[postgis-users] Selecting polygons circled by one only polygons

[Randall, Eric]

You could try making a polygon out of the interior ring and using that with a within or contains:
 
st_buildarea(st_interiorringn(geometryn(geom,1),1))
 
-Eric

-----Original Message-----
From: postgis-users-bounces at postgis.refractions.net [mailto:postgis-users-bounces at postgis.refractions.net]On Behalf Of Andrea Peri
Sent: Thursday, October 28, 2010 6:07 AM
To: PostGIS Users Discussion
Subject: [postgis-users] Selecting polygons circled by one only polygons


Hi,

I have a table of polygon where every polygon can be holed.
And in the hole can be inside another polygon (another record of the table, no multipolygons).

I need to detect all the polygon that are inside a hole of another polygon.

Initially I think this was easy but
after some test I notice this is not so easy because the polygon inside the hole is formerly disjoint from the polygon with hole.

For more example I don't search the polygon that are full circled by more than 1 polygon, but only the polygon circled by 1 only polygon

There is some method to detect this type of situations ?


Thx,

Andrea peri.

-- 
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Andrea Peri
. . . . . . . . . 
qwerty àèìòù
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