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flash.pac
 Post subject: How make two one-to-one relations to inherited classes?
PostPosted: Fri Mar 05, 2004 3:15 pm 
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Joined: Thu Dec 11, 2003 12:10 pm
Posts: 16
I have 2 inherited classes.
LimitedAccount extends Account, these classes are correctly stored with hibernate, in the same table using discriminator.

Now I need 2 instances in other class called Application
in the java code is this way:
Code:
private Account bankAccount;
private LimitedAccount communityAccount;


How can I map these relations?????


Thanks alll!!!
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anthony
 Post subject:
PostPosted: Fri Mar 05, 2004 3:18 pm 
Hibernate Team
Hibernate Team

Joined: Thu Dec 18, 2003 9:55 am
Posts: 1977
Location: France
give details on the relationnal model and fk
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flash.pac
 Post subject:
PostPosted: Fri Mar 05, 2004 3:35 pm 
Newbie

Joined: Thu Dec 11, 2003 12:10 pm
Posts: 16
I have two tables: members and accounts

Application instance is a row in members and accounts has Account and LimitedAccount
instances.

the class Account is mapped as:
Code:
<class name="nl.strohalm.cyclos.entities.accounts.Account" table="accounts" discriminator-value="account">
    <id name="id" type="long" column="account_id">
         <generator class="native"/>
    </id>
    <discriminator column="subclass" type="string" force="true"/>
      
    <property name="creationDate" column="creationDate" type="calendar"/>
    <property name="lastAmount" column="lastAmount" type="float"/>

    <many-to-one name="owner" column="owner_id" class="nl.strohalm.cyclos.entities.accounts.IAccountOwner"/>
       
    <subclass name="nl.strohalm.cyclos.entities.accounts.LimitedAccount" discriminator-value="limited_account"/>
</class>


So I have owner field as a FK. Application, Member and other classes implements IAccountOwner interface too.
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anthony
 Post subject:
PostPosted: Fri Mar 05, 2004 3:45 pm 
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Joined: Thu Dec 18, 2003 9:55 am
Posts: 1977
Location: France
does a member have an Account AND a LimitedAccount or
a member have an Account OR a LimitedAccount (more logic no?)
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flash.pac
 Post subject:
PostPosted: Fri Mar 05, 2004 3:52 pm 
Newbie

Joined: Thu Dec 11, 2003 12:10 pm
Posts: 16
Application is a special member and it has a Account AND LimitedAccount instances!!

Code:
private Account bankAccount;
private LimitedAccount communityAccount;
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anthony
 Post subject:
PostPosted: Fri Mar 05, 2004 3:54 pm 
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Joined: Thu Dec 18, 2003 9:55 am
Posts: 1977
Location: France
so in your member table, you might have two field, something like accountId and limitedAccountId isn't it?
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flash.pac
 Post subject:
PostPosted: Fri Mar 05, 2004 4:06 pm 
Newbie

Joined: Thu Dec 11, 2003 12:10 pm
Posts: 16
No, becouse is better to have a FK into account table setting a PK in member table.

This way:
Code:
accounts table
+------------+------------------+---------------------+------------+----------+
| account_id | subclass         | creationDate        | lastAmount | owner_id |
+------------+------------------+---------------------+------------+----------+
|          1 | account          | 2004-03-05 16:49:14 |          0 |        1 |
|          2 | limited_account  | 2004-03-05 16:49:14 |          0 |        1 |


Code:
members table
+-----------+---------------+
| member_id | subclass      |
+-----------+---------------+
|         1 | application   |
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anthony
 Post subject:
PostPosted: Fri Mar 05, 2004 4:14 pm 
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Hibernate Team

Joined: Thu Dec 18, 2003 9:55 am
Posts: 1977
Location: France
the way you can do it is:
declare on the member mapping file a one(member) to many(accounts) using a collection, this collection will always contains 2 accounts, one typed Account, the other typed LimitedAccount.

So the attribute mapped is List accounts
but you can write 2 other attributes
Account account
LimitedAccount limitedAccount and implement the getter and setter of these two attributes...
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flash.pac
 Post subject:
PostPosted: Fri Mar 05, 2004 4:21 pm 
Newbie

Joined: Thu Dec 11, 2003 12:10 pm
Posts: 16
Ok, is this???

<one-to-many class="Account">

And Hibernate will return both accounts(Account and LimitedAccount)??
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anthony
 Post subject:
PostPosted: Fri Mar 05, 2004 4:51 pm 
Hibernate Team
Hibernate Team

Joined: Thu Dec 18, 2003 9:55 am
Posts: 1977
Location: France
look doc about one to many, you'll have to declare something like that
<set name="accounts >
<key="owner_id"/>
<one-to-many class="nl.strohalm.cyclos.entities.accounts.Account"/>
</set>

But on your Member class, the property that is really mapped will be a Collection accounts

and as i said this Collection, in your case, will contain one Account and one LimitedAccount so if you want to have a getAccount() and a getLimitedAccount (and i suppose setters too), you'll have to code these methods...

Maybe there is a way to map your classes differently, but i don't know how
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