object « Fetch « JPA Q&A

1. hibernate how to retrieve a hierarchy object    stackoverflow.com

I have the following beans Task, ServerDetails and ApplicationDetails. I wish to retrieve all tasks, their server details and application details based on a specific application name. From the result i expect to ...

2. Hibernate one-to-one: getId() without fetching entire object    stackoverflow.com

I want to fetch the id of a one-to-one relationship without loading the entire object. I thought I could do this using lazy loading as follows:

class Foo { 

3. How can I retrieve multiple objects with JPA?    stackoverflow.com

I'm using JPA2/hibernate with this data model:

class Stock {
  private StockGroup stockGroup;
  private boolean visible;
class StockGroup {
  @OneToMany(mappedBy = "stockGroup")
  private List<Stock> stocks;
I would like ...

4. How to fetch classified objects with jpa(hibernate)?    stackoverflow.com

there are 3 classes here:

abstract class AbstractClass{@Column("type") public int type;......}
class A extends AbstractClass{......}
class B extends AbstractClass{......}
in database, when type=1 means A and type=2 means B. So how can i fetch these ...

6. Hibernate: Join fetching (non lazy) of an object.    coderanch.com

I have an Address table that has many-to-one relationship to an AddressType table. I want to load (initialize) AddressType for every Address object loaded. I modified the address.hbm file to look like this When I query by addressID, addressType is initialized fine. However, when I query for a list of addresses, the addressType is not initialized. Any ...

7. Inner object fetching problem    forum.hibernate.org

Hi all I am facing a problem while using hibernate criteria query My object structure as follows StockBatch { Long id; String batchNumber; Date batchdate; Collection stock; Item item; } Stock { Long id; double quantity; Unit atUnit; String stockStatus; } Unit{ Long id, String name,(e.g :Chenni) String location } Item { Long id, String name, (e.g :N79 Mobile) String code; ...

8. Eagerly fetching lazy collection of lazy objects    forum.hibernate.org

select bands1_.bnd_id as bnd_id0_, bands1_.bnd_id as bnd_id1_, bands1_.ast_id as ast_id0_, bands1_.bdt_id as bdt_id0_, bands1_.bnd_delete_fl as bnd_dele4_0_, bands1_.bnd_external_reference as bnd_exte5_0_, bands1_.bnd_name as bnd_name0_, bands1_.bnd_point_to_point_fl as bnd_poin7_0_, bands1_.cmp_id as cmp_id0_, bands1_.ets_code as ets_code0_, bands1_.trb_id as trb_id0_, bands1_.ast_id as ast_id1_, bands1_.bdt_id as bdt_id1_, bands1_.bnd_delete_fl as bnd_dele4_1_, bands1_.bnd_external_reference as bnd_exte5_1_, bands1_.bnd_name as bnd_name1_, bands1_.bnd_point_to_point_fl as bnd_poin7_1_, bands1_.cmp_id as cmp_id1_, bands1_.ets_code as ets_code1_, bands1_.trb_id as trb_id1_, ...

9. reattaching object causes fetch of uninitialized to-ones    forum.hibernate.org

If I fetch an object in one session and close that session before initializing any relationships, then attach that object to a new session, Hibernate is immediately doing one fetch for each to-one relationship. Uninitialized to-many relationships do not get automatically fetched. This leads to n+1 select problems when attaching objects. In my case, I don't even need the unitialized to-one ...

10. join fetch query returns redundant objects    forum.hibernate.org

firstly, in my understanding, hibernate should deal with the redundant rows, as it does when I ussue the simple join fetch without the extra exists clause. secondly, as it is so obvious, I have tried adding the distinct before posting here. It turns out that the way the SQL is generated, the distinct clause is applied to the whole row, which ...

11. Why does hibernate fetch objects lazy on access?    forum.hibernate.org

Why does hibernate fetch objects lazy on access? I can make this test, which in my opinion is kind of weird: Code: public void testTest() { Region region = getRegionPersistent(); regionDao.getHibernateTemplate().evict(region); Country c = null; try { ...

12. beginner question: retrieve Object by Collection lookup    forum.hibernate.org

This is the code: @Entity class A{some fields and methods} @Entity class B extends A{ String _name; String getName(){...} } @Entity class C extends A{ ArrayList _someB; addB(B b){...} } class DaoForC{ List findByB(String name){ //return all C that have a B in _someB //with B._name=name Query q = session.createQuery(???); return q.list(); } } Question 1: Any suggestions how to fill ...

13. Does not fetch mutliple objects in Set -    forum.hibernate.org

Does not fetch mutliple objects in Set - com.sun.jdi.InvocationException The mapping I have used is

14. Join fetch returns only 1 object in set    forum.hibernate.org

I am executing the following query (minimized): Code: Machine machine = (Machine) getSession().createQuery( "from Machine m" + //other query stuff " left join fetch m.things t" + ...

15. Fetching of objects when using a JTree in a rich client    forum.hibernate.org

Hi together, although I've read the threads in this forum, I can't find the best way to solve my current problem. We've got a rich client (spring rcp) and are trying to display the complex data structure in a JTree. So far we've used the eager fetching mode, but as the project's elements increased, the performance degrades more and more. My ...

16. remove object from collection without collection fetching    forum.hibernate.org

Hibernate version:3.2.6 Hello, I have bi-directional association between parent/child. Parent can have too many children and I want to add and remove to "children" (inverse=true) collection without loading collection. "children" collection mapped as . With adding to collection I have no problem, but when I try to remove from this collection, collection perform initialization. Java class: Code: public class MyObject { ...