LINQ to Foursquare Data

This article illustrates using LINQ to access tables within the Foursquare via the CData ADO.NET Data Provider for Foursquare. To achieve this, we will use LINQ to Entity Framework, which facilitates the generation of connections and can be seamlessly employed with any CData ADO.NET Data Providers to access data through LINQ.

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

1. In a new project in Visual Studio, right-click on the project and choose to add a new item. Add an ADO.NET Entity Data Model.
2. Choose EF Designer from Database and click Next.
3. Add a new Data Connection, and change your data source type to "CData Foursquare Data Source".

4. Enter your data source connection information.

   Using API Key Authentication

   Foursquare Places API uses Service Key (Bearer token) authentication. To obtain a Service Key:

   1. Go to the Foursquare Developer Console at https://foursquare.com/developers/
   2. Create a new project or select an existing one
   3. Navigate to the API Keys section
   4. Generate a new Service Key for the Places API

   After setting the following connection properties, you are ready to connect:

   • AuthScheme: Set this to APIKey.
   • ServiceKey: Set this to your Foursquare Service Key obtained from the Developer Console.
   • XPlacesApiVersion: (Optional) Set this to the API version date. Defaults to 2025-06-17.

   Example APIKey connection string

   Profile=C:\profiles\Foursquare.apip;AuthScheme=APIKey;ProfileSettings='APIKey=your_personal_access_token';
   

   Below is a typical connection string:

   Profile=C:\profiles\Foursquare.apip;AuthScheme=APIKey;ProfileSettings='APIKey=your_personal_access_token';

👁 Required connection properties for the data source. (QuickBooks is shown.)

5. If saving your entity connection to App.Config, set an entity name. In this example we are setting APIEntities as our entity connection in App.Config.
6. Enter a model name and select any tables or views you would like to include in the model.

Using the entity you created, you can now perform select commands. For example:

APIEntities context = new APIEntities();

var autocompleteQuery = from autocomplete in context.Autocomplete
 select autocomplete;

foreach (var result in autocompleteQuery) {
 Console.WriteLine("{0} {1} ", result.Id, result.);
}

See "LINQ and Entity Framework" chapter in the help documentation for example queries of the supported LINQ.