无法从 JPA Hibernate 的反面看到拥有方

Question

I have this piece of code:

@Entity(name = "Person")
@Table(name = "person")
public class Person {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @OneToMany( mappedBy = "person", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    private List<Post> posts = new ArrayList<Post>();
}

and:

@Entity(name = "Post")
@Table(name = "post")

public class Post extends BaseEntity{
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

@ManyToOne(
        fetch = FetchType.LAZY
)
@JoinColumn(name="person_id")
Person person;
@Column(name = "text", nullable = true)
private String text;
}

The issue is that when I connect to my Hibernate database I can see the Person Id in the Post entity, but can't see the Post id in the Person entity. There is no person_post table neither. How can I see the posts that belong to the person? I want to list the posts from the person using thymeleaf but something like this doesn't work:

  <tr th:each="post : ${person.posts}">
            <td th:text="${post.text}">nothing in here</td>
 </tr>

Error says that thymeleaf can't see the posts in Person. Is this how it is supposed to work? How can I list the posts from person? Thanks in advance, Tomasz

Answer 1

You are defining a 1:N relationshop, that means that in the Post table there is the person_id foreign key, but no intermediate table person_post. However person.posts should give you the result you are looking for - can you add the logic how you add the Person / Post and the controller method of the template?

It's recommended to user LAZY fetching, by the way: https://vladmihalcea.com/eager-fetching-is-a-code-smell/