How to update entity from new created detached entity

Question

Let's say I created a new product like this:

Product p=new Product(){ Id= 2,Name="some name"};

My product variable has never been attached to a data context, how can I attach this entity so that my existing product in the database with Id=2 gets update with the name of my detached product?

Answer 1

I hope something similar would work

 Datacontext db = new Datacontext(); // replace with your DataContext
 Product originalProduct = 
         db.Products.Single(p => p.Id == 2); // get product with Id 2

 originalProduct.Name = "SomeName";  // only reset Name prop
 originalProduct = p;                // or you may assign p to originalProduct
 db.SubmitChanges();                 // submit changes to DB