Hi there.

I have a tree of hibernate objects - it looks something like

A -> multiple B's -> multiple C's -> Multiple D's

There are times when I create an A, add a B to it, add some C's to B, and then add a D to each C.
Then I do session.save(A). This works fine in MySQL, but trying to do it on PostgreSQL causes a foreign key constraint, because it tries to do the insert the D's before it's inserted the A.

Is there any way to enforce the insertion order, or am I missing something, or...?

Thanks,

Hunter

Are you sure that's what's happening? I've been suspicious of that several times but it's never been Hibernate's fault. :)

Typically it doesn't matter what order you save the records in as long as you don't have not-null constraints on your foreign keys. You may want to set show_sql=true and make sure you understand what is being inserted.

Good luck!
Jenica

Well I do have not-null constraints on the keys. It's perfectly reasonable to do that, and still expect Hibernate to do the insertions in the correct order.

Can't it just start at the top and work it's way downwards? I actually only save the top object, so it's doing the inserts for the cascades, but for some reason is doing the children first, which, in the case of constrained foreign keys, is incorrect.

And the more I think about it, it's also more inefficient to insert the child, insert the parent, and then update the child with the parent key, when it could insert the parent, and then the child...

H

Use cascade="save-update"

I have cascade="all-delete-orphan".

It's doing the cascade, it's just doing it in the wrong order.

H

So, find your bug then.

I am having a similar problem:

my mapping between objects is as follows:

C1 -> C2
^ ^
B1 -> B2
^ ^
A1 -> A2

all haev cascade all constraint, the order i would expect them is:
A1, A2, B1, B2, C1, C2 or
A1, B1, C1, A2, B2, C2

but the order i get is:
A1, B1, C1, C2, A2, B2

so it seems that it doesn evaluate the dependencies correctly when there are more than one parent, is there any way to force it to iterate in the right order?

thanks,
tomer

I also tried specifying not-null on all parents adn got this exception:

org.hibernate.PropertyValueException: not-null property references a null or transient value

so it doesnt affects the order of saving the entities