How come Spring Data Rest only allows updates from the owner side of ManyToOne/ManyToMany? [DATAREST-1449]

gigecogary opened DATAREST-1449 and commented

I downloaded a sample project from here https://www.baeldung.com/spring-data-rest-relationships

I then ran it and did some test REST calls. As far as I can tell you can only update association from the owner side using SDR. What I mean is

public class Book { @ManyToOne @JoinColumn(name = "library_id") private Library library; }

and

public class Library { @OneToMany(mappedBy = "library") private List<Book> books; }

You can't actually make post/put calls to /libraries/1/books. Server return 204 but no effect on the db whatsoever.

You can however, make post/put calls to /books/1/library and everything works as intended including keeping the other entity in sync.

Is this normal? It's the same behaviour for @ManyToMany as well. Is there a way to allow for updates from both sides? If I write my own API I can certainly make this the case. Why does SDR not do this?

Affects: 3.2 GA (Moore)

Reference URL: https://stackoverflow.com/questions/58685582/how-come-spring-data-rest-only-allows-updates-from-the-owner-side-of-manytoone-m