Unidirectional « Relationship « JPA Q&A

1. Does anyone have a real world example of unidirectional many to many relationship? stackoverflow.com

It seems that a many to many relationship should always be bidirectional since each side is probably interested in accessing the other side's collection. Does anyone have a real world example where ...

2. New/Entity Classes from Database (JPA): doesn't generate unidirectional relationships forums.netbeans.org

I find that even though my mysql database schema incorporates a whole bunch of ALTER TABLE ... ADD CONSTRAINT FK_... FOREIGN KEY (...) REFERENCES ... (id); that netbeans does not create ...

3. Can't figure out unidirectional one-to-one relationship forum.hibernate.org

I have a class "A" that has a property of abstract class "B" in a one to one relationship. "A" will have only one "B", but the "B" will change from time to time to different subclasses. Any instantiated "B" subclass will only be related to one "A". "B" does not have a reference to "A". Code: public class A { ...

4. unidirectional one-to-many relationship forum.hibernate.org

I have two classes, Patient and Report. In patient, there is a collection of Reports. Reports doesn't know about Patient, so the association is Unidirectional. This is my mapping file definition for the Patinet object, Patient.hbm.xml and I've done it according to the documentation. However when I persist the patient object, it ...

5. unidirectional 1-1 relationship. forum.hibernate.org

In a uni-directional one-to-one relationship, where or how can I specify the foreign key column that one object/table refers to. e.g. I have a Person object and an Address object. Person knows about address, but address need not know about Person, so the relationship is unidirectional. e.g. public class Person { private Address address public Address getAddress() { return address; } ...

6. Unidirectional many-to-one relationship with same superclass forum.hibernate.org

Hi! I'm trying to model a parent/child relationship (as in biological parent) and I just ran into a bit of trouble. I have a unidirectional many-to-one relation from Child to Parent, and as long as I keep my Child and Parent classes separated, it works fine. But when I add a common superclass, i.e. Person (strategy=JOINED), I get an error: "No ...

7. unidirectional many2many relationship with own primary key forum.hibernate.org

hallo alltogether, until now I have found how to map a many2many-relationship between to tabels "s" and "d" with the third table "map". Normaly you will use the tweo foreign key as tablekey for map. But in the legacy database I work with the map table also has a own primary key. How to map this without a own Java entity? ...

8. Unidirectional one-to-many relationship forum.hibernate.org

Parent { Parent_Id; Name; Desc; } Child { Child_Id; Name Parent_Id (not-null) } @Entity public class Parent implements Serializable { @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER) @JoinColumn(name="PARENT_ID") public Set getChilds() { ... } @Entity public class Child implements Serializable { ... //no bidir } I dont want Child to have reference of parent, but hibernate seems to be not identifying the parent of child by ...

9. Unidirectional One-To-Many relationship forum.hibernate.org

@Entity @Table(name = "cell") public class Cell implements Serializable{ @Id @GeneratedValue(strategy = GenerationType.AUTO) int id; @OneToMany( mappedBy="cellId", cascade = CascadeType.ALL, fetch = FetchType.EAGER, targetEntity=TeamPoint.class ) ...