Hi there,

Imagine the following situation:

I have an application that deals with user orders. An order can have one or more orderlines. The orderlines are the children of the order which is the parent. An orderline has a relationship with a ticket. A ticket (parent) can be connected to more than one orderline (children).

Order --1--------N--< Orderline >--N--------1-- Ticket

Question:

I create a new ticket object, assign this ticket object to one or more orderlines and finally the orderlines are connected to the order object. Is it possible to insert all the records with a simple 'save(order)'? Is Hibernate intelligent enough to see it must first insert the Ticket, then the Order and finally the Orderline object?

Erwin.

As far as I know, you can cascade a save along a one-to-many association in the one-to-many direction (i.e. from 1 to N) but not along the many-to-one direction (i.e. from N to 1). So in your case, you would need to save the ticket and the order, but the orderlines could get saved via cascade.

But I may be wrong :-)
Cheers!
Rob

<!ELEMENT many-to-one (meta*,column*)>
<!ATTLIST many-to-one cascade (none|all|save-update|delete) #IMPLIED> <!-- default: none -->

I guess that it does not work in the way I want. I must first save the ticket than the order and at last the orderline. Am I right?

Erwin.

No. What Christian is saying (in his endearingly cryptic way :-) is that you CAN cascade along a many-to-one relationship.

Basically, I think that you can probably do what you want. But you should try it yourself and see :-) Christian, can you cascade in BOTH directions of a bidirectional relationship? And if not, then in Erwin's case, should he cascade from Order to Orderline to Ticket?

(My guess is yes: Erwin, if I were you, I would first try cascade="all-delete-orphan" on the Order-to-Orderline association, and cascade="save-update" on the OrderLine-to-Ticket association. And then I think Hibernate will probably do the right thing.)

Cheers!
Rob

Guys, try it. It will work as you expect it to work.

the question was : "How intelligent is Hibernate"
i think i have the answer: "extremely intelligent" or "as intelligent as the way you're writing your mapping file...."

Hibernate is as intelligent as the user who is using it...obviously the range of intelligence varies greatly.

;)

i only wanted to say that the tool is not going to do all the work ;)

What do you mean with that?
According to the previous answers Hibernate is intelligent enought to see when objects must be inserted and in which order (parent first then child)!

It is still not working, what kind of work must I do by myself?

Erwin.

Does anyone know if it is possible to to a lazy many-to-one association, I bet it is.

it is, just use outer-join = false on the many-to-one node, by default:
outer-join = true (always load the to-one object) and lazy = true (never load the to-many list)

I think he just meant that you must understand exactly what cascades you want to implement, and which associations should be cascaded, and which direction those cascades should happen on.

Hibernate will do all the work for you *if* you tell it exactly what work you want it to do. Figuring out what you want, and describing it in your mapping, is *your* job :-)

Cheers,
Rob

yes Rob, that was exactly what i wanted to say lol

Actually the common way it to proxy the class in the one side. Default for outer-join is auto.