I have been all day trying to solve this. I have read multiple sites and documentation, but I can go through this. I'm using Java with ObjectDB.
I have a clase named Pedido, that have a reference ManyToOne to a clase Cliente.
@Entity
public class Pedido {
@Id @GeneratedValue
private long id;
@Embedded private Direccion origen;
@ManyToOne(optional=true)
private Cliente cliente; //Opcional
@Basic(optional=false) private Date fechaYhora; //Fecha en que se debe enviar el coche
}
@Entity
public class Cliente extends Persona{
@OneToMany(mappedBy="Pedido.cliente")
public List<Pedido> pedidos;
}
The class Persona, has nothing in special. Just a few variables. String, int, and an embedded class.
The problem is that, when I try to get a list of Client, I get an error.
static public List<Cliente> getClientes() throws Exception{
em = EMF.createEntityManager();
List<Cliente> results = null;
try{
TypedQuery<Cliente> query = em.createQuery("SELECT c FROM Cliente c", Cliente.class);
results = query.getResultList();
}finally{
em.close();
}
return results;
}
At the end of this method, "results" is null.Even affter the query. And on em.close() I get an exception:
com.objectdb.o._PersistenceException: Failed to write the value of field field entidades.Cliente.pedidos using reflection
What's wrong with this? I suppose i'm making a bad connection on the oneToMany - manyToOne. But I can't figure it out.
How can I make a correct connection? How to retrieve the list sucefull?
