查重复记录：

select *
  from oe_order_headers_all t
 where t.order_number in (select order_number
                            from oe_order_headers_all
                           group by order_number
                          having count(*) > 2)

官方答复参考：

=== ODM Answer ===

1. Modify sales order number created sequence rule for preventing duplicate sales order number problem.

2. Make customization for form. LOV, also will provided some reference notes for help.
*For customize your LOV on FORM, please reference notes as follow, hope could give you help as much as possible.
<1>. Oracle Applications Multiple Organizations Access Control for Custom Code (Doc ID 420787.1)
<2>. How To Customize a LOV using Form. Personalization? (Doc ID 726324.1)
<3>. How To Set Up Order Organizer Organization Access (Doc ID 841771.1)
<4>. How to Restrict Operating Unit By Responsibility in OM (Doc ID 1053023.1)
<5>. Control - Parameters: Setup (Doc ID 114801.1)
<6>. Control - Parameters: Troubleshooting (Doc ID 114802.1)