EntityManger.merge() and Cascade.Remove

[hfarid]

Hi,
I am having a problem with cascade delete on "OneToMangy" relation

I have two entities "Tag" and "EquivalentTag" with oneToMany relation from the "tag" side

Tag code

@Entity()
@Table(name="tag")
public class Tag implements Serializable{

 private int id;
 private String name;
 private String description;
 private Set<EquivalentTag> equivalentTags;

 @Id(generate = GeneratorType.AUTO)
 @Column(name = "id")
 public int getId() {
 return id;
 }
...
 @OneToMany(cascade = CascadeType.ALL, mappedBy="tag", fetch=FetchType.EAGER )
 public Set<EquivalentTag> getEquivalentTags() {
 return equivalentTags;
 }

 public void setEquivalentTags(Set<EquivalentTag> equivalentTags) {
 this.equivalentTags = equivalentTags;
 }

}

EquivalentTag code

@Entity()
@Table(name="equivalenttag")
public class EquivalentTag implements Serializable{

 private int id;
 private int eqid;
 private String eqname;
 private Tag tag;


 @Id(generate = GeneratorType.AUTO)
 @Column(name = "id")
 public int getId() {
 return id;
 }
...
 @ManyToOne
 @JoinColumn(name="tag")
 public Tag getTag() {
 return tag;
 }

 public void setTag(Tag tag) {
 this.tag = tag;
 }

}

My client add/remove EquivalentTags to a tag object... pass it on to the session bean which in turns calls EntityManager.merge(tag)

in case of adding new EquivalentTag ... eman.merge() is creating all the new objects in the equivalenttag table
But in case of removing EquivalentTag ... eman.merge() basically does not do anything

Did I miss anything in my code ?? do I have the wrong understanding of Cascade.Remove (please correct me if this is true). Do I have to do the delete manually ?

Thanks

My setup
- PC (windows XP Pro)
- Release ID: JBoss [Zion] 4.0.3RC2 (build: CVSTag=Branch_4_0 date=200508131404)
- jboss-EJB-3.0_RC3

[alximik]

merge won't delete such objects. You can try hibernate's org.hibernate.annotations.CascadeType.DELETE_ORPHAN annotation.

But I'm thinking its a kludge. Better delete the objects yourself in setEquivalentTags method.

@OneToMany(cascade = CascadeType.ALL, mappedBy="tag", fetch=FetchType.EAGER )
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.ALL, org.hibernate.annotations.CascadeType.DELETE_ORPHAN } )
public Set<EquivalentTag> getEquivalentTags()
.....

[hfarid]

works very nicely for a kludge :-)
I am kinda surprised that merge does not delete the many side of the relation since it does create/update when needed

anyway, thanks for the hint.

[tonylai]

To epbernard:
Yes, DELETE_ORPHAN can resolve the problem, but it's really not graceful and untransplantable. The entity bean is tightly bounded with hibernate persist. For hibernate 2, there's no DELETE_ORPHAN. And we are all confused why you guys import such a unusable feature?

[epbernard]

"tonylai" wrote:
To epbernard:
Yes, DELETE_ORPHAN can resolve the problem, but it's really not graceful and untransplantable. The entity bean is tightly bounded with hibernate persist. For hibernate 2, there's no DELETE_ORPHAN. And we are all confused why you guys import such a unusable feature?

Stop claiming false statements. It's not my fault if the EJB3 EG has decided not to standardize this feature. Every single EJB3 implementor will need an extra annotation to support that.
And of course, delete-orphan was part of hibernate2!!
Annotation makes no change in the way to use that feature compared to Hibernate core.