Difference between Cascade.ALL and separated options

sridhar.signon · **Joined:** Fri Sep 18, 2009 12:45 pm **Posts:** 2

I have Cluster/Shelf relation(parent/child) like this.
Cluster.java
----------

Code:

@OneToMany(cascade = { CascadeType.PERSIST,CascadeType.MERGE,CascadeType.REMOVE }, mappedBy = "cluster")
@org.hibernate.annotations.Cascade(value = org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
public List<ShelfDBObj> getShelves() {
  return shelves;
}

Between a start and commit transaction for Cluster/Shelf

Code:

Cluster exists in database
..starttrx
ClusterDBObj cluster = //query cluster
ShelfDBObj shelf = new ShelfDBObj();
cluster.addShelf(shelf);
 dao.persist(shelf);    [b](Is Needed to save in database)[/b]
commit trx

I have Shelf/Card relation(parent/child) like this.
Shelf.java
---------

Code:

@OneToMany(cascade = CascadeType.ALL, mappedBy = "shelf")
public List<CardDBObj> getCards() {
  return cards;
}

Between a start and commit transaction for Shelf/Card

Code:

Shelf exists in database
..starttrx
ShelfDBObj shelf = //query shelf
CardDBObj card = new CardDBObj();
shelf.addCard(card);
commit trx // dao.persist(card) is not needed

At the point of commit transaction, the first trx needs an explicit save and the second trx does not need an explicit save. Why? What are the differences in the Cascade types. Please explain.

Froestel · **Posted:** Fri Sep 18, 2009 7:33 pm

Hi sridhar.signon,

the Hibernate docs state something about cascading in Sec. 10.11 http://docs.jboss.org/hibernate/stable/core/reference/en/html/objectstate.html#objectstate-transitive and there are already some possible hints in Sec. 10.2 http://docs.jboss.org/hibernate/stable/core/reference/en/html/objectstate.html#objectstate-makingpersistent.

So, if you read carefully and put it all together you might figure out that CascadeType.ALL includes save-update. save-update will pass a transient object to save(). Referring to Sec. 10.2 http://docs.jboss.org/hibernate/stable/core/reference/en/html/objectstate.html#objectstate-makingpersistent, save() results in an immediate DB hit whereas persist() might be postponed.

CU
Froestel