Why are Line item copy status and Line#/Status on PO screen different

Question

Why doesn't the line item status that shows for a line when viewing the PO header tab match the status that displays on the Copy tab of the Detailed Line Item View?

Answer

A line item's actual status is shown on the Copy tab of the Detailed Line Item view and is stored in the database as the line_item_status column in the line_item_copy_status table.  

The status shown for a line item when viewing the PO header tab is a dynamic status not stored in the database; if there are multiple copies on order for a line and only 1 has been received, the status here will show as Received Partial, though the Detailed Line Item view for the line that has been received will correctly say Received and the status for the line that hasn't yet been received will correctly say Approved.  If there is a single line item on order and that line item is being received, the status that shows on the PO will say Received Complete even if the line item is a serial and shows Received Partial in the Detailed Line Item view.