public class Guitar { 
 
    private long serialNumber; 
    private int price; 
    GuitarSpec specification; 
} 
 
public class GuitarSpec { 
 
    private long specId; 
    private String builder; 
    private String model; 
    private String type; 
    private int numStrings; 
    private String backWood; 
    private String topWood; 
} 
 
<hibernate-mapping package="com.transcend.music.entity"> 
    <class name="Guitar" table="t_guitar"> 
        <id name="serialNumber" type="long"> 
            <generator class="native"/> 
        </id> 
        <property name="price" type="integer" /> 
        <many-to-one name="specification" column="specification_id" 
                     class="GuitarSpec" cascade="all" not-null="true" /> 
    </class> 
</hibernate-mapping> 
 
<hibernate-mapping package="com.transcend.music.entity"> 
    <class name="GuitarSpec" table="t_guitar_specs"> 
        <id name="specId" type="long"> 
            <generator class="native"/> 
        </id> 
        <property name="builder" type="string" length="100" not-null="false"/> 
        <property name="model" type="string" not-null="false"/> 
        <property name="type" type="string" not-null="false"/> 
        <property name="numStrings" type="integer" not-null="false"/> 
        <property name="backWood" type="string" not-null="false"/> 
        <property name="topWood" type="string" not-null="false"/> 
    </class> 
</hibernate-mapping>

    Query query = session 
            .createQuery("from GuitarSpec where builder=:builder and model=:model and type=:type and numStrings=:numStrings and backWood=:backWood and topWood=:topWood"); 
            query.setParameter("builder", spec.getBuilder()); 
            query.setParameter("model", spec.getModel()); 
            query.setParameter("type", spec.getType()); 
            query.setParameter("numStrings", spec.getNumStrings()); 
            query.setParameter("backWood", spec.getBackWood()); 
            query.setParameter("topWood", spec.getTopWood()); 
            List results = query.list(); 
             
            GuitarSpec guitarSpec = null; 
            Guitar guitar; 
            Long specId=0L; 
            if (results.size() > 0)   
            { 
                specId = new Long((((GuitarSpec) results.get(0)).getSpecId())); 
                guitarSpec = (GuitarSpec) session.get(GuitarSpec.class, specId); 
            } 
         
            Query queryGuitar = session 
            .createQuery("from Guitar where specification=:specification"); 
            query.setParameter("specification", guitarSpec); 
             
            List guitars = queryGuitar.list();   

Query queryGuitar = session.createQuery("from Guitar g join g.specification s where s.specId=:specId"); 
queryGuitar.setParameter("specId", specId);