Connect to NASA Data from PowerBuilder via ADO.NET

This article demonstrates using the CData API Driver for ADO.NET in PowerBuilder, showcasing the ease of use and compatibility of these standards-based controls across various platforms and development technologies that support Microsoft .NET, including Appeon PowerBuilder.

This article shows how to create a basic PowerBuilder application that uses the CData API Driver for ADO.NET to retrieve data.

1. In a new WPF Window Application solution, add all the Visual Controls needed for the connection properties. Below is a typical connection string:

   Profile=C:\profiles\NASA.apip;AuthScheme=APIKey;APIKey=YOUR_NASA_API_KEY

   Using API Key Authentication

   Most NASA API endpoints (APOD, NeoWS, DONKI, TechTransfer) require a NASA API key. Register for a free key at https://api.nasa.gov. The default DEMO_KEY provides limited access (30 requests/hour, 50 requests/day); a registered key allows 1,000 requests/hour.

   The following endpoints do not require an API key and work without authentication: EONET (Earth Observatory Natural Event Tracker), EPIC (Earth Polychromatic Imaging Camera), NASA Image and Video Library, and TechPort.

   After obtaining your API key, set the following connection properties:

   • AuthScheme: Set this to APIKey.
   • APIKey: Set this to your NASA API key. Use DEMO_KEY for limited testing.

   Example Connection String

   Profile=C:\profiles\NASA.apip;AuthScheme=APIKey;APIKey=YOUR_NASA_API_KEY
   

   Connecting to NASA

   Once the authentication is configured, you can connect to NASA and query data from any of the available tables such as AstronomyPictureOfDay, NearEarthObjectFeed, EonetEvents, and NasaImageLibrary.

2. Add the DataGrid control from the .NET controls.
3. Configure the columns of the DataGrid control. Below are several columns from the Account table:

   
   <DataGrid AutoGenerateColumns="False" Margin="13,249,12,14" Name="datagrid1" TabIndex="70" ItemsSource="{Binding}">
   <DataGrid.Columns>
       <DataGridTextColumn x:Name="idColumn" Binding="{Binding Path=Id}" Header="Id" Width="SizeToHeader" />
       <DataGridTextColumn x:Name="nameColumn" Binding="{Binding Path=}" Header="" Width="SizeToHeader" />
   		...
   	</DataGrid.Columns>
   </DataGrid>
   

4. Add a reference to the CData API Driver for ADO.NET assembly.

Connect the DataGrid

Once the visual elements have been configured, you can use standard ADO.NET objects like Connection, Command, and DataAdapter to populate a DataTable with the results of an SQL query:

System.Data.CData.API.APIConnection conn 
conn = create System.Data.CData.API.APIConnection(connectionString)

System.Data.CData.API.APICommand comm 
comm = create System.Data.CData.API.APICommand(command, conn)

System.Data.DataTable table
table = create System.Data.DataTable

System.Data.CData.API.APIDataAdapter dataAdapter
dataAdapter = create System.Data.CData.API.APIDataAdapter(comm)
dataAdapter.Fill(table)	
datagrid1.ItemsSource=table.DefaultView

The code above can be used to bind data from the specified query to the DataGrid.