asked on

SQL Date Function

Hi, I need help with a udf function in MSSQL, please. We have a program that we put a due date in a particular field and we have child events that generate from that date and are uploaded to Outlook through Exchange. What we are trying to do is make those child events never pop on a weekend. If the date falls on a Saturday it needs to push back to Thursday and the Sunday date would push back to Friday. We had someone write a script for us but we can't make it work. I am pasting it in here in hopes that someone may be able to help.

Thanks,
Tony.

--------------------------------

USE [Lawbase]
GO

/****** Object: UserDefinedFunction [dbo].[udf_WKDELIM] Script Date: 01/21/2013 12:15:46 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE FUNCTION [dbo].[udf_WKDELIM] (@dtDate DATETIME, @strPrev VARCHAR(10))
RETURNS DATETIME
AS
BEGIN
DECLARE @intDay INT
DECLARE @rtResult DATETIME
SET @intDay = DATEPART(weekday,@dtDate)
--To find Previous working day
Set @strPrev = 'Previous'
IF @intDay = 1
SET @rtResult = DATEADD(d,-2,@dtDate)
ELSE
IF @intDay = 2
SET @rtResult = DATEADD(d,-3,@dtDate)

--Default case returns date passed to function
ELSE
SET @rtResult = @dtDate
RETURN @rtResult
END

GO

Simone B

Try this:

CREATE FUNCTION [dbo].[udf_WKDELIM2] (@dtDate DATETIME)
RETURNS DATETIME
AS
BEGIN

DECLARE @rtResult DATETIME

IF DATENAME(dw,@dtDate) = 'Saturday' OR DATENAME(dw,@dtDate) = 'Sunday'

SET @rtResult = DATEADD(d,-2,@dtDate)
ELSE

SET @rtResult = @dtDate

RETURN @rtResult
END

canteyhanger

ASKER

Thanks, I will try it and let you know how it works out.

owenja

This does seem to be working in that is does return the Friday date if that is passed to the script - I have stripped out the second variable as that seems to be the issue - the solution above will not work as Saturday will return Thursday as the last working day rather than Friday - the following code highlights that the script works - you just need to use the returned date without the variable as I don't know what it fulfils - following code will demonstrate

CREATE FUNCTION [dbo].[udf_WKDELIM](@dtDate DATETIME)
RETURNS DATETIME
AS
BEGIN
DECLARE @intDay INT
DECLARE @rtResult DATETIME
SET @intDay = DATEPART(weekday,@dtDate)
--To find Previous working day

IF @intDay = 1
SET @rtResult = DATEADD(d,-2,@dtDate)
ELSE
IF @intDay = 2
SET @rtResult = DATEADD(d,-3,@dtDate)

--Default case returns date passed to function
ELSE
SET @rtResult = @dtDate
RETURN @rtResult
END

GO 

SELECT [dbo].[udf_WKDELIM](GETDATE()-1) AS DayOfWeek

Open in new window

You will then get Friday for sat sunday or the current date if it is not weekend

Just set the getdate - number to show a weekend day such as -3 today will give you Saturday and you can see the effect.

ASKER CERTIFIED SOLUTION

Mark Wills

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

owenja

Hi mark_wills,
Just a quick question about the return dateadd(day,-2,@dtdate) clause - if it's Saturday and you apply a -2 wouldn't that give you Thursday rather than Friday? Should there not be a case of -1 for Saturday and -2 for Sunday?

Regards

owenja

Sorry mark_wills just reread the requirement - thought a weekend was to be read as a Friday hence the case statement - I think the previous working day fro the original scriopt send me down the wrong road.
REgards

Mark Wills

No worries :)

canteyhanger

ASKER

First of all, thanks to everyone for the help. We are SQL neophites and can get into trouble trying to do this on our own!

Buttercup,
We tried yours and still got no dates to move back. Not sure what happened there.

Owenja,
Yours worked for Sunday but Saturday stayed on Saturday.

Mark_Wills,
Yours we have not tried yet but looks a lot simpler than the others. I can even understand it! I will let you know how it comes out as we try this solution.

You guys are great, all of you!

Simone B

How are you testing? These are the results I got:

SELECT DATENAME(dw,dbo.udf_WKDELIM2('jan 28, 2013')) AS MondayTest,
DATENAME(dw,dbo.udf_WKDELIM2('jan 29, 2013')) AS TuesdayTest,
DATENAME(dw,dbo.udf_WKDELIM2('jan 30, 2013')) AS WednesdayTest,
DATENAME(dw,dbo.udf_WKDELIM2('jan 31, 2013')) AS ThursdayTest,
DATENAME(dw,dbo.udf_WKDELIM2('feb 1, 2013')) AS FridayTest,
DATENAME(dw,dbo.udf_WKDELIM2('feb 2, 2013')) AS SaturdayTest,
DATENAME(dw,dbo.udf_WKDELIM2('feb 3, 2013')) AS SundayTest

Open in new window

canteyhanger

ASKER

We are just adding the udf in a var. for a test case we set up. We created the case and created a workflow within and called the udf from in there. I guess we weren't smart enough to try it inside SQL! That would have been the easy way. I will get with my other compadre today and try it all again.

Thanks.

canteyhanger

ASKER

To all, thank you for helping us with this. We got it to work as expected.