Current Month and Prior Month in a new column

[#1]

Hi dear,

How can i do it below?

Current State
KEY	MONTH	PRODUCT
1001	2012/01	A
1001	2012/02	A1
1001	2012/03	XX
New State (that i need to do)
KEY	MONTH	PRODUCT	PRIOR PRODUCT
1001	2012/01	A
1001	2012/02	A1	A
1001	2012/03	XX	A1

Thank you

[Gysbert_Wassenaar]

In a straight table or pivot chart you can use the above() function: above(PRODUCT)

In the script you can use the previous() function: if(KEY=previous(KEY),previous(PRODUCT)) as PRIOR PRODUCT. You may have to create another table first if your source data isn't sorted on KEY first and MONTH next.