[postgis-users] ST_Difference query returns a dissolved result

[Max Demars]

Hi!

I am using the ST_Difference to erase multipolygon feature by a mask.
However, the query returns a dssolved multipolygon.

The query is the following:

'''SELECT ST_AsGeoJSON(ST_Collect(geom))
::json
   FROM (SELECT (
     ST_Dump (

ST_Difference(ST_GeomFromGeoJSON('%s'),ST_GeomFromGeoJSON('%s')))).geom)
             As f''' % (feature,mask)

Please take a look at those images above to understand the problem:

Input: http://i.stack.imgur.com/QO4MN.png
Output: http://i.stack.imgur.com/Slw32.png

Thank you all,
-Max Demars
-- 
Stack Overflow: http://stackoverflow.com/users/1914034/burton449
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