28

I'd like to do a GeoJSON dump of a PostGIS table, but I want to export features (the geometry and the properties) not just the geometry. I've been digging into the ST_AsGeoJSON function but it looks like I can only get the coordinate information (which makes sense since it's a geometry function).

For example:

select st_asgeojson(the_geom) from street_centerline limit 1;

Returns:

{"type":"MultiLineString","coordinates":[[[-65.591776562805038,41.682190576167052],[-65.591998971284028,41.682082119060382],[-65.592001213509064,41.682081025737766],[-65.593689871787177,41.681257533373952],[-65.595415661879244,41.680415888937219],[-65.595440519465640,41.680403765889309],[-65.595603134242481,41.680324459445771]]]}

I'm curious if anyone knows of a simple way to get the property information as well. Has anyone written a pgsql2geojson script yet?

1
  • Is PostGIS able to leverage the improvements in PostgreSQL 9.2? As postgres now natively supports 9.2, is anyone aware of a similar development in PostGIS? Would be nice to do without the ogr2ogr segway.
    – user12212
    Oct 24, 2012 at 14:53

3 Answers 3

29

For completeness here's an actual example with ogr2ogr:

ogr2ogr -f GeoJSON out.json \
  "PG:host=localhost dbname=gis user=ubuntu password=toomanysecrets" \ 
  -sql "select way,name,amenity from planet_osm_point a where a.amenity is not null"

Make sure your user has read access to the geometry_columns table.

Specifically:

GRANT SELECT ON geometry_columns to ubuntu;
GRANT SELECT ON geography_columns to ubuntu;
GRANT SELECT ON spatial_ref_sys to ubuntu;
2
  • I'm curious about this output. I mean, since this is required to output geojson files, isn't the output have to be out.geojson and not out.json ??? I'm new to this. Thank you
    – Stefanos
    Feb 1, 2017 at 18:55
  • 2
    Well, that's just the filename. There isn't really a standard on that - some systems expect .json (because, well, they are JSON files), other systems expect .geojson, others don't care. Feb 2, 2017 at 4:50
28

Just to provide info on an old question if someone encounters this:

as of PostgreSQL 9.5+

SELECT jsonb_build_object(
    'type',     'FeatureCollection',
    'features', jsonb_agg(feature)
)
FROM (
  SELECT jsonb_build_object(
    'type',       'Feature',
    'id',         gid,
    'geometry',   ST_AsGeoJSON(geom)::jsonb,
    'properties', to_jsonb(row) - 'gid' - 'geom'
  ) AS feature
  FROM (SELECT * FROM input_table) row) features;

Taken from full original answer here

3
  • 3
    WHAT THE ACTUAL F... I've looked for years for a way to perform a SELECT * EXCEPT COLUMNS (a,b) and you had the answer all along...
    – ffflabs
    Feb 8, 2019 at 16:23
  • 1
    omg. Justa came across this, to_jsonb(row) - 'gid' - 'geom' is gold
    – arredond
    Oct 22, 2021 at 11:41
  • I'm having some problems with the - operator ("Delete key/value pair or string element from left operand"). But it's working well with the related #- operator. That is, I'm using: to_jsonb(row) #- '{gid}' #- '{geom}' Jan 26 at 18:40
19

Here is an obvious solution to my own question - ogr2ogr! I'm not sure why I didn't think of it sooner. It has both PostGIS and GeoJSON drivers so this should work great.

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