Chapter 5. Adding Database Support and Exception Handling to the RealNorthwind WCF Service

In the previous chapter, we created a WCF service with two layers. We didn't add the third layer, that is, the data access layer. Therefore, all of the service operations just returned a fake result from the business logic layer.

In this chapter, we will add the third layer to the WCF service. We will also introduce message contracts for service message exchange and fault contracts for service error handling.

We will accomplish the following tasks in this chapter:

• Create the data access layer project

• Modify the business logic layer to call the data access layer

• Prepare the Northwind database for the service

• Connect the WCF service to the Northwind database

• Test the service with the data access layer

• Add a fault contract to the service

• Throw a fault contract exception to the client

• Catch the fault contract in the client program

• Test the service fault contract