LINQ to OpenWeatherMap Data

This article illustrates using LINQ to access tables within the OpenWeatherMap via the CData ADO.NET Data Provider for OpenWeatherMap. 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 OpenWeatherMap Data Source".

4. Enter your data source connection information.

   Using API Key Authentication

   To obtain an API key, sign up for a free account at https://openweathermap.org/api and navigate to the API keys section of your dashboard. Copy your API key for use in the connection configuration.

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

   • AuthScheme: Set this to APIKey.
   • APIKey: Set this to your OpenWeatherMap API key.

   Below is a typical connection string:

   Profile=C:\path\to\OpenWeatherMap.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your_openweathermap_api_key";


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 accumulatedprecipitationQuery = from accumulatedprecipitation in context.AccumulatedPrecipitation
  select accumulatedprecipitation;

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

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