public void Demonstrate_DbReference() { var session = new MongoSession(); var supplier = new Supplier { Name = "Acme" }; session.Save(supplier); var product = new Product { Name = "Shovel", Price = "17.50", Sku = "a3k4j22je9", Weight = "11", Supplier = new DbReference<Supplier>(supplier.Id) }; session.Save(product); var fetched = session.Query<Product>().Where(x => x.Sku == product.Sku); Assert.AreEqual(fetched.First().Supplier.Id, supplier.Id); var fetchedSupplier = fetched.First().Supplier.Fetch(() => session.GetDb()); Assert.AreEqual(fetchedSupplier.Name, supplier.Name); }