[Mapserver-users] Virtual Spatial Data Wiki Question

[Frank Warmerdam]

Nikolai Schwertner wrote:
> Hi all,
> 
> I am following the instructions from the wiki on "Virtual Spatial Data" to
> create a virtual layer from an ODBC data source (under Windows 2000). The
> OVF file works great with ogrinfo.exe, but fails with the following message
> when I try to load it in MapServer:
> 
>   msDrawMap(): Image handling error. Failed to draw layer named 'sb_pt'.
>   msOGRFileOpen(): OGR error. Open failed for OGR connection
> `w:\app\virtual.ovf'. File not found or unsupported format.
> 
> Past posts suggest that this problem may be related to the permissions of
> the Apache user over the OVF file. I don't think that this is the problem in
> this case. All permissions are in order and Apache has no problem accessing
> the file.
> 
> I will appreciate any suggestions regarding this problem.

Nikolai,

The other very common reason is when people have a new GDAL/OGR, but
an old MapServer.  For complex reasons, on windows it isn't enough to
update the GDAL11.DLL to make MapServer use a newer version of GDAL/OGR.
MapServer needs to be relinked.

Also, ensure you are using ODBC System DSNs, not User DSNs.  Otherwise the
user the web server (and MapServer) runs as won't see the DSN.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent