUTE, n, @start) AS [from]
         , DATEADD(MINUTE, n + @slotDuration, @start) AS [to]
         , n AS slot
    FROM #numbers
   WHERE n <= @intervals
), tm_mult (slot, [from], [to], dt, payload) AS (
  SELECT slot
         , [from]
         , [to]
         , dt
         , payload
    FROM #tmstmp
   INNER JOIN ranges
      ON [from] <= dt
     AND dt < [to]
)
SELECT MIN([from]) AS [from]
       , MAX([to]) AS [to]
       , SUM(payload) AS sum_payload
  FROM tm_mult
 GROUP BY slot
 ORDER BY slot;

来自	到	总有效负载
2024-01-01 12:00:00	2024-01-01 12:05:00	124
2024-01-01 12:01:00	2024-01-01 12:06:00	120
2024-01-01 12:02:00	2024-01-01 12:07:00	125
...	...	...
2024-01-01 12:14:00	2024-01-01 12:19:00	19

虽然这在这个玩具示例中有效，但我的真实数据中有数十万个时间戳，最糟糕的是我对索引的影响很小。我的直觉告诉我，我会用我的不平等

JOIN

创造相当多的重复，我想知道这是否是规范的做法，或者是否有更多

SQL-onic

的做法？ （就像

pythonistas

喜欢调用某些代码

pythonic

，如果它使用语言固有的概念而不是尝试使用通用工具来解决它）。

Answer 1

sql 中的窗口函数 (WINDOW - microsoft.com / OVER - microsoft.com) 是添加到 SQL 工具带的重要资产。也特别规范； Windows 自 SQL Server 2005 以来就已存在。

下面是一个例子：

SELECT
    [From],
    DATEADD(MINUTE, 1, [To]) [To],
    payload
FROM (
    SELECT
        dt,
        MIN(dt) OVER(ORDER BY dt ROWS BETWEEN 4 PRECEDING AND CURRENT ROW) [From],
        dt [To],
        SUM(payload) OVER(ORDER BY dt ROWS BETWEEN 4 PRECEDING AND CURRENT ROW) payload
    FROM (
        SELECT
            DATEADD(MINUTE, DATEDIFF(MINUTE, 0, dt), 0) dt,
            SUM(payload) payload
        FROM #tmstmp
        GROUP BY DATEADD(MINUTE, DATEDIFF(MINUTE, 0, dt), 0)
    ) q
) q
WHERE DATEDIFF(MINUTE, [From], [To]) > 3

我想提请注意

4 PRECEDING

和

DATEADD(MINUTE, DATEDIFF(MINUTE, 0, dt), 0)

。由于后者实际上将日期时间降低到分钟，因此

2024-01-01 12:04:00.000

包含到

2024-01-01 12:04:59.999

，但不包括

2024-01-01 12:05:00.000

。希望这就是您正在寻找的功能。

这是一个小提琴