SSRS 2005 Previous sum of date and time - sql-server

Question

I have an SSRS report which when I try to calculate the previous value the first line always gives incorrect value since there is no previous number for it to calculate.
=CDec(format(DateDiff("s",previous(Fields!SyncDate.Value),Fields!Date.Value)/60,"0.00"))
The value of the first line comes out 1059831848.62
Is there a way to tell it to skip first line?
Because also i need to sum it all to get total which counts the first line and gives a huge total.
My query consists of the following:
SELECT ToppingCount, DriverName, COUNT(Pizza) AS Count, Date, SyncDate, BranchName, Branch
FROM System
WHERE (Date BETWEEN #datefrom AND #DateTo) AND (Branch IN (#branch)) AND (SystemSource = 'newsys') AND (SystemSource <> 'oldsys')
GROUP BY Pizza, ToppingCount, DriverName, Date, SyncDate, BranchName, Branch
ORDER BY Branch, DriverName, Date
Thanks

Answer 1

You could add a Row_Number column to your query like so..
SELECT ToppingCount,
DriverName,
COUNT(Pizza) AS Count,
Date,
SyncDate,
BranchName,
Branch,
ROW_NUMBER() OVER (ORDER BY Branch,DriverName,Date) Rn
FROM System
WHERE (Date BETWEEN #datefrom AND #DateTo)
AND (Branch IN (#branch))
AND (SystemSource = 'newsys')
AND (SystemSource <> 'oldsys')
GROUP BY Pizza,
ToppingCount,
DriverName,
Date,
SyncDate,
BranchName,
Branch
ORDER BY Branch,
DriverName,
Date
Then just check to see if you are on Rn = 1 before you do your calculation.
=iif(Fields!Rn.Value = 1, "", CDec(format(DateDiff("s",previous(Fields!SyncDate.Value),Fields!Date.Value)/60,"0.00")))
or
=iif(Fields!Rn.Value = 1, 0, CDec(format(DateDiff("s",previous(Fields!SyncDate.Value),Fields!Date.Value)/60,"0.00")))
if you need to reset the Row_Number for groupings, you can add Partition By to reset the number to 1

Answer 2

You can check the value of the previous sync date field and output a 0 or blank if required.
=CDec(iif(IsNothing(previous(Fields!SyncDate.Value)), 0.0, format(DateDiff("s",previous(Fields!SyncDate.Value),Fields!Date.Value)/60,"0.00")))
Without row_number you can use an outer apply to get the last sync date in the query and pre-calculate the 'sync delta':
SELECT
p.ToppingCount,
p.DriverName,
p.Date,
p.SyncDate,
CASE
WHEN i.SynchDate IS NULL THEN 0.0
ELSE DATEDIFF(SS, l.SyncDate, p.Date) / 60.0
END AS SyncTimeDelta,
p.BranchName,
p.Branch,
COUNT(p.Pizza) AS Count
FROM System p
OUTER APPLY
(
-- Join clause depends on how you're grouping
-- in the report.
SELECT TOP 1
i.SyncDate
FROM System i
WHERE
i.SystemSource = 'newsys'
AND i.Branch = p.Branch
AND i.DriverName = p.DriverName
AND i.Date < p.Date
ORDER BY
i.SyncDate DESC
) l
WHERE
(p.Date BETWEEN #datefrom AND #DateTo) AND
(p.Branch IN (#branch)) AND
(p.SystemSource = 'newsys') AND
(p.SystemSource <> 'oldsys') -- This will never be evaluated
GROUP BY
p.Pizza, p.ToppingCount, p.DriverName, p.Date, p.SyncDate, p.BranchName, p.Branch, l.SyncDate
ORDER BY
p.Branch, p.DriverName, p.Date
This way you can just sum the sync delta in the report. I don't know enough about the query but I've made the assumption that:
You want the time between the last sync date before the current [date] column as per your formula for the given branch and driver.
I apologize if there are syntax issues, I'm typing this up without reference.