[Geopackage] [SpatiaLite-Users] GeoPackage (GPKG) support in 4.2.0

a.furieri at lqt.it a.furieri at lqt.it
Wed May 21 18:33:55 EDT 2014

On Thu, 22 May 2014 00:11:06 +0200, Even Rouault wrote:
> Le mercredi 21 mai 2014 23:34:18, Even Rouault a écrit :
>> Sandro,
> While looking at the code, I see that in SUPPORTED_GEOMETRY_TYPES 
> array in
> gpkgAddGeometryColumn.c there is "GEOMCOLLECTION". I think it should 
> be
> "GEOMETRYCOLLECTION" instead as in table 44 of Annex E (
> http://www.geopackage.org/spec/#geometry_types )
> But... the string GeomCollection appears at a few occurrences in the
> GeoPackage specification, so CC'ing the GeoPackage list so that they
> share some
> light. Looks like there is an inconsistency
> SFS traditionnaly has called it GEOMETRYCOLLECTION AFAIK. But damned! 
> when
> checking ogc 99-049 OpenGIS Simple Features Specification For SQL I 
> can see
> that both are used !


you are reading directly into my mind ...

Yes, I noticed that the GPKG specs are rather obscure / unclear
about this topic; anyway I received the personal impression that
GEOMCOLLECTION was someway the preferred name.
(being probably based on the more recents "top secret" ISO
SQL/MM specs)

I suppose than when reading from a GPKG being prepared to support
both alias names indifferently should probably be the safer approach.

International Standard: a polite name to define a messy chaos :-D

bye Sandro

... a further doubt: it looks like every GPKG table shall necessarily
have a Primary Key declared as "INTEGER AUTOINCREMENT"
What's happen e.g. while exporting form an origin table presenting
a multi-column PK ?
we could eventually ignore the original PK, then defaulting to
some other INTEGER AUTOINCREMENT id; but this will obviously
kill any possible relationship based on Foreign Keys referencing
the original multi-column PK

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