Displaying 1 result from an estimated 1 matches for "purchase_amount".
2011 Mar 09
2
Differences per group
...chase amount, what
I would like to do is to show the difference between amount purchased
compared to the month before per customer.
I have made some attempts myself using diff, but what i can not get to work
is that each different customer starts with a 0.
This is an example of what I have:
>purchase_amount
customer amount
123 6
123 5
123 9
123 8
123 11
123 7
230 19
230 18
230 12
230 17
380 7
380 9
380 2
380 7
380 8
380 8
380 6
380 8
How I would like it to look like:
customer amount difference
123 6 0
123 5 -1
123 9 4
123 8 -1
123 11 3
123 7 -4
230 19 0
230 18...