How to Assign a Column Value from a Polygon to a Point

Learn how to assign a polygon attribute to intersecting points.

Overview

Assigning column values from a polygon dataset to the points that intersect them is a common geospatial task. This requires using the ST_Intersects PostGIS function to match points with their containing polygons.

Solution

Use an inner join query with the spatial intersection function:

SELECT pois.*,
       polys.column
  FROM table_points pois
INNER JOIN table_polygons polys
        ON ST_Intersects(
               pois.the_geom,
               polys.the_geom
           )

This query selects all point attributes and adds the desired polygon column by joining tables where the point geometry intersects the polygon geometry.