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

Using the QuickBooksOnlineDataAdapter

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 QuickBooksOnlineDataAdapter is slower than the QuickBooksOnlineDataReader because the Fill method needs to retrieve all data from the data source before returning.

The following example selects the Id and GivenName columns of the Customers table:

C#

string connectionString = "InitiateOAuth=GETANDREFRESH;";

using (QuickBooksOnlineConnection connection = new QuickBooksOnlineConnection(connectionString)) {
  QuickBooksOnlineDataAdapter dataAdapter = new QuickBooksOnlineDataAdapter(
  "SELECT Id, GivenName FROM Customers", connection);

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

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

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

VB.NET

Dim connectionString As String = "InitiateOAuth=GETANDREFRESH;"

Using connection As New QuickBooksOnlineConnection(connectionString)
  Dim dataAdapter As New QuickBooksOnlineDataAdapter("SELECT Id, GivenName FROM Customers", connection)

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

  Console.WriteLine("Contents of Customers.")

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