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 ApacheCouchDBDataAdapter

Use the adapter's Fill method to retrieve data from the data source. An empty DataTable instance is passed as an argument to the Fill method. When the method returns, the DataTable instance is populated with the queried data. Note that the ApacheCouchDBDataAdapter is slower than the ApacheCouchDBDataReader because the Fill method needs to retrieve all data from the data source before returning.

The following example selects the MovieRuntime and MovieRating columns of the Movies table:

C#

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

using (ApacheCouchDBConnection connection = new ApacheCouchDBConnection(connectionString)) {
  ApacheCouchDBDataAdapter dataAdapter = new ApacheCouchDBDataAdapter(
  "SELECT MovieRuntime, MovieRating FROM Movies", connection);

  DataTable table = new DataTable();
  dataAdapter.Fill(table);

  Console.WriteLine("Contents of Movies.");

  foreach (DataRow row in table.Rows) {
    Console.WriteLine("{0}: {1}", row["MovieRuntime"], row["MovieRating"]);
  }
}

VB.NET

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

Using connection As New ApacheCouchDBConnection(connectionString)
  Dim dataAdapter As New ApacheCouchDBDataAdapter("SELECT MovieRuntime, MovieRating FROM Movies", connection)

  Dim table As New DataTable()
  dataAdapter.Fill(table)

  Console.WriteLine("Contents of Movies.")

  For Each row As DataRow In table.Rows
    Console.WriteLine("{0}: {1}", row("MovieRuntime"), row("MovieRating"))
  Next
End Using