[postgis-users] ST_NumPoints

Fred Lehodey lehodey at gmail.com
Fri May 22 02:07:07 PDT 2009


Kis,
"true news" here:
http://postgis.refractions.net/documentation/manual-1.3

Fred


2009/5/22 Kis János Tamás <kijato at gmail.com>

> Thank you!
>
> I read some false news  from:
>
> http://webhelp.esri.com/arcgisserver/9.3/dotNet/geodatabases/st_numpoints.htm
>
> Thx,
> kjt
>
> 2009/5/21, Fred Lehodey <lehodey at gmail.com>:
> > Hi,
> > try ST_npoints(geometry)
> > (ST_NumPoints(geometria) is only for linestring)
> >
> >
> > Fred
> >
> >
> >
> >
> > 2009/5/21 Kis János Tamás <kijato at gmail.com>
> >
> >> Hi,
> >>
> >> I have a big table (with 21000 rows):
> >>
> >> CREATE TABLE kecskemet_k.foldreszletek
> >> ( sorszam bigserial NOT NULL,
> >>  hrsz text,
> >>  geometria geometry --POLYGON
> >> ) WITH (OIDS=TRUE);
> >> CREATE INDEX i_foldreszletek_geometria ON kecskemet_k.foldreszletek
> >> USING gist (geometria);
> >>
> >> I'd like to know, how many point exists each geometry.
> >>
> >> When I use the next SQL:
> >>
> >> SELECT hrsz, round(ST_Area(geometria)), ST_NumPoints(geometria),
> >>              CASE WHEN ST_NumPoints(geometria) IS NULL THEN '-' ELSE
> >> else '+' END
> >> FROM kecskemet_k.foldreszletek
> >> ORDER BY 2 DESC
> >> LIMIT 10;
> >>
> >> the result is:
> >>   hrsz    | round | st_numpoints | case
> >> -----------+-------+--------------+------
> >>  0118/4    |  2913 |              | -
> >>  01521/172 | 21738 |              | -
> >>  0183/27   |  2877 |              | -
> >>  0855/53   |  5169 |              | -
> >>  0413/43   |  1025 |              | -
> >>  094/65    |  3130 |              | -
> >>  0747/2    |  2877 |              | -
> >>  01183/4   |   326 |              | -
> >>  01609/79  |  2737 |              | -
> >>  0801/163  |  1924 |              | -
> >> (10 rows)
> >>
> >> Why I got NULL value in the st_numpoints?
> >>
> >> thx,
> >> kjt
> >> _______________________________________________
> >> postgis-users mailing list
> >> postgis-users at postgis.refractions.net
> >> http://postgis.refractions.net/mailman/listinfo/postgis-users
> >>
> >
> _______________________________________________
> 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/20090522/e39bf852/attachment.html>


More information about the postgis-users mailing list