ADO.NET Provider for Apache Kafka

Build 21.0.7940

Querying with the DataReader

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

Using the ApacheKafkaDataReader

The ApacheKafkaDataReader retrieves data faster than the ApacheKafkaDataAdapter because it can retrieve data in pages. As you read data from the ApacheKafkaDataReader, 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 SampleTable_1 table:

C#

string connectionString = "User=admin;Password=pass;BootStrapServers=https://localhost:9091;Topic=MyTopic;";

using (ApacheKafkaConnection connection = new ApacheKafkaConnection(connectionString)) {
  ApacheKafkaCommand cmd = new ApacheKafkaCommand("SELECT * FROM SampleTable_1", connection);
  
  ApacheKafkaDataReader rdr = cmd.ExecuteReader();

  while (rdr.Read()) {
    Console.WriteLine(String.Format("\t{0} --> \t\t{1}", rdr["Id"], rdr["Column1"]));
  }
}

VB.NET

Dim connectionString As String = "User=admin;Password=pass;BootStrapServers=https://localhost:9091;Topic=MyTopic;"

Using connection As New ApacheKafkaConnection(connectionString)
  Dim cmd As New ApacheKafkaCommand("SELECT * FROM SampleTable_1", connection)

  Dim rdr As ApacheKafkaDataReader = cmd.ExecuteReader()

  While rdr.Read()
    Console.WriteLine([String].Format(vbTab & "{0} --> " & vbTab & vbTab & "{1}", rdr("Id"), rdr("Column1")))
  End While
End Using

Copyright (c) 2021 CData Software, Inc. - All rights reserved.
Build 21.0.7940