[gdal-dev] Ogr2ogr, SQLite and overwriting existing database

[Rahkonen Jukka (MML)]

Hi Even,

Thanks for the clarification. By the way, the behavior with QuietDelete may be different with  SQLite driver but the messages are the same:

GDAL: GDALOpen(foo.sqlite, this=0000000001DD6450) succeeds as SQLite.
RASTERLITE: SQLite DB Open
OGR: Unloading VirtualOGR module
GDAL: GDALClose(foo.sqlite, this=0000000001DD6450)
SQLITE: OGR style SQLite DB found !
OGR: Unloading VirtualOGR module
GDAL: QuietDelete(foo.sqlite) invoking Delete()
GDAL: GDALDriver::Create(SQLite,foo.sqlite,0,0,0,Unknown,0000000000000000)
ERROR 1: It seems a file system object called 'foo.sqlite' already exists.
ERROR 1: sqlite driver failed to create foo.sqlite

-Jukka-


Lähettäjä: Even Rouault [mailto:even.rouault at spatialys.com]
Lähetetty: 9. toukokuuta 2018 19:43
Vastaanottaja: gdal-dev at lists.osgeo.org
Kopio: Rahkonen Jukka (MML) <jukka.rahkonen at maanmittauslaitos.fi>
Aihe: Re: [gdal-dev] Ogr2ogr, SQLite and overwriting existing database


Hi,



> What is the expected behavior if user asks ogr2ogr to create a SQLite

> database that already exists? The driver page

> http://www.gdal.org/drv_sqlite.html tells that "The SQLite driver supports

> creating new SQLite database files, or adding tables to existing ones. Note

> that a new database file cannot be created over an existing file."



Outdated statement from 1.X era (just removed it). Now that the SQLite driver is a GDAL driver, it follows the general mechanism of deleting the existing file.



>

> But if I lock the existing database by creating a connection into it I get

> these messages: ERROR 1: A file system object called 'foo.gpkg' already

> exists.

> ERROR 1: gpkg driver failed to create foo.gpkg

>

> Does "ERROR 1: A file system object called 'foo.gpkg' already exists." mean

> that the purpose to prevent overwriting but the check does not work? I have

> been using quit overwriting as a feature but is it actually a bug?



This is a particularity of the GPKG driver. The file should have normally deleted but due t thhe lock QuietDelete() failed. And the GPKG driver has a specific code to prevent overwriting of an exiting file in its Create() method. In fact it errors out if APPEND_SUBDATASET=YES is not specified, and if it is specified it happens a new raster dataset to the existing file



Even



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