[appengine-java] Re: primary key portability
I ported my Open Source EJB3/JPA application to Google App Engine many months ago and almost at the beginning it was obvious that I had to split my entity classes to two versions: Google App Engine and non Google App Engine. Impossible to achieve 100% source compatibility. "Primary key not compatible" is only the one element of the whole story. http://hoteljavaopensource.blogspot.com/2009/09/migration-to-google-app-engine.html --~--~-~--~~~---~--~~ 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 google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: primary key portability
Ok, thanks. That is helpful to know. leszek wrote: > I ported my Open Source EJB3/JPA application to Google App Engine many > months ago and almost at the beginning it was obvious that I had to > split my entity classes to two versions: Google App Engine and non > Google App Engine. Impossible to achieve 100% source compatibility. > "Primary key not compatible" is only the one element of the whole > story. > > http://hoteljavaopensource.blogspot.com/2009/09/migration-to-google-app-engine.html > > --~--~-~--~~~---~--~~ 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 google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: primary key portability
For very simple models (i.e. no relationships), you can use Long- and String-based primary keys to maintain portability, but if you do want to use relationships, at least one model will have to rely on the com.google.appengine.api.datastore.Key class. - Jason On Thu, Oct 22, 2009 at 6:52 PM, Rusty Wright wrote: > > With Google App Engine you are invariably required to use the class > com.google.appengine.api.datastore.Key for your primary key. > > I would like to be able to compare the behaviour of of DataNucleus JDO > between an RDBMS (e.g., HSQL) and Google's Big Table data store. But I > can't see any nice way to do this without having to have duplicate > model/domain objects, as well as duplicate DAOs, because of the primary key > difference. > > Is anybody doing this, and if so, how are you handling it? > > > > --~--~-~--~~~---~--~~ 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 google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
