Working with REST Data in LINQPad

The CData ADO.NET Provider for REST enables you to use standard ADO.NET interfaces like LINQ and the Entity Framework to work with REST data. This article will demonstrate the process of establishing a connection from LINQPad and executing LINQ queries.

Create the Data Model

After downloading and installing both the provider and LINQPad, create a new class library project within Visual Studio.

See the help documentation for a guide to setting up an EF 6 project to use the provider.

1. Right-click your project and click Add -> New Item -> ADO.NET Entity Data Model. In the resulting dialog, select Code First from database. Click New Connection and specify the connection string options in the resulting wizard.

   See the Getting Started chapter in the data provider documentation to authenticate to your data source: The data provider models REST APIs as bidirectional database tables and XML/JSON files as read-only views (local files, files stored on popular cloud services, and FTP servers). The major authentication schemes are supported, including HTTP Basic, Digest, NTLM, OAuth, and FTP. See the Getting Started chapter in the data provider documentation for authentication guides.

   After setting the and providing any authentication values, set to "XML" or "JSON" and set to more closely match the data representation to the structure of your data.

   The property is the controlling property over how your data is represented into tables and toggles the following basic configurations.

   • Document (default): Model a top-level, document view of your REST data. The data provider returns nested elements as aggregates of data.
   • FlattenedDocuments: Implicitly join nested documents and their parents into a single table.
   • Relational: Return individual, related tables from hierarchical data. The tables contain a primary key and a foreign key that links to the parent document.

   See the Modeling REST Data chapter for more information on configuring the relational representation. You will also find the sample data used in the following examples. The data includes entries for people, the cars they own, and various maintenance services performed on those cars.

   Below is a typical connection string:

   DataModel=Relational;URI=C:/people.xml;Format=XML;

   👁 The required connection properties in the Entity Data Model Configuration Wizard. (JSON is shown.)
   

2. Select the desired tables and views and click Finish to create the data model.

   👁 The last step of the Entity Data Model Configuration Wizard, where tables are imported into the entity model.
   
3. Build the project. The generated files can be used to create the REST connection in LINQPad.

Connect to REST Data in LINQPad

After you have obtained the required connection properties and created the data model assembly, follow the steps below to start using the data model in LINQPad.

1. Open LINQPad and click Add Connection.

2. Select the "Use a typed data context from your own assembly" option.

3. Select Entity Framework DbContext.

   👁 The Choose Data Context dialog.
   

4. Click Browse next to the Path to Custom Assembly box and browse to your project folder. Browse to the .dll or .exe under the bin folder.

5. Select the name of the DbContext.
6. If you saved your connection string in App.Config, specify the path to the App.config.

You can now query REST data through LINQPad. For examples of the supported LINQ queries, see the "LINQ and Entity Framework" chapter in the help documentation.