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Posted to ojb-user@db.apache.org by Sebastien Cesbron <se...@laposte.net> on 2003/08/05 13:51:42 UTC
QueryByMtoNCriteria
While investigating on how to solve my problem I found the
QueryByMtoNCriteria class.
I don't know if it could solve my problem but I wonder if there is any
example somewhere (I found nothing in the doc and in the distrib examples) ?
Thanx
Seb
Jim Moore wrote:
> I guess I don't understand the question: That's a very basic 1:n
> relationship, exactly what OJB does easily, with a clear "path."
>
> http://db.apache.org/ojb/tutorial3.html#mapping%201:n%20associations
>
> So you XML would look like
>
> <class-descriptor class="User" table="USER">
> <field-descriptor
> name="userId"
> column="ID"
> jdbc-type="INTEGER"
> primarykey="true" />
> <field-descriptor
> name="groupName"
> column="KategorieName"
> jdbc-type="VARCHAR" />
> <field-descriptor
> name="description"
> column="Beschreibung"
> jdbc-type="VARCHAR" />
> <collection-descriptor
> name="emailsSent"
> element-class-ref="Email">
> <inverse-foreignkey field-ref="senderId"/>
> </collection-descriptor>
> <collection-descriptor
> name="emailsReceived"
> element-class-ref="Email">
> <inverse-foreignkey field-ref="receiverId"/>
> </collection-descriptor>
> </class-descriptor>
>
> <class-descriptor class="User" table="EMAIL">
> <field-descriptor
> name="emailId"
> column="ID"
> jdbc-type="INTEGER"
> primarykey="true" />
> <field-descriptor
> name="sendId"
> column="SENDER_ID"
> jdbc-type="INTEGER" />
> <field-descriptor
> name="receiverId"
> column="RECEIVER_ID"
> jdbc-type="INTEGER" />
> <reference-descriptor
> name="sender" class-ref="User">
> <foreignkey field-ref="senderId"/>
> </reference-descriptor>
> <reference-descriptor
> name="receiver" class-ref="User">
> <foreignkey field-ref="receiverId"/>
> </reference-descriptor>
> </class-descriptor>
>
>
> -----Original Message-----
> From: Sebastien Cesbron [mailto:sebastien.cesbron@laposte.net]
> Sent: Friday, August 01, 2003 1:30 PM
> To: OJB Users List
> Subject: Re: Query a non navigable path
>
>
> The connexion is that my email have one sender and one receiver. For this
> example, the database looks like
>
> create table EMAIL
> (
> ID integer not null,
> SENDER_ID integer not null,
> RECEIVER_ID integer not null,
> primary key (ID),
> foreign key (SENDER_ID) references USER(ID),
> foreign key (RECEIVER_ID) references USER(ID)
> );
>
> create table USER
> (
> ID integer not null,
> primary key (ID)
> );
>
> Seb
>
> PS : Sorry if there is syntax erros, I can't cut and paste my sql
>
> Jim Moore wrote:
>
>>Do you have anything that would connect them? What does your database
>>definition look like for those tables?
>>
>>
>>-----Original Message-----
>>From: Sebastien Cesbron [mailto:sebastien.cesbron@laposte.net]
>>Sent: Friday, August 01, 2003 1:07 PM
>>To: ojb-user@db.apache.org
>>Subject: Query a non navigable path
>>
>>
>>Hi,
>>
>>I'am always on the way of integrating ojb in my project. It works very
>>well but I am in front of a problem I can't solve.
>>I have for example this classes :
>>Class Email
>>{
>>private User sender;
>>private User receiver;
>>}
>>Class User
>>{
>>// No link to the * emails I sent or received
>>}
>>
>>I am using the PB-API an I want to retrieve a liste of all users that
>>were receivers of email I sents. How can I do that ?
>>As queries are based on path expressions and I don't have path from
>>receiver I don't know how to do such a query
>>
>>Thanks in advance for any help
>>
>>Seb
>
>
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Re: QueryByMtoNCriteria
Posted by Jakob Braeuchi <jb...@gmx.ch>.
hi sebastien,
QueryByMtoNCriteria is used internally.
hth
jakob
Sebastien Cesbron wrote:
> While investigating on how to solve my problem I found the
> QueryByMtoNCriteria class.
