Problems with Join Fetch using Criteria API

Hibernate ORM
1

Hello. I’m having trouble with making my query to DB. I’m have updated dependencies in my project, and spring-boot-starter-jpa was updated too, so org.hibernate.orm:hibernate-core dependency went from something like 6.1.7 to 6.6.2.Final.

I have 3 entities, lets say A, B, C
A has One-To-Many relation to B (FetchType.LAZY in mapping at A class) , B has One-To-Many relation to C (FetchType.EAGER in mapping at B class).

I have repository for A entity that extends interface JpaSpecificationExecutor<A>, here is a method used:
fun findAll(spec: Specification<A>, pageable: Pageable): Slice<A>

Before update I had such code:

entityARepo.findAll(
                Specification.where(
                    %some criteria%)
                .and(%some another criteria%)
            , page)

It worked properly before updating, making 1 query to A table in DB (with no JOINs), and N queries to B table in DB (with LEFT JOIN on C), N is a number of A entities that I got in first query (for every A entity in resultList, 1 query to B (+ join C) table)

After updating dependencies to spring-boot-starter-jpa:3.4.0 (hibernate-orm:6.6.2.Final), I startet getting this error:org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: EntityA.bEntities : could not initialize proxy - no Session
I read this article: and decided to use fetching. I wrote such code:

val fetch: (SetAttribute<A, B>, SetAttribute<B, C>, JoinType) -> Specification<A> =
    { entityAattribute, entityBattribute, joinType ->
        Specification<A> { root, _, _ ->
            root.fetch(entityAattribute, joinType)
                   .fetch(entityBattribute, joinType)
            null
        }
    }

And so method invocation looks like this:

entityARepo.findAll(
                criteria
                    .and(fetch(A_.bEntities, B_.cEntities, JoinType.LEFT))
                    .and(%some another criteria%)
            , page)

Error LazyInitializationException disappeared, but now I’m getting org.hibernate.query.SemanticException: Query specified join fetching, but the owner of the fetched association was not present in the select list [SqmSetJoin(EntityA(83).bEntities(84))]

Hibernate makes 1 big query to A table, with LEFT JOINs on B and C

How can I fix this?

2

You seem to be using Spring Data with Kotlin, but Hibernate ORM is a Java framework that is not affiliated in any way with the Spring ecosystem, so people here generally have no clue what all these code samples you’re posting mean.

If you have questions about Hibernate ORM, then ask about Hibernate ORM things like a HQL or JPA Criteria query, but please ask Spring Data usage questions in Spring forums instead.