using (IDbConnection connection = new SAConnection("DSN=SQL Anywhere 12 Demo")) {
    connection.Open();

    String oldValue = null;
    using (IDbCommand command = connection.CreateCommand()) {
      command.CommandText = "SELECT Surname FROM Contacts WHERE ID = 1";
      oldValue = command.ExecuteScalar().ToString();
    }

    try {
      using (IDbTransaction transaction = connection.BeginTransaction()) {
        using (IDbCommand command = connection.CreateCommand()) {
          command.Transaction = transaction;
          command.CommandText = String.Format("UPDATE Contacts SET Surname = '{0}' " +
            "WHERE Id = 1", oldValue + "x");
          command.ExecuteNonQuery();

          throw new Exception();
        }
        transaction.Commit(); // never reached in this example
      }
    }
    catch (Exception) {
      // go ahead
      // but transaction isn't rollbacked
    }

    // -> the surname of contact 1 is now "Hildebrandx" and the transaction is still open

    using (IDbTransaction transaction = connection.BeginTransaction()) {
      // It's not possible to open a new transaction because the first
      // transaction isn't commited or rolled back
    }
  }