Entity graph not honoured when quering entity with component
Description
When using EntityManager::createQuery with a entity graph hint (e.g. javax.persistence.fetchgraph) the entity graph is ignored when encountering an entity with a component (called Embeddable in JPA). See test case at:
Interestingly using EntityManager::find with entity graph does work as expected (also see test case).
I also tried running the test case with a certain other JPA implementation and that one did honour the entity graph in both cases (find & query).
I am not familiar with the Hibernate code base, however through some debugging I think I found the location in the code with the problem in EntityGraphQueryHint:
shows the first not handling component types while the second does.
From browsing the code it seems that this issue has been around for a while, confirmed in 5.4 and 5.6, I assume it is also present in 5.5.
It would be really great if this issue could be solved. Would be even greater if the fix could be backported to 5.4 so that I can use it in a Spring Boot application.
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SuperFMarch 29, 2022 at 7:08 PM
Any update about this issue? It makes it impossible to efficiently use EntityGraphs with embeddables.
Here a use case from my own testing code:
A Person (class) has an Address (class), and each address has an owner (a person). For the test, I created an EntityAddress (entity) and an EmbeddableAddress (embeddable). The entitygraph works as expected for EntityAddress, for which it performs a sql join, but it doesn’t work for EmbeddableAddress.
When using EntityManager::createQuery with a entity graph hint (e.g. javax.persistence.fetchgraph) the entity graph is ignored when encountering an entity with a component (called Embeddable in JPA). See test case at:
https://github.com/laurensb/hibernate-component-entitygraph
Interestingly using EntityManager::find with entity graph does work as expected (also see test case).
I also tried running the test case with a certain other JPA implementation and that one did honour the entity graph in both cases (find & query).
I am not familiar with the Hibernate code base, however through some debugging I think I found the location in the code with the problem in EntityGraphQueryHint:
https://github.com/hibernate/hibernate-orm/blob/e76241a3091078713dd4b57de085f5fadce5e0db/hibernate-core/src/main/java/org/hibernate/engine/query/spi/EntityGraphQueryHint.java#L125-L164
comparing this to the code used by EntityManager::find in LoadQueryJoinAndFetchProcessor:
https://github.com/hibernate/hibernate-orm/blob/e76241a3091078713dd4b57de085f5fadce5e0db/hibernate-core/src/main/java/org/hibernate/loader/plan/exec/internal/LoadQueryJoinAndFetchProcessor.java#L133-L154
shows the first not handling component types while the second does.
From browsing the code it seems that this issue has been around for a while, confirmed in 5.4 and 5.6, I assume it is also present in 5.5.
It would be really great if this issue could be solved. Would be even greater if the fix could be backported to 5.4 so that I can use it in a Spring Boot application.