How can you make a Collection (set/list/array/etc.) use a field other than the class's id, as the collection's key? I'm asking because I'm only seeing references to the <key> tag being stuck on the class.id, not the class.someFieldName. The forums, reference PDF, mapping DTD and examples aren't giving me (at least not clearly) what I need.

Can someone point me in the right direction?

The simple details are this:
An order (id field = mysql native generator) has order_items. Each order_item (id field = mysql native generator) needs to be looked up via the field batchid, which is a property of the order and a property of the order_items. Unfortunately, everything I've tried has stuck the order.id in the order_item.batchid field when I need it to be the order.batchid used in the order_item.batchid field.

Thanks for any suggestions,
David

Why do you even need a key for the collection. Just stick the parent batchid into the child batchid before the save.

Hope this helps. If not, you might post the code and mappings

Jeff

Jeff,

My DB is a legacy db and I need to have the order_detail based off the batchid. The problem is that both classes have an id that is mysql-auto-generated and need to link off the property field batchid. I don't see anything in the mapping DTD (not that I'm good at reading a DTD) suggesting specifying a field other than the <id../> for collections to use as their lookup key.

Do you know of any way to make the collection key off a <property.../> or any field for that matter which isn't the class's <id.../> field?

Below are the relevant snippets from my hibernate mapping.

Thanks,
David

<class name="db.order" table="purchasers">
<id name="id"
type="long"
unsaved-value="0"
column="id">
<generator class="assigned"/>
</id>
<property name="batchid" type="long" column="batchid"/>
<property name="ccnumber" type="string" column="ccnumber" length="20"/>
<property name="ccmon" type="string" column="ccmon" length="20"/>
<property name="ccyear" type="string" column="ccyear" length="5"/>
<set name="items" lazy="true" cascade="all">
<key column="batchid"/>
<index column="id"/>
<one-to-many class="org.hawaiifun.model.v4.PurchaseDetail"/>
</set>
</class>

<class name="db.orderDetail" table="purchases">
<id name="id"
type="long"
unsaved-value="0"
column="id">
<generator class="native"/>
</id>
<property name="batchid" type="long" column="batchid"/>
<property name="lineitem" type="int" column="lineitem"/>
etc....
</class>

db.order / purchasers
- id (PK - assigned)
- batchid
- ccnumber
- ccmon
- ccyear
- items

db.orderDetail / purchases
- id (PK - generated
- batchid
- lineitem



I don't get what you mean here but perhaps I'm just slow.

What's the FK to db.order in db.orderDetail? batchid? If so then what is db.order.id? You can't have 2 different PK's.

Jeff