Hello I have serious problem and I can't find solution.
My problem is in mapping this example:
----------------------------------------------------
//Class Order reperesent basic order, can containts more OrderItem
class Order {
private int id_o;
private Set<OrderItem> orderItems;
...
}

//class reprezent oreder item and can contain only one product and its //quantity
class OrderItem {
private int quantity;
private Product product;
}

//class represent basic product
class Product {
private int id_p;
private String name;
.....
}
I would like to map it into join table , but i don't know how should map atrribute quantity.
I know that I should use many-to-many mapping, but i know only use it when I don't have attribute quantity.

ERD:(Tables)

ORDER
------------
ID_O integer auto_increment PK

PRODUCT
-----------
ID_P integer auto_increment PK
NAME varchar(20)

ORDER_ITEM
-----------------
ID_O PK,FK
ID_P PK,FK
QUANTITY integer

But how should it map in hibernate, I really don't know.
If someone know, please help me.
Thanks for your help
geN.

You probably don't want a many-to-many here. You could do it with composite-element, but a better (IMO) solution is to copy the Customer/Order/Product example in section 23.3 of the ref docs. The LineItem table in that example exactly matches your OrderItem table. Just convert the <list> in the example to the <set> that you're using, and it should work perfectly.

Hey, You have right that I don't need many-to-many-mapping.
I use this mapping in Order.hbm.xml

....
<set name="orderItems" table="ORDER_ITEM">
<key column="ID_O" />
<composite-element class="package.OrderItem">
<many-to-one name="product" class="package.Product">
<column name="ID_P" />
</many-to-one>
<property name="quantity" column="QUANTITY" />
</composite-element>
</set>

...

It works correcty, but maybe the solution that you've written is better, I will check it.

Thanks a lot

.geN