If the /vsimem/... file hasn't been created, then it won't be opened.
This is like a regular file system
If you want to copy an existing file to /vsimem/, you can do something like
gdal.FileFromMemBuffer("/vsimem/foo.gpkg", open("source.gpkg", "rb").read())
do something
gdal.Unlink("/vsimem/foo.gpkg")
or you can ogr.GetDriverByName(...).CreataDataSource("/vsimem/foo") to
create a new one
Even
Le 22/08/2023 à 16:11, Meyer, Jesse R. (GSFC-618.0)[SCIENCE SYSTEMS AND
APPLICATIONS INC] via gdal-dev a écrit :
As per your workaround suggestion,
Are these intended to work? The returned datasource is None.
Removing the `/vsimem` preamble returns the disk-backed geopackage
datasource as expected.
tree_canopy_mem_ds
=ogr.Open('/vsimem/Users/jrmeyer3/Downloads/features.gpkg')
tree_canopy_mem_ds
=ogr.GetDriverByName("GPKG").Open('/vsimem/Users/jrmeyer3/Downloads/features.gpkg')
*From: *Even Rouault <even.roua...@spatialys.com>
*Date: *Monday, August 21, 2023 at 6:22 PM
*To: *"Meyer, Jesse R. (GSFC-618.0)[SCIENCE SYSTEMS AND APPLICATIONS
INC]" <jesse.r.me...@nasa.gov>, "gdal-dev@lists.osgeo.org"
<gdal-dev@lists.osgeo.org>
*Subject: *[EXTERNAL] Re: [gdal-dev] Is SQLITE dialect supported on
Memory OGR datasets?
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care when clicking links or opening attachments. Use the "Report
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Jesse,
No it wasn't. Fix in https://github.com/OSGeo/gdal/pull/8247
Potential workaround: use a in-memory SQLite or GeoPackage with a
/vsimem/ filename
Even
Le 21/08/2023 à 21:30, Meyer, Jesse R. (GSFC-618.0)[SCIENCE SYSTEMS
AND APPLICATIONS INC] via gdal-dev a écrit :
Hi,
This works:
tc_lyr =execute_SQL(tree_canopy_mem_ds,"select * from
trees",/spatialFilter/=c_geo)
However, this:
tc_lyr =execute_SQL(tree_canopy_mem_ds,"select * from
trees",/spatialFilter/=c_geo,/dialect/="SQLITE")
Returns:
In Initialize(): sqlite3_step(SELECT _rowid_, * FROM 'trees' LIMIT
1): SQL logic error
Where execute_SQL = ogr.DataSource.ExecuteSQL
Which is naturally a surprise given that I’m not explicitly asking
for the rowid, nor to limit the number of returned rows.
The docs claim that the SQLite dialect can be used with any OGR
datasource, so I did expect this to work. The input datasource is
GeoPackage, which is based on SQLite, so I assume my install is
built with SQLite, though I’d welcome advice on how to explicitly
demonstrate this.
My GDAL version install is 3.6.4, on OSX 13.5.
Thanks,
Jesse
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_______________________________________________
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--
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My software is free, but my time generally not.
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