[gdal-dev] Merge all features in polygon shapefile with gdal

Steven Lutz steven at ruggedrocksoffroad.com
Mon Jul 6 16:13:24 PDT 2015

I've found some examples of how to dissolve features in a polygon using 
gdal but I'm not familiar with how to implement them.
here is an example of what I've found, but I'm having trouble modifying it

this is what I've come up with:

|ogr2ogr output.shp input.shp -dialect sqlite -sql
"SELECT ST_Union(geometry), dissolve_field FROM input GROUP BY dissolve_field"|

it looks to me that it is trying to do this operation based on specific 
attribute entries but I'm looking to ignore the attribute entrie and 
make all features into one.
This is what I've tried:
the 32768.shp has an attribute named BLOCK and it's still not working.. 
any ideas? >ogr2ogr -f "ESRI Shapefile" output.shp 32768.shp -dialect 
sqlite -sql "select ST_union(block) from '32768'" Warning 6: 
Normalized/laundered field name: 'ST_union(block)' to 'ST_union(b

I am confused as to what I should be putting in the parenthasis of 

Please advise.
Thank you

Steven Lutz
Rugged Rocks, LLC
Sales & Support: (909)547-4651
Nissan 4x4 Parts <http://ruggedrocks.com> / Off Road GPS Units & Maps 
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