c# Linq Compound Froms

I’m a bit embarrassed to admit this, but even after using linq in it’s various form for a couple of years now, I hadn’t really ever noticed compound from expressions e.g.

   1:  public void Linq16()

   2:  {

   3:      List<Customer> customers = GetCustomerList();

   4:   

   5:      var orders =

   6:          from c in customers

   7:          from o in c.Orders

   8:          where o.OrderDate >= new DateTime(1998, 1, 1)

   9:          select new { c.CustomerID, o.OrderID, o.OrderDate };

  10:   

  11:      ObjectDumper.Write(orders);

  12:  }

(from 101 LINQ samples)

Very handy for flattening an object hierarchy, etc. In the end though it’s just syntactic sugar over SelectMany (like a good deal of many LINQ functions). Anyway, another tool in the belt.