Hi EveryBody

I have very Requirement, It not mine only, It's requirement for all Application Developer.

I have One Class- Let Explain

Invoice
========
InvoiceDate, Item, Qty, Price, Total

I want to create another LIstView for Monthly Sale based on Invoice.
Select InvoiceDate, Sum(Total) From Invoice Group By InvoiceDate.
How do I implement this Query By XPCollection on another ListView 

Thanks

Hemant