Refer to the attached ER diagram
(the actual diagram has several tables hanging off ChartEvent) or the @Entity below. Current to add something to aspectDisplay table do:
void putAspectdisplayData(ChartEvent ce, Set<AspectId> data) {
Aspectdisplay ad = new Aspectdisplay();
ad.setChevPK(ce.getChevPK());
ad.setChartEvent(ce);
ad.setDat(new AspectdisplayData(add03));
em.persist(ad);
doCommit();
ce.setAspectdisplay(ad);
}
I thought there might be a way to redefine the mappings so that the owner of the relationship is ChartEvent and make the relationship uni-directional (Aspectdisplay does not need a reference to ChartEvent). Ideally, it could be specified so that the add looks like
void putAspectdisplayData(ChartEvent ce, Set<AspectId> data) {
Aspectdisplay ad = new Aspectdisplay();
ad.setDat(new AspectdisplayData(add03));
ce.setAspectdisplay(ad);
em.persist(ce); // not really needed assuming ce in persistence context
doCommit();
}
Note that the primary key is not being set, it seems there's enough info around so the persistence layer could assign it. I tried a variety of things to make ChartEvent the relationship owner, usually involving specifying @JoinColumns and/or @JoinTable; most attempts failed with "Multiple writable mappings exist for the field" exception, except when I used a 'table="ASPECTDISPLAY"', then I got something about the ASPECTDISPLAY not being in the Entity, maybe it thought this was a secondary table. Is it possible to make ChartEvent the owner of a uni-directional 1-1? If the owner *must* be the holder of the foreign key, then out of luck. Is there some mapping that doesn't care about foreign keys that just does the join?
Curiously, while keeping Aspectdisplay the owner, putting "ad.setChevPK(ce.getChevPK())" into the second put method and using it updates the database even though ChartEvent is the inverse side. But the spec, 3.2.4, says
Bidirectional relationships between managed entities will be persisted based on
references held by the owning side of the relationship.
so I guess this is non-portable (and a spec violation). Is something like this worth filing a bug report?
@Entity
@Table(name = "CHART_EVENT", catalog = "", schema = "ERNIE")
public class ChartEvent implements Serializable {
private static final long serialVersionUID = 1L;
@EmbeddedId
protected ChevPK chevPK;
@OneToOne(mappedBy = "chartEvent")
private Aspectdisplay aspectdisplay;
@OneToMany(mappedBy = "chartEvent", orphanRemoval=true)
private Collection<Aspectgroup> aspectgroupCollection;
@Entity
@Table(name = "ASPECTDISPLAY", catalog = "", schema = "ERNIE")
public class Aspectdisplay implements Serializable {
private static final long serialVersionUID = 1L;
@EmbeddedId
protected ChevPK chevPK;
@Basic(optional = false)
@Lob
@Column(name = "DAT", nullable = false)
private AspectdisplayData dat;
@JoinColumns({
@JoinColumn(name = "CHART_ID", referencedColumnName = "CHART_ID",
nullable = false, insertable = false, updatable = false),
@JoinColumn(name = "EVENT_ID", referencedColumnName = "EVENT_ID",
nullable = false, insertable = false, updatable = false)})
@OneToOne(optional = false)
private ChartEvent chartEvent;
