sum two values from different datasets using lookups in report builder - ssrs-2008

Question

I have a report that should read values from 2 dataset by Currency:
Dataset1: Production Total
Dataset2: Net Total
Ive tried to use:
Lookup(Fields!Currency_Type.Value,
Fields!Currency_Type1.Value,
Fields!Gross_Premium_Amount.Value,
"DataSet2")
This returns only the first amount from dataset 2.
I've tried Lookupset function as well but it didn't SUM the retrieved values.
Any help would be appreciated.

Answer 1

Thanks Jamie for the reply.
THis is what i have done and it worked perfect:
From Report Properties--> Code , write the below function:
Function SumLookup(ByVal items As Object()) As Decimal
If items Is Nothing Then
Return Nothing
End If
Dim suma As Decimal = New Decimal()
Dim ct as Integer = New Integer()
suma = 0
ct = 0
For Each item As Object In items
suma += Convert.ToDecimal(item)
Next
If (ct = 0) Then return 0 else return suma
End Function
Then you can call the function:
code.SumLookup(LookupSet(Fields!Currency_Type.Value, Fields!Currency_Type1.Value,Fields!Gross_Premium_Amount.Value, "DataSet2"))

Answer 2

Yes, Lookup will only return the first matching value. Three options come to mind:
Change your query, so that you only need to get one value: use a GROUP BY and SUM(...) to combine your two rows in the query. If you are using this query other places, then make a copy and change that.
Is there some difference in the rows? Such as one is for last year and one is for this year? If so, create an artificial lookup key and lookup the two values separately:
=Lookup(Fields!Currency_Type.Value & ","
& YEAR(DATEADD(DateInterval.Year,-1,today())),
Fields!Currency_Type1.Value & ","
& Fields!Year.Value,
Fields!Gross_Premium_Amount.Value,
"DataSet2")
+
Lookup(Fields!Currency_Type.Value & ","
& YEAR(today()),
Fields!Currency_Type1.Value & ","
& Fields!Year.Value,
Fields!Gross_Premium_Amount.Value,
"DataSet2")
Use the LookupSet function as mentioned. With this you'll get a collection of the values back, and then need to add those together. The easiest way to do this is with embedded code in the report. Add this function to the report's code:
Function AddList(ByVal items As Object()) As Double
If items Is Nothing Then
Return 0
End If
Dim Total as Double
Total = 0
For Each item As Object In items
Total = Total + CDbl(item)
Next
Return Total
End Function
Now call that with:
=Code.AddList(LookupSet(Fields!Currency_Type.Value,
Fields!Currency_Type1.Value,
Fields!Gross_Premium_Amount.Value,
"DataSet2"))
(Note: this code was not tested. I just composed it in the Stack Overflow edit window & I'm no fan of VB. But it should give you a good idea of what to do.)