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

Using the GoogleSheetsDataReader

The GoogleSheetsDataReader retrieves data faster than the GoogleSheetsDataAdapter because it can retrieve data in pages. As you read data from the GoogleSheetsDataReader, it periodically requests the next page of results from the data source, if required. This causes results to be returned at a faster rate. The following example selects all the columns from the Spreadsheet1_Sheet1 table:

C#

string connectionString = "InitiateOAuth=GETANDREFRESH;Spreadsheet=NorthwindOrders";

using (GoogleSheetsConnection connection = new GoogleSheetsConnection(connectionString)) {
  GoogleSheetsCommand cmd = new GoogleSheetsCommand("SELECT * FROM Spreadsheet1_Sheet1", connection);
  
  GoogleSheetsDataReader rdr = cmd.ExecuteReader();

  while (rdr.Read()) {
    Console.WriteLine(String.Format("\t{0} --> \t\t{1}", rdr["Id"], rdr["Column1"]));
  }
}

VB.NET

Dim connectionString As String = "InitiateOAuth=GETANDREFRESH;Spreadsheet=NorthwindOrders"

Using connection As New GoogleSheetsConnection(connectionString)
  Dim cmd As New GoogleSheetsCommand("SELECT * FROM Spreadsheet1_Sheet1", connection)

  Dim rdr As GoogleSheetsDataReader = cmd.ExecuteReader()

  While rdr.Read()
    Console.WriteLine([String].Format(vbTab & "{0} --> " & vbTab & vbTab & "{1}", rdr("Id"), rdr("Column1")))
  End While
End Using