ADO.NET Provider for REST

Build 20.0.7654

Querying with the DataAdapter

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

Using the RESTDataAdapter

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 RESTDataAdapter is slower than the RESTDataReader 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.xml;Format=XML";

using (RESTConnection connection = new RESTConnection(connectionString)) {
  RESTDataAdapter dataAdapter = new RESTDataAdapter(
  "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.xml;Format=XML"

Using connection As New RESTConnection(connectionString)
  Dim dataAdapter As New RESTDataAdapter("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

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Build 20.0.7654