Hi,
in https://github.com/OSGeo/gdal/pull/8301, I've added the capability to
select/filter using the FID column name (when it is not empty) with the
SQLite dialect as well.
The behaviour of OGR SQL regarding FID use is documented at
https://gdal.org/user/ogr_sql_dialect.html#fid , and for the SQLite
dialect at https://gdal.org/user/sql_sqlite_dialect.html#feature-id
Even
Le 01/09/2023 à 10:28, Rahkonen Jukka a écrit :
Hi,
Feature IDs are confusing. Some formats require FID, some do not
directly support FID at all (shapefile). Sometimes FID must be an
integer, sometimes it is always a string (gml_id), and sometimes it is
either or (GeoJSON). Ogr2ogr has 3 parameters for FIDs, and vector
drivers add their own options. Primary key acts usually as a FID, but
can a composite PK be a FID? FIDs are really meant for the machines
and GDAL usually hides FIDs, but they may be meaningful also for
humans as well and sometimes users would like to expose them as a
normal attribute with tricks like SELECT *, fid_field as my_fid.
I agree that something like a dedicated wiki page about FIDs in GDAL
would be nice to have. Maybe documenting how OBJECTID in FileGDB
behaves with different SQL dialects is a rather small detail to be
documented separately.
-Jukka Rahkonen-
*Lähettäjä:* andy <aborr...@gmail.com>
*Lähetetty:* perjantai 1. syyskuuta 2023 9.54
*Vastaanottaja:* Rahkonen Jukka <jukka.rahko...@maanmittauslaitos.fi>
*Kopio:* gdal dev <gdal-dev@lists.osgeo.org>
*Aihe:* Re: [gdal-dev] sqlite dialect: OpenFileGDB and FID Column
selection
Hi Jukka,
On Fri, 1 Sept 2023 at 07:42, Rahkonen Jukka
<jukka.rahko...@maanmittauslaitos.fi> wrote:
When the SQLite dialect is used, a temporary SQLite database is
created. OBJECTID is a feature identifier (FID) and I guess that
the FID gets converted into a primary key with the SQLite
defaults. So maybe you can find the OBJECTID from ROWID.
it works, thank you very much.
Maybe a little related note in the documentation would do. What do you
think about it?
Thank you again
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