Re: Flush Mode

[Craig L Russell]

Hi Gurkan,








Hope this clarifies what you're seeing.

Craig

On Sep 17, 2007, at 9:35 AM, Gurkan Erdogdu wrote:

JPA is designed to provide transaction isolation between EntityManagers. So, if two EntityManagers do not share the same transaction, changes made in one must not be visible in the other. In your case, the query from the second EntityManager should not be able to see the changed made (but not committed) by the first EntityManager. What the flush() method does is to write the changes to the database so they are visible to queries *made by the same EntityManager*.

public void method1 (){
        EntityManager m = null;
        String result = null;
        EntityTransaction transaction = null;
        try{
            m = SessionOperations.getEntityManager();
            transaction = SessionOperations.getTransaction(m);

            transaction.begin();

              m.setFlushMode(FlushModeType.AUTO);

            q.setParameter("oid", getOid());

            //Before set state = 'B'
            User s = (User)q.getResultList().get(0);
            s.setState('E');

              m.flush(); //actually print update but not synch with DB

           method2();

        }catch(Exception e){
            transactionHandler(e, transaction);
            exceptionHandler(e);

        }finally{
            if(transaction != null && transaction.isActive())
                SessionOperations.commitTransaction(transaction);
            if(m != null)
                SessionOperations.closeEntityManager(m);
        }
}

 public void method2(){
        EntityManager m = null;

        try{

            m = SessionOperations.getEntityManager();



            q.setParameter("oid", getOid());









        }finally{
            if(m != null)

                SessionOperations.closeEntityManager(m);

        }
}



----- Original Message ----
From: Patrick Linskey <[EMAIL PROTECTED]>
To: users@openjpa.apache.org
Sent: Monday, September 17, 2007 6:37:48 PM
Subject: Re: Flush Mode

Can you post the actual code plus your persistence.xml file please?

-Patrick

On 9/17/07, Gurkan Erdogdu <[EMAIL PROTECTED]> wrote:

Query q = m.createQuery("select c from User c where c.oid=:oid"); Query q = m.createQuery("select c from User c where c.oid=:oid"); User s = (User)q.getResultList().get(0); //In this user state still with 'B' persistence-xml just contains entity class definitions, and datasource specific properties. EJB 3.0 spec says that when entitymanager or query flush mode is AUTO then, all queries after that will contain new values. But I am not sure this is in the same entity manager, because in method1 and method2, I use two different entitymanager.

Hi;



public void method1(){
EntityManager m;
EntityTransaction t;

m.setFLushMode(AUTO);
t = m.gettransaction();
t.begin;
Query q = some query to get User

User user = q.getResultLsit(0);
user.setState('T');


t.commit();

m.close;

runNewQuery();
}




EntityManager m;
Query q = some quety

User user = get user

but user status not changed.



What is the problem guys?




http://mobile.yahoo.com/go?refer=1GNXIC

When I change User status in method1 using flush, it does not sync with the database. It still looks the same status value in other method. m.flush(); //Actually write sql update to the console but not synch with database Then in runNewQueryMethod just select user with new status but seems status not changed If I look console it prints, update sql to the database while flushing, but not update to the database. _____________________________________________________________________ _______________ Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more.

--
Patrick Linskey
202 669 5907







http://farechase.yahoo.com/

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Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!

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