[GRASS-user] GeoPackage and multiple tables

[Ken Mankoff]

Hello,

After learning from Markus & Moritz I see that the GPKG files are as they should be - vector features are not in triplicate. I think there are some strange QGIS import issues where it imports everything 3x but this is not a GRASS issue.

Thanks,

  -k.

On 2019-03-16 at 09:37 -0700, Moritz Lennert
<mlennert at club.worldonline.be> wrote...
> Le Sat, 16 Mar 2019 09:20:17 -0700, Ken Mankoff <mankoff at gmail.com> a
> écrit :
>
>> Hi Moritz [and Markus]
>> 
>> On 2019-03-16 at 08:24 -0700, Moritz Lennert
>> <mlennert at club.worldonline.be> wrote...
>> > Try running v.out.ogr three times, changing layer each time and
>> > using the -u flag for updating the existing gpkg file:
>> >
>> > v.out.ogr -c input=pal output_layer=pal1 output=pal.gpkg layer=1
>> > v.out.ogr -c input=pal output_layer=pal2 output=pal.gpkg layer=2 -u
>> > --o v.out.ogr -c input=pal output_layer=pal3 output=pal.gpkg
>> > layer=3 -u --o
>> 
>> That seems to work. When I then read in the GeoPackage and diff,
>> things look better.
>> 
>> v.in.ogr input=pal.gpkg output=pal2 --o diff <(v.db.connect -g pal)
>> <(v.db.connect -g pal2) # no major diff, but table name is not
>> preserved.
>> 
>> But the vector data is also included 3x now. This may be due to
>> v.patch? I'm adding Markus because he suggested the method to patch
>> different layers. After I patch the three layers:
>> 
>> rm -fR ./nc_spm_08_grass7/gpkg grass ./nc_spm_08_grass7/PERMANENT
>> g.mapset -c gpgk g.copy vector=poi_names_wake at PERMANENT,points g.copy
>> vector=lakes at PERMANENT,areas g.copy vector=railroads at PERMANENT,lines
>> v.category in=areas out=areas_2 op=chlayer layer=1,2 --o v.category
>> in=lines out=lines_3 op=chlayer layer=1,3 --o v.patch
>> in=points,areas_2,lines_3 output=pal --o
>> 
>> I would expect that v.info reports different information if I use the
>> "layer" option. But all three layers report IDENTICAL info. This diff
>> command is silent:
>> 
>> diff3 -A <(v.info pal layer=1) <(v.info pal layer=2) <(v.info pal
>> layer=3)
>
> By default v.info provides geometry information which is indeed the
> same, as the map contains all these geometries. IIUC, the layer option
> for v.info is meant for the v.info -c flag to decide which table's
> columns to display.
>
>> 
>> Also, the final export commands suggested by Moritz: Layers are
>> v.out.ogr -c input=pal output_layer=tbl_pts output=pal.gpkg layer=1
>> --o v.out.ogr -c input=pal output_layer=tbl_areas output=pal.gpkg
>> layer=2 -u --o v.out.ogr -c input=pal output_layer=tbl_lines
>> output=pal.gpkg layer=3 -u --o
>> 
>> seem to export everything 3x. This is based on 1) the message
>> "Exporting 15279 areas (may take some time)..." repeated each time 2)
>> the file size increasing by 12 MB each time, and 3) reading in,
>> displaying, and clicking brings up everything 3x in the "Query
>> Results" window.
>> 
>> Should I just keep my vectors and databases each as a separate vector
>> and not use layers?
>> 
>
> That is my fault: I shouldn't have used the -c flag. Try without it.
> You will see different feature counts in each layer when you run
>
> ogrinfo pal.gpkg -so pal1
>
> Moritz