2

I have

  1. a placename point table in postgis with 'district' column.

  2. a districts polygon shapefile with district name in 'Name' column. See the image below.

I would like to update the 'district' columns(in placename psql table) with the corresponding district name from the shapefile polygons in which each placename point feature reside.

How can I do this in QGIS? Or Is there any other way? enter image description here

5

Postgis way : (import polygon shape to postgis using shp2psql )

UPDATE points SET district = poly.district FROM poly WHERE ST_Within(points.geom, poly.geom)

see ST_Within

and i cant remember easy QGIS way , but its possible

  • Can we update multiple columns in single update query? like, "province" also.. – mapsir Mar 21 '14 at 11:49
  • See postgresql.org/docs/9.2/static/sql-update.html UPDATE points SET (district, province) = (poly.district, poly.province) FROM poly WHERE ST_Within(points.geom, poly.geom) That may work , didn't test. But it should be possible. – simplexio Mar 21 '14 at 13:48
  • Should I use any EPSG codes? If, yes, how? Point geom is in 900913. And poly geom does not show any. – mapsir Mar 24 '14 at 6:08
  • both need to be in same system (ST_SetSrid(geom, srid) can be used to set srid and ST_Transform(geom,srid ) can be used to transform to different projection – simplexio Mar 24 '14 at 7:40
  • should I add this along with the update query? – mapsir Mar 24 '14 at 9:02

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