Hi jukka. I guess empty geometry is a not null geometry. Il 26 mag 2016 4:34 PM, "Rahkonen Jukka (MML)" < [email protected]> ha scritto:
> Hi, > > We spent some time with empty geometries in OpenJUMP and I attach some > test data from those experiments. Feel free to use it in the QGIS feature > request. Zip contains point, line, and polygon shapefiles, each having 8 > features but only one feature with geometry. From the WKT files you can > see that there are actually different kind of empty geometries. I even did > not bother to think about Z, M, and ZM geometries. > > POINT EMPTY > MULTIPOINT EMPTY > LINESTRING EMPTY > MULTILINESTRING EMPTY > POLYGON EMPTY > MULTIPOLYGON EMPTY > GEOMETRYCOLLECTION EMPTY > > One may say that empty is always just empty but one needs also to think > what happens if user copies POLYGON EMPTY and tries to paste it into a > point layer. Should copy be denied or empty geometry converted into POINT > EMPTY? For OpenJUMP that does not matter because it can handle all kind of > geometries on the same layer. However, saving POINT EMPTY into polygon > shapefile may fail and therefore OpenJUMP can convert even empty geometries > like POINT EMPTY ->POLYGON EMPTY. > > -Jukka Rahkonen- > > Andrea Peri wrote: > > Hi Jukka, > yes is exactly this the question. > > The QGIS don't show any record with null geometry so is impossible for me > to add a geometry to it. Or delete it definitivelly. > > But the record with null geometry is however saved when I export the > shapefile from qgis. > > So the QGIS show me 14 records but export a shapefile with 16 records > (2 records has null geometry). > > So when load it in a spatialite or on a postgis environment or open it > using another GIS like arcview3 from esri. > I see this two more records with null geometry. > > AFAIK this is a chaotic situation for who work using qgis and produce a > shapefile to distribute to other users that has other gis softwares. > > A. > > > 2016-05-26 10:24 GMT+02:00 Jukka Rahkonen < > [email protected]>: > > Nicolas Cadieux <nicolas.cadieux@...> writes: > > > >> > >> > >> Hi, > >> Is it possible that the 2 missing records were deleted in another GIS? > > There is an issue with deleting records in shape file as there are > > many ways to do that. If the record were deleted in another GIS, they > > may show up (or > > not) in another software. Could that be it... > >> Nicolas > > > > Hi, > > > > I suppose that Andrea means a valid situation with real existing > > features which just do not have geometry. They are valid in shapefiles > > but many GIS software have difficulties in dealing with them. > > Naturally they cannot be showed on the map and spatial queries can't > > find them but they should be found from attribute view and be editable > there. > > > > -Jukka Rahkonen- > > _______________________________________________ > > Qgis-user mailing list > > [email protected] > > List info: http://lists.osgeo.org/mailman/listinfo/qgis-user > > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user > > > > -- > ----------------- > Andrea Peri > . . . . . . . . . > qwerty àèìòù > ----------------- >
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