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<div>sorry strk, you are right</div>
<div> </div>
<div>I was mixing symdifference with something else in my head.</div>
<div>Both should work</div>
<div> </div>
<div>Sorry</div>
<div>/Nicklas<br />
<br />
2009-04-28 strk wrote:<br />
<br />
On Tue, Apr 28, 2009 at 03:16:04PM +0200, Malm Paul wrote:<br />
>> Hi,<br />
>> I have 2 polygons (rectangeles) p1 and p2, they intersect each other.<br />
>> I would like to select all geometries within p1 excluding all geometries within p2.<br />
>> <br />
>> How can I do this with postGIS and SQL ?<br />
><br />
>I suggest you first get p3 as difference(p1, p2),<br />
>then use ST_intersect on p3 and your geom column.<br />
><br />
>You should be careful in the way you construct the query <br />
>so that difference() is computed only once, and make sure<br />
>the gist index is used by ST_intersect.<br />
><br />
>--strk;<br />
><br />
> Free GIS & Flash consultant/developer () ASCII Ribbon Campaign<br />
> http://foo.keybit.net/~strk/services.html /\ Keep it simple! <br />
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