> I don't know if it could solve my problem but I wonder if there is any
> example somewhere (I found nothing in the doc and in the distrib
> examples) ?
>
> Thanx
>
> Seb
>
>
>
> Jim Moore wrote:
>
>> I guess I don't understand the question: That's a very basic 1:n
>> relationship, exactly what OJB does easily, with a clear "path."
>>
>> http://db.apache.org/ojb/tutorial3.html#mapping%201:n%20associations
>>
>> So you XML would look like
>>
>> <class-descriptor class="User" table="USER">
>> <field-descriptor
>> name="userId"
>> column="ID"
>> jdbc-type="INTEGER"
>> primarykey="true" />
>> <field-descriptor
>> name="groupName"
>> column="KategorieName"
>> jdbc-type="VARCHAR" />
>> <field-descriptor
>> name="description"
>> column="Beschreibung"
>> jdbc-type="VARCHAR" />
>> <collection-descriptor
>> name="emailsSent"
>> element-class-ref="Email">
>> <inverse-foreignkey field-ref="senderId"/>
>> </collection-descriptor>
>> <collection-descriptor
>> name="emailsReceived"
>> element-class-ref="Email">
>> <inverse-foreignkey field-ref="receiverId"/>
>> </collection-descriptor>
>> </class-descriptor>
>>
>> <class-descriptor class="User" table="EMAIL">
>> <field-descriptor
>> name="emailId"
>> column="ID"
>> jdbc-type="INTEGER"
>> primarykey="true" />
>> <field-descriptor
>> name="sendId"
>> column="SENDER_ID"
>> jdbc-type="INTEGER" />
>> <field-descriptor
>> name="receiverId"
>> column="RECEIVER_ID"
>> jdbc-type="INTEGER" />
>> <reference-descriptor
>> name="sender" class-ref="User">
>> <foreignkey field-ref="senderId"/>
>> </reference-descriptor>
>> <reference-descriptor
>> name="receiver" class-ref="User">
>> <foreignkey field-ref="receiverId"/>
>> </reference-descriptor>
>> </class-descriptor>
>>
>>
>> -----Original Message-----
>> From: Sebastien Cesbron [mailto:sebastien.cesbron@laposte.net] Sent:
>> Friday, August 01, 2003 1:30 PM
>> To: OJB Users List
>> Subject: Re: Query a non navigable path
>>
>>
>> The connexion is that my email have one sender and one receiver. For
>> this
>> example, the database looks like
>>
>> create table EMAIL
>> (
>> ID integer not null,
>> SENDER_ID integer not null,
>> RECEIVER_ID integer not null,
>> primary key (ID),
>> foreign key (SENDER_ID) references USER(ID),
>> foreign key (RECEIVER_ID) references USER(ID)
>> );
>>
>> create table USER
>> (
>> ID integer not null,
>> primary key (ID)
>> );
>>
>> Seb
>>
>> PS : Sorry if there is syntax erros, I can't cut and paste my sql
>>
>> Jim Moore wrote:
>>
>>> Do you have anything that would connect them? What does your
>>> database definition look like for those tables?
>>>
>>>
>>> -----Original Message-----
>>> From: Sebastien Cesbron [mailto:sebastien.cesbron@laposte.net]
>>> Sent: Friday, August 01, 2003 1:07 PM
>>> To: ojb-user@db.apache.org
>>> Subject: Query a non navigable path
>>>
>>>
>>> Hi,
>>>
>>> I'am always on the way of integrating ojb in my project. It works very
>>> well but I am in front of a problem I can't solve.
>>> I have for example this classes :
>>> Class Email
>>> {
>>> private User sender;
>>> private User receiver;
>>> }
>>> Class User
>>> {
>>> // No link to the * emails I sent or received
>>> }
>>>
>>> I am using the PB-API an I want to retrieve a liste of all users that
>>> were receivers of email I sents. How can I do that ?
>>> As queries are based on path expressions and I don't have path from
>>> receiver I don't know how to do such a query
>>>
>>> Thanks in advance for any help
>>>
>>> Seb
>>
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: ojb-user-unsubscribe@db.apache.org
>> For additional commands, e-mail: ojb-user-help@db.apache.org
>>
>>
>
>
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>
>
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