How to print the serial number for the groups in SSRS

Hello;

I am having the data as below

Part 1 10
Part 2 20
Part 1 30
Part 1 40

and I want it to be appearing in the SSRS report as below

S# Part TotalQty
1 Part 1 80
2 Part 2 20

I used the expression
=RowNumber(“Part_Num”) over (OrderBy Fields!OrderDtl_PartNum.Value)

Its giving me an expression error. Please suggest me a solution

Thanks friends

You need to use the groupings in SSRS and it will auto sum them for you. So, in your example, you should create a row group on Part and then add a detail group below it. Do not use the detail group in the report body, enter all of your fields in the Part Group row.

Hi John I am getting the total qty correctly but I am not able to populate the Serial Number

Serial Number? Do you mean Lot instead? 1 SN can only be assigned to 1 part, it is not 1 to many.