删除多对多关系（JPA）中的所有内容

Question

I have the following model (reduced):

@Entity
public class Video {
    @ManyToMany(fetch=FetchType.EAGER, cascade=CascadeType.ALL)
    @JoinTable(name = "video_tag", joinColumns = {
            @JoinColumn(name = "video_id", referencedColumnName = "id") }, inverseJoinColumns = {
                    @JoinColumn(name = "tag_id", referencedColumnName = "id") })
    private Set<Tag> tags;
}

@Entity
public class Tag {
    @ManyToMany(mappedBy="tags", fetch=FetchType.LAZY)
    private Set<Video> videos;
}

I have a database where videos are connected to multiple tags and vice versa. I want to delete all videos and cascade it to delete all tags as well. Calling remove on a Video entity results in a cycle and after a few round of going back and forth between a tag and a video, the java compiler prints a stack dump of the cycle.

How can I remove a video / all videos using JPA , preferably by removing all videos and cascading the remove to the tags.

Answer 1

The actions are:

1. Breakdown relationships (object schema)
2. Update owner entity (video in this case)

3. Remove videos entities also remove tag entities because cascade anotation in Video Class.

    //Remove relationships List<Video> videoList; for (Video v : videoList) { for(Tag t : video.getTags()){ t.getVideos.remove(v); v.getTags.remove(t); } } //Update owner entities for (Video v : videoList) { Session sess = HibernateUtil.getSessionFactory().openSession(); Transaction tx = sess.beginTransaction(); sess.update(v); tx.commit(); sess.close(); } //Remove owner entities for (Video v : videoList) { Session sess = HibernateUtil.getSessionFactory().openSession(); Transaction tx = sess.beginTransaction(); sess.delete(v); tx.commit(); sess.close(); }