code: protected int update (final String query)
          throws PersistenceException
      {
          return executeUpdate(new Operation<Integer>() {
              public Integer invoke (Connection conn, DatabaseLiaison liaison)
                  throws SQLException, PersistenceException
              {
                  Statement stmt = null;
                  try {
                      stmt = conn.createStatement();
                      return stmt.executeUpdate(query);
                  } finally {
                      JDBCUtil.close(stmt);
                  }
              }
          });
      }
docs: Executes the supplied update query in this repository, returning the number of rows
  modified.