[postgis-users] [!! SPAM] multipolygon to single polygon

[Nicolas Ribot]

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.ribot at 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 <merkek at 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-bounces at postgis.refractions.net [mailto:
>> postgis-users-bounces at 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 at 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.guilloux at 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 at postgis.refractions.net
>> http://postgis.refractions.net/mailman/listinfo/postgis-users
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20120426/8f29b28f/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 11627 bytes
Desc: not available
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20120426/8f29b28f/attachment.png>