CODEWITHSUNDEEP
javahibernatejpaormannotations
masterdany88
masterdany88

Reputation: 5351

hibernate/jpa how to store relation between one entity

I would like to store hierarchical folders in database. F.e

@Entity
public class Folder {

int id
String name
Folder parentFolder

}

So if folder is in subfolder he should store information about parentFolder If Folder is in root/top folder, it dosnt have any parentFolder, so there will be null

How should I set hibernate using annotation to achive this?

My entity class:

@Entity
@Table(name="common__Role")
public class Role {

/** The id. */
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
public Long id;

/**
 * Parent Role id.
 */
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="ROLE_ID")
public Role role;

/** The name. */
@Constraints.Required
public String name;

Upvotes: 1

Views: 563

Answers (1)

Xstian
Xstian

Reputation: 8282

This should be your Entity ..

@Entity
@Table("FOLDER")
public class Folder {

  @Id
  private long id;

  @Column(name="NAME")
  private String name;

  @ManyToOne(fetch=FetchType.LAZY,cascade = {CascadeType.PERSIST,CascadeType.MERGE })
  @JoinColumn(name="PARENT_ID")
  private Folder parentFolder;


  //Getter and Setter
}

Maybe you should follow this tutorial

How to persist ManyToOne

Folder f= new Folder();
f.setName("name");

Folder fParent = entityManager.find(Folder .class, 1L);
f.setParent(fParent);

entityManager.persist(f);

See also this tutorial

Upvotes: 2

Related Questions