hibernate session.save() does not reflect in database

Question

According to my understanding in hibernate (please confirm)

1- You have to session.close() if you get it by getSessionFactory().openSession()

Answer 1

I was also trying to understand the point: save() can perform Insert operation outside transaction boundary so I did something like this

SessionFactory factory = new Configuration().configure()
                    .buildSessionFactory();
            Session session = factory.openSession();

            session.save(user);

            session.close();

But data not inserted in database.So I again tried this and now it worked for me and data inserted sucessfully:

in configuration file:

  <property name="connection.autocommit">true</property>

and in java code:

    SessionFactory factory = new Configuration().configure()
            .buildSessionFactory();
    Session session = factory.openSession();

    session.save(user);

    session.flush();
    session.close();

Answer 2

session.close() is only responsible to close the session https://docs.jboss.org/hibernate/orm/3.5/javadocs/org/hibernate/Session.html#close()

how to work with hibernate session: https://docs.jboss.org/hibernate/orm/3.3/reference/en/html/transactions.html#transactions-basics

// Non-managed environment idiom
Session sess = factory.openSession();
Transaction tx = null;
try {
    tx = sess.beginTransaction();

    // do some work
    ...

    tx.commit();
}

catch (RuntimeException e) {
    if (tx != null) tx.rollback();
    throw e; // or display error message
}
finally {
    sess.close();
}

As it wrote in the documentation: a much more flexible solution is Hibernate's built-in "current session" context management:

// Non-managed environment idiom with getCurrentSession()
try {
    factory.getCurrentSession().beginTransaction();

    // do some work
    ...

    factory.getCurrentSession().getTransaction().commit();
}
catch (RuntimeException e) {
    factory.getCurrentSession().getTransaction().rollback();
    throw e; // or display error message
}

Answer 3

if there is DB manipulation operation then it should be in transaction
if you call session.save(object)
hibernate create bellow query only .
select hibernate_sequence.nextval from dual
so right code is here
Transaction  t=session.beginTransaction();
session.save(obect);
t.commit(); should not forgot to commit.
session.close();