Dear all,

I'm a bit curious why Hibernate doesn't do fetch join or subselect when I told it to do so.

I have an entity T with some subclasses (T1, T2 ...) mapped using Joined inheritance. T has one-to-one relationship with another entity U using:



From the document, if I retrieve T, U should be retrieved with T by using join. However, Hibernate is using another select to get U.

My query is like:



and I get one select for U for each T returned from the above query.

I try to change the query to:



and:



but Hibernate is still doing the same.

I try to add to the association, but it doesn't help (nor does BatchSize).

There is another relation on U to V (ManyToMany Set) that has similar problem. On this relation, @FetchMode doesn't work (both JOIN and SUBSELECT), but @BatchSize do work.

Is this Hibernate's optimization for DB2 or I am doing something wrong?

I'm using:
- Hibernate 3.2.6
- Hibernate EntityManager 3.3.2
- DB2Dialect, DB2 Express-C v9

Thank you in advance,
Pongtawat

Hello again,

It's mistake, actually "left join fetch" does work as expected.

However FetchMode still doesn't.

Thank you,
Pongtawat

Any idea?

Thanks