I want to create an attribute-form that displays some fields in value-related dropdowns. The goal is to limit the options in the second dropdown dependent upon the selection in the first dropdown. In my case, I have the following two fields that should be related:

  1. List "Schwachstelle" with attributes ID (PK) and Name
  2. List "Schwachstelle_spez" with attributes ID (PK), Name and ID_Schwachstelle

The key-attributes between the two lists are the ID of "Schwachstelle" and ID_Schwachstelle of "Schwachstelle_spez".

The filter I wrote for the value-dependent dropdown ("Schwachstelle_spez") is the following:

"ID" = current_value( 'Schwachstelle_ID' )

However, this does still show all possible values in the "related" dropdown.

(I took https://www.youtube.com/watch?v=8shIZrwlQt4 as an example)

This is what the layer, where I specify the Dropdown-values, looks like: no image description

And this is the layer, on which the upper layer is dependent on: no image description

Attribute table of "Schwachstelle": no image description

Attribute table of "Schwachstelle_spez": no image description

If the user were to choose "Nutzungskonflikte", "Umwege" would not apperar in the following dropdown.

  • 1
    Could you show your code? – The Rabbit Oct 28 '19 at 10:12
  • 2
    This should be possible by simply defining the value-relations in the attribute-table in the layer-properties of the qfield-project. So, there's no code except for the filter-expression. – Lara Oct 28 '19 at 10:23
  • 1
    As far as I know, QGIS does not support depending lists. So I am afraid you have to write your own code. I have the same task... – The Rabbit Oct 28 '19 at 10:49
  • 1
    Your filter looks ok, how does your lookup table/value relation layer look like? – nepluisse Oct 28 '19 at 12:21
  • I uploaded some screenshots above. – Lara Nov 4 '19 at 9:23

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