The DataNucleus docs talk a lot about detached objects and what it means to be detached, but, for new users, they kind of skip over the simplistic: What does it mean to be attached?
Using JDO / DataNucleus / NeoDatis datastore I added @Unique to a field of a persistable object, however I am allowed to create multiple objects which violate the unique constraint. The docs for Data
I\'m trying to find a w开发者_如何学Goay to accomplish a xsd schema to datastore roundtrip, with minimum effort.
I recently made a change to one of my app engine models.I changed a Key field to a String.I forgot to remove all the old records.I have already added new records that have strings in开发者_如何学运维
I have the following data model class defined: @PersistenceCapable public class TestSerializableModelObj {
I\'m creating an MVC Spring webapp. Using: Jetty (servlet container), DataNucleus (dao platform), DB4O (embedded datastore).
I\'m using the GAE datastore with JDO to hold course information.Each Course has a List of GradeDefinition objects (e.g. \"A=90%+\", \"B=80%+\", etc)
I have existing entities of a type in my gae datastore to which i want to add a new primitive property of primitive type \"long\":
I\'m trying to understand when I should call Query.close(Object) or Query.closeAll(); From the docs I see that it will \"close a query result\" and \"release all resources associated with it,\" but w
I am having trouble with subquery counts with JDOQL (using DataNucleus). The following query SELECT this.price
加载中,请稍侯......