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

Using the ADLSDataAdapter

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

The following example selects the FullPath and Permission columns of the Resources table:

C#

string connectionString = "Account=MyStorageAccount;FileSystem=MyBlobContainer;AccessKey=myAccessKey;";

using (ADLSConnection connection = new ADLSConnection(connectionString)) {
  ADLSDataAdapter dataAdapter = new ADLSDataAdapter(
  "SELECT FullPath, Permission FROM Resources", connection);

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

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

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

VB.NET

Dim connectionString As String = "Account=MyStorageAccount;FileSystem=MyBlobContainer;AccessKey=myAccessKey;"

Using connection As New ADLSConnection(connectionString)
  Dim dataAdapter As New ADLSDataAdapter("SELECT FullPath, Permission FROM Resources", connection)

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

  Console.WriteLine("Contents of Resources.")

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