unable to sum related records via portal
I have two tables items required and product weight required which are connected via the relationship:-
items required:delivery date =production weight required :delivery date
items required :: recipe = production weight required
and then i have a field in the production weight required table called "grand production weight" which is the sum of the related values of the field total weight of items required:-
production weight:grand production weight= sum(items required:total weight of items required).
However the value of grand production weight is always coming up as blank..