ADO.NET Provider for Quandl

Build 20.0.7587

Querying with the DataAdapter

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

Using the QuandlDataAdapter

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

The following example selects the High and Date columns of the AAPL table:

C#

string connectionString = "ApiKey=abc123;DatabaseCode=WIKI;";

using (QuandlConnection connection = new QuandlConnection(connectionString)) {
  QuandlDataAdapter dataAdapter = new QuandlDataAdapter(
  "SELECT High, Date FROM AAPL", connection);

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

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

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

VB.NET

Dim connectionString As String = "ApiKey=abc123;DatabaseCode=WIKI;"

Using connection As New QuandlConnection(connectionString)
  Dim dataAdapter As New QuandlDataAdapter("SELECT High, Date FROM AAPL", connection)

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

  Console.WriteLine("Contents of AAPL.")

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

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Build 20.0.7587