Getting ready

Make sure you have a sample database, such as Northwind, installed in a local SQL Server instance. You can use an SQL Express instance (the free version of SQL Server) for convenience.

The source code for this recipe can be found in the \ch01\ODataLINQ2SQLServiceSln\ directory.

How to do it...

You can follow the steps given for creating an OData service from LINQ to SQL data entities:

How it works...

Although we directly use the LINQ to SQL data model class as the data source, the WCF Data Service runtime actually treats the LINQ to SQL data model class like a custom data source type. Therefore, any public member (of the data model class) who implements the IQueryable interface will be exposed as an entity set in the generated service. We will talk more about using custom data source type for WCF Data Service within the Using custom data objects as the data source of WCF Data Service recipe of this chapter.

There's more...

By default, the WCF Data Service, which uses the LINQ to SQL data model class, does not support editing/updating operations. In order to make the LINQ to SQL based WCF Data Service support editing/updating, we need to implement the IUpdatable interface (under System.Data.Services namespace) on the LINQ to SQL data model class (see the following code snippet).

partial class NorthwindDataContext: IUpdatable
{
......
}

For detailed information about implementing IUpdatable interface for LINQ to SQL data model class, you can refer to the following MSDN reference:

How to: Create a Data Service Using a LINQ to SQL Data Source (WCF Data Services) available at http://msdn.microsoft.com/en-us/library/ee373841.aspx

See also