persistence

I want to know the differences/similarities between Hibernate and simple persistence in Java EE 5? I'm not clear if Hibernate implements Java EE 5 persistence implementation or if it is a totally different approach to data representation over back-end systems. I'm confused about Hibernate and its relation with the concepts about java persistence given in the Java EE 5 tutorial... could you clarify the role of Hibernate in the context of Entities and EJBs? Also, I want to know other approaches (frameworks) like JPA or Spring... Pascal Thivent I want to know the differences/similarities between

I'm writing a J2SE app (no enterprise container) that uses JPA for persistence. Here is my persistence.xml : <persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" version="2.0"> <persistence-unit name="dbstats"> <!-- TODO: why is this needed? --> <class>dreambear.stats.data.GamePlayedEvent</class> <class>dreambear.stats.data.HyveMemberCountPoll</class> <class>dreambear.stats.data.ProfileCountPoll</class> <class

The following code is from JPA specs. I could not understand why em.joinTransaction() is required in createLineItem(int quantity) . Can anyone provide an apt explanation? @Stateful public class ShoppingCartImpl implements ShoppingCart { @PersistenceUnit private EntityManagerFactory emf; private EntityManager em; private Order order; private Product product; @PostConstruct public void init() { em = emf.createEntityManager(); } public void initOrder(Long id) { order = em.find(Order.class, id); } public void initProduct(String name) { product = (Product) em .createQuery("select p from Product p

I got an Java application using SQL tables that contains an ordered list of entities, ordered by an order column. I would like to add/remove things in/from the middle of the list. Now, I'm wondering if some persistence framework / orm / you-name-it could provide this kind of functionality with batch update of order column. At the basic case Hibernate (and probably others also) provide this functionality. The problem is that the objects are handled one at time, which becomes problem when the list is large enough. Alternate solution would be to do the thing with a batch SQL update, like the

The hibernate entity I am saving in the database (Oracle) has very complex relations, in the sense that it has many related entities. It looks something like this... @Table(name = "t_HOP_CommonContract") public class Contract { @Id private ContractPK id; @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL) @PrimaryKeyJoinColumn private ContractGroupMember contractGroupMember; @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY) @JoinColumns({ @JoinColumn(name = "TransactionId", referencedColumnName = "TransactionId"), @JoinColumn(name = "PrimaryContractId",

I'm struggling with Slick's lifted embedding and mapped tables. The API feels strange to me, maybe just because it is structured in a way that's unfamiliar to me. I want to build a Task/Todo-List. There are two entities: Task: Each task has a an optional reference to the next task. That way a linked list is build. The intention is that the user can order the tasks by his priority. This order is represented by the references from task to task. TaskList: Represents a TaskList with a label and a reference to the first Task of the list. case class Task(id: Option[Long], title: String, nextTask: