Вот фрагмент кода, который работает:
XmlTextWriter myXW = new XmlTextWriter(@"C:\NewXmlFile.xml", Encoding.UTF8)
myXW.WriteStartDocument();
myXW.WriteStartElement("Customers");
string strConn = myConnectionString;
OleDbConnection myConn = new OleDbConnection(strConn);
myConn.Open();
OleDbCommand myCMD = new OleDbCommand("select * from customers", myConn);
OleDbDataReader myRdr = myCMD.ExecuteReader();
while (myRdr.Read())
{
myXW.WriteStartElement("Customer");
myXW.WriteAttributeString("id", myRdr.GetString(0));
myXW.WriteElementString("companyname", myRdr.GetString(1));
myXW.WriteElementString("contactname", myRdr.GetString(2));
myXW.WriteElementString("contactname", myRdr.GetString(3));
myXW.WriteElementString("address", myRdr.GetString(4));
myXW.WriteElementString("city", myRdr.GetString(5));
myXW.WriteElementString("country", myRdr.GetString(8));
myXW.WriteElementString("phone", myRdr.GetString(9));
myXW.WriteElementString("fax", myRdr.GetString(10));
myXW.WriteEndElement();
}
myXW.WriteEndElement();
myXW.WriteEndDocument();
myXW.Flush();
myXW.Close();