<div dir="ltr"><div dir="ltr">Hi, from what I saw in the docs, you should be able to append to layers with the filewriter option AppendToLayerNoNewFields?</div><div>The <span style="font-family:"Courier New"">CreateOrOverwriteLayer</span> overwrites the layer completely. </div><div dir="ltr"><br></div><div>Cheers,</div><div>Andrea</div><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Apr 26, 2023 at 2:58 PM Anne B. Nilsen via QGIS-User <<a href="mailto:qgis-user@lists.osgeo.org">qgis-user@lists.osgeo.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="msg-3234098741214079493">
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<p class="MsoNormal"><span lang="EN-GB">I’m not a pyQGIS-expert, but with help from <a href="http://gis.stackechange.com" target="_blank">gis.stackechange.com</a> I have managed to create an empty geopackage file and then adding several layers to it with this code:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">…<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">gpkg_reg = "karplanteregistrering.gpkg" # the NEW gpkg to be created<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">if os.path.exists(gpkg_reg): # If gpkg-file already exists, delete it<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> os.remove(gpkg_reg)<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">…<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""># <a href="https://gis.stackexchange.com/questions/417916/creating-empty-layers-in-a-geopackage-using-pyqgis?noredirect=1&lq=1" target="_blank">
https://gis.stackexchange.com/questions/417916/creating-empty-layers-in-a-geopackage-using-pyqgis?noredirect=1&lq=1</a><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">def create_blank_gpkg_layer(gpkg_path: str, layer_name: str, geometry: int,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> crs: str, fields: QgsFields, append: bool = False<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> ) -> bool:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> # To add a layer to an existing GPKG file, pass 'append' as True<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> options = QgsVectorFileWriter.SaveVectorOptions()<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> options.driverName = "GPKG"<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> options.layerName = layer_name<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> if append:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> options.actionOnExistingFile = QgsVectorFileWriter.CreateOrOverwriteLayer<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> writer = QgsVectorFileWriter.create(<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> gpkg_path,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> fields,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> geometry,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> QgsCoordinateReferenceSystem(crs),<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> QgsCoordinateTransformContext(),<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> options)<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> del writer<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> return True<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">…<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""># Layer 1 oversikt – creating an empty layer with attributes read from a csv-file<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">f = open("./egenskaper/egenskaper_oversikt.csv",'r') # open file<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">f.readline() # read the first line of the file (the "metadata"/heading)<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">layer_name = "oversikt" # set layer name<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">print('creates layer', layer_name) # print layer name<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">geom = QgsWkbTypes.PointZ # geometrytype<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">crs = 'epsg:25832' # coordinate system<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">fields = QgsFields()<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">for line in f: # Read attrubutes from csv-file<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> </span>
<span style="font-family:"Courier New"">r = {}<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> r = line.split(';') # 0 navn, 1 QVariant-type, 2 lengde og 3 presisjon<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> </span><span lang="EN-GB" style="font-family:"Courier New"">fname = r[0]<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> l = int(r[2])<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> p = int(r[3])<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> try:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> fields.append(QgsField(fname,set_variant(r[1]),'',l,p)) # add field to layer
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> </span>
<span style="font-family:"Courier New"">except:<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> print("Noe gikk galt - får ikke laget egenskaper fra " +str(f))<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">f.close() # close file<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">create_blank_gpkg_layer(gpkg_reg, layer_name, geom, crs, fields) # Do NOT include True when the FIRST layer is created<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""># Layer 2 arter (to be added to the same new gpkg-file just created above)<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">f = open("./egenskaper/egenskaper_arter.csv",'r') # open file<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">f.readline()<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">layer_name = "arter"
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">print('creates layer', layer_name) # print layer name<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">geom = QgsWkbTypes.PointZ # geometrytype<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">crs = 'epsg:25832' # coordinate system<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">fields = QgsFields()<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">for line in f: # Read attrubutes from csv-file<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> </span>
<span style="font-family:"Courier New"">r = {}<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> r = line.split(';') # 0 navn, 1 QVariant-type, 2 lengde og 3 presisjon<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> </span><span lang="EN-GB" style="font-family:"Courier New"">fname = r[0]<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> l = int(r[2])<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> p = int(r[3])<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> try:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> fields.append(QgsField(fname,set_variant(r[1]),'',l,p)) # add field to layer
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New""> </span>
<span style="font-family:"Courier New"">except:<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> print("Noe gikk galt - får ikke laget egenskaper fra " +str(f))<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">f.close() # close file<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Courier New"">create_blank_gpkg_layer(gpkg_reg, layer_name, geom, crs, fields, True) # Include True to add a new layer to the SAME gpkg-file<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">…<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Note the difference in the use of True and not when calling create_blank_gpk_layer().<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Perhaps something similar may be the solution to your problem.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Kind regards<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Anne<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
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