Hello,

Hibernate throws a lazy exception even if I used setFetchMode(..., FetchMode.JOIN).

More in details :

Entities :


We need to retrieve the underlyings and all associated products :


Here, the query is working : the products are retreived (no lazy exception).

But we also need to order by product maturity, so we added to the previous statement :

With this order by, the the products stop being retrieved and Hibernate throws a lazy exception.

The question is simple : Does Hibernate forbid the use of the fetched entities in the order by clause ?
At first sight, it seems that using an order-by on the fetched entities (setFetchMode("productList", FetchMode.JOIN) cancels the fetch join, as if it wasn't done (the products are not loaded).


Info:

Hibernate version: 3.1.2
The generated SQL:


Full stack trace of any exception that occurs:



Thanks for your help,

Tom

Any ideas ?
Is the answer so simple (RTFM ;-) ) ?

Currently, underlyings and products are fetched (inner join) but there is still the Lazy Exception when accessing the productList from an underlying.

Any help is welcome.

Regards,

Tom

When are you attempting to access the productList? The error is that there is no session associated with the current thread at the time the productList collection is loaded. You could try setting lazy to true just to see if it clears up the error. If it does, that would indicate that your session management approach has some problem. You normally see this error when an object is loaded while a session is available, but a collection of persistent objects assocaited with that object was not loaded at that time. Later, when code attempts to access the collection, Hibernate attempts to retrieve the persistent objects in the collection from the database, but there is no current session at that point.

The session has been closed when we accessed the 'productList' field. This is why we need to pre-load the products (the joinfetch) when the session is still opened.

If the session is open when we access the 'productList', Hibernate runs the corresponding queries for getting the products for each underlyings. This is the known n+1 select in this case : on select for all underlyings, one select for each product list of each underlying.

So, why the join fetch on "productList" is "disabled" if a Criteria on "productList" is added ?

Thanks,

Tom

Any Idea on why a join fetch is "disabled" if a Criteria is created on this join fetch ?