Hi All,

In Hibernate Session there is a method get(Class klass, Serializable id, LockMode lockMode). Why is the JPA EntityManager missing an analogous method?

For example, in order to perform a "select for update" in JPA it is needed to get an entity first and then lock it:

Employee emp = em.find(Employee.class, 123L);
em.lock(emp, LockModeType.READ);

That will result in 2 selects:

1. select ... from Employee
2. select ... from Employee for update.

In Hibernate, however, I could just write:

session.get(Employee.class, 123L, LockMode.UPGRADE);

which will just run a "select for update" and return an entity.

So, my question is whether it is possible to get an entity in JPA and perform a "select for update" at the same time? Or am I missing somethong.


Cheers,

Dimitrio

interesting.
This is not supported out of the box with JPA.
The reason is that JPA does not support the select for update thing, it's left to the implementation. What is supported is some kind of transaction isolation level guaranty (which is only mandatory on versioned entities).