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Hi all,<BR>
<BR>
I need help with an unusual query (at least for me :] )<BR>
<BR>
The objective is to find road segments with a type defined to tunnel within a given distance.<BR>
This is needed because of gps signal spikes (speed-wise) at tunnel exits...<BR>
<BR>
Now given the following scenario of road segments:<BR>
<BR>
=====*-----------------*==========<BR>
====V===*========================* *======<BR>
=====*-----------------*==========<BR>
|<BR>
|<BR>
|<BR>
|<BR>
|<BR>
|<BR>
|<BR>
|<BR>
|<BR>
|==========-----------------------=======================<BR>
<BR>
= | road<BR>
- tunnel<BR>
* nodes<BR>
V vehicle<BR>
<BR>
Now when I execute a distance-based query (for road segments of tunnel type) I get the lower tunnel, which is closer.<BR>
But I want the upper one which is actually the one on the top.<BR>
<BR>
the actual query is as follows (tunnels (road type=67) within a 150 metres radius) -- the road map is in WGS84:<BR>
SELECT name, road_type FROM $road_net WHERE <BR>
transform(geometry,$srid) && setsrid(expand(transform(geomfromtext('POINT($lon $lat)',4326),$srid),150),$srid) <BR>
AND distance(transform(geomfromtext('POINT($lon $lat)',4326),$srid), transform(geometry,$srid)) <=150 AND road_type=67;<BR>
<BR>
Already thankful for any tips,<BR>
<BR>
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-- <BR>
Pedro Doria Meunier <<A HREF="mailto:pdoria@netmadeira.com">pdoria@netmadeira.com</A>>
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