Recursive Bidirectional entity

[oliverchua]

@Entity
public class Unit implements Serializable{
 @Id @GeneratedValue
 private Long unitCode;
 private String unitName;
 @ManyToOne @JoinColumn(name="superUnitCode")
 private Unit superUnit;
 @OneToMany(mappedBy="subUnits")
 private Set<Unit> subUnits;
 @Transient
 private String superUnitCode;

Hi I have this entity class.
The OneToMany is bidirectional and recursive.
IT adds
CONSTRAINT `FK284DA4E626B09B` FOREIGN KEY (`unitCode`) REFERENCES `unit` (`unitCode`)
that prevents any inserts to the table.

What should I do to remove the constraint?
Thanks in advance.

[epbernard]

constraints does not prevent bidirectional and recursive associations

[oliverchua]

Hi Emmanuel, this is the script of the table that was created by hibernate...

CREATE TABLE `intranetejb`.`unit` (
 `unitCode` bigint(20) NOT NULL auto_increment,
 `unitName` varchar(255) default NULL,
 `superUnitCode` bigint(20) default NULL,
 PRIMARY KEY (`unitCode`),
 KEY `FK284DA4E626B09B` (`unitCode`),
 KEY `FK284DA41AB47516` (`superUnitCode`),
 CONSTRAINT `FK284DA41AB47516` FOREIGN KEY (`superUnitCode`) REFERENCES `unit` (`unitCode`),
 CONSTRAINT `FK284DA4E626B09B` FOREIGN KEY (`unitCode`) REFERENCES `unit` (`unitCode`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

When I am trying to insert a record in the database (not in EJB)

INSERT INTO `unit` (`unitCode`, `unitName`, `superUnitCode`) VALUES
(1,'My unit',NULL)

I get this error...

Cannot add or update a child row: a foreign key constraint fails (`intranetejb/unit`, CONSTRAINT `FK284DA4E626B09B` FOREIGN KEY (`unitCode`) REFERENCES `unit` (`unitCode`))

When I delete the constraint, I'm able to insert the record.

[epbernard]

Oh I found you problem, mappedBy="subUnits" should be mappedBy="superUnit", you should reference the many side not something else

[oliverchua]

Emmanuel,

Thanks! that solved the problem