The concept of object relational mapping (ORM) is not new. An ORM is a class (called an entity in this context) that has properties or fields that map to database columns. In this article, I will show you how easy it is to use LINQ to SQL to define an ORM, mapping a class to a database table, and then query that table with LINQ using a DataContext. A DataContext plays the role of the connection here.
The article continues at http://www.developer.com/db/article.php/3732556