Database Reference
In-Depth Information
b.geom, b.pop))) AS population FROM
zoo_bikezone AS a, census as b
WHERE
ST_Intersects(ST_Transform(a.the_geom, 3734),
b.the_geom)
GROUP BY a.id;
The output is as follows:
population
------------
167714
(1 row)
So,howdoestheprecedingoutputcomparetowhatwewouldgetifwelookatthe
buffered distance?
SELECT
ROUND(SUM(chp02.proportional_sum(ST_Transform(a.the_geom,3734),
b.the_geom, b.pop))) AS population FROM
(SELECT 1 AS id,
ST_Buffer(ST_Transform(the_geom, 3734), 21120)
AS the_geom FROM cleveland_ways_vertices_pgr
WHERE id = 165232) AS a,
census as b
WHERE
ST_Intersects(ST_Transform(a.the_geom, 3734),
b.the_geom)
GROUP BY a.id;
population
------------
2341662
(1 row)
