Interesting. It seems like it should have worked without the
cascade... the nullify is what is supposed to do the trick... the
cascade should just affect when you're deleting the parent, so you can
delete the parent and all of the children at the same time. I'd be
curious to see you try the same code with 3.0M6, with the parent's
delete rule unset (ie: no action), and the child's set to nullify. In
any event, glad things are working for you now.
Cheers,
Robert
On Oct 22, 2009, at 10/2212:40 AM , Mark Fraser wrote:
Thanks Robert. Changing to cascade on the parent did the
trick....the array members get removed just by calling deleteObjects
on the data context. Makes sense but this isn't mentioned anywhere
that I can see in the deleteting objects documentation.
Mark
Robert Zeigler wrote:
Hi Mark,
The tips Andrus provided should work, in particular, making sure
your delete rules are correct.
So the delete rule from for the relationship in the parent entity
should (probably) be marked cascade (if the children can't exist w/
out the parent; otherwise nullify), and the delete rule for the
relationship on the child side should definitely be nullify. I've
used this plenty of times and it works. :) So if it's not working
for you, maybe something else is going on? Are you using
inheritance, by chance?
Robert
On Oct 22, 2009, at 10/2212:08 AM , Mark Fraser wrote:
>you may want to change delete rule to "Nullify" from many side to
one side of the relationship
No effect.
>Otherwise you'd have to explicitly unset the relationship before
deleting an object.
I'm not sure what you mean by this. Do you mean doing something
like this?:
this.unsetReverseRelationship("toArtists", this.getToPaintings());
..in the tomany (painting) object?
I tried that and it didn't work (still getting
ConcurrentModificationException).
I just want to delete all of the objects and have it properly
reflected in the parent's array. It seems like a very everyday
operation. Is it really this difficult?
Thanks
Andrus Adamchik wrote:
Hi Mark,
However in the modeler the delete rule for both sides of the
relationship is "No Action".
you may want to change delete rule to "Nullify" from many side to
one side of the relationship. Otherwise you'd have to explicitly
unset the relationship before deleting an object.
Andrus
On Oct 21, 2009, at 10:37 AM, Mark Fraser wrote:
Hello,
I am using Cayenned 2.0.4.
What is the proper way to delete the full collection of tomany
objects and have the target object's array correctly reflect the
deletion?
The manual (http://cayenne.apache.org/doc20/deleting-
objects.html) says to use dataContext.deleteObjects if you want
to delete all objects in the collection.
What it does not say is that the target object's array will
still contain references to objects that are scheduled for
deletion (or have been deleted after committal).
I have code like this:
System.out.println("paintings: " +
artist.getPaintingsArray().size()); // "1"
dataContext.deleteObjects(artist.getPaintingsArray());
System.out.println("paintings: " +
artist.getPaintingsArray().size()); // "1"
dataContext.commitChanges();
System.out.println("paintings: " +
artist.getPaintingsArray().size()); // "1"
But if I try to delete the objects myself using an iterator as
described on that manual page I get a
ConcurrencyModificationException--which is warned about on that
page. It says this may result from the object being deleted
having a "nullify delete rule". However in the modeler the
delete rule for both sides of the relationship is "No Action".
I would appreciate if someone could suggest how I am supposed to
do this (without switching Cayenne versions).
Thanks,
Mark
