Re: Join fetch not working properly

[Rick Curtis]

Can you load operation lazily? ie: Call DrawingMapItem.getOperation() on a
DrawingMapItem that is returned from
getDrawingMapItemsWithOperationsByDrawingMapId(...)?

Also, how are you enhancing your Entities?

Thanks,
Rick

On Thu, Mar 29, 2012 at 12:24 PM, Bruno Dusausoy <bdusau...@yp5.be> wrote:

> Hi,
>
> I have a problem with the "join fetch" JPQL clause (OpenJPA 2.1.1).
>
> The SQL executed underneath is ok, the "joins" are done and if I
> copy/paste the generated SQL request in SQL Server 2005, it returns the
> right results : right number of records, right number of columns, ...
> But it seems there's a problem with the "mapping"; OpenJPA forgets somehow
> to map the Operation columns back to an entity.
> My operation are always null.
>
> Do I have to specify something to OpenJPA in order to force it to map the
> Operation entity ?
>
> Here's the snippet for my entity :
>
> @Entity
> @Table(name = "PDrawingMapItems")
> public class DrawingMapItem {
>
>    @Id
>    @GeneratedValue(strategy = GenerationType.IDENTITY)
>    @Column(name = "Id")
>    private Long id;
>
>    @ManyToOne(fetch = FetchType.LAZY)
>    @JoinColumn(name = "OperationId")
>    private Operation operation;
>
>    @ManyToMany(fetch = FetchType.EAGER)
>    @JoinTable(
>            name = "PDrawingMapItemMarkingLevels"**,
>            joinColumns = {@JoinColumn(name = "ItemId")},
>            inverseJoinColumns = {@JoinColumn(name = "MarkingId")}
>    )
>    private List<MarkingLevel> markingLevels;
>
>    @Enumerated(EnumType.STRING)
>    private TraceabilityType traceabilityType;
>
>    @ManyToOne
>    @JoinColumn(name = "DrawingMapId")
>    private DrawingMap drawingMap;
>
>    // Getters and setters omitted
> }
>
> And here's what I'm trying to execute :
>
> private List<DrawingMapItem> 
> getDrawingMapItemsWithOperatio**nsByDrawingMapId(Long
> mapId) {
>        final String queryString = "select dmi from DrawingMapItem dmi join
> fetch dmi.operation where dmi.drawingMap.id = :mapId order by dmi.id";
>        List<DrawingMapItem> mapItems =
>                entityManager.createQuery(**queryString,
> DrawingMapItem.class).**setParameter("mapId", mapId).getResultList();
>        return mapItems;
> }
>
> Regards.
> --
> Bruno Dusausoy
> Software engineer
> YP5 Software
> --
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>



-- 
*Rick Curtis*