Re: [Hibernate] confirm 9450b97270917ddaf59faa6fb2a16df9d93669e3

[Yu D. <yud...@gm...>]

Query:
1. from invItem c where c.regularDoc is null; ---no rows return, should be a
large number of rows
2. from invItem c where c.regularDoc is not null; --- returned the correct
rows, cast (InvDecalItem) to get the rows.
3. from invItem c left join c.regularDoc doc where doc is null; --- returned
rows, but I got cast exception (I cast the row to (InvDecalItem) as well as
(InvItem) type) when I want to get row information.
4. from invItem c left join c.regularDoc doc where doc is not null; ---
returned rows, the same as 3.

I think of using join, I want to know that how to cast the result rows?


below are related definations and classes:

<hibernate-mapping>
    <class name="InvItem">
    <id name="id" column="id">
           <generator class="hilo"/>
        </id>
    <discriminator column="invType" length="1"/>
    <many-to-one name="transferredDetails"/> <!-- FK: Points to
corresponding entry for transferred inventory items -->
    <subclass name="InvDecalItem" discriminator-value='D'>
        <one-to-one  name="regularDoc" property-ref="decalNew"
access="field" /> <!-- nullable: an item maybe not attach to a document -->
    </subclass>
    </class>
</hibernate-mapping>


</hibernate-mapping>
    <class name="AbstractRegularDoc" table="RegularDoc">
        <id name="id">
           <generator class="hilo"/>
        </id>
    <many-to-one name="decalNew" index="decalIdx" access="field"
unique="true"/>
     </class>
</hibernate-mapping>



public abstract class AbstractRegularDoc{
    private InvDecalItem decalNew;
        ...
    public InvDecalItem getDecalNew()

    {

        return decalNew;

    }


    public void setDecalNew(InvDecalItem decalNewParam)

    {

        if (decalNewParam != null)

            decalNewParam.setRegularDoc(this);

    }
}



public class InvDecalItem extends InvItem
{
    private AbstractRegularDoc regularDoc;

    public AbstractRegularDoc getRegularDoc()

    {

        return regularDoc;

         }


    public void setRegularDoc(AbstractRegularDoc regulardocs)

    {
         if (this.regularDoc != null)

            this.regularDoc.setDecalNew(this);

    }
}