I have the following code that defines the relationship between three tables.

public class Attachment implements Serializable {

@Id
@Column(name="attachment_id")
private int attachmentId;

@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="reference_id")
private Reference reference;

@OneToMany(mappedBy="attachment")
private List<Reference> references;

MORE STUFF;


}

public class Uuid implements Serializable {

@Id
@Column("name=uuid_id")
@GeneratedValue(strategy=GenerationType.IDENTITY)
private int uuidId;

@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="reference_id")
private Reference reference;

MORE STUFF


}

public class Reference implements Serializable {

@Id
@Column(name="reference_id")
@GeneratedValue(strategy=GenerationType.IDENTITY)
private int referenceId;

@OneToMany(mappedBy="reference")
private List<Attachment> attachments;

@ManyToOne(cascade=CascadeType.MERGE)
@JoinColumn(name="attachment_id")
private Attachment attachment;

@OneToMany(mappedBy="reference")
private List<Uuid> uuids;

MORE STUFF


}

I have some more code that picks the specific "uuid" object/row that needs to be deleted, and the idea is that anything in the other tables that needs deleting because they share the same reference_id should be deleted too. The code that does this is:

try {

final EntityTransaction transaction = em.getTransaction();

transaction.begin();

em.remove(data);

transaction.commit();
}

catch (final PersistenceException e) {

throw new CPDPersistenceException(e);


}

When the delete is performed it throws Exception "Cannot delete or update parent row: a foreign key constraint fails. I posted something on a variation of this before. Does anybody have any ideas? Thanks for your time.

data

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