休眠一对多从父关系中分离子对象

Question

I have 2 entities film (Parent) and episode (Child) with one-to-many relationship, whenever I create a film object with collection of episode objects, everything works normal, parent and related child objects are created. But when I try to update a `film' by removing bunch of 'episode' objects nothing seems to work out

Here what I am trying to do, When i remove a bunch of episode objects from film , those removed objects should not be deleted but kept as episode without linked to any parent object . Is this possible?

Film entity

    import org.hibernate.annotations.*;

    import javax.persistence.*;
    import javax.persistence.CascadeType;
    import javax.persistence.Entity;
    import javax.persistence.Table;
    import java.util.Set;

    @Entity
    @Table(name = "FILM")
    @Getter
    @Setter
    public class Film {
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private long id;

        @Column(name = "ORIGINAL_TITLE", nullable = false)
        private String originalTitle;


        @OneToMany(targetEntity=FilmEpisode.class, mappedBy="film", cascade=CascadeType.ALL,fetch=FetchType.EAGER, orphanRemoval = true)
        private Set<FilmEpisode> filmEpisodes;

        @Column(name = "SHOW_ON_LANDING_PAGE")
        private Boolean showOnLandingPage;
    }

FilmEpisode entity

    import javax.persistence.*;
    import javax.persistence.CascadeType;
    import javax.persistence.Entity;
    import javax.persistence.Table;
    import java.util.Set;

    @Entity
    @Table(name = "FILM_EPISODE")
    @Getter
    @Setter
    public class FilmEpisode {
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private long id;

        @Column(name = "ORIGINAL_TITLE", nullable = false)
        private String originalTitle;

        @ManyToOne
        @JoinColumn(name = "FILM_ID")
        private Film film;
    }

In DAO I am just saving film with saveOrUpdate method like below

session.saveOrUpdate(film);

Am I missing something..??

Answer 1

orphanRemoval = true is making unreferenced entities from parent entity being deleted. Change it to orphanRemoval = false and child entities will not be removed from database. You can delete it too as it defaults to false :

Answer 2

In .NET I had the same problem to exclude a child. I decided carrying a session from parent and then setting a merge in session .

Using:

Map Parent

HasMany(x => x.Child) .KeyColumn("id") .AllDeleteOrphan();

On Update method:

public void Update(Parent model)
{
   var session = _sessionFactory.GetCurrentSession();

   using (var transaction = session.BeginTransaction())
   {
       session.Load<Parent>(model.Id);
       session.Merge(model);
       transaction.Commit();
   }
}

To load the list in .load in the database, returned three rows, and the last object in the method has only 2 rows. Making the .Commit, the line I removed the object was deleted from the database.