merge « Update « JPA Q&A

1. JPA Merge Is Causing Duplicates

I have the entity classes below. When a user first signs up, only the username and password are supplied, so the list of accounts (think profiles) is empty. Later, ...

2. JPA merge problem

In my spring/openjpa based application, I have two simple entities:

public class Game {

protected Long id;
@JoinColumn(name = "target_id")
protected GameObject target;

public class GameObject {

protected Long id;
protected String name;
@OneToMany(mappedBy = "target", cascade = CascadeType.ALL)
protected ...

3. merging / re-attaching IN JPA / Hibernate without updating the DB

Working with JPA / Hibernate in an OSIV Web environment is driving me mad ;) Following scenario: I have an entity A that is loaded via JPA and has a collection of ...

4. jpa merge not working

I have a problem with merging of objects using JPA. My code goes like this.

EntityTransaction entr = em.getTransaction();


Query q = em
  .createQuery("SELECT filterName FROM IbFilterName filterName where"

5. merge is used only for creating or updating?

If i use ex.merge(obj), now if in object obj i set the primary key to a value which is not present in database, will it create a new record or will ...

6. what is the difference between persist() and merge() in hibernate..?

my question is what is the difference between persist() and merge() in hibernate..? because Persist() can create a UPDATE & INSERT Query ex..


7. hibernate envers: merge & saveOrUpdate

I am working on an spring-hibernate-envers application. After lot of googling things are finally working for me but i have still got couple of questions.

  1. Earlier i was using saveOrUpdate ...

8. Different behavior of hibernate merge, and saveOrUpdate

in one particular case, i have to use merge instead of saveOrUpdate.

// item is detached object.
Category category = item.getCategory();
the thing is category name doesn't get updated while using merge, but it ...

9. Some more explanation of Hibernate's merge

I need some clarification on Hibernate merge method. How does it exactly work. When i have an entity that is detached, and I want it to get reatached, does Hibernate look ...

10. Merge or update persistence objects

I've got a hibernate interfaced mysql database with a load of different types of objects, some of which are periodically retrieved and altered by other pieces of code, which are operating ...

11. using Merge in hibernet and JPA

12. hibernate won't merge my changes

hi.. i have a detached object instance which i'm trying to merge it's changes back into the session, the session already has another object with the identifier re-assoicated previously with lock.none , when i try to do a merge on that object , nothing happens. the session is bound to a jta transaction under spring.

13. New to hibernate: Merge() is not updating

Hi, I'm stumped right now as to why my database table isn't being updated after I set one of the properties and then do a merge(). Here is what I have: Profile profile = profileStore.getProfile(profileId); //Set the new image name profile.setImage(fileName); profileStore.mergeProfile(profile); this is my hibernate file: public void mergeProfile(Profile profile) { try { System.out.println("My value was passed!!! : " + ...

14. merge() operation in hibernate

package Koushks10; import java.util.Collection; import java.util.Date; import java.util.List; import javax.persistence.*; import; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.AnnotationConfiguration; import org.hibernate.tool.hbm2ddl.SchemaExport; public class PersonTest { public static void main(String args[]) { AnnotationConfiguration c = new AnnotationConfiguration(); c.addAnnotatedClass(Koushks10.satyajeet.class); c.configure("hibernate.cfg.xml"); new SchemaExport(c).create(true, true); SessionFactory sf = c.buildSessionFactory(); /* Transient state to persistent state*/ Session s = sf.openSession(); s.beginTransaction(); satyajeet ref=new satyajeet(); ref.setName("satyajeet"); ref.setEmail("");; ...

15. Trying to understand the behaviour of Hibernate merge

Applogies if this question have already been asked. I've searched the Hibernate docs and forum for a while without finding an answer. I have a Spring - Hibernate application. When merge(Object o) is called and an error is encountered an exception is immediately thrown, but if I use for example update(Object o) the exception doesn't get thrown until a flush is ...

16. Is there any precedent to merge hibernate configurations?

So if I've got two different xml configurations is there anyway to take them a build one session factory from them so I can operate on all tables within the same session? I've got two different models but they are both referencing database objects in the same database/schema. I have a business object model and an application model and I want ...

17. SaveorUpdate() causing merging of previous and current entry

Hi I am new to hibernate.I found particular problem while working with attachdirty() stuff. My links is a collection , which is being obtained from a form bean and when i process my form bean(service method defined below) and say attachdirty(*); in attach dirty i am using saveorUpdate() this saveorupdate() is causing merging and of pervious entries and my current form ...

18. jpa merge without synching to the database?

If I have a detached entity and I do a merge() for various reasons Hibernate does a SELECT against the database. My question is: if I have a detached entity and I know that it exists in the database and the data that it holds is identical to the one in the database, is there is a way to prevent Hibernate ...

19. Correct use of the "merge()" function

Hello, I'm quite a beginner using Hibernate and after reading several tutorials the following issue has arisen in my project. I've an entity that has a large number of relationships, where some of them have also several relationships with other entities. If my understanding of the tutorials is right, I should use session.update() only if I am completely sure that the ...

20. Update vs Merge

21. what is the technical difference between Merge and persist

In case anybody finds this thread... persist() is well defined. It makes a transient instance persistent. However, it doesn't guarantee that the identifier value will be assigned to the persistent instance immediately, the assignment might happen at flush time. The spec doesn't say that, which is the problem I have with persist(). persist() also guarantees that it will not execute an ...

22. * [HHH-529] - Bug in merge()

23. Using Hibernate Merge

I want to use the merge functionality, whereby a record is updated if it already exists in the database and create new row if it doesn't. I was able to use the session.merge() function for a class(table) having single column as primary key. but was unable to do so for class having composite primary key. I get constraintViolationException for the same. ...

24. Merge or Update?

If you want to update the parent, then get/load/find the parent, make your necessary updates on the POJO retrieved, and save that object. Hibernate will detect by itself that you didn't change the children, and won't bother about them. If you didn't map the parent-child relationship as lazy="false", the children won't even have been read (unless you accessed them in your ...

25. Experience in merge strategies

26. Hibernate Support for Upsert/Merge?

Does Hibernate support upsert/merge? In other words, automatically insert the record if it doesn't exist in the database and automatically update the record if it already does exist? I have come across a scenario where this would come in handy. I have numerous threads which can potentially write to the same record in a table. If the record doesn't exist, it ...

27. When do i have to use merge?

28. Regarding Merge Dir

Need help with Hibernate? Read this first: ... AskForHelp [b]Hibernate version:2[/b] [b]Name and version of the database you are using:Oracle9i[/b] [b]The generated SQL (show_sql=true):[/b] In Hibernate in every .hbm.xml file generated by XDoclet I see a Hibernate comment as follows --------