object « Relationship « JPA Q&A





1. How do I specify the foreign key on a many-to-one relationship when is not a property on the object itself?    stackoverflow.com

I'm trying to map a many-to-one relationship from MarketMenuBranch to Market. My classes look like:

public class Market implements Serializable {
    private int id;
    private ...

2. How does Hibernate detect dirty state of an entity object?    stackoverflow.com

Is it using some kind of byte codes modification to the original classes? Or, maybe Hibernate get the dirty state by compare the given object with previously persisted version? I'm having a problem ...

3. Optional two/three levels one-to-many object relationship?    forum.hibernate.org

Hi, I was trying to model the following but got performance issue (might be incorrect modelling?). Please give me your professional advice. There are three objects in the following relationship: 1. Country |-------- Region |-------- City 2. Region |-------- City 3. City In sentense, a "City" could belong to a "Region" and must belong to a "Country". "Region" must belong to ...

4. How to Avoid Unwanted relationship b/w Objects..    forum.hibernate.org

In my project i'm using 26 classes..That means i used 26 tables to store that objects in DB.And my DB schema is some what complex..In one class i'm using multiple Object references.. For Ex: class Car { int id; Tyre tyre; Glass glass; ... } Now i'm coming to Issue..,I created the object for Tyre below : Tyre mrf=new Tyre(); tyre.setName("MRF"); ...

5. Problem with multiple relationships between two objects    forum.hibernate.org

We have two objects that have a rather complex relationship. One is the User object, the other is called a Proof. The proof has a many to one relationship with the User as a field called creator. The user has two sets of proofs. One is proofs that the user created (a one-to-many relation), and the other is proofs that the ...

6. Multiple relationships between two objects    forum.hibernate.org

Newbie Joined: Sun Mar 05, 2006 7:52 am Posts: 4 Hi all, I need to define two relationships between two objects and am not sure which is the best approach to do the same. I have two objects, employees and departments, which share a many-to-many relationship. Apart from this I also need to know who (employee) is the creator of a ...

7. Circular relationship between objects.    forum.hibernate.org

Hi All, As per DB design i have circular relationship between objects. for eg, take,object1,object2 and object3 object1 has many to one relationship with object2 and object2 has many-to-one relationship with object3 and object3 has many-to-one relationship with object1. Is this mapping scenerio is possible in Hibernate? Note: all objects having bidirectional relationship between them. I tried for this mapping and ...

8. Unable to make relationship between two table object    forum.hibernate.org

Newbie Joined: Thu Apr 19, 2007 12:34 am Posts: 8 Hi I have two table.ops_rsn and ops_flt_leg ops_rsn has one composite primary key consisting of six columns.There is no referential integrety established at back end between ops_flt_leg and ops_rsn table.I need to write a query with a outer join between two tables on column ops_flt_leg.irrops_rsn_cd=ops_rsn.rsn_cd. Hibernate is not supporting oracle (+) ...

9. Removing relationship between many-to-many objects?    forum.hibernate.org

Clearing the collections will only remove entries from the non-inverse mapping i.e. relatedToListNodes. Were there definitely entries in the relatedTo collection? Because the relationship is bi-directional you should implement methods in the ListNode class to properly update the relationships. Calling clear() on the collections leaves the data in an inconsistent state - node A might no longer point TO node B ...