使用另一个LINQ对象更新一个LINQ对象中的列

I have two LINQ objects which have exactly the same columns and I would like to be able to update one with the fields from the other. I first create a new object from some data in a file, then I query the database for an existing item with the same ID. What I would like to be able to do is update the existing objects details with the newly created objects details. I have two LINQ objects which have exactly the