Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1031
  • Last Modified:

SQL query - inclue only work days

Hi experts,

I have to create a query that determines the difference in time between two dates and then calculate the average time difference based on a grouping of another field. There is a trick however - the calculation of the difference in time should exclude Saturdays and Sundays. The query as follows:

SELECT t.name, AVG(DATEDIFF(dd,t.dateone,t.datetwo) AS time
FROM db.dbo.table t
GROUP BY t.name

I have no idea how to do the exclusion of  Saturdays and Sundays in the calculation. Any help would be much appreciated.

Thanks!
0
avdvyver
Asked:
avdvyver
  • 3
  • 2
1 Solution
 
avdvyverAuthor Commented:
My apologies - the query as follows:

SELECT t.name, AVG(DATEDIFF(dd,t.dateone,t.datetwo)) AS time
FROM db.dbo.table t
GROUP BY t.name
0
 
Aneesh RetnakaranDatabase AdministratorCommented:
use this function to get the no of working days b/w 2 dates

CREATE FUNCTION dbo.GetWorkingDays
( @StartDate datetime,
@EndDate datetime )
RETURNS INT
AS
BEGIN
DECLARE @WorkDays int, @FirstPart int
DECLARE @FirstNum int, @TotalDays int
DECLARE @LastNum int, @LastPart int
IF (DATEDIFF(day, @StartDate, @EndDate) < 2)
BEGIN
RETURN ( 0 )
END
SELECT
@TotalDays = DATEDIFF(day, @StartDate, @EndDate) - 1,
@FirstPart = CASE DATENAME(weekday, @StartDate)
WHEN 'Sunday' THEN 6
WHEN 'Monday' THEN 5
WHEN 'Tuesday' THEN 4
WHEN 'Wednesday' THEN 3
WHEN 'Thursday' THEN 2
WHEN 'Friday' THEN 1
WHEN 'Saturday' THEN 0
END,
@FirstNum = CASE DATENAME(weekday, @StartDate)
WHEN 'Sunday' THEN 5
WHEN 'Monday' THEN 4
WHEN 'Tuesday' THEN 3
WHEN 'Wednesday' THEN 2
WHEN 'Thursday' THEN 1
WHEN 'Friday' THEN 0
WHEN 'Saturday' THEN 0
END
IF (@TotalDays < @FirstPart)
BEGIN
SELECT @WorkDays = @TotalDays
END
ELSE
BEGIN
SELECT @WorkDays = (@TotalDays - @FirstPart) / 7
SELECT @LastPart = (@TotalDays - @FirstPart) % 7
SELECT @LastNum = CASE
WHEN (@LastPart <> 0) THEN @LastPart - 1
ELSE 0
END
SELECT @WorkDays = @WorkDays * 5 + @FirstNum + @LastNum
END
RETURN ( @WorkDays )
END
GO

0
 
Patrick MatthewsCommented:
Hi avdvyver,

Aneesh's function will get you there, unless you have to consider "holidays", days that are Mon-Fri but for
one reason or another should not be counted as work days.  Will you need to do this?  If so, then you would
have to maintain a table of such days, and modify Aneesh's function to refer to that table.

Regards,

Patrick
0
 [eBook] Windows Nano Server

Download this FREE eBook and learn all you need to get started with Windows Nano Server, including deployment options, remote management
and troubleshooting tips and tricks

 
avdvyverAuthor Commented:
Hi Patrick,

Luckly I don't have to cater for holiday during the working week.
0
 
avdvyverAuthor Commented:
Hi aneeshattingal,

I don't want to sound stuipd ... but I don't understand where the origional query fits into your answer. I'm sure it works, I just don't know where exactly to fit my query in. :)
0
 
Aneesh RetnakaranDatabase AdministratorCommented:
SELECT t.name, AVG(dbo.GetWorkingdays(t.dateone,t.datetwo) AS time
FROM db.dbo.table t
GROUP BY t.name
0

Featured Post

Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

  • 3
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now