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

Using the AzureDataCatalogDataAdapter

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

The following example selects the DslAddressDatabase and Type columns of the Tables table:

C#

string connectionString = "InitiateOAuth=GETANDREFRESH;";

using (AzureDataCatalogConnection connection = new AzureDataCatalogConnection(connectionString)) {
  AzureDataCatalogDataAdapter dataAdapter = new AzureDataCatalogDataAdapter(
  "SELECT DslAddressDatabase, Type FROM Tables", connection);

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

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

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

VB.NET

Dim connectionString As String = "InitiateOAuth=GETANDREFRESH;"

Using connection As New AzureDataCatalogConnection(connectionString)
  Dim dataAdapter As New AzureDataCatalogDataAdapter("SELECT DslAddressDatabase, Type FROM Tables", connection)

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

  Console.WriteLine("Contents of Tables.")

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