sql-server - SQL Server - 生成重复日期的计划列表

Question

我们有一组记录，其中每条记录(工作)都有一个以天为单位的周期(或频率)，用于确定工作何时出现在某人的工作列表中。 E.G

作业 A 每 7 天生成一次作业 B 每 14 天生成一次。

每个工作还有一个开始日期。

我需要生成一个表格，其中包含一个日期范围内所有可能的工作日期。

这是我生成可能日期的代码的第一部分。

DECLARE @ForecastEarliestStartDate as DATETIME, @formStartDate as DATE,@formEndDate as DATE, @cycleInDays as BIGINT;

--set input param values
SET @ForecastEarliestStartDate = CAST('2017-07-03' AS DATETIME)
SET @formStartDate = getdate();
SET @formEndDate = getdate()+60;
SET @cycleInDays = 28;


WITH mycte AS
(
  SELECT @ForecastEarliestStartDate DateValue
  UNION ALL
  SELECT   DateValue + @cycleInDays
  FROM    mycte   
  WHERE   DateValue + @cycleInDays < @formEndDate
)

SELECT  *
FROM    mycte
WHERE DateValue between @formStartDate and @formEndDate
OPTION (MAXRECURSION 0);

这对于单个作业来说效果很好，但是我如何针对整个作业表运行它，其中 @ForecastEarliestStartDate、@formStartDate、@formEndDate、@cycleInDays 是表中的字段？

Answer 1

我经常使用 TVF 来创建动态日期/时间范围。通常比递归 CTE 更快，并且它是参数驱动的。您提供日期/时间范围、日期部分和增量。

例如

Select * From [dbo].[udf-Range-Date]('2017-07-03',getdate()+60,'DD',7)

返回

RetSeq  RetVal
1   2017-07-03
2   2017-07-10
3   2017-07-17
4   2017-07-24
5   2017-07-31
6   2017-08-07
7   2017-08-14
8   2017-08-21
9   2017-08-28

UDF(如果有兴趣)

CREATE FUNCTION [dbo].[udf-Range-Date] (@R1 datetime,@R2 datetime,@Part varchar(10),@Incr int)
Returns Table
Return (
    with cte0(M)   As (Select 1+Case @Part When 'YY' then DateDiff(YY,@R1,@R2)/@Incr When 'QQ' then DateDiff(QQ,@R1,@R2)/@Incr When 'MM' then DateDiff(MM,@R1,@R2)/@Incr When 'WK' then DateDiff(WK,@R1,@R2)/@Incr When 'DD' then DateDiff(DD,@R1,@R2)/@Incr When 'HH' then DateDiff(HH,@R1,@R2)/@Incr When 'MI' then DateDiff(MI,@R1,@R2)/@Incr When 'SS' then DateDiff(SS,@R1,@R2)/@Incr End),
         cte1(N)   As (Select 1 From (Values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N(N)),
         cte2(N)   As (Select Top (Select M from cte0) Row_Number() over (Order By (Select NULL)) From cte1 a, cte1 b, cte1 c, cte1 d, cte1 e, cte1 f, cte1 g, cte1 h ),
         cte3(N,D) As (Select 0,@R1 Union All Select N,Case @Part When 'YY' then DateAdd(YY, N*@Incr, @R1) When 'QQ' then DateAdd(QQ, N*@Incr, @R1) When 'MM' then DateAdd(MM, N*@Incr, @R1) When 'WK' then DateAdd(WK, N*@Incr, @R1) When 'DD' then DateAdd(DD, N*@Incr, @R1) When 'HH' then DateAdd(HH, N*@Incr, @R1) When 'MI' then DateAdd(MI, N*@Incr, @R1) When 'SS' then DateAdd(SS, N*@Incr, @R1) End From cte2 )

    Select RetSeq = N+1
          ,RetVal = D 
     From  cte3,cte0 
     Where D<=@R2
)
/*
Max 100 million observations -- Date Parts YY QQ MM WK DD HH MI SS
Syntax:
Select * from [dbo].[udf-Range-Date]('2016-10-01','2020-10-01','YY',1) 
Select * from [dbo].[udf-Range-Date]('2016-01-01','2017-01-01','MM',1) 
*/

Edit - Working Example of CROSS APPLY

Declare @YourTable table (JobName varchar(50),StartDate date,Interval int)
Insert Into @YourTable values
 ('Job A','2017-07-03',7)
,('Job B','2017-07-03',14)


Select A.JobName
      ,JobDate = B.RetVal
 From @YourTable A
 Cross Apply [dbo].[udf-Range-Date](A.StartDate,getdate()+60,'DD',A.Interval) B

返回

JobName JobDate
Job A   2017-07-03
Job A   2017-07-10
Job A   2017-07-17
Job A   2017-07-24
Job A   2017-07-31
Job A   2017-08-07
Job A   2017-08-14
Job A   2017-08-21
Job A   2017-08-28
Job B   2017-07-03   -- << Notice differant span for Job B
Job B   2017-07-17
Job B   2017-07-31
Job B   2017-08-14
Job B   2017-08-28