Hello,

Hello, I would like to know if it is possible to map several tables to one class ?
Here is a description of my problem : I have a class Product which contains a list of Quantities (a property of type Weight, which is a class I have defined). Those quantities are stored in a separate table and I would like to map each of them to the class Weight. Moreover, Product has a property called UnitWeight which is of type Weight and which data are sored in the Product table. I would also like to map this field "UnitWeight" to the Weight class. Is it possible ?


Hier is my map file :

<class name="Product" lazy="false">
<id name="Id">
<generator class="identity" />
</id>
<bag name="MinQuantity" table="MinQuantity" lazy="false" order-by="MinQuantity">
<key column="Product_Id" />
<one-to-many class="Quantity" />
</bag>
<one-to-one name="UnitWeight" class="Weight" />
</class>

<class name="Quantity" table="MinQuantity" lazy="false">
<id name="Id">
<generator class="identity" />
</id>
<discriminator column="Unit" type="String" />
<subclass name="Weight" discriminator-value="kg">
<property name="Value" column="MinQuantity" />
</subclass>
<subclass name="NumberOfPiece" discriminator-value="p.">
<property name="Value" column="MinQuantity" />
</subclass>
</class>

<class name="Weight" table="Product">
<id name="Id">
<generator class="identity" />
</id>
<property name="Value" column="UnitWeight" />
</class>

For the moment, this doesn't work. I get an error :
Duplicate class/entity mapping Weight

Do you have an idea to solve this problem ?

thanks.
[/b]

There is a <join> element in the current trunk. That would require downloading a building the source.

More likely, for such a lightweight object as 'Weight' you should not use a separate table, but instead map it as a <component> (see [url]
http://www.hibernate.org/hib_docs/nhibe ... nents.html[/url]).

Thank you very much. :-)
Using a <component> is perfect for my case.


For more complex classes it could be interessant. I would like to have a look at this. Where could I find this building source ?