Question

I am trying to get the first order that has been placed by each customer based on a Timestamp.

Below is some pseudo code, that doesn’t compile :

var minOrders = (from Orders in DataSet.Orders select Orders.OrderTimestamp).Min()
                 join Customers in DataSet.Customers on Orders.CustomerId equals Customers.CustomerId
                 select new
                 {
                    Customers.Name,
                    Orders.OrderAmount
                 });

Any pointers as to the correct LINQ structure would be great, Thanks.

Joe

Answer 1

Based on the code you have written i supose you need the first order of each costumor

Your statement would be then

var minOrders = from customer in DataSet.Customers
                let order = (from o in DataSet.Orders
                             where o.CustomerId == customer.CustomerId
                             order by o.OrderTimestamp
                             select o).first()
                select new
                 {
                    customer.Name,
                    order.OrderAmount
                 });