The LINQ to SQL platform works faster than the ADO.NET Entity Framework. It occurs because LINQ to SQL has no difficult mappings which exist in ADO.NET Entity Framework. However, many examples, which are shown in ADO.NET Data Services, are based on ADO.NET Entity Framework. It is logical, that in the loaded applications, the power of ADO.NET Entity Framework is not important; however, a speed criterion is very important. ADO.NET Data Services platform does not impose constraints on data access technology and also allows construction of web service on the basis of LINQ to SQL.

However, in practice, while using ADO.NET Data Services together with LINQ to SQL, some questions may appear. The goal of this article is to clear up such questions and to use ADO.NET Data Services and LINQ to SQL correctly.

There are two problems which appear while using LINQ to SQL as a data access platform for service of ADO.NET Data Services: detection of key fields in data model and updating of data.