Question

How do you do OrderBy on a collection within an entity?

For example, this sorts Customers by Name (string)

entities.Customers.OrderBy(c => c.Name) ...

If Customer had an Orders property that was a collection of Order entities and for some reason you wanted to sort Customers on that (lets say by order date), can you do that?

entities.Customers.OrderBy(c => c.Orders.?)

Answer 1

It’s not clear how to sort customers without orders, so

var query = entities.Customers
                    .Where(c => c.Order.Any())
                    .OrderBy(c => c.Orders.FirstOrDefault().Date)