AW: AW: [eclipselink-users] questiona about JPQL and Collections

[<Daniel.Stucky@xxxxxxxxxxx>]

Thanks Tom !
Sometimes it's just too easy :-)

Bye,
Daniel


> -----Ursprüngliche Nachricht-----
> Von: eclipselink-users-bounces@xxxxxxxxxxx [mailto:eclipselink-users-
> bounces@xxxxxxxxxxx] Im Auftrag von Tom Ware
> Gesendet: Donnerstag, 29. Januar 2009 15:17
> An: EclipseLink User Discussions
> Betreff: Re: AW: [eclipselink-users] questiona about JPQL and
> Collections
> 
> Try calling readAllQuery.dontUseDistinct().
> 
> -Tom
> 
> Daniel.Stucky@xxxxxxxxxxx wrote:
> > Hi Tom,
> >
> > thanks for your help, in general it works as described by you.
> >
> > However, I forgot to include the following member of RecordDao in the
> sample code:
> >   @Column(name = "RECORD")
> >   private byte[] _serializedRecord;
> >
> > The generated SQL query contains DISTINCT, which is not usable with
> queries containing BLOBs.
> > Any suggestions how to handle this ?
> >
> >
> > Bye,
> > Daniel
> >
> >> -----Ursprüngliche Nachricht-----
> >> Von: eclipselink-users-bounces@xxxxxxxxxxx [mailto:eclipselink-
> users-
> >> bounces@xxxxxxxxxxx] Im Auftrag von Tom Ware
> >> Gesendet: Mittwoch, 28. Januar 2009 21:12
> >> An: EclipseLink User Discussions
> >> Betreff: Re: [eclipselink-users] questiona about JPQL and
> Collections
> >>
> >> Hi Daniel,
> >>
> >>    Because BasicCollection is not a part of the JPA specification
> yet,
> >> JPQL
> >> cannot currently query across BasicCollections.  (That behavior is
> >> expected in
> >> the upcoming JPA 2.0 specification)
> >>
> >>    To access a BasicCollection in a query, you will have to use
> >> EclipseLink's
> >> criteria API instead.
> >>
> >>    Your code will look something like this:
> >>
> >> ReadAllQuery query = new ReadAllQuery(RecordDAO.class);
> >> ExpressionBuilder record = new ExpressionBuilder();
> >> Expression attributes = record.anyOfAttributes("attributes");
> >> Expresion criteria =
> >> attributes.get("_name").equal(record.getParameter("name"));
> >> criteria =
> >>
> criteria.and(attributes.anyOf("_values").equal(record.getParameter("val
> >> ue")))
> >> query.setSelectionCriteria(criteria);
> >>
> >> This query can be added as a named query through a SessionCustomizer
> by
> >> calling
> >> the addQuery(name, query) method.
> >>
> >>    That is the basics of how it should look.  With a little
> massaging
> >> of the
> >> code, it should be possible to use this query just like any other
> named
> >> query in
> >> JPA.
> >>
> >> BTW: Here is the Customizer doc:
> >>
> >>
> http://wiki.eclipse.org/Using_EclipseLink_JPA_Extensions_%28ELUG%29#Usi
> >> ng_EclipseLink_JPA_Extensions_for_Customization_and_Optimization
> >>
> >> -Tom
> >>
> >>
> >>
> >>
> >> Daniel.Stucky@xxxxxxxxxxx wrote:
> >>> Hi all,
> >>>
> >>> given the following Entities, how can I express a named query that
> >>> selects all Records where AttributeDao._name = "X" and
> >>> AttributeDao._values.contains("Y")
> >>>
> >>>
> >>> @Entity
> >>> @Table(name = "RECORDS")
> >>> public class RecordDao implements Serializable {
> >>>
> >>>   @Id
> >>>   @Column(name = "ID")
> >>>   private String _idString;
> >>>
> >>>   @Column(name = "SOURCE")
> >>>   private String _source;
> >>> ...
> >>> }
> >>>
> >>> @Entity
> >>> @Table(name = "ATTRIBUTES")
> >>> public class AttributeDao {
> >>>
> >>>   @Id
> >>>   @GeneratedValue(strategy=GenerationType.AUTO)
> >>>   @Column(name = "ATT_ID")
> >>>   private String _id;
> >>>
> >>>   @Column(name = "ATT_NAME")
> >>>   private String _name;
> >>>
> >>>   @BasicCollection (
> >>>     fetch=FetchType.EAGER,
> >>>     valueColumn=@Column(name="ATT_VALUE"))
> >>>     @CollectionTable (
> >>>         name="ATTRIBUTE_VALUES",
> >>>         primaryKeyJoinColumns=
> >>>         {@PrimaryKeyJoinColumn(name="ATT_ID",
> >>> referencedColumnName="ATT_ID")}
> >>>     )
> >>>   private List<String> _values;
> >>> ...
> >>> }
> >>>
> >>>
> >>>
> >>> I tried something like this
> >>>
> >>> @NamedQueries({
> >>>     @NamedQuery(name="RecordDao.findByAttribute",
> >>>       query="SELECT DISTINCT r FROM RecordDao r JOIN r._attributes
> a
> >>> JOIN a._values v WHERE a._name = :name AND v._values = :value")
> >>>
> >>> })
> >>>
> >>>
> >>> but during EntityManager creation I get the following error:
> >>>
> >>> Exception [EclipseLink-8030] (Eclipse Persistence Services - 1.0.2
> >>> (Build 20081024)): org.eclipse.persistence.exceptions.JPQLException
> >>> Exception Description: Error compiling the query
> >>> [RecordDao.findByAttribute: SELECT DISTINCT r FROM RecordDao r JOIN
> >>> r._attributes a JOIN a._values v WHERE a._name = :name AND
> v._values
> >> =
> >>> :value], line 1, column 63: unknown state or association field
> >> [_values]
> >>> of class [org.eclipse.smila.datamodel.persistence.AttributeDao].
> >>>
> >>>
> >>> I expect the syntax for "AND v._values = :value" to be not valid,
> but
> >> I
> >>> wonder why it complains about JOIN a._values v.
> >>> Anyone any ideas/suggestions ?
> >>>
> >>>
> >>> Bye,
> >>> Daniel
> >>> _______________________________________________
> >>> eclipselink-users mailing list
> >>> eclipselink-users@xxxxxxxxxxx
> >>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users
> >> _______________________________________________
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> >> eclipselink-users@xxxxxxxxxxx
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