Dear all,


I have a question about "setLockMode" for Query
some codes as following....

===================================
Transaction tx= session.beginTransaction();
Query q = session.createQuery(" from Add as addr");
q.setLockMode("addr", LockMode.UPGRADE);
result = q.list();
......
tx.commit()
......
===================================


logically,
When the code "q.list()" is executed, hibernate will connect to the database(DB2) and fetch records using "select ... for update"
and, all records will be locked.



But I failed....
I set "q.list()" as a breakpoint.

concurrently,
run a prog to update(or insert) data
It still works.... (shock)


anybody can tell me what's wrong.....

Well, this will work:

aEmp = (Employee)session.load(Employee.class, aPK);
session.lock(aEmp, LockMode.UPGRADE);
session.refresh(aEmp);
Transaction tx = session.beginTransaction();
aEmp.setXxx(xxx);
...
tx.commit();

To refresh() after lock() will let the 2nd concurrent thread re-read database after the blocking of lock is released. I tested it in the ThreadLocal pattern where there are separate Hibernate sessions maintaining different copies of PO relative to the same db record.
Also, Oracle9 dialect is used to ensure DB native lock scheme.

I think the main issue is that both session.lock() and session.load() with a nontrivial LockMode lock the record AFTER the data is retrieved. There is no method in Hibernate Session to lock BEFORE retrieve.