Book Image

WCF 4.0 Multi-tier Services Development with LINQ to Entities

By : Mike Liu
Book Image

WCF 4.0 Multi-tier Services Development with LINQ to Entities

By: Mike Liu

Overview of this book

WCF is the Microsoft model for building services, whereas LINQ to Entities is the Microsoft ORM for accessing underlying data storage. Want to learn both? You would normally have to dig through huge reference tomes—so wouldn't you agree that a simple-to-follow practical tutorial on WCF and LINQ to Entities is the way to get ahead?This book is the quickest and easiest way to learn WCF and LINQ to Entities in Visual Studio 2010. WCF and LINQ to Entities are both powerful yet complex technologies from Microsoft—but you will be surprised at how easily this book will get you get up and running with them.Mastery of these two topics will quickly enable you to create Service-Oriented applications, and allow you to take your first steps into the world of Service Oriented Architecture without becoming overwhelmed.Through this book, you will learn what's going on behind the scenes with WCF, and dive into the basic yet most useful techniques for LINQ to Entities. You will develop three real-world multi-tiered WCF services from beginning to end, with LINQ to Entities being used in the data access layer of the services. Various clients including windows console applications, the WCF Test Client, Windows Form applications and WPF applications will be created to test these WCF services. By the end of this book, you will be 100% confident that you know WCF and LINQ to Entities, not only in theory, but with sound real-world experience.
Table of Contents (16 chapters)
WCF 4.0 Multi-tier Services Development with LINQ to Entities
About the Author
About the Reviewers

Testing concurrency with WCF Test Client

Now we have concurrent support added to the service let's test it with the built-in WCF Test Client.

Press Ctrl + F5 to start the program. Click on GetProduct, enter a valid product ID, and then click on the Invoke button to get the product details. You should have a screen like the following image.

From this image we know the product, RowVersion, is returned from the database to the client. It is of the Byte[] type.

Now click on UpdateProduct and enter the same product ID, a new name, quantity per unit, and unit price. However, you can't enter a value to the RowVersion field for this update because it is of the byte[] type.

If you click on the Invoke button to call the service you will get an exception like this:

From this image we can see that the update failed due to concurrency control (actually a concurrency exception is thrown in the data access layer). The reason is that we didn't pass in the original RowVersion for the object to be updated and...