Hi, Answers to your questions are in http://code.google.com/appengine/docs/java/datastore/transactions.html#Using_Transactions
To do what you want, you only have to delete the book to remove it from entity group A and recreate it in entity group B (assuming the root entity - cat B - has been created already else you need to create it before) Deleting then recreating allow the datastore to move your entity from the ds server for cat A to the ds server for cat B in order to provide the apppropriate scalability NB: you won't be able to do both ops in 1 transaction as 1 transaction can only touch entities from a single entity group. You need to do that via 2 transactions. The best (only ?) way to continue guaranteeing integrity of your data in to do it via a task for the second action (recreate) that you make transactional with the 1st (delete). regards didier On Dec 6, 7:57 am, asianCoolz <[email protected]> wrote: > if have i have pojo like categoryA -> subcategoryA--> book > relationship. > subcategoryA is child of parent categoryA. book is child of > subcategoryA > in this case, everything is inside same entitygroup > > if i need to move 'book' to another subcategory-B. i need to delete > subcategoryA and categoryA, and recreate categoryA -> subcategoryA--> > without book ? and recreate categoryb -> subcategoryb--> > book ,other-book, other-book3 ? -- 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.
