Incrementing value in table with automation

I'm not sure how can I add specific value to vlalue existing in table without ending up with "~circular~ref~".
I have two tables:
and kpi_car_load (Initially empty)

what I need to do is: each time new row is added to f_collection_activity i need to perform:
update: kpi_car_load[bags_number]
using value calculated as: f_collection_activity[bags_number] + kpi_car_load[bags_number]
where: driver_code equals for both tables.

I'm trying to do as below:

But I'm receiving circular reference in kpi_car_load table:

I understand that reason for receiving circular reference is because I'm trying to take existing value, use it in calculation and save in same place. How can I do this differently?

Hi @Andr-576d,

I would like to know more about your use case. Correct me if I'm wrong. Driver A may have multiple entries in f_collection_activity, so if a new entry is added for a driver A to f_collection_activity then:

  1. In kpi_car_load, if Driver A exists, add the new bag number to the previous bag number
  2. Write a new entry of Driver A in kpi_car_load if Driver A does not exist in kpi_car_load.

I look forward to hearing from you.