How to perform correctly “group by” in linq on DataTable inside vb code?

Question

Why isn\'t the following group by clause working? The original question was how do I perform group in LINQ inside vb code (dot.net v4.0) with DataTable and sum on the group?

Answer 1

Dim testQuery =
                 (From e In table
                  Group e By Key = New With {.GroupName = e("GroupName")}.GroupName,
                                   New With {.ProductName = e("ProductName")}.ProductName Into Group
              Select New With {
                .ProductName = ProductName,
                .QTY = Group.Sum(Function(x) Convert.ToInt32(x("QTY"))),
                .GroupName = Key.ToString
             })