[Qgis-developer] about ogr provider

[sebastian sauer]

Mon 30 Jul 2007 19:38, Marco Hugentobler wrote:
> The ogr provider is mostly used for reading shapefiles and GML. Afaik those 
> datasources have only one layer per file (which fits perfectly with the 
> approach in qgis). 
> Is it possible that oracle, mysql, postgresql in ogr have multiple layers per 
> datasource?
i dont know for oracle, mysql, postgresql but ogr supports that if the
fileformat allows it.. cf. e.g. the GRASS OGR driver..

http://www.gdal.org/ogr/drv_grass.html

(note however layered files are not that common in the standard use of
GRASS GIS)

> If yes, then we should think about how to handle that in QGIS. 
> I'm in favour that the plugin asks the ogrprovider how many layers are 
> present
that sounds reasonable..

> and the plugin then creates one Vectorlayer for each ogr layer.
that's not such a good idea. before any layer is created QGIS the
user should have the possibility to select the layers s/he wants.

my cent,
s.