The CData ADO.NET Provider for FreshBooks implements two ADO.NET interfaces you can use to retrieve data from FreshBooks: FreshBooksDataAdapter and FreshBooksDataReader objects. Whereas FreshBooksDataAdapter objects retrieve a single result set of all the data that matches a query, FreshBooksDataReader objects fetch data in subset increments as needed.

Using the FreshBooksDataAdapter

Use the adapter's Fill method to retrieve data from the data source. An empty DataTable instance is passed as an argument to the Fill method. When the method returns, the DataTable instance is populated with the queried data. Note that the FreshBooksDataAdapter is slower than the FreshBooksDataReader because the Fill method needs to retrieve all data from the data source before returning.

The following example selects the Email and Username columns of the Clients table:

C#

string connectionString = "InitiateOAuth=GETANDREFRESH;OAuthClientId=MyClientId;OAuthClientSecret=MyClientSecret;CallbackURL=http://localhost:33333";

using (FreshBooksConnection connection = new FreshBooksConnection(connectionString)) {
  FreshBooksDataAdapter dataAdapter = new FreshBooksDataAdapter(
  "SELECT Email, Username FROM Clients", connection);

  DataTable table = new DataTable();
  dataAdapter.Fill(table);

  Console.WriteLine("Contents of Clients.");

  foreach (DataRow row in table.Rows) {
    Console.WriteLine("{0}: {1}", row["Email"], row["Username"]);
  }
}

VB.NET

Dim connectionString As String = "InitiateOAuth=GETANDREFRESH;OAuthClientId=MyClientId;OAuthClientSecret=MyClientSecret;CallbackURL=http://localhost:33333"

Using connection As New FreshBooksConnection(connectionString)
  Dim dataAdapter As New FreshBooksDataAdapter("SELECT Email, Username FROM Clients", connection)

  Dim table As New DataTable()
  dataAdapter.Fill(table)

  Console.WriteLine("Contents of Clients.")

  For Each row As DataRow In table.Rows
    Console.WriteLine("{0}: {1}", row("Email"), row("Username"))
  Next
End Using