Make a difference between two columns into rule engine node

[giad]

Hello!
I need to create a column with the difference between two columns in a table. I have used rule engine but I do not know how to write the difference between two columns.
i attach the example:

I need to say:
if the difference between count(appliance_id) and count(appliance_id)_2019 is bigger than 0, write positive
otherwise write negative.

I need also to put another rule engine into another column with the value from the difference. not the word positive but the number. how can I do that?

Thanks!
Giada

[HansS]

Hi @giad

First calculate the difference (as a value) with the Math Formula node. The output of this node (column) can be input for the Rule Engine node .
gr. Hans

[tbtt]

Why do you want to calculate the difference to see which one is bigger? Just compare directly using “>”:

$Count(applicance_id)$ > $Count(applicance_id)_2019$ => “Positive”

[ipazin]

Hi there @giad,

agree with @tbtt that calculating difference is not necessary in your case. Additionally Column Expressions node can handle conditions with calculations together with ability to output multiple columns.

Br,
Ivan