[gdal-dev] OGR FileGDB driver: 'OBJECTID' not recognised as an available field

[Tamas Szekeres]

Hi,

I've already reported an issue a while back related to the OGRSQL dialect
along with the FDGB driver, when the where clause contains expression for
the FID column. I'm still experiencing the problem in GDAL master, where
the following query doesn't seem to apply the specified filter:

*ogrinfo "mydata.gdb" -dialect OGRSQL -sql "select * from tablename where
FID=..."*

but this one (without dialect) returns the correct result:

* ogrinfo "mydata.gdb" -sql "select * from tablename where FID=..."  *

I'm a bit uncertain about whether it should be fixed in the generic SQL
layer or the FGDB layer (which doesn't expose OBJECTID in the layer defn.),
since the FGDB layer reports the name "OBJECTID" in GetFIDColumn, therefore
the gen SQL layer could automatically consider it in the layer definition
when processing the attribute filter. When adding the OBJECTID to the query
it fixes the problem, but that seems to be a bit awkward:

*ogrinfo "mydata.gdb" -dialect OGRSQL -sql "select *, OBJECTID from
tablename where FID=..." *

Any ideas in this topic would be helpful?

Best regards,

Tamas


Tamas Szekeres <szekerest at gmail.com> ezt írta (időpont: 2019. szept. 5.,
Cs, 22:51):

> Hi,
>
> I'm not sure if bForwardWhereToSourceLayer should not be set in this case,
> since the special field FID in pszWHEREIn has already been replaced.
> Or the OpenFileGDB driver should indeed expose OBJECTID as a column
> according to #4253
>
> Best regards,
>
> Tamas
>
>
>  Even Rouault <even.rouault at spatialys.com> ezt írta (időpont: 2019.
> szept. 5., Cs, 13:13):
>
>> On mercredi 4 septembre 2019 22:13:40 CEST Tamas Szekeres wrote:
>> > Hi,
>> >
>> > It looks like  the sql queries with -dialect "OGRSQL" doesn't seem to
>> work
>> > as expected. When I specify the FID in the where clause, it doesn't
>> filter
>> > anything. The same query is also described as a solution in the
>> following
>> > ticket https://trac.osgeo.org/gdal/ticket/4253 but I doubt if that
>> works at
>> > all.
>> >
>> > The code causing this problem is fairly generic (ogr_gensql.cpp)
>> >
>> > if( psSelectInfo->where_expr && pszDialect != nullptr &&
>> >             EQUAL(pszDialect, "OGRSQL") )
>> >         {
>> >             int nMinIndexForSpecialField =
>> > poSrcLayer->GetLayerDefn()->GetFieldCount();
>> >             bForwardWhereToSourceLayer =
>> > !OGRGenSQLResultsLayerHasSpecialField
>> >                             (psSelectInfo->where_expr,
>> > nMinIndexForSpecialField);
>> >         }
>> >         if (bForwardWhereToSourceLayer)
>> >             pszWHERE = CPLStrdup(pszWHEREIn);
>> >         else
>> >             pszWHERE = nullptr;
>> >
>> > In the "where" expression, the FID field is thanslated to OBJECTID and
>> it
>> > is now treated as a special field, therefore the "where" expression is
>> not
>> > being passed to the driver.
>> >
>> > I'm also unsure if that is a correct action to omit passing "where" to
>> the
>> > layer instead of providing an error message.
>>
>> Actually the where isn't completely discarded. It is set on the
>> OGRGenSQLResultsLayer per
>>
>>     if( !bForwardWhereToSourceLayer )
>>         OGRGenSQLResultsLayer::SetAttributeFilter( pszWHEREIn );
>>
>> around line 492
>>
>> The issue is that the GenSQL layer has no FID column set, and thus this
>> filter
>> fails. One could potentially set the FID Column name on it from the
>> source
>> layer, but that wouldn't be really appropriate in the case of JOIN. That
>> said
>> I see a poDstFeat->SetFID( poSrcFeat->GetFID() ); at line 1332 of
>> TranslateFeature(), so...
>>
>> (there might have been other fixes since #4253 that have made this case
>> broken)
>>
>> --
>> Spatialys - Geospatial professional services
>> http://www.spatialys.com
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/gdal-dev/attachments/20200123/acbf80db/attachment.html>