Bug report #20232

Bug when i try to export into shapefile a tempory layer that have a geometry type changed from original layer

Added by Fabio Scarpari almost 2 years ago. Updated almost 2 years ago.

Affected QGIS version:3.2.3 Regression?:No
Operating System:Windows 7 64 bit Easy fix?:No
Pull Request or Patch supplied:No Resolution:wontfix
Crashes QGIS or corrupts data:No Copied to github as #:28053


Hi, i write to report a bug of QGIS 3.2.3. A few days ago i wanted a new shapefile with geometry "Line (LineString)" from a shapefile with the geometry type "Line (MultiLineString)". I saw on forum that there are not only way to change geometry type: 1) "Convert format" from "processing toolbox" (GDAL-Vector conversion-Convert format), 2) with a script on Windows 7 64bit launched with cmd. Here there is a example: ogr2ogr -f "ESRI Shapefile" E:\Prova\Pippo\test.shp E:\test.shp -dim XY . Outputs of both command are right, but are virtual layers. When i export temporary layers into shapefiles both layers changes from "Line (LineString)" to "Line (MultiLineString)". I tried to use also command v.out.ogr, loaded on postgis the layer, changed the geometry and inserted into QGIS. QGIS showed not Line (LineString). I tried to convert geometry type of layer from multiline to single line inserted z. The geometry type was now singleline with(z). I exported and the output is right but had also z. For this reason i did "Drop M,Z values" and then exported in shapefile, but the result is Line (multiline string). Thanks for support.


#1 Updated by Nyall Dawson almost 2 years ago

  • Resolution set to wontfix
  • Status changed from Open to Closed

Since QGIS 3.0 line or polygon shapefiles are always loaded into QGIS as multilinestring/multipolygon. If you require a format with single/multi type constraints, you need to use a more modern format like geopackage.

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