@ManyToOne and inner join

borgel · **Joined:** Thu May 08, 2008 9:00 am **Posts:** 4

Hibernate version: 3.2.1.ga

Hi,

I am using JPA and Hibernate as JpaVendor.
I have some @ManyToOne relations. Hibernate generates LEFT OUTER JOIN for the SELECT statements. I wish to use INNER JOIN for some of the selects. I have tried with

Code:

@ManyToOne(optional=false)

and

Code:

@JoinColumn(name="id", nullable=false, unique=true)

This does not have any effect. Is there some way to achieve an INNER JOIN, using annotations?

Thanks

hardy.ferentschik · **Posted:** Thu May 08, 2008 10:11 am

Hi,

there is the @Fetch annotation, but I believe that even if you specify JOIN you will end up with an outer join. In fact there seems to be a jira issue for that: http://opensource.atlassian.com/projects/hibernate/browse/HHH-1940.

--Hardy

borgel · **Joined:** Thu May 08, 2008 9:00 am **Posts:** 4

Thanks for your reply.

I got it working with JPQL.
It seems like Hibernate generates more queries than neccessary though.

spa · **Joined:** Fri May 09, 2008 9:57 am **Posts:** 1

Hi borgel,

I am having same issue (want inner join but hibernate keep doing left outer join) with manytoone annotation and I tried few things and can not get it working. Can you please tell me how you fix this issue.

Thanks for your help.

borgel · **Joined:** Thu May 08, 2008 9:00 am **Posts:** 4

Hi Spa,

sorry for my very late reply.

Instead of em.find(entityClass, primaryKey) i did the following:
Query q = em.createQuery("SELECT customer FROM Customer customer WHERE customer.id=:id");
q.setParameter("id", id);

myCustomer = (Customer)q.getSingleResult();

This results in several queries, but the result is as expected. I don't think it is possible to get Hibernate to do inner joins.

andydale · **Posted:** Tue Jun 03, 2008 6:12 am

Hi,

I have used Hibernate via JPAQL to generate inner joins, do the following:

Code:

em.createQuery("SELECT me FROM MyEntity me INNER JOIN me.<many to one getter>");

Cheers,

Andy

borgel · **Joined:** Thu May 08, 2008 9:00 am **Posts:** 4

andydale wrote:

Hi,

I have used Hibernate via JPAQL to generate inner joins, do the following:

Code:

em.createQuery("SELECT me FROM MyEntity me INNER JOIN me.<many to one getter>");

Cheers,

Andy

I also tried this, but when I looked at the queries Hibernate generated it was a lot of other queries going on...