SQL Server: calculating date ranges

I'm trying to get a date range from the beginning of this month (previous year) to current day (previous year). Is there a way to simplify this code?

SELECT 'From the beginning of month to this day, previous year' AS Label,
       CONVERT (DATETIME, CAST (DATEPART(YY, GETDATE()) - 1 AS CHAR (4)) + CASE 
                                                                           WHEN DATEPART(MM, GETDATE()) < 10 THEN '-0' + CAST (DATEPART(MM, GETDATE()) AS CHAR (1)) ELSE '-' + CAST (DATEPART(MM, GETDATE()) AS CHAR (2)) 
                                                                           END + '-01') AS Begin_date,
       CONVERT (DATETIME, CAST (DATEPART(YY, GETDATE()) - 1 AS CHAR (4)) + CASE 
                                                                           WHEN DATEPART(MM, GETDATE()) < 10 THEN '-0' + CAST (DATEPART(MM, GETDATE()) AS CHAR (1)) ELSE '-' + CAST (DATEPART(MM, GETDATE()) AS CHAR (2)) 
                                                                           END + CASE 
                                                                                 WHEN DATEPART(DD, GETDATE()) < 10 THEN '-0' + CAST (DATEPART(DD, GETDATE()) AS CHAR (1)) ELSE '-' + CAST (DATEPART(DD, GETDATE()) AS CHAR (2)) 
                                                                                 END) AS End_date

回答1:

SELECT  'Anything' as Label
        ,DATEADD(month, DATEDIFF(month, 0, GETDATE()), 0) as firstdaythismonth
        ,DATEADD(day, DATEDIFF(day, 0, GETDATE()), 0) as today
        ,DATEADD(year, -1, DATEADD(month, DATEDIFF(month, 0, GETDATE()), 0)) as firstdaythismonth_lastyear
        ,DATEADD(year, -1, DATEADD(day, DATEDIFF(day, 0, GETDATE()), 0)) as today_lastyear

回答2:

SELECT 
     DATEADD(yy, -1, CONVERT(VARCHAR(25),
     DATEADD(dd,-(DAY(GETDATE())-1),GETDATE()),101)) AS Date_Value,
     'First Day of Current Month Of Last Year' AS Date_Type
UNION
SELECT 
     DATEADD(yy, -1, GETDATE()) AS TodayLastYear, 'Today Last Year'

Or if you just want the values and no description

SELECT 
     DATEADD(yy, -1, CONVERT(VARCHAR(25),
     DATEADD(dd,-(DAY(GETDATE())-1),GETDATE()),101))
UNION
SELECT 
     DATEADD(yy, -1, GETDATE()) AS TodayLastYear

You use DATEADD and specify yy to subtract years. Just use a negative value.

I'll also share a set of common date functions I use. Just create this as a table valued function:

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go

CREATE FUNCTION [dbo].[udfCommonDates] (@date datetime)
RETURNS @t table (week_start datetime,
                  week_end datetime,
                  lastweek_start datetime,
                  lastweek_end datetime,
                  month_start datetime,
                  month_end datetime,
                  lastmonth_start datetime,
                  lastmonth_end datetime,
                  yesterday_start datetime,
                  yesterday_end datetime,
                  today_start datetime,
                  today_end datetime,
                  thisweek_monday_start datetime,
                  thisweek_monday_end datetime,
                  year_start datetime,
                  year_end datetime,
                  tomorrow_noon datetime,
                  today_noon datetime,
                  date_only datetime)
BEGIN
   INSERT @t
   SELECT
   dbo.get_week_start ( @date ) AS week_start,
   dbo.get_week_end   ( @date ) AS week_end,
   dbo.get_week_start ( DATEADD(d, -7, @date ) ) AS lastweek_start,
   dbo.get_week_end   ( DATEADD(d, -7, @date ) ) AS lastweek_end,
   dbo.get_month_start( @date ) AS month_start,
   dbo.get_month_end  ( @date ) AS month_end,
   dbo.get_month_start ( DATEADD(m,-1, @date) ) AS lastmonth_start,
   dbo.get_month_end  ( DATEADD(m,-1,@date) ) AS lastmonth_end,
   dbo.get_yesterday_start ( @date ) AS yesterday_start,
   dbo.get_yesterday_end ( @date ) AS yesterday_end,
   dbo.get_today_start (@date) AS today_start,
   dbo.get_today_end ( @date ) AS today_end,
   dbo.get_weekday_start(1,@date) AS thisweek_monday_start,
   dbo.get_weekday_end(1,@date) AS thisweek_monday_end,
   dbo.get_year_start(@date) AS year_start,
   dbo.get_year_end(@date) AS year_end,  
   dbo.get_tomorrow_noon(@date) AS TomorrowNoon,
   dbo.get_today_noon(@date) AS TodayNoon,
   dbo.get_date_only(@date) AS DateOnly
RETURN
END

Here are the scalar valued functions for these:

    CREATE FUNCTION [dbo].[get_date_only] (@date datetime)
    RETURNS datetime
    WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
    AS    
    BEGIN
        RETURN dateadd(day, DateDiff(day, 0, GetDate()), 0)
    END
    GO

CREATE FUNCTION [dbo].[get_month_end] (@date datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    
BEGIN
   RETURN dateadd(ms, -3, dateadd (m,datediff(m,0,
          dateadd(m,1,@date)),0))
END
GO

