Thank you Phil.

I'll try it and give you a feedback

Regards
Sylvain

-----Message d'origine-----
De: Phil Warrick [mailto:[EMAIL PROTECTED]]
Date: lundi, 16. d�cembre 2002 17:01
�: OJB Users List
Objet: Re: OJB and recursive relationship


Sylvain,

Something like this?

<class-descriptor
       class="A"
       table="A"
    >
       <field-descriptor id="1"
          name="A_id"
          column="A_ID_PK"
          jdbc-type="INTEGER"
          primarykey="true"
          autoincrement="true"
       />
       <field-descriptor id="2"
          name="name"
          column="NAME"
          jdbc-type="VARCHAR"
       />
       <reference-descriptor
          name="qualifiedARef"
          class-ref="QualifiedARef"
       >
          <foreignkey field-id-ref="4"/>
       </reference-descriptor>
</class-descriptor>

<class-descriptor
       class="QualifiedARef"
       table="QualifiedARef"
    >
       <field-descriptor id="1"
          name="qualifiedId"
          column="QUALIFIEDAREF_PK"
          jdbc-type="INTEGER"
          primarykey="true"
          autoincrement="true"
       />
       <field-descriptor id="2"
          name="A_id"
          column="A_ID_FK"
          jdbc-type="INTEGER"
       />
       <field-descriptor id="3"
          name="relationInfo"
          column="RELATION_INFO"
          jdbc-type="VARCHAR"
       />
       <reference-descriptor
          name="classARef"
          class-ref="A"
       >
          <foreignkey field-id-ref="2"/>
       </reference-descriptor>
</class-descriptor>

Phil

[EMAIL PROTECTED] wrote:
> Phil,
> 
> Ok but how do you do the self-reference?
> 
> Sorry I don't understand.
> 
> Sylvain
> 
> 
> -----Message d'origine-----
> De: Phil Warrick [mailto:[EMAIL PROTECTED]]
> Date: lundi, 16. d�cembre 2002 16:43
> �: OJB Users List
> Objet: Re: OJB and recursive relationship
> 
> 
> Sylvain,
> 
> Only one A fk is required in the QualifiedARef table:
> 
> QualifiedARef
> -------------
> int qualifiedARef_PK
> String relationInfo
> int A_id_FK
> 
> Phil
> 
> 
>  >
> [EMAIL PROTECTED] wrote:
> 
>>So, more in practise:
>>
>>Classes:
>>
>>Class A {                                             Classe QualifiedARef {
>>int A_id                                              int qualifiedId
>>String name                                           A classARef
>>QualifiedARef qualifiedARef                   String relationInfo     
>>...                                                   int A_id
>>}                                                     ....
>>                                                      }
>>
>>
>>Relationnal tables:
>>
>>A                                             QualifiedARef
>>-                                             -------------
>>int A_id_PK                                   int qualifiedARef_PK
>>String name                                   int A_id_class_ref_FK
>>                                              String relationInfo
>>                                              int A_id_FK
>>
>>
>>Am I on the right way?
>>is there a probem in the QualifiedARef table because there are 2 FK for A??
>>
>>Thank you
>>Regards
>>Sylvain
>>
>>
>>
>>
>>-----Message d'origine-----
>>De: Phil Warrick [mailto:[EMAIL PROTECTED]]
>>Date: lundi, 16. d�cembre 2002 15:59
>>�: OJB Users List
>>Objet: Re: OJB and recursive relationship
>>
>>
>>Hi Sylvain,
>>
>>Yes, then class A instead has a reference to a class QualifiedARef (or a 
>>collection of these).  QualifiedARef holds the relation info and a 
>>reference to the target A.  If bidirectionality is important, it can 
>>hold a reference to both of the As in the relation.
>>
>>Phil
>>
>>[EMAIL PROTECTED] wrote:
>>
>>
>>>Hi Phil,
>>>
>>>Thank you for your answer.
>>>Is it also possible if you qualified this self reference (add information about 
>relation)?
>>>
>>>For example if class A have a reference to another instance of class A and this 
>reference has information like reference_name or something like that.
>>>
>>>Regards
>>>Sylvain
>>>
>>>-----Message d'origine-----
>>>De: Phil Warrick [mailto:[EMAIL PROTECTED]]
>>>Date: lundi, 16. d�cembre 2002 15:14
>>>�: OJB Users List
>>>Objet: Re: OJB and recursive relationship
>>>
>>>
>>>Hi Sylvain,
>>>
>>>OJB handles self references fine.  In other words class A can have a 
>>>reference to another instance of class A or a collection of class As. 
>>>You may need to make these proxies if the graph is very large and you 
>>>need to control the hits to the db.
>>>
>>>Phil
>>>
>>>[EMAIL PROTECTED] wrote:
>>>
>>>
>>>
>>>>Hello,
>>>>
>>>>I have a situation with recursive relationship:
>>>>
>>>>I have a class Software that represents the softwares that could be installed on 
>my machine. Some of these softwares must have other softwares installed before to be 
>able to be installed.
>>>>So, I have a recurvive relationship here.
>>>>
>>>>How do you implement this relationship with OJB?
>>>>
>>>>Thank you
>>>>Sylvain
>>>>
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>>>
>>>
>>>
>>>
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>>
>>
>>
>>
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> 
> 
> 
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