Hello,

I have many-to-one relation, where A can have many B entities, and B can have only one A.

I define annotation in A like:

@OneToMany(targetEntity=B.class, fetch=FetchType.LAZY, mappedBy="blah", cascade=CascadeType.ALL)
@Column(name="someID", nullable=false) // inverse=true
private Set<B> childs = new HashSet<B>();

In B i have something like this:

@ManyToOne(targetEntity=A.class, fetch=FetchType.LAZY)
@JoinColumn(name="someID", referencedColumnName="...", nullable=false)
private A a;

When i add new B entities in childs set, or modify some entity in set and save A everything propagates well, and
B updates in database properly.
However when i remove some elements from set changes are not propagated, and all B entities remain in
database.

Can someone help me about this, i have no idea what i am doing wrong.

Best regards.

Take a look at the DELETE_ORPHAN CascadeType, it should answer your problem!
By the way, why do you have an annotaion @Column on your OneToMany mapping? Seems wrong to me ...

Thank you for fast reply, that is exactly what i want. I used javax.persistance.CascadeType.ALL and
there is no DELETE_ORPHAN CascadeType at all.

Best regards.

This is directly taken from the Hibernate Doc:



But I'm assuming here that you are using Hibernate and not another implementation of JPA ...
Because not all implementations of JPA contains the DELETE_ORPHAN CascasdeType! (Actually Hibernate might even be the only one which has it ...)

Hello,

I think that CascadeType.DELETE_ORPHAN is exactly what i need, but i have another problem now,
which i don't have before.

If i want to modify foreign key in class A which contains set of B objects i got following exception:
Don't change reference to a collection with cascade="all-delete-orphan".
I must say that this foreign key is not primary key of A, but surrogate key of table which just have a unique constraint.

Any help?

Hi,

If you need to modify in class A the value you are using as reference to the collection of B objects then perhaps this value is just not a good choice for a FK!!

Hi,

But i need this option. At the beggining i used primary key of table A to be foreign key in B, but
then i realized that sometimes i need to change that value. So i choose other field to be FK.
For example:
I have Person table which can have many properties, and some unique identifier PersonNumber, which can be
modified. Then i have Account table, one person can have one or more accounts and every
account belongs to only one Person.
My idea is to set that unique indentifier PersonNumber to be FK in Account table. But Hibernate don't let me
to change it's value if i use DELETE_ORPHAN.

What other options i have?