CREATE FUNCTION [dbo].[get_month_start] (@date datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    
BEGIN
   RETURN dateadd(m,datediff(m,0, @date),0)
   END
GO

CREATE FUNCTION [dbo].[get_today_end] (@today datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    
BEGIN
   return dateadd(ms, -3, datediff(d,0,dateadd(d,1,@today)))
END
GO

CREATE FUNCTION [dbo].[get_today_noon](@date datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
   RETURN DATEADD(hh, 12, DATEADD(d,DATEDIFF(d,0, @date),0))
END
GO

CREATE FUNCTION [dbo].[get_today_start] (@today datetime)
RETURNS datetime 
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
   return dateadd(day, 0, datediff(d,0,@today))
END
GO

CREATE FUNCTION [dbo].[get_tomorrow_noon](@date datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
   RETURN DATEADD(hh, 12, DATEADD(d,DATEDIFF(d,-1, @date),0))
END
GO

CREATE FUNCTION [dbo].[get_week_end] (@date datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
   return dateadd(yyyy, datepart(yyyy,
      dateadd(weekday,7-datepart(weekday, @date),@date))-1900, 0)
    + dateadd(ms, -3,
      dateadd(dy, datepart(dy,
     dateadd(weekday,7-datepart(weekday, @date),@date)),0) )
END
GO

CREATE FUNCTION [dbo].[get_week_start] (@date datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
   return dateadd(yyyy, datepart(yyyy,
      dateadd(weekday,1-datepart(weekday, @date),@date))-1900, 0)
    + dateadd(dy, datepart(dy,
      dateadd(weekday,1-datepart(weekday, @date),@date))-1,0)
END
GO

CREATE FUNCTION [dbo].[get_weekday_end] (@weekday tinyint,
                                 @date datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
   return dateadd(yyyy, datepart(yyyy,
      dateadd(weekday,@weekday-
      datepart(weekday, @date),@date))-1900, 0)
    + dateadd(ms, -3,
      dateadd(dy, datepart(dy,
      dateadd(weekday,@weekday-datepart(weekday, @date),
                                        @date)),0) )
END
GO

CREATE FUNCTION [dbo].[get_weekday_start] (@weekday tinyint,
                                   @date datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
   return dateadd(yyyy, datepart(yyyy,
      dateadd(weekday,@weekday-
      datepart(weekday, @date),@date))-1900, 0)
    + dateadd(dy, datepart(dy,
      dateadd(weekday,@weekday-datepart(weekday, @date),
                                        @date))-1,0)
END
GO

CREATE FUNCTION [dbo].[get_year_end] (@date datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
RETURN DATEADD(year, DATEDIFF(year, 0, GetDate())+1, 0)-1
END
GO

CREATE FUNCTION [dbo].[get_year_start] (@date datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
   RETURN DATEADD(year,DATEDIFF(year,0, @date),0)
END
GO

CREATE FUNCTION [dbo].[get_yesterday_end] (@today datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
   return dateadd(ms, -3, datediff(d,0,@today))
END
GO

CREATE FUNCTION [dbo].[get_yesterday_start] (@today datetime)
RETURNS datetime
WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT
AS    BEGIN
   RETURN dateadd(day, -1, datediff(d,0,@today))
END
GO

These were really helpful for me because I used this in reporting services for date parameters. You could simply create a dataset referencing this table function and then use these in the parameters for any datetime within RS.

You could execute this entire table-valued function like so:

SELECT * FROM [MyDB].[dbo].[udfCommonDates] (GetDate())

The result is like so

For Reporting Services Folks

Now I mentioned earlier that I use these for reporting services. Now the RS folks might be thinking but how does this help me as I need a dataset and a dataset can only be based on a Stored Procedure or a direct table. No problem create the following stored procedure:

CREATE PROCEDURE [dbo].[uspCommonDates] AS
begin
   set datefirst 1
   declare @date datetime
   set @date = getdate()
   select * from dbo.udfCommonDates(@date)
end

Now you've got a stored procedure to use as a dataset...Now in reporting services add a new dataset:

Now go to the report parameters section of the report:

Now pick that dataset dsFunctions (or whatever you called it) and then pick any of the value fields from the scalar functions such as:

Now when you run the report it uses the scalars:

回答3:

You can use the DATEADD functions to help:

 SELECT 'From the beginning of month to this day, previous year' AS Label,
DATEADD(YY,-1,DATEADD(DD,-(day(getdate())-1),DATEDIFF(dd, 0, GETDATE()))) AS Begin_date,
DATEADD(YY,-1,DATEDIFF(dd, 0, GETDATE()))  AS End_date

回答4:

For 2010-04-01 , 2010-04-04 how about;

SELECT 
CAST(DATEADD(DAY, -365 + -(DAY(GETDATE())-1), GETDATE()) AS DATE), 
CAST(DATEADD(YEAR, -1, GETDATE()) AS DATE)

回答5:

SELECT  'From the beginning of month to this day, previous year' AS Label,
        CONVERT(DATETIME,LEFT(CONVERT(VARCHAR(6),DATEADD(YEAR,-1,GETDATE()),112),6)+'01') Begin_date,
        DATEADD(YEAR,-1,GETDATE()) End_date