var commandText = "UPDATE Sales.Store SET Demographics = @demographics WHERE CustomerID = @ID;";
using (SqlConnection connection = new SqlConnection(connectionString))
{
SqlCommand command = new SqlCommand(commandText, connection);
command.Parameters.AddWithValue("@ID", customerID);
command.Parameters.AddWithValue("@demographics", demoXml);
connection.Open();
command.ExecuteNonQuery();
}