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

Different between Events and Delegates

Main Differences

1. events can be used in an interface
2. events can be only fired from the class in which it is declared

The below article explains about the difference between Events and Delegates.
http://blog.monstuff.com/archives/000040.html

TableSplitting with Entity Framework

Table Splitting is design of mapping Multiple Conceptual Entities to Single Storage Table.

Check this link for more info

http://www.deveducate.com/blog/post/2010/12/14/Entity-Framework-Modeling-Table-Splitting.aspx

MetadataException: Unable to load the specified metadata resource

I faced an issue while trying to open an EntityConnneciton with the following message.

MetadataException: Unable to load the specified metadata resource.

The issue is the i had the Entity Model in a seperate assembly and the assembly doesn't load itsef if you try to connect to it using EntityConnection classes. If you use the object context class generated by the model then we don't face this issue.