Testes_PostGIS_Raster

testes_postgis_raster.sql

/*

value = classe de capacidade na tabela vetorial

pixel_value = classe de capacidade ma tabela raster

*/

-- Abordagem tradicional (vetor/vetor):
SELECT foo.value, ST_area(foo.geom::geography)/10000 AS area_ha
 FROM ( SELECT c.value,
               ST_Union(ST_Intersection(f.geom, c.geom)) as geom
        FROM fazendas f, capacidade_vect c
        WHERE  ST_Intersects(f.geom, c.geom)
        AND f.gid = 6
        GROUP BY c.value
       ) as foo
ORDER BY foo.value;

-- PostGIS Raster (vetor/raster):
SELECT tmp.pixel_value, ST_area(Geography(ST_Union(ST_Intersection(f.geom, tmp.geom))))/10000 AS area_ha
FROM fazendas f,(
		 SELECT (ST_DumpAsPolygons(ST_Clip(c.rast, ST_Buffer(f.geom, 0.01), TRUE))).val AS pixel_value,
		        (ST_DumpAsPolygons(ST_Clip(c.rast, ST_Buffer(f.geom, 0.01), TRUE))).geom AS geom
		 FROM fazendas f, capacidade_rast c
		 WHERE  ST_Intersects(ST_Buffer(f.geom, 0.01), c.rast)
		 AND f.gid = 6
		) AS tmp
WHERE  ST_Intersects(f.geom, tmp.geom)
GROUP BY tmp.pixel_value
ORDER BY tmp.pixel_value;