problem with a relation on a calculus field
I have a database with three tables: months, incidencies and days, with the following fields:
months: __kp_idmotn, year, month, num_incidences=count(incidencies::__kp_idincidences), zg_zero=0
incidences: __kp_idincidence, date, year=year(date), month=months(date), total=sum(days::cost)
days: __kp_idday, _kf_idincidence, cost
incidencies and days a related by the fields incidences::__kp_idincidence = days::_kf_idincidence
What I want to do is to count for each month the incidences of the month that have total>0.
So I have set a complex relation between months and incidences:
months::year = incidences::yerar
months::month = incidencies::month
months::zg_zero < incidences::total
For this complex relation to work, I have had to set the calculus fields on incidences as indexed as needed, and it works fine for year and month. But I cannot set incidences::total this way, as it is dependent of another relation, and the field months::num_incidences show a question mark.
What am I doing wrong?