postgispostgresqlqgisshapefile
I have
a placename point table in postgis with 'district' column.
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?
Excellent answers provided by @ChrisW and @CAccesible, both describe techniques which should do what you want. Just to add on what @ChrisW mentioned, a spatial join tool called Join by location would provide your points layer with another attribute column containing the names of the polygon it resides in, regardless of how many points there are in a polygon. I use this function many times with the following parameters to obtain results similar to what you want:
I propose to split this task in three steps:
To import the shapefile in a temporary table (e.g. you call it temp) you can use a tool like shp2pgsql. It is included in the PostGIS installation. A tutorial is here avaible.
The following statement will update the geom column of your existing table city_data with the geom from the table temp.
UPDATE city_data a
SET a.geom = b.geom
FROM temp b
WHERE a.city_id = b.city_id;
At the end delete the table temp.
DROP TABLE temp;
Best Answer
Postgis way : (import polygon shape to postgis using shp2psql )
see ST_Within
and i cant remember easy QGIS way , but its possible