[gdal-dev] sqlite dialect: OpenFileGDB and FID Column selection

[Even Rouault]

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 <aborruso at gmail.com>
> *Lähetetty:* perjantai 1. syyskuuta 2023 9.54
> *Vastaanottaja:* Rahkonen Jukka <jukka.rahkonen at maanmittauslaitos.fi>
> *Kopio:* gdal dev <gdal-dev at 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.rahkonen at 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
>
>
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/gdal-dev

-- 
http://www.spatialys.com
My software is free, but my time generally not.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/gdal-dev/attachments/20230901/c1113a5d/attachment.htm>