This is a very simple code sample to update the purchase order partner details. The following function modules are used:
CRMD_PARTNER table contains partner details .
BBP_PD_PO_GETDETAIL : Read the details of a Purchase Order
BBP_PD_PO_UPDATE : Updates the details of a Purchase Order
BBP_PD_PO_SAVE : Finally called to save the details of a Purchase Order
This is just an illustrative example and can be enhanced to update any existing detail of a purchase order.