I have been having this problem with displaying data from the Inkoop table or the inkoop_items table on the producten table via a portal.
The setup of the relationship is as follows (see the picture) :
I have a producten (which means products) table from which I made a layout from where each product is displayed (see picture 2). On this page i made a portal to display data from the inkoop_table. The inkoop_table is then linked to the inkoop_items table from where product purchases from suppliers can be made. These product purchases are the same products as the products displayed in the producten table.
The relationship of the table are as follows:
producten:: primary key is linked to inkoop::foreign key
Inkoop:: primary key is linked to inkoop_items::foreign key
and then there is a link from inkoop_items::foreign key to the inkoop_items proud::primary key (table occurence of the producten table)
I have tried different combinations of linking the tables and nothing seems to work.