On QGIS Attribute Forms, I want to display related Features which are connected via a many-to-many relationship table:
Tables / QGIS Layers:
Feature a: a_id, geometry, some more attributes
Feature b: b_id, geometry, some more attributes
Join table: join_a_to_b: a_id, b_id
Now I define one-to-many-Relations via Project Properties:
Relation 1: Parent: Feature a, Child: Join Table referencing a_id
Relation 2: Parent: Feature b, Child: Join Table, referencing b_id
This way I can show all connected join table entries in the attribute form, but I do not manage to show connected Features of type "b" directly in an "a" attribute Form.
From the docs, this should be possible this way - any hints what I'm doing wrong? Swapping Parent and Child wont work either.
Using QGIS 3.4.3 on Windows 7 (same behaviour with Linux) on top of PostgreSQL