[postgis-users] exterior rings in multipolygons

[Mr. Puneet Kishor]

On Jul 26, 2011, at 9:34 AM, Sandro Santilli wrote:

> On Tue, Jul 26, 2011 at 09:31:50AM -0500, Mr. Puneet Kishor wrote:
> 
>> 	ERROR:  function st_interiorringn(geometry) does not exist
> 
> Check your parens, the call above is missing a parameter (ring number).
> 

That is a bit embarrassing. Yes, I had missed out on giving the ring number. However, still no luck --

SELECT objectid, 
	ST_NRings(the_geom) num_of_rings, 
	ST_NumInteriorRings(the_geom) num_of_int_rings, 
	ST_NumPoints(ST_ExteriorRing(ST_GeometryN(the_geom,1))) num_of_points_ext_ring,
	ST_AsText(the_geom) wkt_feature, 
	ST_AsText(ST_MakePolygon(ST_ExteriorRing(ST_GeometryN(the_geom, 1)))) wkt_ext_ring,
	ST_AsText(ST_MakePolygon(ST_InteriorRingN(ST_GeometryN(the_geom, 2), 2))) wkt_int_ring_a,
	ST_AsText(ST_MakePolygon(ST_GeometryN(the_geom, 2))) wkt_int_ring_b
FROM table 
WHERE objectid = 280;

objectid: 280;
num_of_rings: 4;
num_of_int_rings: 3;
num_of_points_ext_ring: 496;
wkt_feature: "MULTIPOLYGON(((<1>),(<2>),(<3>),(<4>))";
wkt_ext_ring: "POLYGON((<1>))";
wkt_int_ring_a: "";
wkt_int_ring_b: ""

As you see, I tried to get the interior ring "n" two different ways. Not getting anywhere.

Puneet.