What is the equivalent of native:aggregate() in QGIS Field Calculator?

Question

I have two layers which I want to connect using the aggregate() function with the Field Calculator. I can do this using the processing tool:

processing.run("native:aggregate", {
    'INPUT' : 'XX.gpkg|layername=obj_flurname',
    'GROUP_BY' : '"Aufn_Nr"',
    'AGGREGATES': [
        {'aggregate': 'first_value','delimiter': ',','input': '"Aufn_Nr"','length': 50,'name': 'Aufn_Nr','precision': 0,'sub_type': 0,'type': 10,'type_name': 'text'},
        {'aggregate': 'concatenate_unique','delimiter': ', ','input': '"name"','length': 254,'name': 'name','precision': 0,'sub_type': 10,'type': 11,'type_name': 'stringlist'}],
    'OUTPUT' : 'TEMPORARY_OUTPUT'
    })

When I want to implement the same thing in the Field Calculator, I don't have the option to group_by like in the native:aggrregte function. Is it possible to add this group_by, or do I have to run this with the advanced field calculator (with Python)?

My efforts so far:

aggregate(
    layer:='XXX_1da2ccba_0147_4280_a0e9_439870e296c4',
    aggregate:='concatenate_unique',
    expression:="name",
    concatenator:=', '
    )

But this only aggregates all possible unique values to all rows. How could I change this so that it works?

Answer 1

Instead of the aggregate() function, use the concatenate_unique() function: there, you have the option to set a group_by argument.