D4Modelizer is a free tool to generate C# code from a datasource (SqlServer, Access, mySQL, DB/2, MSDE, etc.).
It creates objects from tables and fields, and manages persistence, adding methods like AddObject, RemoveObject, modifyObject, getObject. The vendor notes that more methods and Databases will be added soon.
The current version can produce Visual Studio objects including library generation.
You can download a free and complete version on our website.