code: @Override
      public void update(DBConnection dbc, String sql) throws SQLException {
          final Connection con = dbc.getConnection();
          // Note current autocommit status -- we're turning it off.
          final boolean ac = con.getAutoCommit();
          con.setAutoCommit(false);
  
          final Statement stmt = con.createStatement();
          try {
              stmt.execute(sql);
              con.commit();
              stmt.close();
          } catch (SQLException e) {
              con.rollback();
              throw e;
          } finally {
              // Restore autocommit status.
              con.setAutoCommit(ac);
          }
      }
docs: {@inheritDoc}