How to generate one geojson file from several rows in Postgres/PostGIS?

Question

I have a table with geospatial objects, in particular, polygons. I know that I can generate from one row a geoJSON string using ST_AsGeoJSON(http://www.postgis.org/docs/ST_AsGeoJSON.html). But I would like to generate one geoJSON from all the table. Is this possible? How can I do it?

Thanks in advance

Answer 1

Already make a comment but in addition if you choose OGR2OGR, the way to export to GeoJSON is the following:

If you want to keep original SRS

ogr2ogr -f "GeoJSON" yourdataoutputname.geojson PG:"host=localhost user=username dbname=yourdatabasename password=yourpassword" "yourpostgistable"

If you want to convert to default SRS for GeoJSON (EPSG 4326)

ogr2ogr -f "GeoJSON" yourdataoutputname.geojson -t_srs EPSG:4326 PG:"host=localhost user=username dbname=yourdatabasename password=yourpassword" "yourpostgistable"

Answer 2

i think, you need generate row by row with this function ST_AsGeoJSON or export database/table with org2ogr