[gdal-dev] GML, MySQL data sources and preserve_fid

[Attila Csipa]

On Sunday 06 April 2008 19:54:02 you wrote:
> Le Sunday 06 April 2008 18:49:36 Attila Csipa, vous avez écrit :
> > I'm just experimenting with having some of my data in MySQL, but I'm
> > getting strange results regarding the FID - losing it, that is. It might
> > be just that I have overlooked something obvious, but google and the ogr
> > wiki pages turned up nothing that caught my eye...
>
> You're not doing anything wrong. In fact, the problem is not with the mysql
> driver, but with the GML one. The GML driver cannot currently read
> correctly the FIDs written. This is a known bug : see
> http://trac.osgeo.org/gdal/ticket/1017

Ah. I'm thinking that perhaps the preserve_fid switch can address the 
concerns ? If the switch is not present, we use our own FIDs, if it is, we 
take over the GML one (our best guess of it, at least), with a caveat emptor 
note ? That's roughly how the other direction worked, I think it would be the 
most intuitive way to do it. If the main concern is data integrity, I don't 
really see why the mysql driver respect this either - if the table was not 
created/maintained by OGR, the FID values could be just as misleading.