How to mark duplicate records in HANA graphical calculation veiws

Hi,

I hope to mark duplicate records in HANA graphical calculation views, could anyone help to shed some light? Thank you.

Data sample:

Order WBS Amount

OR1 WBS1 10

OR1 WBS1 20

OR1 WBS2 30

OR2 WBS1 40

OR2 WBS3 50

So my expected output is based on Order number, the Counter will mark 1 for first Order, and for any duplicate order, mark as 0, so I could count the unique order when sum the total. Thank you so much.

Order WBS Amount Counter

OR1 WBS1 10 1

OR1 WBS1 20 0

OR1 WBS2 30 0

OR2 WBS1 40 1

OR2 WBS3 50 0