Programming Entity Framework

Programming Entity Framework is a thorough introduction to Microsoft's new core framework for modeling and interacting with data in .NET applications. This highly-acclaimed book not only gives experienced developers a hands-on tour of the Entity Framework and explains its use in a variety of applications, it also provides a deep understanding of its architecture and APIs. Although this book is based on the first version of Entity Framework, it will continue to be extremely valuable as you shift to the Entity Framework version in .NET Framework 4.0 and Visual Studio 2010. From the Entity Data Model (EDM) and Object Services to EntityClient and the Metadata Workspace, this book covers it all.

Working with Object Services

(Excerpt from Chapter 9)

Most of the work that you will do in the Entity Framework will involve the objects that are based on the entities in your Entity Data Model (EDM). The Object Services API is the part of the framework that creates and manages these objects. Although you have worked with Object Services in much of the code you wrote in earlier chapters, and you have touched on a variety of its topics along the way, you haven't yet seen the big picture. The API has a lot of tools that you can access directly to take charge of your entity objects.

This chapter is devoted to giving you a better understanding of the Object Services API: what it is responsible for, what it does under the covers, and some of the ways that you can take advantage of it.
You will learn about how queries are processed and turned into objects, how these objects are managed during their life cycle, and how Object Services is responsible for the way entities are related to each other. You will see how the ObjectQuery works and how it relates to LINQ to Entities queries under the covers. This chapter will also give you a better understanding of how Object Services manages an entity's state, beyond what you learned in Chapter 5.
As you become more familiar with the purpose, features, and implementation of Object Services, you will be better prepared to solve some of the challenges you will face as you move from using the `drag-and-drop` application-building features that Visual Studio provides to building enterprise applications where you need to have much more control over how all of the pieces of the application interact with one another.

Where Does Object Services Fit into the Framework?

Object Services is at the top of the food chain in the Entity Framework. The namespace for this API is System.Data.Objects, and it provides all of the necessary functionality for generating and interacting with the objects that are shaped by the conceptual layer and are populated from a data store.
As shown in the figure, Object Services initially processes your LINQ to Entities and ObjectQuery queries, as well as materializes the query results into objects.

Object Services as it relates to the rest of the Entity Framework stack
You can divide the core functionality of Object Services into seven areas:
1) Query processing
2) Object materialization
3) Object management
4) Object relationship management
5) Object state management
6) Database Manipulation Language (DML) command processing
7) Additional features

User review
Your Train to the Data Access Future has Arrived!
Over the past 20 years of my career as a software developer, application architects have recommended that enterprise applications be developed using multiple tiers to separate the concerns of the user interface, business logic and data access layers. The challenge for programmers has been to determine how one would actually build and maintain such a beast. Microsoft has addressed part of the data portion of this architecture recommendation by introducing the `Entity Framework` (EF) to the .Net technology stack.

In most cases, databases are designed for the database administrator and not the application developer. The EF allows a programmer to add an Entity Data Model (EDM) to a client application. With an EDM, programmers can create application centric object interfaces to their data sources without having to concern themselves with the nuances of the underlying data structures. The EF takes care of translating these application objects to the SQL statements that interact with the database. So, what will lead us on this journey?

The `Programming Entity Framework` book can be divided into two major sections. Chapters 1-14 provides an introduction to all the major EF concepts while Chapters 15-23 covers advanced topics. There is a website at http://learnentityframework.com/learnentityframework/ that supports the book and allows you to download database scripts and sample applications. (As a side note, I learned from this site that the author has agreed to update her book to cover changes introduced in the 2010 version of Visual Studio.)

I like the fact that Ms. Lerman provides both VB and C# code side by side with all of her examples (my personal goal is to become fluent in both languages). The book is peppered with side notes (designated by three paw prints) that make some clarification or add pertinent information to the page.

I did a search of alternative books that cover this same subject. I investigated the online information provided by Microsoft. None of the books I researched (as well as the Microsoft articles online) came close to the scope and readability of this book. Lerman does a great job of balancing her independent point of view on this subject with the insider tips and information that make for a good read.

The myriad of tools and components contained in the EF are now a strategic part of Microsoft's data access strategy going forward. So don't get left behind. I recommend `Programming Entity Framework` as your train to the data access future. I guess that would make Julia Lerman your Conductor and Engineer on this trip as well ,,. ;-).


User review
Not well executed, but better than nothing
EF is a reasonably complex topic and I applaud anyone who makes a sincere attempt to write about it. However, months after reading this book, I have decided that it only marginally helped me in my training for EF. It is written in a disjointed fashion as if the author was still puzzling the material even as she was submitting it for publication. If her knowledge of the subject is comprehensive, then the problem is she doesn't have the ability to convey it in a comprehensible way. I got it because there was, and is, still relatively little material on the market about EF. It did help me a little when I decided to use it as an occasional reference; sometimes I found a concept that helped me in isolation. Until a lot more and better quality material information is published, if you must learn EF for a medium to large project, then I recommend getting everything you can get your hands on including this book, but rely more on MSDN, StackOverflow, random Google searches and, of course, experimentation to round out your education.

Where is Stephen Walther when you really need him?

FWIW: The good news is that once you understand EF, it really will change the way you write code, and your applications will absolutely fly.

User review
Impressed
I have hundreds of computer books on programming in the last 24 years. This is by without a doubt the best written, most informative on the subject matter of any book I ever purchased. Julia Lerman knows her subject matter and is able to pass her knowledge on without losing the reader along the way. O'Reilly needs to hear more from her! Great author and excellient work! I want to thank Julia Lerman for her time and attention to details she put into this effort! Thanks

User review
Great book!
This is a great book for both the beginner programmer willing to know about the EF and for the seasoned coder who wants the details of this new data access technology.
Sample code is available in both VB and C#, with good examples and techniques.

User review
Pour it on,,
This book is absoluetely amazing.
If you don't know what you are talking after doing the hands on, on this book, then the book has done it's job
The first ten chapters are intro to advance ling sql entity framework-the author waste no time explaining the approach in lamens- this i liked alot me being a learner
I espectially liked the N-tier implementation towards the end of the book
The book has included some wcf and wpf implementations too- no chance of getting bored with this book