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Posts Tagged ‘First Date of Previous Week’

Sometimes, we come across a case where we have given one date and we need to calculate multiple dates based on this date. This can be achieved in the earlier versions of the SQL Server (earlier than 2022), but we had to use multiple functions like CONVERT(), DATEADD(), DATEDIFF() etc with lots of complexity.

Fortunately, a new function shipped in SQL Server 2022 namely DATETRUNC() which helps us to achieve this scenario easily.

Compatibility Level:

Your database compatibility level MUST be 160 or higher to use this new function.

 ALTER DATABASE tempdb SET COMPATIBILITY_LEVEL = 160 

Prerequisite:

In order to set the first day of the week as Monday, we need to run the below script.


SET DATEFIRST 1;
GO

First Date of Previous Week

  • Old Approach

In the old approach, we have to extract first date of the previous week using multiple functions (CONVERT(), DATEADD(), DATEDIFF()) as shown below.

DECLARE @Date DATE;
SET @Date = GETDATE();

SELECT  @Date							 AS [Current Date]
	  , CONVERT(DATE
	  , DATEADD(WEEK
	  , DATEDIFF(WEEK, 0, @Date) -1, 0)) AS [First Date Of Previous Week];
GO
--OUTPUT

  • New Approach

In the new approach, we can extract the first date of the previous week using DATETRUNC() & DATEADD() function as shown below.

DECLARE @Date Date;
SET @Date = GETDATE();

SELECT  @Date					  AS [Current Date]
	  , DATEADD(WEEK, -1
	  , DATETRUNC(WEEK, @Date))   AS [First Date Of Previous Week];
GO
--OUTPUT

Last Date of Previous Week

  • Old Approach

In the old approach, we have to extract last date of the previous week using multiple functions (CONVERT(), DATEADD(), DATEDIFF()) as shown below.

DECLARE @Date DATE;
SET @Date = GETDATE();

SELECT  @Date							  AS [Current Date]
      , CONVERT(DATE
	  , DATEADD(WEEK
	  , DATEDIFF(WEEK, 0, @Date) +0, -1)) AS [Last Date Of Previous Week];
GO
--OUTPUT

  • New Approach

In the new approach, we can extract the last date of the previous week using DATETRUNC() & DATEADD() function as shown below.

DECLARE @Date DATE;
SET @Date = GETDATE();

SELECT  @Date					  AS [Current Date]
	  , DATEADD(DAY, -1
	  , DATEADD(WEEK, 0
	  , DATETRUNC(WEEK, @Date)))  AS [Last Date Of Previous Week];
GO
--OUTPUT

First Date of Current Week

  • Old Approach

In the old approach, we have to extract first date of the current week using multiple functions (CONVERT(), DATEADD(), DATEDIFF()) as shown below.

DECLARE @Date DATE;
SET @Date = GETDATE();

SELECT  @Date							 AS [Current Date]
	  , CONVERT(DATE
	  , DATEADD(WEEK
	  , DATEDIFF(WEEK, 0, @Date) +0, 0)) AS [First Date Of Current Week];
GO
--OUTPUT

  • New Approach

In the new approach, we can extract the first date of the current week using DATETRUNC() function as shown below.

DECLARE @Date Date;
SET @Date = GETDATE();

SELECT  @Date				   AS [Current Date]
	  , DATETRUNC(WEEK, @Date) AS [First Date of Current Week];
GO
--OUTPUT

Last Date of Current Week

  • Old Approach

In the old approach, we have to extract last date of the current week using multiple functions (CONVERT(), DATEADD(), DATEDIFF()) as shown below.

DECLARE @Date DATE;
SET @Date = GETDATE();

SELECT  @Date							  AS [Current Date]
      , CONVERT(DATE
	  , DATEADD(WEEK
	  , DATEDIFF(WEEK, 0, @Date) +1, -1)) AS [Last Date Of Current Week];
GO
--OUTPUT

  • New Approach

In the new approach, we can extract the last date of the current week using DATETRUNC() & DATEADD() function as shown below.

DECLARE @Date DATE;
SET @Date = GETDATE()

SELECT  @Date					 AS [Current Date]
      , DATEADD(DAY, -1
	  , DATEADD(WEEK, 1
	  , DATETRUNC(WEEK, @Date))) AS [Last Date Of Current Week];
GO
--OUTPUT

First Date of Next Week

  • Old Approach

In the old approach, we have to extract first date of the next week using multiple functions (CONVERT(), DATEADD(), DATEDIFF()) as shown below.

DECLARE @Date DATE;
SET @Date = GETDATE();

SELECT  @Date							 AS [Current Date]
	  , CONVERT(DATE
	  , DATEADD(WEEK
	  , DATEDIFF(WEEK, 0, @Date) +1, 0)) AS [First Date Of Next Week];
GO
--OUTPUT

  • New Approach

In the new approach, we can extract the first date of the next week using DATETRUNC() & DATEADD() function as shown below.

DECLARE @Date DATE;
SET @Date = GETDATE();

SELECT  @Date					 AS [Current Date]
	  , DATEADD(WEEK, 1
	  , DATETRUNC(WEEK, @Date))  AS [First Date Of Next Week];
GO

--OUTPUT

Last Date of Next Week

  • Old Approach

In the old approach, we have to extract last date of the next week using multiple functions (CONVERT(), DATEADD(), DATEDIFF()) as shown below.

DECLARE @Date DATE;
SET @Date = GETDATE();

SELECT  @Date							  AS [Current Date]
      , CONVERT(DATE
	  , DATEADD(WEEK
	  , DATEDIFF(WEEK, 0, @Date) +2, -1)) AS [Last Date Of Next Week];
GO
--OUTPUT

  • New Approach

In the new approach, we can extract the last date of the next week using DATETRUNC() & DATEADD() function as shown below.


DECLARE @Date DATE;
SET @Date = GETDATE();

SELECT  @Date					 AS [Current Date]
      , DATEADD(DAY, -1
	  , DATEADD(WEEK, 2
	  , DATETRUNC(WEEK, @Date))) AS [Last Date Of Next Week];
GO
--OUTPUT

Conclusion:

We used DATETRUNC() function to achieve it and found it easier & simpler as compared to earlier version of SQL Server.

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