Dear Even Rouault I was also wondering to know if it is possible to rename the raster bands ?
Bas On Thu, Jul 17, 2014 at 8:29 PM, Even Rouault <[email protected]> wrote: > Nik, > > > I have two simple questions (not sure if the answers are as simple)... > > > > 1. Is it possible to rename an OGR layer in place within a writeable > data > > store without first creating a copy of the entire layer? > > There's no provision in the OGR API to do that currently. Although it > could be > nice to have. That would require of course updating the drivers that would > support that capability, and which are coded currently under the > assumption that > the layer name is immutable. > For which driver(s) would you be interested to have that capability ? > > > > > The only way I've found to do this is to use OGR_DS_CopyLayer() (or > similar) > > and then delete the old layer which is fairly expensive as it has to > copy all > > of the features as well. > > For drivers that are related to SQL databases, issuing an "ALTER TABLE foo > RENAME TO bar" with ExecuteSQL(), and re-opening the datasource afterwards > (OGR > will not notice the change) should do it. > > > > > 2. Is it possible to change the order of layers within a writeable OGR > data > > store? (Ie, change the ordering/indexing of layers as they would be > > retrieved with OGR_DS_GetLayer() ). > > That would be much more involved, not to say impossible. For example, for > SQL > based drivers, the driver list is issued from a request in system tables or > other tables and there's nothing to control the order of retrieval. > For filebased drivers, such as a directory of shapefiles, it depends on the > order of the operating system in which it return the filenames. Nothing > you can > have control on. > To make it possible reliably would probably involve adding a special OGR > metadata table with (order_number, layer_name) columns. > A potential workaround is to use a OGR VRT file as a thin wrapper above > your > "real" datasource. The layers will be ordered in the order they are listed > in > the VRT. > > Best regards, > > Even > > -- > Geospatial professional services > http://even.rouault.free.fr/services.html > > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev >
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