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

Using the ExcelOnlineDataAdapter

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

The following example selects the Id and Column1 columns of the Test_xlsx_Sheet1 table:

C#

string connectionString = "InitiateOAuth=GETANDREFRESH;";

using (ExcelOnlineConnection connection = new ExcelOnlineConnection(connectionString)) {
  ExcelOnlineDataAdapter dataAdapter = new ExcelOnlineDataAdapter(
  "SELECT Id, Column1 FROM Test_xlsx_Sheet1", connection);

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

  Console.WriteLine("Contents of Test_xlsx_Sheet1.");

  foreach (DataRow row in table.Rows) {
    Console.WriteLine("{0}: {1}", row["Id"], row["Column1"]);
  }
}

VB.NET

Dim connectionString As String = "InitiateOAuth=GETANDREFRESH;"

Using connection As New ExcelOnlineConnection(connectionString)
  Dim dataAdapter As New ExcelOnlineDataAdapter("SELECT Id, Column1 FROM Test_xlsx_Sheet1", connection)

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

  Console.WriteLine("Contents of Test_xlsx_Sheet1.")

  For Each row As DataRow In table.Rows
    Console.WriteLine("{0}: {1}", row("Id"), row("Column1"))
  Next
End Using