Question

例如，我有这样的数据

min     max        time                      batch    sensor 
-------------------------------------------------------------------    
10      20         2018-07-20 10:15:00:00      x      abc
15      30         2018-07-20 10:14:00:00      x      abc
15      30         2018-07-20 10:16:00:00      x      abc
|     |    |         |                         |       |
|     |    |         |                         |       |                
20      30         2018-07-20 11:15:00:00      x      abc

现在我想要每小时的数据

                                                    min   max 
 ------------------------------------------------------------                                                                     
 2018-07-20 10:15:00:00   2018-07-20 11:15:00:00    10    10

Answer 1

此处的复杂性在于，您每分钟都要检查一个小时范围的窗口，因此，如果要整整一天报告为1,440行。这是一些可以做到的代码：

SET NOCOUNT ON
-- Create a temporary numbers table to demonstrate its use. 
-- We need numbers up to 24*60-1 (24 hours * 60 minutes -1 for based on zero)

Declare @DailyIntervals int,

SET @DailyIntervals = 24 * 60 - 1
--SELECT @DailyIntervals

-- This calculates the number of recursive inserts needed to reach at least your maximum value
-- NOTE: This is based off of manually inserting your first four values into the table first!

DECLARE @loop int
SET @loop = CEILING(Log(@DailyIntervals,2))-2

Declare @m int
CREATE TABLE ##Nums (i int primary key clustered);

INSERT INTO ##Nums VALUES (1), (2), (3), (4);   -- Seed the table

SET @m = 4

WHILE @loop > 0
BEGIN
    INSERT INTO ##nums SELECT I + @m FROM ##Nums
    SET @m = @@ROWCOUNT * 2 -- max value in table now
    SET @loop = @loop - 1
END

INSERT INTO ##nums Values (0)   -- add the zero value

--SELECT MAX(I) FROM ##Nums

-- Look at July 20th
DECLARE @BeginDt datetime = '2018-07-20'

-- Build a working table of one minute intervals for a full day
WITH hhrs as (
    SELECT Dateadd(MINUTE, i, @BeginDt) as StartTm,
        Dateadd(MINUTE, i+59, @BeginDt) as EndTm
    FROM ##Nums
    WHERE i BETWEEN 0 and @DailyIntervals
    ),

SELECT 
    StartTm,
    EndTm,
    min([Min]) as [Min], 
    max([max]) as [Max]
FROM hhrs h
INNER JOIN MyData m 
    ON m.[Time] Between @StartTm and @EndTm
ORDER BY StartTm

DROP TABLE ##Nums

从开始时间获取每小时数据

1 个答案: