Hi,

I have two classes: Player and Address. There is a one-to-one association between them. Player has set/getAddress methods.

I have two database tables, one for each. On Player there is a fk which should hold the id of the Address for that Player.

The mappings for each are:


<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping
package="football">

<class name="Address">
<id name="ID">
<generator class="native">
</generator>
</id>
<property name="number" not-null="true"/>
<property name="street" not-null="true"/>
<property name="city" not-null="true"/>
<property name="postCode" not-null="true"/>
</class>

</hibernate-mapping>



<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping
package="football">

<class name="Player">
<id name="ID">
<generator class="native">
</generator>
</id>
<property name="firstName" not-null="true"/>
<property name="lastName" not-null="true"/>
<property name="number" not-null="true"/>
<property name="position" not-null="true"/>
<property name="transferFee" not-null="false"/>
<one-to-one name="address" class="Address" outer-join="auto" constrained="true" foreign-key="ADDRESS_ID"/>
<!-- <many-to-one name="address" class="Address" outer-join="auto" foreign-key="ADDRESS_ID"/> -->
</class>

</hibernate-mapping>

You'll notice that I've commented out the many-to-one tag. I found that when I save an Address and a Player using many-to-one, the fk column in the Player table is updated correctly. When I use one-to-one, the fk column has null.

Any suggestions?

I'm using Hibernate 2.1 with a Pointbase db.

Regards,

Don

try this:
<one-to-one name="address" class="Address" outer-join="auto" constrained="true" property-ref="ID"/>

Tried that:
MappingException property-ref not found: ID in class: football.Address

There is an ID in Address class and there are get/set methods and Address instances can be saved in the database.

I don't know how using this would allow Hibernate to know that the column ADDRESS_ID in table PLAYER is meant to hold the ID of the Address.

I think it is supposed to find it since the name points to a name (ID) in the Address class. That would be <id name="ID"> in Address... I have tried this aswell but i get the same MappingException as you do...

Sorry cant help you ... just confirm that i have the same problem as you do...

regards,
Kristoffer

Hi,

It's good to know that it's just not me. I'm tempted to infer that what I'm trying to do, although seemingly very simple, is not possible using Hibernate.

Regards,

Don

It's not one-to-one relation, it's many-to-one.



Read documentation:
http://www.hibernate.org/hib_docs/refer ... pping-s1-9

And this:
http://www.xylax.net/hibernate/

Regards
Artur

So, one-to-one where they entities have the same value for primary key is <one-to-one> but where a one-to-one where a fk is used is a <many-to-one>.

And of course in the second one-to-one, using my example, I couldadd the same Address to multiple Person entities, which is not my intent.

I must check what would happen using EJBs and CMR..........