Totò wrote > So the mistake I was making is using a virtual field (maybe it's a bug?)
Hi Salvatore, you are right: it seem the expression is not correctly evaluated in a virtual field (using the Field Calculator with the "Create a new field" and "Create virtual field" options both checked). Instead it is evaluated correctly with a non virtual field by either using directly the Field Calculator with only the "Create a new field" option checked or first creating a new empty field and then using the Field Calculator with the "Update existing field" option checked. Anyway I wrote a typo in the expression (but it is irrelevant in this case): if( "zona" is Null, attribute( get_feature_by_id( @layer, $id-1 ), 'zona_fill2' ), "zona" ) [note << "zona" is Null >> instead of << "zona" is empty >>] For a more general case, if fields values could be Null or '' then << nullif("zona", '') is Null >> should be used to catch both cases. It may be worth investigating why the expression is not working in a virtual field. Best regards. Andrea -- Sent from: http://osgeo-org.1560.x6.nabble.com/QGIS-User-f4125267.html _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user