code: @Override
      public long nextSequence(final ConnectionResource _con,
                               final String _name)
          throws SQLException
      {
          final long ret;
          final String cmd = new StringBuilder()
                  .append("SELECT " + _name + ".nextval from dual")
                  .toString();
          final Statement stmt = _con.createStatement();
          try {
              final ResultSet resultset = stmt.executeQuery(cmd);
              if (resultset.next()) {
                  ret = resultset.getLong(1);
              } else  {
                  throw new SQLException("fetching new value from sequence '" + _name + "' failed");
              }
              resultset.close();
          } finally {
              stmt.close();
          }
          return ret;
      }
docs: {@inheritDoc}