Multiple Ring Buffer with PostGIS

MultipleRingBufferPostGIS.sql

--using set returning function generate_series
--https://www.postgresql.org/docs/9.1/static/functions-srf.html
WITH buffer_values as (
	SELECT * FROM generate_series(5, 20, 5) AS dist
)

SELECT 
	CAST(p.id AS INT), p.name, b.dist, ST_Buffer(p.geom, b.dist) AS Poly 
FROM 
	nyc_subway_stations p
CROSS JOIN 
	buffer_values b
WHERE
	p.id < 10
ORDER BY 
	p.id, b.dist;