在SQL Server 2012中使用CTE獲取連續日期

我必須爲Microsoft SQL Server中一年中兩個代碼之間交替的一個特定房間分配顏色代碼。唯一字段是日曆的每個單獨日期。在SQL Server 2012中使用CTE獲取連續日期

因此示例行將如下所示。

weekDay  colorName RoomNum 
2017-01-01 Blue  100 
2017-01-02 Red   100

顏色代碼需要分配給2種顏色之間的每個周交替從星期一（即在一週的開始）至週日算作周的端部。因此，2017年起週一1月2日，我需要下面的模式，通過下一日曆年如此繼續的2018年

2017-01-02 Red   100 
2017-01-03 Red   100 
2017-01-04 Red   100 
2017-01-05 Red   100 
2017-01-06 Red   100 
2017-01-07 Red   100 
2017-01-08 Red   100 
2017-01-09 Blue  100 
2017-01-10 Blue  100 
2017-01-11 Blue  100 
2017-01-12 Blue  100 
2017-01-13 Blue  100 
2017-01-14 Blue  100 
2017-01-15 Blue  100 
2017-01-16 Red   100 
. 
. 
.

我有以下CTE結束，但它的第一個每週6天分配，然後分配14從每個星期一到星期天開始，每隔7天開始一週。我究竟做錯了什麼？謝謝！

DECLARE @tableTest TABLE (weekDay datetime, colorName varchar(50), roomNum int); 

DEClARE @begindate datetime = '01/02/17'; 
declare @enddate datetime = '12/31/18'; 

;with 
N0 as (SELECT 1 as n UNION ALL SELECT 1) 
,N1 as (SELECT 1 as n FROM N0 t1, N0 t2) 
,N2 as (SELECT 1 as n FROM N1 t1, N1 t2) 
,N3 as (SELECT 1 as n FROM N2 t1, N2 t2) 
,N4 as (SELECT 1 as n FROM N3 t1, N3 t2) 
,N5 as (SELECT 1 as n FROM N4 t1, N4 t2) 
,N6 as (SELECT 1 as n FROM N5 t1, N5 t2) 

,nums as (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 1)) as num FROM N6) 
INSERT @tableTest (weekDay, roomNum) 
SELECT DATEADD(day,num-1,@begindate) as thedate, 100 
FROM nums 
WHERE num <= DATEDIFF(day,@begindate,@enddate) + 1 

;with weekNumber as (
SELECT weekDay, colorName, roomNum, (DATEPART(ww, weekDay)/2) % 2 as schedule FROM @tableTest 
) 
UPDATE weekNumber 
SET colorName = CASE WHEN weekNumber.schedule = 0 THEN 'Red' ELSE 'Blue' END 

SELECT * FROM @tableTest

來源

2016-03-03 Tom Joy

您正在進行除法和模數，這會導致您將模數的「寬度」加倍，如果該術語對您有意義的話。：）

換句話說，而不是做模對1，2，3，4等。

你做得對模1，1.5，2，2.5％，3，等明白了嗎？

總之，解決的辦法是你最後的更新改成這樣：

;with weekNumber as (
SELECT weekDay, colorName, roomNum, (DATEPART(ww, weekDay)) % 2 as schedule FROM @tableTest 
) 
UPDATE weekNumber 
SET colorName = CASE WHEN weekNumber.schedule = 0 THEN 'Red' ELSE 'Blue' END

來源

2016-03-03 19:55:53

在SQL Server 2012中使用CTE獲取連續日期

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