使用单列日期分隔记录以共享日期范围

Seperate Records to share Date Range utilizing a single column of dates

我的 table 支出记录中有以下记录。我喜欢做的是根据仅使用 1 列日期的开始和结束服务日期将每条记录分解成单独的记录集。

 DisbursementID ServiceProviderID Original CircuitID   Beginning_Service_Date Ending_Service_Date Amount
 -------------- ----------------- -------- ----------- ---------------------- ------------------- -----------
 53562          673               0        1814        2015-12-01             2015-12-31          531
 53563          673               0        1814        2015-11-01             2015-11-30          531

我的目标结果看起来像

 DisbursementID ServiceProviderID Original CircuitID   Date Range  Amount
 -------------- ----------------- -------- ----------- ---------- -------
 53562          673               0        1814        2015-12-01 531
 53562          673               0        1814        2015-12-02 531
 53562          673               0        1814        2015-12-03 531
 53562          673               0        1814        2015-12-04 531
 53562          673               0        1814        2015-12-05 531
 53563          673               0        1814        2015-11-01 531
 53563          673               0        1814        2015-11-02 531
 53563          673               0        1814        2015-11-03 531
 53563          673               0        1814        2015-11-04 531
 53563          673               0        1814        2015-11-05 531

相反，我的结果看起来像

 DisbursementID ServiceProviderID Original CircuitID   Date Range  Amount
 -------------- ----------------- -------- ----------- ---------- -------
 53562          673               0        1814        2015-12-01 531
 53563          673               0        1814        2015-11-01 531
 53563          673               0        1814        2015-11-02 531
 53563          673               0        1814        2015-11-03 531
 53563          673               0        1814        2015-11-04 531
 53563          673               0        1814        2015-11-05 531

以下是我找到的一段代码，但适合我的需要。它几乎解决了我的问题，但我不知道如何从我的第一条记录中包含范围日期块。我知道为什么会这样，但不知道如何正确修复它：

 ;With Dates as
 ( 
 Select DisbursementID, ServiceProviderID,Original,CircuitID
 ,Beginning_Service_Date as BeginDate, Ending_Service_Date as EndDate
 ,Amount From Disbursement

 Union All

 Select DisbursementID, ServiceProviderID, Original,CircuitID
 ,DATEADD(day,1,BeginDate) as CalenderDate, EndDate
 ,Amount 
 From Dates
 Where DATEADD(day,1,BeginDate) <= EndDate
 )

 Select DisbursementID, ServiceProviderID,Original,CircuitID
,BeginDate as [Date Range], Amount from Dates
Order By CircuitID
Option (MAXRECURSION 366);

如果您没有或不能使用 Tally/Calendar Table，另一种方法是使用临时计数 table.

Declare @YourTable table (DisbursementID int, ServiceProviderID int, Original int, CircuitID int, Beginning_Service_Date date, Ending_Service_Date date, Amount int)
Insert Into @YourTable values
 ( 53562,673,0,1814,'2015-12-01','2015-12-31',531)
,( 53563,673,0,1814,'2015-11-01','2015-11-30',531)

;with cte1 as (
                 Select MinDate=min(Beginning_Service_Date)
                       ,MaxDate=max(Ending_Service_Date)
                 From @YourTable )
     ,cte2 as (
                 Select Top (DateDiff(DD,(select MinDate from cte1),(select MaxDate from cte1))+1) 
                        D = DateAdd(DD,-1+Row_Number() Over (Order By (Select null)),(select MinDate from cte1)) 
                  From  master..spt_values A -- ,master..spt_values B  -- If you need more than 6 years
 )
Select A.DisbursementID 
      ,A.ServiceProviderID 
      ,A.Original 
      ,A.CircuitID 
      ,[Date Range] = B.D
      ,A.Amount
 From  @YourTable A
 Join cte2 B on B.D between A.Beginning_Service_Date and A.Ending_Service_Date

使用递归 cte 是生成一系列日期的最糟糕的方法之一。 John Cappelletti 的回答是 much better 按需生成日期范围而不是使用递归 cte。

如果您要在 55,000 多行中使用它，并且您将 运行 这种操作不止一次，您最好只创建 Dates 或 Calendar table.

对于只有 152kb 的内存，你可以在一个 table 中有 30 年的日期，你可以这样使用它：

/* dates table */ 
declare @fromdate date = '20000101';
declare @years    int  = 30;
/* 30 years, 19 used data pages ~152kb in memory, ~264kb on disk */
;with n as (select n from (values(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) t(n))
select top (datediff(day, @fromdate,dateadd(year,@years,@fromdate)))
    [Date]=convert(date,dateadd(day,row_number() over(order by (select 1))-1,@fromdate))
into dbo.Dates
from n as deka cross join n as hecto cross join n as kilo 
               cross join n as tenK cross join n as hundredK
order by [Date];
create unique clustered index ix_dbo_Dates_date 
  on dbo.Dates([Date]);

并像这样使用 Dates table：

select 
    t.DisbursementID
  , t.ServiceProviderID
  , t.Original
  , t.CircuitID
  , d.[date]
  , t.Amount
from t
  inner join dates d
    --on d.date >= t.Beginning_Service_Date
   --and d.date <= t.Ending_Service_Date
  /* if you want to have the date range work when 
      Beginning_Service_Date and Ending_Service_Date are backwards
      you could use between */
    on d.date between t.Beginning_Service_Date
                  and t.Ending_Service_Date

rextester 演示：http://rextester.com/WNMJW41879

数字和日历table参考：