Connect to REST Data from PowerBuilder via ADO.NET

This article demonstrates using the CData ADO.NET Provider for REST 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 ADO.NET Provider for REST to perform reads and writes.

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

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

   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.

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=[ personal.name.first ]}" Header="[ personal.name.first ]" Width="SizeToHeader" />
   		...
   	</DataGrid.Columns>
   </DataGrid>
   

4. Add a reference to the CData ADO.NET Provider for REST 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.REST.RESTConnection conn 
conn = create System.Data.CData.REST.RESTConnection(connectionString)

System.Data.CData.REST.RESTCommand comm 
comm = create System.Data.CData.REST.RESTCommand(command, conn)

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

System.Data.CData.REST.RESTDataAdapter dataAdapter
dataAdapter = create System.Data.CData.REST.RESTDataAdapter(comm)
dataAdapter.Fill(table)	
datagrid1.ItemsSource=table.DefaultView

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