[FWTools] case sensitivity in ovf?

David Fawcett david.fawcett at gmail.com
Tue Apr 4 12:21:19 EDT 2006

I have gdal 1.3.1 on my desktop Win32 box and on a linux server.  I am using
a virtual datasource to connect to a MySQL database.

On my desktop, I can successfully get the layer from the database using the
following .ovf file.


    <OGRVRTLayer name="aqidata">

    <GeometryField encoding="PointFromColumns" x="x" y="y"/>


Here is the returned data including the first two features:

C:\CFusionMX7\wwwroot\aqi>ogrinfo newlocal.ovf -al
ERROR 4: Update access not supported for VRT datasources.
Had to open data source read-only.
INFO: Open of `newlocal.ovf'
using driver `VRT' successful.

Layer name: aqidata
Geometry: Point
Feature Count: 9
Extent: (278128.625000, 4874412.500000) - (747461.095000, 5317595.030000)
Layer SRS WKT:
areaID: String (10.0)
x: Real (0.0)
y: Real (0.0)
sampleValue: Integer (0.0)
  areaID (String) = 2
  x (Real) = 282951.219
  y (Real) = 5188779.5
  sampleValue (Integer) = 20
  POINT (282951.21899999998 5188779.5 0)

  areaID (String) = 1
  x (Real) = 407618.438
  y (Real) = 5134528.5
  sampleValue (Integer) = 20
  POINT (407618.43800000002 5134528.5 0)

I edit this file, changing only the user, password, and host to match the
database user on the server, and it does not work with ogrinfo on the
server.  A little redundant, but here is the .ovf.


    <OGRVRTLayer name="aqidata">
    <GeometryField encoding="PointFromColumns" x="x" y="y"/>


The error that I get is:
ERROR 4: Update access not supported for VRT datasources.
ERROR 1: Failed to open datasource
Unable to open datasource `/web/maps/aqi/aqidata.ovf' with the following
  -> ESRI Shapefile
  -> UK .NTF
  -> SDTS
  -> TIGER
  -> S57
  -> MapInfo File
  -> DGN
  -> VRT
  -> AVCBin
  -> REC
  -> Memory
  -> CSV
  -> GML
  -> ODBC
  -> PGeo

I don't believe that it is an issue with the user, password, table, or host
because when I tweak these on my desktop and hit the file with ogrinfo, I
get a more specific error message that references the parameter that is

If I use the mysql client on the server to connect directly to the database
with this user, password, host, a SELECT query successfully returns the
expected data.  To determine if the db user needed more than SELECT rights,
I expended the user rights to ALL and this didn't change anything.  I also
expanded file rights for the dir that the .ovf is in.

Could there be a case sensitivity issue on the linux box?  (I believe that
all case is correct though)  I can't really think of anything else.

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