Opened 7 years ago

Last modified 6 years ago

#3248 closed defect

v.external: mixed up IDs from PostGIS tables — at Version 1

Reported by: sbl Owned by: grass-dev@…
Priority: normal Milestone: 7.2.3
Component: Vector Version: 7.0.5
Keywords: v.external Cc:
CPU: Unspecified Platform: Unspecified

Description (last modified by martinl)

I tried to link a PostGIS table to GRASS GIS 7 for point sampling using v.external (in GRASS 7.0.6 and GRASS 7.2.1svn).

With that linked layer (which is not in public schema and has column "point_id" as primary key) I get a lot of:

WARNING: No record for category XXXX in table
         <myschema.points>

when I use v.what.rast on that layer.

The results suggest that not the proper IDs were used when values were loaded to attribute table. Because values in the attribute table of the points do not match with values in the raster at point locations. Furthermore, some points, which are supposed to have values in the attribute table, have none...

With the attaced data, the issue can be reproduced like this:

ogr2ogr -f PostgreSQL "PG:dbname=gisdata schemas=myschema" points.sqlite points
v.external --overwrite input=PG:dbname=gisdata layer=points output=points_pg -o
g.region -p -a vector=points_pg res=250
r.random.surface --overwrite --verbose output=rand
v.what.rast map=points_pg raster=rand column=morphology

Linking the SQLite data source however seems to work fine. No errors for:

v.external --overwrite input=points.sqlite layer=myschema.points output=points_sqlite -o
v.what.rast map=points_sqlite raster=rand column=morphology

This is my PostGIS / GRASS environment:

PostgreSQL 9.5.2 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 4.8.2-19ubuntu1) 4.8.2, 64-bit
POSTGIS="2.2.2 r14797"
GEOS="3.5.1-CAPI-1.9.1 r4171"
SFCGAL="1.3.0"
PROJ="Rel. 4.9.2, 08 September 2015"
GDAL="GDAL 2.0.3, released 2016/07/01"

For discussion see: https://lists.osgeo.org/pipermail/grass-dev/2017-January/083807.html

Change History (2)

by sbl, 7 years ago

Attachment: points.sqlite added

example points

comment:1 by martinl, 7 years ago

Description: modified (diff)
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