Entities created correctly from Json with @JoinColumn on the opposite side

I thought I understood the JPA's @JoinColumns annotation and mappedBy parameter, but then I needed to create new entities from this Json of a Question. It has a set of answer choices which need to be mapped to new entities as well. I decided that the Question entity is gonna be the owning side, therefore I omitted the mappedBy parameter. When I used the @JoinColumns annotation on the AnswerChoice side, all the entities were created from the Json objects, but the AnswerChoices' FKs to the Question entity were not set.

Putting the @JoinColumns in the Question entity solved the problem, but my question is: is this the correct way? Will I be facing any side effects? Should I instead have run a for-loop on the set of AnswerChoices and set the FK?

Question Json

{
    "text": "Do you know JPA?",
    "answerChoices": [{
        "text": "yes",
    }, {
        "text": "no",
    }, ]
}

Controller with a JpaRepository:

@PostMapping("/questions/create")
@ResponseBody
public String create(@RequestBody Question json) {
    questionRepo.save(json);
}

Question entity:

@Entity
public class Question {
    @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY)
    @JoinColumn(name="question_id")
    private Set<AnswerChoice> answerChoices;
}

AnswerChoice entity:

@Entity
public class AnswerChoice {
    @ManyToOne(fetch = FetchType.LAZY)
    @JsonIgnore
    private Question question;
}

For the sake of brevity I omitted the auto-generated Id's.

Nope, the mapping is not correct. It actually creates two separate associations that happen to share the join column.

Either remove question from Answer, making the association unidirectional (ask yourself if you really need that side of the association) or go back to the original solution and use @JsonBackReference/@JsonManagedReference (so that the field gets automatically populated during deserialization).