How to count a characteristic (Query Design)?

Question

What is the best way to count a characteristic in a query?  To be more specific, I would like to count the number of orders (characteristic 0COORDER).
I have read the whitepapers:
-HowTo Count the occurrences of a characteristic relative to one or more other characteristics
-HowTo Calculate with Attributes
I would like to build a query that looks like the following:
Order Type      # Orders
A                      3
B                      5
C                      4
In my InfoCube,
OrderID OrderLineID MaterialID Quantity Price ZCount
1                             1
1                             2
2                             3
3                             4
3                             5
3                             6
I added a counter to my infoCube which counts the number of line items per order (from HowTo count occurences of characteristic whitepaper).  <b>However, now I need to count the number of orders.</b>
One approach I tried was to create a dummy calculated keyfigure, which i set to a constant of 1.  I then created another calculated keyfigure and used Count ( dummyKeyFigure).  I could have also achieved the same result by using SUMGT (dummyKeyFIgure).  However, this only works if you have orderID in your query row:
OrderID      dummyKeyFigure (hidden)         
1                        1
2                        1
3                        1
Result:                3  (SUMGT of dummyKeyFigure)
I also read a thread that discussed another alternative on how to use a replacement path variable to count a characteristic (using the key)... however the procedure wasn't clear.  When I tried to create a variable on orderID using a replacement path, it asked for either a variable or query to use... and I got "stuck" from there.  Can you use a replacement variable to count the number or orders? 
What are the different alternatives (and procedures) for counting the number of orders?
Thanks,
-B
Message was edited by:
        Brendon Lipchen
Message was edited by:
        Brendon Lipchen

Answer 1

Hey Olivier.
I do have Key Figures in my cube.  However, I only want to count the number of Orders in my InfoCube.
For your solution, you say to create a CKF.  In order to create a CKF, you need a KF to put in your CKF calculation (note you omitted this step from your solution).  There is no KF in the infocube to use for the Order count (we are creating "this" CKF to get the Order Count).  If there is no KF you can use in your InfoCube to get the Order Counter, then you need to create a replacement path variable to use in your CKF calculation.  After you have created a replacement path variable for OrderID, you can place this variable in your CKF calculation (instead of using a KF).  Make sense?