Eclipselink - OneToOne Mapping

Question

I am currently developing a little Group Management System and using java 8 with eclipselink and SqlLite.

@Entity
@Table(name = "T_GROUP")
public class Group {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;

    private String name;
    private List<Permission> permissions;
    private boolean defaultGroup;
    private String prefix;
    private String suffix;
    private int rank;
    private boolean build;
    
    @OneToOne
    private Group inherit;

    /**
     * Instantiates a new Group.
     */
    public Group() {

    }
    
    ...Getters Setters
}

The Field inherit references to another group that has other permissions, but the current group inherits all permissions from the other group. How do I work with the field inherit? It is the same Type. The OneToOne relation gives me following error:

Internal Exception: java.sql.SQLException: [SQLITE_ERROR] SQL error or missing database (near "CONSTRAINT": syntax error)

Error Code: 0

Call: ALTER TABLE T_GROUP ADD CONSTRAINT FK_T_GROUP_INHERIT_ID FOREIGN KEY (INHERIT_ID) REFERENCES T_GROUP (ID)

I changed the Data Model, because the other class was not needed — Lucas Dangl, Oct 11 '16 at 16:52
I deleted my response, because it's not relevant to the now edited post... — David, Oct 11 '16 at 17:08
What sort of "work" do you want to do with the field `inherit`? — David, Oct 11 '16 at 17:09

score -1 · Answer 1 · edited May 23 '17 at 12:06

-1

If your question is how to map the self referencing relationship, you can simply use @OneToOne annotation. This is already answered here JPA: How to have one-to-many relation of the same Entity type

edited May 23 '17 at 12:06

Community

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1

answered Oct 11 '16 at 18:07

hetec

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Eclipselink - OneToOne Mapping

1 Answers1