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List: postgis-users
Subject: Re: [postgis-users] Polygon from MultiPolygon
From: Leknín Řepánek <godzilalalala () gmail ! com>
Date: 2016-02-17 20:12:37
Message-ID: 20160217201235.GA573 () gmail ! com
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Shapefile don`t make difference between multi/single part geometries.
In postgis you can dissolve multipart geometries using ST_Dump.
ST_Dump records record vith geom and path in collection. You should use
somethink like this
SELECT (ST_Dump(geom)).* FROM table
Or ST_GeometryN to obtain n-th geometry from collection/multipart.
ST_GeometryN(geom, 1) returns first geometry of collection/multipart
geometry.
To obtain Exterior Ring of polygon you could use ST_ExterioirRing
for obtain boundary is function ST_Boundary.
On Wed, Feb 17, 2016 at 07:30:26PM +0000, Mustafa Elbehery wrote:
> Hi Folks,
>
> I have create a shapeFile using Vector layer in QGIS .. I have chosen polygon
> type, but the shapeFile contains Multipolygon ..
>
> I am interested only on the Boundary or the outer polygon .. How to capture
> this from Multipolygon ?!!
>
> Regards.
> _______________________________________________
> postgis-users mailing list
> postgis-users@lists.osgeo.org
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