QueryByCriteria not taking all non null fields in account with inheritance object

Hi All,

I do not know whether this is desired behavior but when I use 
QueryByCriteria with an object that maps an inheritance hierarchy, 
only the fields specific for that object are queried (the javadocs 
state:  Builds a Query based on anObject all non null values are used 
as EqualToCriteria).
Consider the mapping below; there are specific detectionmethods 
(rnadetection, dnadetection) inheriting from a generic detectionmethod.
This generic detectionmethod has a geneexptype; the specific 
rnadetection has a rnadetectiontype
When I now query the following

         RnaDetection detection = new RnaDetection();
         detection.setDetectiontype("Rna level");
         detection.setRnadetectiontype("Northern Blot");
         detection.setGeneexptype("Mutant on");

         QueryByCriteria q = new QueryByCriteria(evidence);

q.toString() now gives:

QueryByCriteria from class 
amcplugin.data.persistency.RnaDetection  where [rnadetectiontype = 
Northern Blot]

This finds the wrong object as the fields geneexptype and 
detectiontype are not taken into consideration....
See below for descriptors and classes; maybe there's something wrong 
in the way I implement these using interfaces?
Or is overriding equals, hashcode not allowed (till now I did not 
experience problems with that)

Thanks in advance!

Piet




    <class-descriptor
       class="amcplugin.data.persistency.DetectionMethod"
       table="DETECTION_METHOD"
    >
       <field-descriptor id="1"
          name="methodid"
          column="METHOD_ID"
          jdbc-type="INTEGER"
          primarykey="true"
          autoincrement="true"
       />
       <field-descriptor id="2"
          name="detectiontype"
          column="DETECTION_TYPE"
          jdbc-type="VARCHAR"
       />
       <field-descriptor id="3"
          name="geneexptype"
          column="GENE_EXP_TYPE"
          jdbc-type="VARCHAR"
       />
    </class-descriptor>

    <!-- RnaDetection describes the method of detection on rna level -->
    <class-descriptor
       class="amcplugin.data.persistency.RnaDetection"
       table="RNA_DETECTION"
    >
       <field-descriptor id="1"
          name="methodid"
          column="METHOD_ID"
          jdbc-type="INTEGER"
          primarykey="true"
       />
       <field-descriptor id="2"
          name="rnadetectiontype"
          column="RNA_DETECTION_TYPE"
          jdbc-type="VARCHAR"
       />
       <reference-descriptor name="super"
          class-ref="amcplugin.data.persistency.DetectionMethod"
       >
          <foreignkey field-ref="methodid"/>
       </reference-descriptor>
    </class-descriptor>


public class DetectionMethod implements DetectionMethodInterface
{
     private volatile int hashCode = 0;
     public static String METHOD_ID = "methodid";
     public static String GENE_EXP_TYPE = "geneexptype";
     public static String DETECTION_TYPE = "detectiontype";
     protected Integer methodid;
     protected String geneexptype;
     protected String detectiontype;

     public DetectionMethod()
     {
         this.setDetectiontype("Not specified");
         this.setGeneexptype("Not specified");
     }

     public String getGeneexptype()
     {
         return geneexptype;
     }

     public void setGeneexptype(String geneexptype)
     {
         this.geneexptype = geneexptype;
     }

     public String getDetectiontype()
     {
         return detectiontype;
     }

     public void setDetectiontype(String detectionlevel)
     {
         this.detectiontype = detectionlevel;
     }

     /**
      * @return Returns the methodid.
      */
     public Integer getMethodid()
     {
         return methodid;
     }

     public void setMethodid(Integer methodid)
     {
         this.methodid = methodid;
     }

     public String toString()
     {
         StringBuffer sb = new StringBuffer();
         sb.append(this.getDetectiontype());
         return sb.toString();
     }

     /**
      * Override to compare dataobjects
      *
      * @return
      */
     public boolean equals(Object o)
     {
         if (o == this)
             return true;
         if (o != null && o.getClass().equals(this.getClass()))
         {
             DetectionMethod other = (DetectionMethod) o;
             return ((this.detectiontype == other.detectiontype) || 
(this.detectiontype != null)
                     && this.detectiontype.equals(other.detectiontype))
                     && ((this.geneexptype == other.geneexptype) || 
(this.geneexptype != null)
                             && this.geneexptype.equals(other.geneexptype));
         }
         else
             return false;
     }

     /**
      * When equals overridden than hashCode also
      */
     public int hashCode()
     {
         if (hashCode == 0)
         {
             int dl, ge;
             if (this.detectiontype == null)
                 dl = 0;
             else
                 dl = this.detectiontype.hashCode();
             if (this.geneexptype == null)
                 ge = 0;
             else
                 ge = this.geneexptype.hashCode();
             int result = 17;
             result = 37 * result + dl;
             result = 37 * result + ge;
             hashCode = result;
         }
         return hashCode;
     }
}


public interface DetectionMethodInterface {
     public String getDetectiontype();
     public void setDetectiontype(String detectionlevel);
     public String getGeneexptype();
     public void setGeneexptype(String hostproperties);
     public Integer getMethodid();
     public void setMethodid(Integer methodid);
}

public class RnaDetection extends DetectionMethod implements 
RnaDetectionInterface
{
     public static String RNA_DETECTION_TYPE = "rnadetectiontype";
     private volatile int hashCode = 0;
     protected String rnadetectiontype;

     public RnaDetection()
     {
         super();
         super.setDetectiontype("Rna level");
         this.setRnadetectiontype("Unspecified");
     }

     public String getRnadetectiontype()
     {
         return rnadetectiontype;
     }

     public void setRnadetectiontype(String rnadetectiontype)
     {
         this.rnadetectiontype = rnadetectiontype;
     }

     public String toString()
     {
         StringBuffer sb = new StringBuffer();
         sb.append(getRnadetectiontype());
         sb.append("::");
         sb.append(super.toString());
         return sb.toString();
     }

     /**
      * Override to compare dataobjects
      *
      * @return
      */
     public boolean equals(Object o)
     {
         if (o == this)
             return true;
         if (o != null && o.getClass().equals(this.getClass()))
         {
             RnaDetection other = (RnaDetection) o;
             return ((this.detectiontype == other.detectiontype) || 
(this.detectiontype != null)
                     && this.detectiontype.equals(other.detectiontype))
                     && ((this.geneexptype == other.geneexptype) || 
(this.geneexptype != null)
                             && this.geneexptype.equals(other.geneexptype))
                     && ((this.rnadetectiontype == 
other.rnadetectiontype) || (this.rnadetectiontype != null)
                             && 
this.rnadetectiontype.equals(other.rnadetectiontype));
         }
         else
             return false;
     }

     /**
      * When equals overridden than hashCode also
      */
     public int hashCode()
     {
         if (hashCode == 0)
         {
             int dl, ge, rdt;
             if (this.detectiontype == null)
                 dl = 0;
             else
                 dl = this.detectiontype.hashCode();
             if (this.geneexptype == null)
                 ge = 0;
             else
                 ge = this.geneexptype.hashCode();
             if (this.rnadetectiontype == null)
                 rdt = 0;
             else
                 rdt = this.rnadetectiontype.hashCode();
             int result = 17;
             result = 37 * result + dl;
             result = 37 * result + ge;
             result = 37 * result + rdt;
             hashCode = result;
         }
         return hashCode;
     }

public interface RnaDetectionInterface extends DetectionMethodInterface {
     public String getRnadetectiontype();
     public void setRnadetectiontype(String rnadetectiontype);
}