Ejb 3.0 and JDeveloper

Question

If I drag and drop tables with One to one mapping in an ejb diagram in JDeveloper (one table have having the foreign key as the primary key). If I create ejb 2.1 beans it makes makes a One To One mapping between the entity beans created and if I drop them as ejb 3.0 it makes a OneToMany mapping. this is what I get for the same tables.
for ejb 2.1
<ejb-relation>
<ejb-relation-name>Envincidents - Incidents</ejb-relation-name>
<ejb-relationship-role>
<ejb-relationship-role-name>Envincidents has one Incidents</ejb-relationship-role-name>
<multiplicity>One</multiplicity>
<relationship-role-source>
<ejb-name>Envincidents</ejb-name>
</relationship-role-source>
<cmr-field>
<cmr-field-name>incidents_incidentsId</cmr-field-name>
</cmr-field>
</ejb-relationship-role>
<ejb-relationship-role>
<ejb-relationship-role-name>Incidents may have one Envincidents</ejb-relationship-role-name>
<multiplicity>One</multiplicity>
<relationship-role-source>
<ejb-name>Incidents</ejb-name>
</relationship-role-source>
</ejb-relationship-role>
</ejb-relation>
for ejb 3.0
Envincidents
@Id
@ManyToOne(targetEntity="mypackage.Incidents")
@JoinColumn(name="ENVINCIDENTS.INCIDENTS_ID", referencedColumnName="INCIDENTS.ID")
public Incidents getIncidents() {
return incidents;
public void setIncidents(Incidents incidents) {
this.incidents = incidents;
Incidents
@OneToMany(targetEntity="mypackage.Envincidents")
@JoinColumn(name="ENVINCIDENTS.INCIDENTS_ID", referencedColumnName="INCIDENTS.ID")
public Collection<Envincidents> getEnvincidentsCollection() {
return envincidentsCollection;
public void setEnvincidentsCollection(Collection<Envincidents> envincidentsCollection) {
this.envincidentsCollection = envincidentsCollection;
public Envincidents addToEnvincidentsCollection(Envincidents envincidents) {
getEnvincidentsCollection().add( envincidents );
envincidents.setIncidents( this );
return envincidents;
public Envincidents removeFromEnvincidentsCollection(Envincidents envincidents) {
getEnvincidentsCollection().remove( envincidents );
envincidents.setIncidents( null );
return envincidents;
this causes the following problem.
Exception Description: Multiple writable mappings exist for the field [ENVINCIDE
NTS.INCIDENTS_ID]. Only one may be defined as writable, all others must be spec
ified read-only.
which I have already reported.
I know this is a minor inconvenience and I can hand edit the entity beans and make them one to one for ejb 3.0. But would be to good advantage to have a consistent "dropping of tables" for ejb 2.1 and 3.0. So one can have a similar behavior of entity beans created from tables using ejb 2.1 and 3.0.

Answer 1

I guess this could be desirable if migrating from ejb 2.1 to 3.0 if one has already designed the database.
Dev