[OSGeo-Discuss] ms_link_id

[Frank Warmerdam]

Fatih ÖNCEL wrote:
> i have a dgn file V7.  i try to read this file with mapguide 2009
> fdo.provider 3.3.1 . on my dgn file,  there are mslink_id s. i dont want to
> lose them. but when i open this file, i could reach my data except
> mslink_id. when i connect mapguide and dgn file i could see featID column
> instead of mslink_id. does mapguide 2009 produce featID according to mslink?
>  or mapguide 2009 produce featId according to itself? how can i reach my
> mslink_id in my dgn file?

Fatih,

I think you will get better answers to this on the FDO list.  If you do ask
there, I encourage you to be more specific about the FDO provider you are
using.  Is it the FDO OGR provider?  That provider does have support for
DGN format (though there may be other FDO providers that also have dgn support,
I'm not sure).

If the issue is specifically with the FDO OGR Provider you may find the
gdal-dev mailing list is a better place to ask your question.

I will note that when I use ogrinfo (a commandline program to dump info
on features read with OGR) on a dgn file I get something like:

OGRFeature(elements):20446
   Type (Integer) = 3
   Level (Integer) = 28
   GraphicGroup (Integer) = 0
   ColorIndex (Integer) = 33
   Weight (Integer) = 2
   Style (Integer) = 0
   EntityNum (Integer) = 9
   MSLink (Integer) = 2476
   Text (String) = (null)
   Style = PEN(id:"ogr-pen-0",c:#7300ff,w:2px)
   LINESTRING (3286761.274999999906868 377652.375,3286930.274999999906868 
377909.575000000186265)

Note that the feature id (20446) is not related to the MSLink value in any
way.  DGN files can actually have multiple links per element, but I believe
OGR only returns the first.  I believe the EntityNum and MSLink value need
to be treated together to understand what the table/database is linked to
though I don't recall the details.  You might find the OGR DGN format driver
web page of some help:

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

It is important to remember there are several levels of software involved.
Mapguide, the FDO provider (presumably FDO OGR) implemented primarily by
Traian, the OGR level and then the OGR DGN driver (implemented by me).

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent