[Qgis-user] How to load postgis layer without gid (if possible..)?

[aho]

Hi Pietro,

I had the same in a project with a view. Solved it by using the function 
row_number which can be used as long as it is a usual integer:

CREATE OR REPLACE VIEW cadastre.districtviewAS

SELECT row_number() OVER (ORDER BY d.gid)::integer AS no, 
d.districtcode, d.geom, count(p.gid) ascountfromtopo.districtd
LEFT JOIN cadastre.parcelp ON substring(p.villagecodefrom1 for4) = 
d.districtcodeGroup byd.districtcode, d.geom, d.gid;


so something like:
select row_number() over(order by geom)::integer as no, 
ST_Union(ST_Buffer(geom,500) ) as geom from public.mytable group by geom;

should also work.




Am 11/7/2012 8:38 AM, schrieb Pietro Rossin:
> Hi all
>
> I tried to load in Qgis, by using fast SQL layer, a query like this:
>
> SELECT (select ST_Union(ST_Buffer(geom,500)) FROM public.mytable) as geom;
>
> This query make a buffer of the features in mytable and union them in a
> single polygon (if contiguous).
>
> It works in pgadmin and in openjump but not in Qgis, because Qgis need a
> unique value (integer) column coming from the query.
>
> Of course I can make a SELECT INTO mynewtable adding a serial field "gid",
> but if I have a lot of steps to perform my spatial analysis I fill my db
> with a lot of temp data.
>
> So, is there some way to make a "volatile" integer unique field in the above
> query so Qgis will be happy with it ;-)?
>
> I'm using Qgis 1.8 Postgis 2
>
> Thanks
> Pietro
>
>
>
> --
> View this message in context: http://osgeo-org.1560.n6.nabble.com/How-to-load-postgis-layer-without-gid-if-possible-tp5014459.html
> Sent from the Quantum GIS - User mailing list archive at Nabble.com.
> _______________________________________________
> Qgis-user mailing list
> Qgis-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-user

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20121107/8306a52b/attachment.html>