I used get exception :
Promised date change is not allowed at line level.
Need-by date change is not allowed at line level.
when i tried to update existing PO using API po_change_api1_s.update_po:
In this case you have Pass Shipment number as mandatory.Hence issue resolved.
I was using PO update API po_change_api1_s.update_po ,faced couple of challenges.
1.I was passing null to shipment number hence unable to update promise_date,need_by_date,hence shipment number is required when u want to update dates.
2.Was passing Launch approval flag as Y ,hence PO setup used to fire approval workflow for an approved PO.however requirement was not to change authorization status.
Then i changed tolerances(Purchasing user setup ->tolerance and routing) to max limit and re-ran.API did not hit approval workflow and status remained in approved.
I did not understand you requirements. Are you having problems in using PO Update?
If so kindly refer to
How to use PO_CHANGE_API1_S.update_po to Change Three Lines (Doc ID 1077455.1)
PO_CHANGE_API1_S.UPDATE_PO Does Not Trigger Change Request Flow and Supplier Notification (Doc ID 1946341.1)
Using the PDOI API-PO_CHANGE_API1_S.UPDATE_PO-Which fields in the PO Line can we update? Can we use the Standard PDOI interface to insert line updates to a Standard PO? (Doc ID 1930759.1)
Troubleshooting Assistant: Oracle Purchasing Purchase Document Open Interface and API (Doc ID 1369663.2)