Self-Tracking Entities - Introduction

In an Entity Framework application, an object context is responsible for tracking changes in the entities in an object graph.

However, in N-tier scenarios, the object context might not be available on the tier that modifies the entities. Starting with the .NET Framework version 4, self-tracking entities can help you track changes in any tier.

Starting with Microsoft Visual Studio 2010, the ADO.NET Self-Tracking Entity Generator template generates self-tracking entities.

template item generates two .tt (text template) files:

• <model name>.tt and
• <model name>.Context.tt.

The <model name>.tt file generates

• the entity types and
• a helper class that contains the change-tracking logic that is used by self-tracking entities and
• the extension methods that allow setting state on self-tracking entities.

The <model name>.Context.tt file generates

• a typed ObjectContext and
• an extension class that contains ApplyChanges methods for the ObjectContext and ObjectSet classes