RE: [postgis-users] An I/O error occured while sending to the backend

hi mark, hi list, i have a problem with running these querys: SELECT AddGeometryColumn('public','_g2994','the_geom_1','4326','MULTIPOLYGON',2); ALTER TABLE _g2994 DROP CONSTRAINT enforce_geotype_the_geom_1; ALTER TABLE _g2994 ADD CONSTRAINT enforce_geotype_the_geom_1 CHECK

[postgis-users] what function to dissolve data?

Hi, i want to simplify my data by dissolving lines (borders) between Polygons (the polygons share one line or at least one point) with the same attributes to get a smaller dataset and i did not find a function for that operation (so far). For example i have one million polygons with the same

RE: [postgis-users] what function to dissolve data?

Andreas, I have used the following query with varying degrees of success (that is, sometimes the memory requirements seem to be too much, and it takes forever to complete). The resulting shape occasionally renders strangely in Qgis. SELECT landuse_name, memgeomunion(the_geom) GROUP BY

Re: [postgis-users] what function to dissolve data?

And if that won't do, consider exporting the data to a well known GIS format and operate a join in the GIS. After joining, you can then upload the data back into a table and perform joins and so with postGIS Burgholzer,Robert schreef: Andreas, I have used the following query with varying

[postgis-users] Remove a geometry from a multi feature

All, I have a multipolygon feature that has 12 parts, a couple of which are bad. How can I remove just these geometries and keep the rest as one multi feature? The bad ones are hundreds of miles away from the good ones, so I would like to do something like remove all geomtries from feature x

RE: [postgis-users] monthly climate query

avgpar, FROM weather eliminate the comma. Robert W. Burgholzer Surface Water Modeler Office of Water Supply and Planning Virginia Department of Environmental Quality [EMAIL PROTECTED] 804-698-4405 Open Source Modeling Tools: http://sourceforge.net/projects/npsource/ Web-Based Water

RE: [postgis-users] Remove a geometry from a multi feature

Thanks, that worked very well.broke it apart to a temp table, did a COLLECT for the good features, and updated the original table. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Stephen Woodbridge Sent: Wednesday, August 15, 2007 2:58 PM To: PostGIS

RE: [postgis-users] An I/O error occured while sending to the backend

On Wed, 2007-08-15 at 15:45 +0200, Stefan Zweig wrote: hi mark, hi list, i have a problem with running these querys: SELECT AddGeometryColumn('public','_g2994','the_geom_1','4326','MULTIPOLYGON',2); ALTER TABLE _g2994 DROP CONSTRAINT enforce_geotype_the_geom_1; ALTER TABLE _g2994

[postgis-users] Extracting a line from multilinestring

Hey all, Does anyone if there is a way to extract a line from a MultiLineString? I am trying to make the call SELECT line_interpolate_point(the_geom,line_locate_point(the_geom,PointFromText ('POINT(-74.5 40)'))) FROM roads ORDER BY Distance(the_geom,PointFromText('POINT(-74.5 40)'))

Re: [postgis-users] Extracting a line from multilinestring

Hi Brian... I think you can do one of this things: 1. If you are sure that all your geometries have just one LINESTRING then you can do: SELECT line_interpolate_point(GeometryN(the_geom,1),line_locate_point(GeometryN(the_geom,1),PointFromText('POINT(- 74.5 40)'))) FROM roads ORDER BY

RE: [postgis-users] Extracting a line from multilinestring

Thank you very much. From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rodrigo Martín LÓPEZ GREGORIO Sent: Wednesday, August 15, 2007 5:44 PM To: PostGIS Users Discussion Subject: Re: [postgis-users] Extracting a line from multilinestring Hi