ADO.NET Provider for xBase

Build 23.0.8839

Querying with the DataReader

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

Using the xBaseDataReader

The xBaseDataReader retrieves data faster than the xBaseDataAdapter because it can retrieve data in pages. As you read data from the xBaseDataReader, 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 Orders table:

C#

string connectionString = "Data Source=C:\\MyData;";

using (xBaseConnection connection = new xBaseConnection(connectionString)) {
  xBaseCommand cmd = new xBaseCommand("SELECT * FROM Orders", connection);
  
  xBaseDataReader rdr = cmd.ExecuteReader();

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

VB.NET

Dim connectionString As String = "Data Source=C:\\MyData;"

Using connection As New xBaseConnection(connectionString)
  Dim cmd As New xBaseCommand("SELECT * FROM Orders", connection)

  Dim rdr As xBaseDataReader = cmd.ExecuteReader()

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

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Build 23.0.8839