Excellent! Thanks for the explanation.
Max Ross (Google) wrote:
Hi Rusty,
This is something we've planned to support all along, we just haven't
gotten around to it yet. There's an issue filed for it here:
http://code.google.com/p/datanucleus-appengine/issues/detail?id=86
(already quite a few stars)
There are 2 things that make this work complicated. The first is
explained in the above issue (no way to resolve unowned relationships
inside a txn due to multiple entity groups). The second is that we need
to start storing the Keys of the referenced objects in a list property
on the parent. This is optional for owned relationships because we can
use an ancestor query to find children (this is what we do now), but
required for unowned relationships because there's no other way to store
the relationship. This is one of the things I've been working on the
last few weeks, and once this work is done it unlocks a ton of good
stuff, including unowned relationships.
Max
On Mon, Jan 11, 2010 at 11:50 PM, Rusty Wright <[email protected]
<mailto:[email protected]>> wrote:
If I understand things correctly, it seems to me that a class would
have a field
@Persistent(defaultFetchGroup = "true")
List<Key> myClassKeys; // keys are from MyClass objects
instead of
@Persistent(defaultFetchGroup = "true")
List<MyClass> list;
because in the latter case, when an object is added to the List,
it's parented to the enclosing object. In the case of the List of
Key, no parenting happens so you can add keys for objects that are
already parented or at the root level.
Why can't you create an annotation parameter or new annotation so
that we can use the latter form, and the annotation specifies that
the objects' parenting remains unchanged? So under the hood it
behaves like the former List of Key, but it provides a cleaner
interface like the latter.
--
You received this message because you are subscribed to the Google
Groups "Google App Engine for Java" group.
To post to this group, send email to
[email protected]
<mailto:[email protected]>.
To unsubscribe from this group, send email to
[email protected]
<mailto:google-appengine-java%[email protected]>.
For more options, visit this group at
http://groups.google.com/group/google-appengine-java?hl=en.
------------------------------------------------------------------------
--
You received this message because you are subscribed to the Google
Groups "Google App Engine for Java" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/google-appengine-java?hl=en.
--
You received this message because you are subscribed to the Google Groups
"Google App Engine for Java" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/google-appengine-java?hl=en.
