Is there anyway to add a nested object, Agentry-smp3.0

Hello Gurus,

I have two objects: PurchaseOrders and PurchaseItems. 1 PurchaseOrder has more than 1 PurchaseItems. In my Java code, I create a Item array in PurchaseOrder object to keep the PurchaseItems.

Now I want to add a PurchaseOrder in SAP and created a transaction to do so.

What should I do to add the PurchaseItems into the created PurchaseOrder? Do I have to create another transaction for it?

Any suggestion is highly appreciated. Thank you very much.