Question

我们需要获得月份输出的周开始日期和结束日期，如下所示：

Week#   StartDate   EndDate
Week 1  2017-03-01  2017-03-04 
Week 2  2017-03-05  2017-03-11 
Week 3  2017-03-12  2017-03-18 
Week 4  2017-03-19  2017-03-25 
Week 5  2017-03-26  2017-03-31

Answer 1

这应该有效：

    declare @first_day_of_month date = '20170301'
    declare @days_in_month int = datediff(day, @first_day_of_month, dateadd(month, 1, @first_day_of_month))

    ;with x as (
        select datepart(week, dateadd(day, n-1, @first_day_of_month))+1 wk, dateadd(day, n-1, @first_day_of_month) dy
        from (values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10), (11),(12),(13),(14),(15),(16),(17),(18),(19),(20),(21),(22),(23),(24),(25),(26),(27),(28),(29),(30), (31)) as numbers(n)
        where n <= @days_in_month
    )
    select wk - datepart(week, @first_day_of_month) as [Week#], min(dy) as StartDate, max(dy) as EndDate
    from x
    group by wk
    order by wk

如果数据库中有Numbers表，则可以删除values。

Answer 2

这个怎么样：

Declare @StartDate Date = '2017-03-01'
;With Nums
AS
(
    SELECT *
    FROM (VALUES (0),(1),(2),(3),(4)) Nums(n)
),
StartDate
AS
(
    SELECT @StartDate As StartDate, DatePart(dw,@StartDate) As DayWeekNumber
)
SELECT DATEADD(Week, n, CASE WHEN n = 0 THEN StartDate ELSE  DATEADD(Day, DayWeekNumber * -1 + 1, StartDate)  END) As StartDate,
       CASE WHEN DATEPART(Month, DATEADD(Week, n+1, DATEADD(Day, DayWeekNumber * -1 , StartDate))) = DATEPART(Month, @StartDate) 
            THEN  DATEADD(Week, n+1, DATEADD(Day, DayWeekNumber * -1 , StartDate))
            ELSE EOMONTH(@StartDate) END As EndDate
FROM Nums
CROSS JOIN StartDate

Answer 3

选项1：非UDF版本

Declare @Date1 date = '2017-03-01'
Declare @Date2 date = '2017-03-31'

Select [Week#]
      ,StartDate = min(D)
      ,EndDate   = max(D)
 From (
       Select *,[Week#] = concat('Week ',Dense_Rank() over (Partition By Year(D),Month(D) Order By DatePart(WK,D)))
        From (Select Top (DateDiff(DD,@Date1,@Date2)+1) D=DateAdd(DD,-1+Row_Number() Over (Order By Number),@Date1) From  master..spt_values ) A1
       ) A
 Group By [Week#],Year(D),Month(D)
 Order By 2

选项2：TFV版本

我经常使用TVF创建动态日期/时间范围。计数/日历表也可以解决问题，但UDF提供了一些动态选项。您提供日期范围，日期分和增量

Declare @Date1 date = '2017-03-01'
Declare @Date2 date = '2017-03-31'

Select [Week#]
      ,StartDate = min(RetVal)
      ,EndDate   = max(RetVal)
 From (
         Select *,[Week#] = concat('Week ',Dense_Rank() over (Partition By Year(RetVal),Month(RetVal) Order By DatePart(WK,RetVal)))
          From  [dbo].[udf-Range-Date](@Date1,@Date2,'DD',1)
       ) A
 Group By [Week#],Year(RetVal),Month(RetVal)
 Order By 2

两者都会返回

Week#   StartDate    EndDate
Week 1  2017-03-01   2017-03-04
Week 2  2017-03-05   2017-03-11
Week 3  2017-03-12   2017-03-18
Week 4  2017-03-19   2017-03-25
Week 5  2017-03-26   2017-03-31

感兴趣的UDF

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) 
*/

Answer 4

对于一次性使用，这将起作用：

rextester：http://rextester.com/WCMZRW61517

declare @FromDate date = '20170301';

with n as (select n from (values(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) t(n))
, d as (
  select DateValue=convert(date,dateadd(day
      , row_number() over (order by (select 1)) -1, @FromDate))
    from         n as deka
      cross join n as hecto
)
 select 
      [Week#]   = dense_rank() over (
                partition by dateadd(month, datediff(month, 0, DateValue)  , 0)
                order by convert(tinyint,datepart(week,DateValue)) 
                )
    , StartDate = min(DateValue) 
    , EndDate   = max(DateValue) 
from d
where dateadd(month, datediff(month, 0, DateValue)  , 0) = @FromDate
group by 
    dateadd(month, datediff(month, 0, DateValue)  , 0)
  , convert(tinyint,datepart(week,DateValue))

如果你想要一个日历表，你可以根据需要参考，这样的东西可以工作：

if object_id('dbo.Calendar') is not null drop table dbo.Calendar;
create table dbo.Calendar (
    [Date]         date     not null
  , [Year]         smallint not null
  , [Month]        tinyint  not null
  , MonthStart     date     not null
  , MonthEnd       date     not null
  , [Week]         tinyint  not null
  , MonthWeek      tinyint  not null
  , MonthWeekStart date     not null
  , MonthWeekEnd   date     not null
  , constraint pk_Calendar primary key clustered (date)
  );

declare @FromDate date = '20170101';
declare @ThruDate date = '20171231';

with n as (select n from (values(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) t(n))
, d as (
  select DateValue=convert(date,dateadd(day
      , row_number() over (order by (select 1)) -1, @fromdate))
    from         n as deka
      cross join n as hecto
      cross join n as kilo     /* 2.73 years */
      cross join n as [tenK]    /* 27.3 years */
      --cross join n as [hundredk] /* 273  years */
)

insert into dbo.Calendar
    ([Date], [Year], [Month],MonthStart, MonthEnd, [Week]
      , MonthWeek, MonthWeekStart, MonthWeekEnd)
  select top (datediff(day, @FromDate, @ThruDate)+1) 
      [Date]        = DateValue
    , [Year]        = convert(smallint,datepart(year,DateValue))
    , [Month]       = convert(tinyint,datepart(month,DateValue))
    , MonthStart    = dateadd(month, datediff(month, 0, DateValue)  , 0)
    , MonthEnd      = convert(date,dateadd(day,-1
                      ,dateadd(Month,datediff(Month,0,DateValue) +1,0) ) )
    , [Week]        = convert(tinyint,datepart(week,DateValue)) 
    , MonthWeek     = dense_rank() over (
                      partition by dateadd(month, datediff(month, 0, DateValue)  , 0)
                      order by convert(tinyint,datepart(week,DateValue)) 
                      )
    , MonthWeekStart = min(DateValue) over (
                         partition by dateadd(month, datediff(month, 0, DateValue)  , 0)
                                    , convert(tinyint,datepart(week,DateValue)) 
                         )
    , MonthWeekEnd   = max(DateValue) over (
                         partition by dateadd(month, datediff(month, 0, DateValue)  , 0)
                                    , convert(tinyint,datepart(week,DateValue)) 
                         )

    from d
    order by DateValue;

select distinct 
      MonthWeek
    , MonthWeekStart
    , MonthWeekEnd 
from dbo.Calendar 
where MonthStart = '20170301'

日历和数字表

SQL Server中本月的开始和结束日期

4 个答案: