How to fetch multiple entities by a list of natural ids with Hiberate or JPA repository?

Question

If I have a list of natural Ids, how can I fetch all the records in the DB associated with these natural Ids at once?

All I've seen are methods that let you find an entity by a natural Id, an example of one is shown below.

    @Override
    public Optional<T> findBySimpleNaturalId(ID naturalId) {

        Optional<T> entity = entityManager.unwrap(Session.class)
                .bySimpleNaturalId(this.getDomainClass())
                .loadOptional(naturalId);

        return entity;
    }

I am looking for a method that can take a list natural Ids and fetch all the entities with these natural Ids. My current Entity has a autogenerated UUID and a naturalId and I'd like to keep it this way.

Is there something like this below

List<Song> songs = entityManager
.unwrap(Session.class)
.byMultipleSimpleNaturalIds(Song.class)
.multiLoad(songGroup.getSongIds());

// or using the repository
customRepository.findAllByNaturalId(...)

`public List findByNaturalIdIn(List naturalIds);` by Chris in the accepted answer worked for me! — Aram, Sep 09 '22 at 16:15

score 2 · Accepted Answer · answered Apr 21 '22 at 14:10

The examples you've seen are showing you how to build them yourself, as spring does not provide individual methods for you; it knows nothing about properties in your entity other than it must have an id. If you want a findAllByNaturalId method, you have to define it in the interface.

Specifying this in your customRepository:

public List<Song> findByNaturalIdIn(List<Int> naturalIds);

Spring should generate an implementation that creates a query similar to "Select s from Song s where s.naturalId In :naturalIds".

If it doesn't, just add that JPQL query string as an annotation and it will execute it for you:

@Query(value = "Select s from Song s where s.naturalId In :naturalIds")
public List<Song> findByNaturalIdIn(List<Int> naturalIds);

Or you can write your own implementation method to execute your loadOptional calls, or any query you wish, but you still must define the method in your repository.

How to fetch multiple entities by a list of natural ids with Hiberate or JPA repository?

1 Answers1