如何在JPA中使用联接的子实体获取继承实体？

Question

Writing the case it will be more simple to explain.

I am using Seam 2.3.1 v Hibernate JPA 2.0 and in our project. I have a base Person Entity Class.

@Entity
@Name("person")
@Inheritance(strategy = InheritanceType.JOINED)
@Table(name = "person")
public class Person extends BaseEntity  {

    private String name;
    private String surName;
    private String email;
    private String phone;

    // getter & setters
}

And I have 3 more Entity extends from Person as @Inheritance(strategy = InheritanceType.JOINED) : Personel , Musteri , DisPaydas

@Entity
@Name("personel")
public class Personel extends Person {

    private String appellation; 
    // getter & setters
}

I want to List personels, musteris and dispaydas in my bean however when I set them in my Group Entity, I want to save them as Person.

In fact in DB there is no difference between person_id and personel_id, they are same. However when I listing it, they are List<Personel>

In summary:

I want to get List<Person> from List<Personel> or Person from Personel object.

Answer 1

You're going to have to define an @Id and @Column in the Person class for the person_id .

However, since the column has a different name in the child entity, you'll need to change it using an @AttributeOverride to point to the personel_id @Column .

It couldn't hurt to use a @DiscriminatorColumn in the parent and @DiscriminatorValue in the children, but I don't think Hibernate requires those.