Group By and Order By And Left Join

使用Northwind內的Table Orders

Dim db As New NorthwndDataClassesDataContext()
Dim query = From p In db.Orders() _
   Group By p.CustomerID _
   Into Total = Count(p.OrderID), avg = Average(p.OrderID) _
   Order By CustomerID _
   Select New NorthwndDLL.ddlCustomerID With {.CustomerID = CustomerID, _
                .Total = Total, _
                .avg = avg}