[postgis-users] Extents

[Sean M. Montague]

This is what I have come up with.  It seems to work.  I am trying to get the extent of the selected geometries.  Not each individual extent.  Below is what best achieved it.  Thanks for the input, it got me working in the right direction.

 

SELECT AsText(box2d(GeomUnion(the_geom)))

>From trails_02a

WHERE objectid = 1 OR objectid = 2 OR objectid = 3;

________________________________

From: postgis-users-bounces at postgis.refractions.net [mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of René F. Viancos S.
Sent: Saturday, October 15, 2005 7:46 AM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] Extents

 

Try SELECT BOUNDARY(the_geom) From trails_02a WHERE objectid = 1 OR objectid = 2 OR objectid = 3;

Then AND condition makes always false the Query and never returns any recordset. Does not exists an element that has tree objectid in the same time. Think the AND operator like Intersection of elements and OR operator like the union of elements. Sorry, i dont see this before.

Regards


-- 
René F. Viáncos S.
Director de Geomática y TIC
Vicerrectoría de Investigación y Desarrollo
Universidad de Chile
Tel (56-2) 632 51 15
Cel (56 9) 933 72 66
rviancos at uchile.cl
rviancos at gmail.com
www.investigacion.uchile.cl 

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