[mapguide-users] Insert Order In MySql Affect to the MapGuideSelection?

[ary sucaya]

http://trac.osgeo.org/mapguide/ticket/313 is not what i'm seeing now. That's another problem of multipolygon. What i don't understand is why the sequence of records insertion affect MGOS select behaviour? If MySql perform geometric operation only on their bounding box, then 'my selection problem' will always happens even i change the sequence of records insertion 

Ary Sucaya



----- Original Message ----
From: Jason Birch <Jason.Birch at nanaimo.ca>
To: MapGuide Users Mail List <mapguide-users at lists.osgeo.org>
Sent: Thursday, November 29, 2007 9:18:39 PM
Subject: RE: [mapguide-users] Insert Order In MySql Affect to the MapGuideSelection?


There is an error in MapGuide with multipolygon selection
 
http://trac.osgeo.org/mapguide/ticket/313
 
but I don't believe that this is what you are seeing, or at least not the only reason...
 
I think that the primary problem that you are seeing is because MySQL does not perform geometric operations on geometries, just their bounding boxes.  My understanding is that someone is working on this for a future MySQL release, but it's a ways out yet?
 
Jason




From: ary sucaya
Subject: [mapguide-users] Insert Order In MySql Affect to the MapGuideSelection?


I'm not sure either this is a problem of MySql or MGOS 1.2. I created some multipolygon in MySql 5.0.45 and I found a problem regarding to interactive selection:
Some of my multipolygon selected when i clicked my mouse outside it's boundary. Furthermore, MGOS give me a wrong selection result, for example, if i do click on a small multipolygon A then the big multipolygon B would be selected. It's look like the biggest part of small mpolygon A occupied by the big mpolygon B. I made a little bit experiment on this issue. I change the order of records insertion meaning that i insert the smallest multipolygon first and bigger multipolygon subsequently and the problem is gone. This problem doesn't happen if i store the data in sdf format instead of MySql. What's wrong with MySql (or probably MGOS 1.2)?


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