I got a feeling I'm missing something very simple here, but how can I use the modeler in QGIS to do the following tasks:
- Adding/Removing a field
- Looping through a field
- Calculate field values based on other fields
I can only find how to do new layers and work with them - but most of the time, I already have the layer loaded in QGIS - I just need to edit the fields. Processing modeler to update table suggests to use the Network plugin, but even then I can't get it to work.
My understanding was, that the layer has to be connected with the field calculator in order to work, like in QGIS 3 Graphical Modeler field calculator with attribute's parameters but when I choose a vector layer as Input in the model builder, I can't choose my existing layer.
How am I supposed to connect them then?
Until now, I used PyQGis to do these basic tasks, but my shapefile is too big and I was hoping the modeler loops through a big attribute table a bit faster.