New object can not update existed child object

Question

I have three classes, they are DraftOrder, Order and SaleItem,
public class DraftOrder{
private List<SaleItem> saleItems; // not check private owned
public class Order{
private List<SaleItem> saleItems; // check private owned
public class SaleItem{
private ValueHolderInterface draftOrder;
private ValueHolderInterface order;
Now, I have one DraftOrder instance, I modify it from UI, and save it as Order, I want to the toplink to do following steps,
1, insert Order data into db
2, update SaleItem into DraftOrder to Order, don't excute delete and insert, only update
3, delete DraftOrder
In my Java code, i have moved the SaleItems to Order,
but toplink dont update the SaleItem,
who can help on it?
thanks in advance.

Answer 1

Hello,
It looks like you have a 1:M from DraftOrder to SaleItem and another 1:M from Order to SaleItem, where SaleItem has a 1:1 backpointer to both. When you set the DraftOrder->SaleItem relationship, you must also be maintaining the SaleItem -> DraftOrder backpointer or the foreign key in the SaleItem table would not be set. When you remove the DraftOrder->SaleItem relations, you must also remove the SaleItem -> DraftOrder relations or again, you will not see the foreign key in SaleItem get set to null. TopLink does not perform relationship maintenance for you by default.
It is the SaleItem -> Order and the SaleItem -> DraftOrder relationship that controls the foreign key in SaleItem's table - you must set these relationships or you will not see the foreign keys be updated. The 1:m is more like a readonly relation that reflects what the 1:1 relationship holds.
Best Regards,
Chris