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

Using the HubDBDataReader

The HubDBDataReader retrieves data faster than the HubDBDataAdapter because it can retrieve data in pages. As you read data from the HubDBDataReader, 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 NorthwindProducts table:

C#

string connectionString = "AuthScheme=OAuth;OAuthClientID=MyOAuthClientID;OAuthClientSecret=MyOAuthClientSecret;CallbackURL=http://localhost:33333;";

using (HubDBConnection connection = new HubDBConnection(connectionString)) {
  HubDBCommand cmd = new HubDBCommand("SELECT * FROM NorthwindProducts", connection);
  
  HubDBDataReader rdr = cmd.ExecuteReader();

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

VB.NET

Dim connectionString As String = "AuthScheme=OAuth;OAuthClientID=MyOAuthClientID;OAuthClientSecret=MyOAuthClientSecret;CallbackURL=http://localhost:33333;"

Using connection As New HubDBConnection(connectionString)
  Dim cmd As New HubDBCommand("SELECT * FROM NorthwindProducts", connection)

  Dim rdr As HubDBDataReader = cmd.ExecuteReader()

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