ADO.NET Provider for Open Exchange Rates

Build 21.0.7930

Querying with the DataAdapter

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

Using the OpenExchangeRatesDataAdapter

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

The following example selects the Id and Statistics_ViewCount columns of the Projects table:


string connectionString = "AppId=abc1234;";

using (OpenExchangeRatesConnection connection = new OpenExchangeRatesConnection(connectionString)) {
  OpenExchangeRatesDataAdapter dataAdapter = new OpenExchangeRatesDataAdapter(
  "SELECT Id, Statistics_ViewCount FROM Projects", connection);

  DataTable table = new DataTable();

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

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


Dim connectionString As String = "AppId=abc1234;"

Using connection As New OpenExchangeRatesConnection(connectionString)
  Dim dataAdapter As New OpenExchangeRatesDataAdapter("SELECT Id, Statistics_ViewCount FROM Projects", connection)

  Dim table As New DataTable()

  Console.WriteLine("Contents of Projects.")

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

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Build 21.0.7930