如何获得第二的数量和第四使用SQL查询

Question

我想获得第二的数量和第4个周六的 2之间的日期

防爆周六的日期正好介于2：

DECLARE @FromDate date='08/01/2016' 
DECLARE @ToDate date='09/20/2016' 

请帮帮我 提前感谢..

Answer 1

我使用UDF来创建动态的日期范围，但理货/日期表会做的伎俩以及

with cteBase as (
    Select * 
      ,RowNr=Row_Number() over (Order by RetVal) 
     From [dbo].[udf-Create-Range-Date]('2016-08-01','2016-09-20','DD',1) 
     Where DateName(DW,RetVal)='Saturday' 
) 
Select RetVal From cteBase Where RowNr in (2,4) 

返回

RetVal 
2016-08-13 00:00:00.000 
2016-08-27 00:00:00.000 

如果需要

CREATE FUNCTION [dbo].[udf-Create-Range-Date] (@DateFrom datetime,@DateTo datetime,@DatePart varchar(10),@Incr int) 

Returns 
@ReturnVal Table (RetVal datetime) 

As 
Begin 
    With DateTable As (
     Select DateFrom = @DateFrom 
     Union All 
     Select Case @DatePart 
       When 'YY' then DateAdd(YY, @Incr, df.dateFrom) 
       When 'QQ' then DateAdd(QQ, @Incr, df.dateFrom) 
       When 'MM' then DateAdd(MM, @Incr, df.dateFrom) 
       When 'WK' then DateAdd(WK, @Incr, df.dateFrom) 
       When 'DD' then DateAdd(DD, @Incr, df.dateFrom) 
       When 'HH' then DateAdd(HH, @Incr, df.dateFrom) 
       When 'MI' then DateAdd(MI, @Incr, df.dateFrom) 
       When 'SS' then DateAdd(SS, @Incr, df.dateFrom) 
       End 
     From DateTable DF 
     Where DF.DateFrom < @DateTo 
    ) 

    Insert into @ReturnVal(RetVal) Select DateFrom From DateTable option (maxrecursion 32767) 

    Return 
End 

-- Syntax Select * from [dbo].[udf-Create-Range-Date]('2016-10-01','2020-10-01','YY',1) 
-- Syntax Select * from [dbo].[udf-Create-Range-Date]('2016-10-01','2020-10-01','DD',1) 
-- Syntax Select * from [dbo].[udf-Create-Range-Date]('2016-10-01','2016-10-31','MI',15) 
-- Syntax Select * from [dbo].[udf-Create-Range-Date]('2016-10-01','2016-10-02','SS',1) 

编辑到

with cteBase as (
    Select * 
      ,RowNr=Row_Number() over (Order by RetVal) 
     From [dbo].[udf-Create-Range-Date]('2016-09-17','2016-10-29','DD',1) 
     Where DateName(DW,RetVal)='Saturday' 
) 
Select RetVal From cteBase Where RowNr % 2 = 0 

退换货范围之内返回每隔周六UDF

RetVal 
2016-09-24 00:00:00.000 
2016-10-08 00:00:00.000 
2016-10-22 00:00:00.000 

Answer 2

你应该养成创建日历表的习惯。如果您根据日期处理大量缺口和岛屿问题或进行大量以日期为中心的处理，它将节省大量时间。同时，我建议您在此期间建立一个内存表来处理您的查询。

DECLARE @DATES TABLE 
(
    Day INT, 
    Month INT, 
    Year INT, 
    DayInWeek INT, 
    WeekInYear INT 
    CalendarDate DATETIME 
) 

DECLARE @FromDate date='08/01/2016' 
DECLARE @ToDate date='09/20/2016' 

WHILE(@FromDate<=@ToDate) BEGIN 
    INSERT INTO @DATE DATEPART(DAY,@FromDate....) 
    SET @FromDate=DATEADD(DAY,1,@FromDate) 
END 

    SELECT 
     * 
    FROM 
    (
     SELECT 
      * 
     FROM 
      @DATE D 
      LEFT OUTER JOIN 
      (
      ...My Query 
      ) MQ ON MQ.Date=D.CalendarDate 
    )AS X   

Answer 3

declare @startDate datetime = '2016-09-16' 
declare @endDate datetime = '2016-10-12' 
declare @DayName Varchar(20) = 'Saturday' 
declare @SelectionType Varchar(20) = '1 And 4' 
-- '1 And 4','1 And 3','2 And 4','All' we can pass what ever we want 
declare @MothstartDateofStartDate datetime 
SELECT @MothstartDateofStartDate = DATEADD(month, DATEDIFF(month, 0, @startDate), 0)-1 

;with dateRange as 
(
    select [Date] = dateadd(dd, 1, @MothstartDateofStartDate), datename(dw,dateadd(dd, 1, @MothstartDateofStartDate)) [DayName] 
    where dateadd(dd, 1, @MothstartDateofStartDate) < @endDate 
    union all 
    select dateadd(dd, 1, [Date]), datename(dw,dateadd(dd, 1, [Date])) [DayName] 
    from dateRange 
    where dateadd(dd, 1, [Date]) < @endDate 
) 
select count(*) from (
select [Date],T0.[DayName],(select count(*) from dateRange T1 
where T1.Date between DATEADD(month, DATEDIFF(month, 0, T0.Date), 0) and T0.Date And T1.[DayName] =T0.[DayName] 
group By T1.[DayName]) PlaceCount 
from dateRange T0 where T0.Date >=@startDate) AA 
where AA.[DayName]= @DayName 
and 
'True'=case when @SelectionType ='1 And 4' then case when PlaceCount in(1,4) then 'True' else 'False' end 
when @SelectionType ='1 And 3' then case when PlaceCount in(1,3) then 'True' else 'False' end 
when @SelectionType ='2 And 4' then case when PlaceCount in(2,4) then 'True' else 'False' end 
when @SelectionType ='All' then 'True' end