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I got a point-layer Points where all points lying exactly on the vertexes of the polygons of a polygon-layer Polygons.

How do I join all numbers of the point-layer to the polygon-layer?

All algorithms I used didn't really work (NNjoin, MMQGIS, select attributes by location etc.).

What I need is to bring the column Nr into multiple columns of the polygon-layer like Nr_1, Nr_2, Nr_3, Nr_4. To bring it into one column like including a separator would also work.

I'm running QGIS 3.16.3.

enter image description here

PolyGeo
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thompson82
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1 Answers1

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You can achieve what you want e.g. by running custom PyQGIS script in QGIS's Python console. First, open attribute table of the polygon layer and create a new column to it (named here as ListOfNrs). Second, go to Python console (Ctrl+Alt+P), open script editor, paste the following code in it and press the green triangle to execute the script.

mapcanvas = iface.mapCanvas()
layers = mapcanvas.layers()

Assuming that first layer contains point data


and second layer contains polygon data


for a in layers[1].getFeatures():
    temp = list()
    prov = layers[1].dataProvider()
    targetfield = layers[1].fields().lookupField('ListOfNrs')
    for b in layers[0].getFeatures():
        if a.geometry().intersects(b.geometry()):
            temp.append(b["Nr"])
    temp2 = ",".join(temp)
    atts = {targetfield: temp2}
    # call changeAttributeValues(), pass feature id and attribute dictionary
    prov.changeAttributeValues({a.id(): atts})
PolyGeo
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Pauliina
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  • it works well if both columns 'Nr' in Layer "Points" and 'ListOfNrs' in Layer "Polygons" are strings. Is there a possibility to extend the code by a buffer if the any point is not exactly on the vertex of a polygon? THX for great help by now – thompson82 Aug 26 '21 at 05:40