[postgis-users] dissolve function

[Nelson Guda]

I was so pleased to find this dissolve function from strk at keybit.net  
among the old posts.  Is there any way that it could be added to the  
online documentation?

In fact, it would be really great if there could be a section in the  
documentation for custom functions such as this.  These are the sort  
of tools that really ramp up the usefulness of postgis.

Thanks,
nelson


CREATE AGGREGATE unite (
         sfunc = GeomUnion,
         basetype = geometry,
         stype = geometry
); -- this creates an aggregate out of GEOS's geomunion()

-- and this is your query 
SELECT your_attribute, unite(the_geom)
	FROM your_table
	GROUP BY your_attribute;
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