Hello Aurora, In ArcGIS it's all different. In PostGIS you can use simple/complex SQL queries to "calculate values" in a similar fashion of arcgis.
The simplest of them all would be, in your case: ALTER TABLE table1 ADD COLUMN area_column double precision; UPDATE table1 SET area_column = ST_AREA(the_geom); You can in that SQL query divide, multiply, and do whatever you want with that result that will be written to the column area_column. I hope that helps George On Fri, Apr 3, 2009 at 12:55 PM, Aurora Geomatics <aurorageomat...@gmail.com > wrote: > Hello PostGIS users, > > I have just installed William Kyng's PostgeSQ/PostGIS packages for Mac OS > X.5 > > I have been playing with pgAdmin and QGIS with importing shapefiles into > PostGIS. Works dandy. > > Now I am wondering how to solve Attribute Calculations. > > Years of using ArcGIS and GRASS it is pretty straightforward on those apps, > and am stumped with PostGIS Attribute calculations.. > > For example, using a polygon feature; > > Creating a new column, say AREA and filling with a calculation that is > Hectares. > > Thanks! > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users >
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