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

Using the AvalaraDataReader

The AvalaraDataReader retrieves data faster than the AvalaraDataAdapter because it can retrieve data in pages. As you read data from the AvalaraDataReader, it periodically requests the next page of results from the data source, if required. This causes results to be returned at a faster rate. The following example selects all the columns from the Transactions table:

C#

string connectionString = "User=MyUser;Password=MyPassword;";

using (AvalaraConnection connection = new AvalaraConnection(connectionString)) {
  AvalaraCommand cmd = new AvalaraCommand("SELECT * FROM Transactions", connection);
  
  AvalaraDataReader rdr = cmd.ExecuteReader();

  while (rdr.Read()) {
    Console.WriteLine(String.Format("\t{0} --> \t\t{1}", rdr["Id"], rdr["TotalTax"]));
  }
}

VB.NET

Dim connectionString As String = "User=MyUser;Password=MyPassword;"

Using connection As New AvalaraConnection(connectionString)
  Dim cmd As New AvalaraCommand("SELECT * FROM Transactions", connection)

  Dim rdr As AvalaraDataReader = cmd.ExecuteReader()

  While rdr.Read()
    Console.WriteLine([String].Format(vbTab & "{0} --> " & vbTab & vbTab & "{1}", rdr("Id"), rdr("TotalTax")))
  End While
End Using