Book Image

Entity Framework Tutorial (Update) - Second Edition

By : Joydip Kanjilal
Book Image

Entity Framework Tutorial (Update) - Second Edition

By: Joydip Kanjilal

Overview of this book

The ADO.NET Entity Framework from Microsoft is a new ADO.NET development framework that provides a level of abstraction for data access strategies and solves the impedance mismatch issues that exist between different data models This book explores Microsoft’s Entity Framework and explains how it can used to build enterprise level applications. It will also teach you how you can work with RESTful Services and Google’s Protocol Buffers with Entity Framework and WCF. You will explore how to use Entity Framework with ASP.NET Web API and also how to consume the data exposed by Entity Framework from client applications of varying types, i.e., ASP.NET MVC, WPF and Silverlight. You will familiarize yourself with the new features and improvements introduced in Entity Framework including enhanced POCO support, template-based code generation, tooling consolidation and connection resiliency. By the end of the book, you will be able to successfully extend the new functionalities of Entity framework into your project.
Table of Contents (16 chapters)
Entity Framework Tutorial Second Edition
About the Author
About the Reviewers

State management, identity management, and relationship management

Change tracking or tracking the modifications to objects in Entity Framework is handled by a component called ObjectStateManager. The context delegates change tracking management calls to this component at runtime. The state manager is responsible for adding, deleting, and attaching entities to and from the context. It also holds the in-memory collection of objects, does the necessary identity checks, and keeps track of relationships of entities. Note that ObjectStateManager is exposed as a property called ObjectStateManager of ObjectContext.

Here's how the ObjectStateManager instance of the SecurityDBEntities class can be accessed:

using (SecurityDBEntitiesvar ctx = new SecurityDBEntities())
         var objStateManager = ctx.ObjectStateManager;

In relational databases, relationships, or associations between the database tables are defined through the use of foreign keys. A foreign key is just another column in...