The CData ADO.NET Provider for DB2 implements two ADO.NET interfaces you can use to retrieve data from DB2: DB2DataAdapter and DB2DataReader objects. Whereas DB2DataAdapter objects retrieve a single result set of all the data that matches a query, DB2DataReader objects fetch data in subset increments as needed.

Using the DB2DataReader

The DB2DataReader retrieves data faster than the DB2DataAdapter because it can retrieve data in pages. As you read data from the DB2DataReader, 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 "Sample"."DB2INST1".Books table:

C#

string connectionString = "Server=10.0.1.2;Port=50000;User=admin;Password=admin;Database=test";

using (DB2Connection connection = new DB2Connection(connectionString)) {
  DB2Command cmd = new DB2Command("SELECT * FROM \"Sample\".\"DB2INST1\".Books", connection);
  
  DB2DataReader rdr = cmd.ExecuteReader();

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

VB.NET

Dim connectionString As String = "Server=10.0.1.2;Port=50000;User=admin;Password=admin;Database=test"

Using connection As New DB2Connection(connectionString)
  Dim cmd As New DB2Command("SELECT * FROM \"Sample\".\"DB2INST1\".Books", connection)

  Dim rdr As DB2DataReader = cmd.ExecuteReader()

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