I\'m new to JDO but I\'m willing to use it to to make my code portable (currently I\'m using AppEngine, thats why). In the following Google Talk: http://dl.google.com/io/2009/pres/W_0415_Building_Scal
I have a User object which has a collection of Transaction objects und开发者_如何学Goer it. I store the object ID for my User object and now need a query to sum the transactions under the User object
I\'m wondering why is ORM so popular and everybody is using ORM implementations of JDO and JDA specifications, instead of using object databases that implements these specifications as well. The perfo
I\'m experimenting with App Engine, using JDO and DataNucleus for persistence.I have a simple domain that includes several unidirectional relationships.The question comes with nesting those relationsh
using App Engine and Java I decided to delete the local datastore located in local_db.bin as I had made some changes to class models contained in it. Mistake!
What will actually happen if I provide a full set of annotations for JPA and JDO on data objects? Can I then switch between them without touching the code? how can I switch what to aplay external con
I\'m working on GAE-based applications, which uses JDO to access datastore. I need to implement polymorphic relationship between persisted objects.
I use ANT to run my JDO application example implemented using Datanucleus solution. When I run it I see a lot of INFO lines generated by Datanucleus. How can I get rid of them?
I have a parent class and I want to store a HashMap within it. However, every time 开发者_如何学运维I try to modify that HashMap I get the following error:
I\'m implementing web application with JDO in Google App Engine. According to documentation, in owned one-to-many relationships, order of elements in \"owner\" object collection is determined either
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