Question

这是我想要做的。我将以下代码更改为SP，它带有两个参数@startdate和@transactionDate，它将返回NextTransactiondate。逻辑是@startdate确定它是星期几。 @NexttransactionDate应该等于transactiondate之后的日期。所以在这个例子中，开始日是星期三，所以下一个交易日期应该是 - 2011-05-04'。在下面的代码中，它总是计算到周五，但它应该根据当天动态计算。任何帮助表示赞赏？

declare @TransactionDate datetime
declare @startDate datetime
declare @startDay int
declare @NextTransactionDate datetime
--Monday
set @TransactionDate = '2011-05-02'
--Wednesday
set @startDate = '2011-04-27'
set @startDay = datepart(dw,@startDate)

set @NextTransactionDate= DATEADD(DAY,(CASE DATEPART(DW,@TransactionDate)
   WHEN 7 THEN 6  
   WHEN 6 THEN 7  
    ELSE 6 - DATEPART(DW,@TransactionDate)
  END),@TransactionDate);  

print @NextTransactionDate

Answer 1

以下适用于我：

declare @TransactionDate DATETIME
DECLARE @TransactionDay tinyint
declare @startDate datetime
declare @startDay int
declare @NextTransactionDate datetime
--Monday
set @TransactionDate = '2011-05-05'
SET @TransactionDay = DATEPART(dw, @TransactionDate)
--Wednesday
set @startDate = '2011-04-27'
set @startDay = datepart(dw,@startDate)



set @NextTransactionDate= DATEADD(DAY, ((@startDay - @TransactionDay) + 7) % 7 ,@TransactionDate);  

select @startDay, DATEPART(dw, @NextTransactionDate), @NextTransactionDate

为了解释它的内容，我发现startDate和transactionDate的星期几有所不同。我添加了14，因为负数模数正数导致负数，这将使你的下一个交易日期过去（你不希望这样）。最糟糕的情况是@startDay为1且@TransactionDay为7时导致-6的差异。添加7确保这个差异是正的，但仍然与ring n mod 7中的实际差异处于同一等价级别（抱歉......我有点像数学书呆子）。

Answer 2

试试这个：


declare @TransactionDate datetime 
declare @startDate datetime 
declare @startDay int 
declare @transactionDay int 
declare @NextTransactionDate datetime 
declare @daysToAdd int

--Monday 
set @TransactionDate = '2011-05-02' 
set @transactionDay = datepart(dw,@TransactionDate)  

--Wednesday 
set @startDate = '2011-04-27' 
set @startDay = datepart(dw,@startDate)  

print @transactionDay
print @startDay

if(@startDay <= @transactionDay)
    set @daysToAdd = (@startDay + 7) - @transactionDay
else
   set @daysToAdd = @startDay - @transactionDay

set @NextTransactionDate = Dateadd(Day,@daysToAdd,@TransactionDate)
print @NextTransactionDate

如果你通过日期，如何获得NextDayofWeek？

2 个答案: