Hello again,
I have the following mappings for a composite-element as a list. I have an Order object and a list of lineitem objects.

<class name="Order" table="orders">
<id name="orderId" column="orderid" type="int">
<generator class="increment"/>
</id>

<property name="username" column="userid" type="java.lang.String" not-null="true" />
<property name="orderDate" column="orderdate" type="java.util.Date" not-null="true" />
<property name="shipAddress1" column="shipaddr1" type="java.lang.String" not-null="true" />


<list name="lineItems" table="lineitem" lazy="false">
<key column="orderid"/>
<index column="linenum"/>
<composite-element class="LineItem">
<property name="quantity" column="quantity"/>
<property name="unitPrice" column="unitprice"/>
<many-to-one name="item" column="itemid" cascade="none"/>
</composite-element>
</list>

</class>

I can insert an oder and a set of lineitems with no problem. But when I read I read the Parent class (Order), the children (lineItems) get loaded. But the attribues for the key column (orderid) and the index column (linenum) do not get loaded. (They are always zero-default value for java). All the other properties (like quantity, unitPrice and Item are loaded).

The orderid and linenum form the primary key in the lineitem table.

Any ideas? Any help would be appreciated.

Thanks
Matt

Before saying something is a bug please read an understand the documentation. The key column and the index columns are no properties of your composite element. Hibernate uses the key column to reference the association between Order and LineItem. The index is used to as the index value of Map/List in java (Map/List are indexed Collections in java) If you want them in your composite element (for whatever reason) you have to name them seperate as properties and even then I don't know if Hibernate accepts it.

Hi Dencel,
My apologies to call it a "bug". I did it to get some attention. Please note that my requirements are similar to example given in chapter 18 of the hibernate refernce documentation. (customers/orders/line_items/products).

Please note that, line_number is a column in the line_items table. The order_id and product_id combined make a primary key. When I save the parent object (Order) with a list of line_items, the item_number is saved as well. Why cannot I read them back? order_id and line_number both are columns in the table. Why cannot I treat them as properties? What if I want line numebers to be sequentially generated instead of going from 0 to the number of line_items for each order.

May be there is a different ways to do this. I am trying to port the jpetstore sample application to spring (The data access is currebtely done by iBatis).

Any thoughts/help on this will be appreciated.

Once again my apologies.

Thanks
Matt Madhavan

For the record: never do this again.

Java List does not have a feature to supply your own index numbering strategy. If you want to use your own sequentially numbering for the List I suggest you add an extra (db indexed) property to Listitem and add order-by="mySequence" to the hibernate mapping of your collection.

Hope this helps.

Hi Dencel,
I went to <set> instead of <list>. It serves my requirements better now.

Instead of :

<list name="lineItems" table="lineitem" lazy="false">
<key column="orderid"/>
<index column="linenum"/>
<composite-element class="LineItem">
<property name="quantity" column="quantity"/>
<property name="unitPrice" column="unitprice"/>
<many-to-one name="item" column="itemid" cascade="none"/>
</composite-element>
</list>

Now I have :

<set name="lineItems" table="lineitem" lazy="false">
<key column="orderid"/>
<!-- index column="linenum"/-->
<composite-element class="LineItem">
<property name="linenum" column="linenum"/>
<property name="quantity" column="quantity"/>
<property name="unitPrice" column="unitprice"/>
<many-to-one name="item" column="itemid" cascade="none"/>
</composite-element>
</set>

It works just fine now.

Thanks
Matt Madhavan