Sorry, I read too quickly. I suggested what you tried ;) what query are you running and what are your data to obtain multipolygons ?
Nicolas On 26 April 2012 17:32, Nicolas Ribot <nicolas.ri...@gmail.com> wrote: > Hi, > > As Julien suggested, you could st_dump to explode multipolygons into > polygons, then union them. > It will produce a single polygon unioning all others: > > with t as ( > select (st_dump(geom)).geom > from my_table > ) select st_union(geom) from t; > > Nicolas > > > On 26 April 2012 17:22, Mehmet Erkek <mer...@reidin.com> wrote: > >> Hi Juilen, thanks for quick answer. **** >> >> ** ** >> >> I have 1 geometry and 1 row on the table. this geometry is multiploygon >> which consists of 4 polygons.**** >> >> I want to convert this mutlipolygon to one single polygon..**** >> >> ** ** >> >> Any idea how I can do this?**** >> >> I hope it is clearer now.**** >> >> ** ** >> >> Thanks.**** >> >> ** ** >> >> ** ** >> >> *From:* postgis-users-boun...@postgis.refractions.net [mailto: >> postgis-users-boun...@postgis.refractions.net] *On Behalf Of *ju >> *Sent:* 26 Nisan 2012 18:02 >> *To:* PostGIS Users Discussion >> *Subject:* Re: [postgis-users] [!! SPAM] multipolygon to single polygon** >> ** >> >> ** ** >> >> not clear... >> >> 1) if you have 4 polygons in 4 rows table distinct, this is not a multi >> object issu. for this case use >> dissolve to group polygone into only one, this is not a topic of dump. >> >> >> 2) if you have 1 geometry and 1 row on the tablme, so this is a multi >> object topic >> you must sperate the differents objet of the collection >> >> here : http://www.postgis.org/docs/ST_GeometryN.html**** >> >> --Extracting all geometries (useful when you want to assign an id)**** >> >> SELECT gid, n, ST_GeometryN(the_geom, n)**** >> >> FROM sometable CROSS JOIN generate_series(1,100) n**** >> >> WHERE n <= ST_NumGeometries(the_geom);**** >> >> >> best regards, julien >> >> >> >> Le 26/04/2012 16:27, Mehmet Erkek a écrit : **** >> >> **** >> >> I have multipolygons which I would like to convert a single polygon. is >> there a way to do this? please check the attached image. I tried st_dump >> and afterwards st_union , but eventually I get a multipolygon again, not >> polygon. **** >> >> **** >> >> **** >> >> **** >> >> **** >> >> *Mehmet Erkek***** >> >> www.REIDIN.com <http://www.reidin.com/> **** >> >> **** >> >> >> This message is for the designated recipient only and may contain >> privileged, proprietary, or otherwise private information. If you have >> received it in error, please notify the sender immediately and delete the >> original. Any other use of the email by you is prohibited. Please Consider >> the Environment Before Printing This Email >> >> >> **** >> >> _______________________________________________**** >> >> postgis-users mailing list**** >> >> postgis-users@postgis.refractions.net**** >> >> http://postgis.refractions.net/mailman/listinfo/postgis-users**** >> >> >> >> **** >> >> -- **** >> >> Julien-Pierre Guilloux**** >> >> Service scientifique - Géomatique**** >> >> Parc National des Ecrins**** >> >> Domaine de Charance**** >> >> 05 000 GAP**** >> >> tél : 04.92.40.20.10**** >> >> fax : 04.92.52.38.34**** >> >> julien.guill...@ecrins-parcnational.fr**** >> >> >> This message is for the designated recipient only and may contain >> privileged, proprietary, or otherwise private information. If you have >> received it in error, please notify the sender immediately and delete the >> original. Any other use of the email by you is prohibited. Please Consider >> the Environment Before Printing This Email >> >> _______________________________________________ >> postgis-users mailing list >> postgis-users@postgis.refractions.net >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> >> >
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