I've got one-to-many relation between class A (Parent/one) and B (child/many) in a way that A contains a list of B's.

I've got the following situation: I know that since I have loaded A and cascaded list of Bs, there was a new B record added having A as parent.

So I use em.refresh(a) to refresh the a instance (of class A). The instance is configured to cascade the refresh on the collection of Bs. When I turn show_sql to true I the following during the refresh:

SELECT B .... WHERE ID=?
SELECT B ... WHERE ID=?
SELECT A .... WHERE ID=?

In the above case the list of B has exactly two elements. So it appears that hiberante reloads the two B records from the database and then it rereads A record.

But what if there was a new B record related to A inserted? In such case the refresh won't extend the collection with the inserted records. It would just read the records it knew about when it loaded the A object.

How do I force hibernate to reread the A/B so it recognizes the inserted data, not just the data that is updated in the database?

Should I consider it a bug? It appears that it doesn't make full refresh - it refreshes the content of the records read previously, but it doesn't refresh relations between records. For me it's quite unexpected behaviour.

If someone is inserting data into the database, you can just have Hibernate refresh its data. But it's not a bug if someone goes in and adds something to the database without Hibernate knowing about it.

Locks on the database might help alleviate this problem.

Let me rephrase the problem - it's not that someone adds record. The problem is that hibernate doesn't read added records during refreshing it's data.

For example - I have an order that I inserted into the database. But due to some business logic triggers the database extends the item list in the database and adds transport cost to the order. I am aware of that logic and I refresh my order to make sure that I synchronized it with the database. Those items that were updated by the trigger refresh fine. However any item that was inserted by the trigger is not visible.

It's not what I would expect from cascaded refresh. I would rather expect that hibernate reads not only updated records, but also all the related inserted records. However looking at the SQL statements generated hibernate cannot deduce related child records added to parent.



The point here is that Hibernate won't refresh the inserted data. It only refreshes updated data, it probably noticed deleted data, but it's simply impossible to grab inserted data with such sql statements. So I can't just have Hibernate refresh its data.