Hello everyone.
I'm learning now about JPA 2.1 with EclipseLink as the JPA Provider, and I have following question about unidirectional @OneToOne mapping.
In JSR-338 there is a section 2.10.3.1 ("Unidirectional OneToOne Relationshps") with following paragraph:
Quote:Table A conttains a foreign key to table B. The foreign key column name is formed as the concatenation of the following: the name of the realtionship property or field of entity A; "_"' the name of the primary key column in table B. The foreign key column has the same type as primary key of table B and there is a unique key constraint on it.
This basically means for me that I can assign target entity to only one source entity. In my opinion EclipseLink in version 2.5.1 with Derby database 10.10.1.1 does not follow JSR-338 in such scenario.
Here is code example:
Source entity:
@Entity
public class FootballPlayer {
@Id
private long id;
@OneToOne
private Ball ball;
public FootballPlayer() {
}
public FootballPlayer(long id) {
this.id = id;
}
public long getId() {
return id;
}
public void setBall(Ball ball) {
this.ball = ball;
}
public Ball getBall() {
return ball;
}
}
Target entity:
@Entity
public class Ball {
@Id
private long id;
public Ball() {
}
public Ball(long id) {
this.id = id;
}
public long getId() {
return id;
}
}
And scenario:
EntityManagerFactory emf = Persistence.createEntityManagerFactory("eclipselink-pu");
EntityManager em = emf.createEntityManager();
Ball ball = new Ball(1L);
FootballPlayer firstPlayer = new FootballPlayer(2L);
FootballPlayer secondPlayer = new FootballPlayer(3L);
firstPlayer.setBall(ball);
secondPlayer.setBall(ball);
em.getTransaction().begin();
em.persist(ball);
em.persist(firstPlayer);
em.persist(secondPlayer);
em.getTransaction().commit(); // Exception?
em.close();
emf.close();
Persistence unit definition in persistence.xml
<persistence-unit name="eclipselink-pu" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>com.mprzybylak.minefields.jpa.relationships.onetoone.uni.Ball</class>
<class>com.mprzybylak.minefields.jpa.relationships.onetoone.uni.FootballPlayer</class>
<properties>
<property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver" />
<property name="javax.persistence.jdbc.url" value="jdbc:derby:memory:eclipselink-test;create=true" />
<property name="javax.persistence.jdbc.user" value="APP" />
<property name="javax.persistence.jdbc.password" value="APP" />
<property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
<property name="eclipselink.logging.level.sql" value="FINE"/>
<property name="eclipselink.logging.parameters" value="true"/>
</properties>
</persistence-unit>
When I add: to ball field in FootballPlayer class - there is an exception as I expect.
So my question is - is there something wrong with my code, or should I report bug?
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