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

Using the ApacheCouchDBDataReader

The ApacheCouchDBDataReader retrieves data faster than the ApacheCouchDBDataAdapter because it can retrieve data in pages. As you read data from the ApacheCouchDBDataReader, 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 Movies table:

C#

string connectionString = "User=abc123; Password=abcdef;";

using (ApacheCouchDBConnection connection = new ApacheCouchDBConnection(connectionString)) {
  ApacheCouchDBCommand cmd = new ApacheCouchDBCommand("SELECT * FROM Movies", connection);
  
  ApacheCouchDBDataReader rdr = cmd.ExecuteReader();

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

VB.NET

Dim connectionString As String = "User=abc123; Password=abcdef;"

Using connection As New ApacheCouchDBConnection(connectionString)
  Dim cmd As New ApacheCouchDBCommand("SELECT * FROM Movies", connection)

  Dim rdr As ApacheCouchDBDataReader = cmd.ExecuteReader()

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