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

Using the MarkLogicDataReader

The MarkLogicDataReader retrieves data faster than the MarkLogicDataAdapter because it can retrieve data in pages. As you read data from the MarkLogicDataReader, 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 [CData].[main].Customer table:

C#

string connectionString = "User='myusername';Password='mypassword';Server='marklogic'";

using (MarkLogicConnection connection = new MarkLogicConnection(connectionString)) {
  MarkLogicCommand cmd = new MarkLogicCommand("SELECT * FROM [CData].[main].Customer", connection);
  
  MarkLogicDataReader rdr = cmd.ExecuteReader();

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

VB.NET

Dim connectionString As String = "User='myusername';Password='mypassword';Server='marklogic'"

Using connection As New MarkLogicConnection(connectionString)
  Dim cmd As New MarkLogicCommand("SELECT * FROM [CData].[main].Customer", connection)

  Dim rdr As MarkLogicDataReader = cmd.ExecuteReader()

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