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

Using the GoogleContactsDataReader

The GoogleContactsDataReader retrieves data faster than the GoogleContactsDataAdapter because it can retrieve data in pages. As you read data from the GoogleContactsDataReader, 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 [My Contacts] table:

C#

string connectionString = "InitiateOAuth=GETANDREFRESH;";

using (GoogleContactsConnection connection = new GoogleContactsConnection(connectionString)) {
  GoogleContactsCommand cmd = new GoogleContactsCommand("SELECT * FROM [My Contacts]", connection);
  
  GoogleContactsDataReader rdr = cmd.ExecuteReader();

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

VB.NET

Dim connectionString As String = "InitiateOAuth=GETANDREFRESH;"

Using connection As New GoogleContactsConnection(connectionString)
  Dim cmd As New GoogleContactsCommand("SELECT * FROM [My Contacts]", connection)

  Dim rdr As GoogleContactsDataReader = cmd.ExecuteReader()

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