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

Using the JSONDataAdapter

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 JSONDataAdapter is slower than the JSONDataReader because the Fill method needs to retrieve all data from the data source before returning.

The following example selects the personal.name.first and personal.name.last columns of the NorthwindOData table:

C#

string connectionString = "DataModel=Relational;URI=C:\people.json";

using (JSONConnection connection = new JSONConnection(connectionString)) {
  JSONDataAdapter dataAdapter = new JSONDataAdapter(
  "SELECT personal.name.first, personal.name.last FROM NorthwindOData", connection);

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

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

  foreach (DataRow row in table.Rows) {
    Console.WriteLine("{0}: {1}", row["personal.name.first"], row["personal.name.last"]);
  }
}

VB.NET

Dim connectionString As String = "DataModel=Relational;URI=C:\people.json"

Using connection As New JSONConnection(connectionString)
  Dim dataAdapter As New JSONDataAdapter("SELECT personal.name.first, personal.name.last FROM NorthwindOData", connection)

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

  Console.WriteLine("Contents of NorthwindOData.")

  For Each row As DataRow In table.Rows
    Console.WriteLine("{0}: {1}", row("personal.name.first"), row("personal.name.last"))
  Next
End Using