Re: Inheritence delete exception

Hi,

mananthakris wrote:
> This is the pseudo code
> 
> Question - base class 
> MultipleChoice question - Subclass of question
> AssessmentGroup - 1: n with Question
> (MultipleChoice  and other sub classes of Question are in the same table
> identified by objconcreteclass)
> 
> 
> code
> Transaction tx - odmg.currentTransaction();
> tx.lock (mutliplechoiceobj)
> db.deletePersistent(multiplechoiceobj)
> 
> Detailed log shows that MutipleChoice is registered and locked, but the
> exception says
> 

This is a strange exception. I didn't find a bug in the source code. OJB 
compares the Identity images of the referenced objects (1:n Question):
If in the new image an Identity from the old image is not contained, the 
object was deleted during tx. In this case OJB try to mark the object 
for deletion.

 > tx.lock (mutliplechoiceobj)

Is "mutliplechoiceobj" a instance of AssessmentGroup? Is implicit 
locking enabled? If not OJB will lock/register "mutliplechoiceobj" 
without the referenced objects.


> Unexpected behaviour, unregistered object to delete:
> com.tk20.bo.evaluationinstrument.Question{100007f15c458c10ff4485144-7d2d},
> main object is
> com.tk20.bo.template.AssessmentGroup{100007f15c458c10ff4485144-7d2f},
> envelope object is
> org.apache.ojb.odmg.ObjectEnvelope@3da1e2[Identity=com.tk20.bo.template.AssessmentGroup{100007f15c458c10ff4485144-7d2f},ModificationState=org.apache.ojb.odmg.states.StateOldDelete]
> 
> 
> Why does it try to see whether the base class is registered or not? Should
> it not identify the exact subclass it is
>

OJB logs only the Identity and Identity.toString only print the 
top-level class + PK's (will improve Identity.toString method for OJB 
1.0.5 to avoid confusion).


> I modified the repository_user.xml for mappings for 
> AssessmentGroup
> <collection-descriptor
>         name="questionsInternal"
>        
> collection-class="org.apache.ojb.broker.util.collections.ManageableArrayList"
>         element-class-ref="com.tk20.bo.evaluationinstrument.Question"
>         auto-retrieve="true"
>         auto-update="object"
>         auto-delete="object">
>        <inverse-foreignkey field-ref="assessmentGroupPk"/>
>      </collection-descriptor>
> 
> Mappings for MutlipleChoice and Question  as
>  <reference-descriptor
>         name="assessmentGroup"
>         class-ref="com.tk20.bo.template.AssessmentGroup"
>         auto-retrieve="true"
>         auto-update="none"
>         auto-delete="object">
>        <foreignkey field-ref="assessmentGroupPk"/>
>      </reference-descriptor>

Which version of OJB do you use? It's not allowed to set attribute 
"auto-update" different from "none", else you could get unexpected behavior.
http://db.apache.org/ojb/docu/guides/odmg-guide.html#Specific+Metadata+Settings

regards,
Armin



> 
> 
> 
> 
> 
> 
> 
> arminw wrote:
>> Hi,
>>
>> mananthakris wrote:
>>> I checked that our repository_user file does not contain auto_XXX for an
>>> reference-desc and collection-desc, are these mandatory and could be
>>> cause
>>> of problems?
>>>
>> It seems that OJB can't find the Question object in intern object 
>> registry using it's Identity. OJB detect that the object no longer 
>> exists in the 1:n reference and try to remove the Question object.
>>
>> To enable cascading delete it's mandatory to set auto-delete="object".
>> http://db.apache.org/ojb/docu/guides/odmg-guide.html#Specific+Metadata+Settings
>>
>> Could you please post the used source or pseudo code?
>>
>> regards,
>> Armin
>>
>>> mananthakris wrote:
>>>> Hi, 
>>>>
>>>> We are using same table for different subclasses using a varchar column
>>>> and define  ojbConcreteClass  to find the actual class.
>>>>
>>>> When we try to delete a object in a relationship , i see an error
>>>> "unregistered object for delete:" . I saw a previous forum question,
>>>> suggestion for the error and implemented writing locks for all objects
>>>> in
>>>> transaction, but we still have the error.
>>>>
>>>> In our case we have an object AssessmentGroup and an object Question in
>>>> 1:n relationship ( Question has different types of questions /subclasses
>>>> in a same table differentiated with classidentity column of the table).
>>>>
>>>> This error occurs when we delete a MultipleChoice sublclass of Question
>>>> and remove its relationship with AssessmentGroup.
>>>>
>>>> Detailed logs shows we are locking
>>>> AssessmentGroup,MultipleChoice(subclass) before delete, 
>>>>
>>>> but the exception shows even when we are writing
>>>> db.deletePersistent(multiplechoiceobj) , it is trying to delete base
>>>> class
>>>> internally. Do you think this is expected behaviour? Are we supposed to
>>>> lock base class inspite of knowing which exact class we are deleting?
>>>>
>>>> The exception is
>>>>
>>>> org.apache.ojb.odmg.Image$ImageException: Unexpected behaviour,
>>>> unregistered object to delete:
>>>> com.tk20.bo.evaluationinstrument.Question{100007f1388e5e10fe3fa0849-7ff1},
>>>> main object is
>>>> com.tk20.bo.template.AssessmentGroup{100007f1388e5e10fe3fa0849-7ff3},
>>>> envelope object is
>>>> org.apache.ojb.odmg.ObjectEnvelope@10a5314[Identity=com.tk20.bo.template.AssessmentGroup{100007f1388e5e10fe3fa0849-7ff3},ModificationState=org.apache.ojb.odmg.states.StateOldClean]
>>>>
>>>>
>>>> We are using obj 1.0.4 odmg api with mysql db.Attached is the
>>>> repository_user.xml
>>>>  http://www.nabble.com/file/5190/repository_user.xml repository_user.xml 
>>>>
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