April 05
Prof. Ismael H. F. Santos -  ismael@tecgraf.puc-rio.br                                                          2
Controlar uma transação
nConnection db = DriverManager.getConnection(url,user,pass);
ndb.setAutoCommit(false);
nStatement st = db.createStatement();
nint ok = st.executeUpdate("update senhas set senha='x' "+
n                          "where nome='joao'");
nSystem.out.println(ok==1 ? "ok." : "nok.");
ndb.rollback(); // ou db.commit();
ndb.setAutoCommit(true);
nResultSet rs = st.executeQuery("select * from senhas");
nwhile (rs.next()) {
n  System.out.println(rs.getString(1)+" "+rs.getString(2));
n}
nrs.close();  st.close();  db.close();