I'm trying to generate JPA entities out of an existing database having an "interesting" design.

Database has a table called UserSet, which can have links to several other UserSets. There is a one to many relation between UserSets and LinkedUserSets. LinkedUserSets also has one to one relation to UserSets.

I tried to generate a JPA Entity out of the database structure using Dali JPA Tools. The resulting entity Linkeduserset misses @Id or @EmbeddedId annotation and thus failes to compile. As the resulting entity contains only two @JoinColumns (which cannot be marked as @Id), I have not so far found a way around this issue.

Database structure can not be modified in any way.

Is there a way to overcome this somehow?

Relevant pars of create table statements:

CREATE  TABLE `LinkedUserSets` (
  `UsrSetID` INT(11) NOT NULL DEFAULT '0' ,
  `ChildID` INT(11) NOT NULL DEFAULT '0' ,
  CONSTRAINT `fk_LinkedUserSets_UserSet1`
    FOREIGN KEY (`UsrSetID` )
    REFERENCES `UserSet` (`UsrSetID` ));

CREATE  TABLE `UserSet` (
  `UsrSetID` INT(11) NOT NULL AUTO_INCREMENT ,
  PRIMARY KEY (`UsrSetID`),
  CONSTRAINT `fk_UserSet_LinkedUserSets1`
    FOREIGN KEY (`UsrSetID` )
    REFERENCES `LinkedUserSets` (`ChildID` ));

Generated entities:

@Entity
@Table(name="linkedusersets")
public class Linkeduserset {
    //bi-directional many-to-one association to Userset
    @ManyToOne
    @JoinColumn(name="UsrSetID")
    private Userset userset1;

    //bi-directional one-to-one association to Userset
    @OneToOne
    @JoinColumn(name="ChildID")
    private Userset userset2;
}


@Entity
@Table(name="userset")
public class Userset {
    private static final long serialVersionUID = 1L;

    @Id
    @Column(name="UsrSetID")
    private int jngSetID;

    //bi-directional many-to-one association to Linkeduserset
    @OneToMany(mappedBy="userset1")
    private Set<Linkeduserset> linkedusersets;

    //bi-directional one-to-one association to Linkeduserset
    @OneToOne(mappedBy="userset2")
    private Linkeduserset linkeduserset;
}

Error message:

Entity "Linkeduserset" has no Id or EmbeddedId