Hibernate version: Hibernate: 2.1.6, 9.8.2004
Hello,
I used hibernate the first time and set up a relation between cds and tracks
(one cd could have many tracks). The java-classes are CD.java and Track.java.
Mapping documents:
Code:
<hibernate-mapping>
<class name="de.rassmann.cdstore.entities.CD" table="cds">
<id name="id" type="integer" column="id" unsaved-value="null" >
<generator class="identity"/>
</id>
<property name="cddbid"/>
<property name="title"/>
<property name="artist"/>
<property name="category"/>
<list name="tracks" lazy="true" inverse="true">
<key column="cd"/>
<index column="track"/>
<one-to-many class="de.rassmann.cdstore.entities.Track"/>
</list>
</class>
</hibernate-mapping>
<hibernate-mapping>
<class name="de.rassmann.cdstore.entities.Track" table="tracks">
<id name="id" type="integer" column="id" unsaved-value="null" >
<generator class="identity"/>
</id>
<many-to-one name="cd" class="de.rassmann.cdstore.entities.CD" column="cd" not-null="true"/>
<property name="track"/>
<property name="song"/>
</class>
</hibernate-mapping>
So far, everything works fine. I can collect my cds and the corresponding list of tracks.
Code between sessionFactory.openSession() and session.close():Code:
Query query = session.createQuery( "from CD as cd where cd.artist = :artistsearch" );
query.setString( "artistsearch", "Beastie Boys" );
List result = query.list();
assertTrue("no datasets found", result.size() > 0);
Iterator it = result.iterator();
while (it.hasNext()) {
CD cd = (CD)it.next();
List tracks = cd.getTracks();
assertNotNull( "no tracks", tracks );
assertFalse( "no tracks", tracks.isEmpty() );
}
Name and version of the database you are using: mysql 4.0.18-logThe query produces the correct results with lazy selects, but I am unsure whether the select-statement is OK: every attribut of "tracks" is collected twice.
Code:
Hibernate: select cd0_.id as id, cd0_.cddbid as cddbid, cd0_.title as title, cd0_.artist as artist, cd0_.category as category from cds cd0_ where (cd0_.artist=? )
[...]
Hibernate: select tracks0_.cd as cd__, tracks0_.id as id__, tracks0_.track as track__, tracks0_.id as id0_, tracks0_.cd as cd0_, tracks0_.track as track0_, tracks0_.song as song0_ from tracks tracks0_ where tracks0_.cd=?
Isn't that a waste of bandwidth?
Is this the correct behavior of hibernate?
Is the mapping OK?
Thx, Tom
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