Newbie question concerning oneToMany

eMPy · **Joined:** Mon Mar 21, 2005 9:41 am **Posts:** 12

Hello to everybody,

i have a problem modelling a bidirectional oneToMany relation where the owning side deletes the owned objects. Here's the code:

owning side:

Code:

@OneToMany(fetch= FetchType.EAGER, cascade={CascadeType.ALL})
   @JoinColumn(name = "sqlInputId")
   @OrderBy("id")
   public Set<DbSqlFieldMapping> getFieldMapping()
   {
      return fieldMapping;
   }

and the owned side:

Code:

@ManyToOne
   @JoinColumn(name="sqlInputId", insertable=false, updatable=false)
   public DbSqlInput getSqlInput()
   {
      return sqlInput;
   }

The foreign key is generated correctly and the owned entities are deleted, when I delete an input. But: when I do something like that:

Code:

input.setFieldMapping(null);

or

Code:

input.getFieldMapping().remove(m);

the owned entities are NOT deleted. Only the foreign keys are set null.

Question: What do I need to change, that the owned entities are deleted when remove from the set?

Thank you in advance
Mathias

stewart.cambridge · **Joined:** Sat Nov 19, 2005 2:46 pm **Posts:** 69

From chapter "11.11 Transitive persistence" of the Hibernate Reference PDF (Hibernate 3.0.5 version)

Quote:

Entities have their own lifecycle, support shared references (so removing
an entity from the collection does not mean it can be deleted), and there is by default no cascading of state from
one entity to any other associated entities. Hibernate does not implement persistence by reachability by default.

Later in the same chapter it says:

Quote:

A special cascade style, delete-orphan, applies only to one-to-many associations, and indicates that the delete()
operation should be applied to any child object that is removed from the association.

Hope that helps. Don't forget to rate :-)