Filling several columns based on conditions from column in QGIS

Question

I've got two additional columns that need to be filled with attributes that are based on values created in the field.

For example, if column "reproduction" = A2 then the value in the value in column "technic" needs to be "acoustic" and the value in column "class" needs to be "adm" and so on.

I know how to update single fields by using case when but I could not find a solution for updating more than one field with one expression.

Answer 1

In Processing Toolbox (Ctrl+Alt+T) one can find the "Refactor fields" algorithm.

You can add new columns or change the value of the existing ones. In the plugin, the registry installs "Append Features to Layer". With both processing algorithms, you can accomplish what you want.

Answer 2

You can use the following code which is very easy to understand. Select the layer, first. You can populate with other logical conditions.

# get the selected layer
layer = iface.activeLayer()

with edit(layer): # open edti sessio for the layer

    for feature in layer.getFeatures():

        # condition 1
        if feature['reproduction'] == 'A2':
            feature['technic'] = 'acoustic'
            feature['class'] = 'adm'

        # condition 2
        elif feature['reproduction'] == 'foo':
            feature['technic'] = 'bar'
            feature['class'] = 'baz'

        # condition 3
        # elif featu.....

        # update feature values
        layer.updateFeature(feature)