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

[Tom Ware <tom.ware@xxxxxxxxxx>]

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
> > > _______________________________________________
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> > > eclipselink-users@xxxxxxxxxxx
> > > https://dev.eclipse.org/mailman/listinfo/eclipselink-users
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