left join with spring data jpa and querydsl

[Frey Zheng]

Hi,

I am using spring data jpa and querydsl and trapped on how to write simple nice query to left join two tables.

Suppose I have an Project entity and a Task entity with OneToMany relationship defined in Project, I would like to do something like:

select * from project p left join task t on p.id = t.project_id where p.id = searchTerm

I have a ProjectRepository interface, which extends JpaRepository and QueryDslPredicateExecutor.

That gives me access to method:

Page<T> findAll(com.mysema.query.types.Predicate predicate, Pageable pageable) 

I know that left join can be easily achieved by creating a new JPAQuery(entityManager). But I do not have entity manager explicitly injected with spring data jpa.

Is there nice and simple way to build a predicate with left join?

Wish someone in this group have experienced this requirement and is able to give me an example.

Thank you.

Frey.

[timowest]

Hi.

left joins can't be really created via predicates.

The closest thing is QProject.project.tasks.any().id.eq(searchTerm), but the effect is different, it's translated into a subquery.

Timo

[Rishu Oberoi]

Anyone found a solution to this yet? Facing the same issue!