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

Using the SFMarketingCloudDataReader

The SFMarketingCloudDataReader retrieves data faster than the SFMarketingCloudDataAdapter because it can retrieve data in pages. As you read data from the SFMarketingCloudDataReader, 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 Subscriber table:

C#

string connectionString = "User=myUser;Password=myPassword;";

using (SFMarketingCloudConnection connection = new SFMarketingCloudConnection(connectionString)) {
  SFMarketingCloudCommand cmd = new SFMarketingCloudCommand("SELECT * FROM Subscriber", connection);
  
  SFMarketingCloudDataReader rdr = cmd.ExecuteReader();

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

VB.NET

Dim connectionString As String = "User=myUser;Password=myPassword;"

Using connection As New SFMarketingCloudConnection(connectionString)
  Dim cmd As New SFMarketingCloudCommand("SELECT * FROM Subscriber", connection)

  Dim rdr As SFMarketingCloudDataReader = cmd.ExecuteReader()

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