Connect to Harvest Data from PowerBuilder via ADO.NET

This article demonstrates using the CData ADO.NET Provider for Harvest 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 Harvest 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\Harvest.apip;ProfileSettings='APIKey=my_personal_key;AccountId=_your_account_id';

   Start by setting the Profile connection property to the location of the Harvest Profile on disk (e.g. C:\profiles\Harvest.apip). Next, set the ProfileSettings connection property to the connection string for Harvest (see below).

   Harvest API Profile Settings

   To authenticate to Harvest, you can use either Token authentication or the OAuth standard. Use Basic authentication to connect to your own data. Use OAuth to allow other users to connect to their data.

   Using Token Authentication

   To use Token Authentication, set the APIKey to your Harvest Personal Access Token in the ProfileSettings connection property. In addition to APIKey, set your AccountId in ProfileSettings to connect.

   Using OAuth Authentication

   First, register an OAuth2 application with Harvest. The application can be created from the "Developers" section of Harvest ID.

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

   • ProfileSettings: Set your AccountId in ProfileSettings.
   • AuthScheme: Set this to OAuth.
   • OAuthClientId: Set this to the client ID that you specified in your app settings.
   • OAuthClientSecret: Set this to the client secret that you specified in your app settings.
   • CallbackURL: Set this to the Redirect URI that you specified in your app settings.
   • InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to manage how the driver obtains and refreshes the OAuthAccessToken.
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=Id}" Header="Id" Width="SizeToHeader" />
   		...
   	</DataGrid.Columns>
   </DataGrid>
   

4. Add a reference to the CData ADO.NET Provider for Harvest 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.