[Gdal-dev] OGR and Python. Accessing spatial data from non-spatial
tables
Frank Warmerdam
warmerdam at pobox.com
Fri Feb 16 19:07:30 EST 2007
Sampson, David wrote:
> Hey Folks,
>
> I'm looking for help using OGR and python. I am pretty novice with
> python at this stage so I think I am loosing sight of what objects need
> to be made. Some guidance would be great.
>
> I am trying to create polygons (rectangles) from an ODBC connection to a
> non-spatial table.
>
> In all I need to access 8 collumns (x and y for four points)
>
> Each polygon is defined by a single row
>
> Groups of rows exist based on a SEGMENT collumn. Each group could have
> upwards of 100 polygons.
>
> This is some of the code I have been working on
Dave,
This script will read a table from an OGR datasource and fetch the
fields you name. In your case instead of test.csv you will want
something like:
"ODBC:" + UID + "/" + PW + "@" + DSN + "," + TBL
But you don't need to open each column seperately.
"""
import ogr
ds = ogr.Open('test.csv')
lyr = ds.GetLayerByName('test')
feat = lyr.GetNextFeature()
while feat is not None:
nw = (float(feat.X_NO),float(feat.Y_NO))
ne = (float(feat.X_NE),float(feat.Y_NE))
sw = (float(feat.X_SO),float(feat.Y_SO))
se = (float(feat.X_SE),float(feat.Y_SE))
print nw, ne, sw, se
feat = lyr.GetNextFeature()
"""
Best regards,
--
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I set the clouds in motion - turn up | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush | President OSGeo, http://osgeo.org
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