Spring Data JPA-如何通過父對象的ID查找嵌套對象？

Question

一些對象：

public class SomeObject {
    @Id
    @GeneratedValue
    private Long id;

    @OneToMany(mappedBy = "someObject")
    @Cascade(CascadeType.ALL)
    private Collection<NestedObject> nestedObjects;

    // ...
}

嵌套對象：

public class NestedObject {
    @Id
    @GeneratedValue
    private Long id;

    @ManyToOne(fetch = FetchType.LAZY)
    private SomeObject someObject;

    // ...
}

我可以通過findAll方法找到所有嵌套的對象，但是我無法通過someObject的ID或自身找到嵌套的對象（我正在獲取空集合）。

public interface NestedObject Repository extends JpaRepository<NestedObject , Long> {

    Collection<NestedObject> findBySomeObject_Id(Long id);

    Collection<NestedObject> findBySomeObject(SomeObject someObject);
}

Answer 1

忘記SomeObject的構造函數NestedObject的initialize SomeObject：

    for (NestedObject nestedObject: nestedObjects)
        nestedObject.setSomeObject(this);