[mapguide-users] RE: Spatial Query

[Dave Wilson]

Oracle may have an SDO_NN (nearest neighbor) type call. I'm not sure about SQL Server. MG doesn't have a closest spatial operator, that would be a good wishlist item.

Dave

From: mapguide-users-bounces at lists.osgeo.org [mailto:mapguide-users-bounces at lists.osgeo.org] On Behalf Of Berdel, Brian
Sent: Wednesday, June 17, 2009 6:09 PM
To: 'MapGuide Users Mail List'
Subject: [mapguide-users] RE: Spatial Query

Thanks for the reply, I will try that approach and see how it turns out.  It does seem like it may be pretty taxing and slow with a lot of points to keep looping different circles around them (I forgot to explain there would be a lot).  Is there anything in the API for "closest" ? Just to get the ID of the segment?  I actually don't need to select them.   I was also going to check into SQL spatial to see if there is any way to do it as well.  Thanks

Brian


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From: mapguide-users-bounces at lists.osgeo.org [mailto:mapguide-users-bounces at lists.osgeo.org] On Behalf Of Dave Wilson
Sent: Wednesday, June 17, 2009 4:54 PM
To: MapGuide Users Mail List
Subject: [mapguide-users] RE: Spatial Query

You could do a spatial query using a circle in a loop continually increasing the radius each time until you get a result. Setting the initial radius and the increments of the circle probably depends on the coordinate system of the data although this is similar to the logic in the selection for a click select in the AJAX Viewer so you could start with that.

Dave

From: mapguide-users-bounces at lists.osgeo.org [mailto:mapguide-users-bounces at lists.osgeo.org] On Behalf Of Berdel, Brian
Sent: Wednesday, June 17, 2009 2:17 PM
To: MapGuide Users Mail List
Subject: [mapguide-users] Spatial Query

What is the best approach to performing a spatial query as such that a road segment closest to a point is selected?  Any examples out there?  Not sure if OpenLayers or Mapguide Api would be best, but appreciate any suggestions.

Thanks!

Brian


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Important notice to recipients:
Copies of documents that may be relied upon by you are limited to the printed copies (also known as 'hard copies') that are signed and sealed by the Engineer and/or Land Surveyor. Files in electronic formats, or other types of information furnished by the Engineer and/or Land Surveyor to you such as text, data or graphics are for your convenience only. Any conclusions or information obtained or derived from such electronic files will be at the user's sole risk. When transferring documents in electronic formats, the Engineer and/or Land Surveyor makes no representation as to long-term compatibility, usability, or readability of the documents resulting from the use of software application packages, operating systems or computer hardware differing from those used by McMahon Associates, Inc. at the beginning of the project.
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