[postgis-users] Can you rebuild a multipolygon from rings?
strk at keybit.net
Fri Oct 21 00:17:03 PDT 2011
On Fri, Oct 21, 2011 at 01:33:43PM +0800, Ben Madin wrote:
> But rebuilding the multipolygons is not so simple (for me) - I need to re-aggregate the remaining rings into a geometry dump to reinsert into the other dumped polygons to rebuild the multipolygon.
> insert into phl (the_geom) select ((st_dump(the_geom))) from summ.ctybnda where year=2005 and ccode like 'PHL';
> insert into phl2 (the_geom) select st_dumprings(((the_geom).geom)) from phl where id = 2601;
You're stripping out the "path" component of output from st_dump
and st_dumprings. Those are the keys to your later rebuilding.
() Free GIS & Flash consultant/developer
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