[GRASSLIST:6572] Re: access to raw vector data

[Radim Blazek]

Look at data provider in QGIS:

http://cvs.sourceforge.net/viewcvs.py/qgis/qgis/providers/grass/qgsgrassprovider.cpp?view=markup

Radim

Andreas Braeu wrote:
> Hi Grass list,
> 
> I'm working on my diploma thesis "federated access to spatial data in grass 
> with DB2 udb".
> 
> That means: In DB2 udb i will create virtual tables, also called 'nicknames', 
> and a wrapper that translates queries on these nickname tables to obtain data 
> from grass. The goal is to integrate several data sources (one source is 
> grass for example) in db2, that appear to users like "normal database tables" 
> they can work on. To add spatial functionality to DB2 there exists the "DB2 
> Spatial Extender", that allows developing GIS-applications using DB2. 
> 
> The db2-wrapper has to be written in C++. I already studied the Grass-C-API, 
> generated the docs and now have some questions:
> 
> The module I'm going to develop needs to run completely noninteractive. Is 
> this possible for example for opening a mapset (I didn't find anything in the 
> documentation)?
> 
> Which functions are intended to return the raw vector data? For instance I 
> want to get all roads from a vector containing roads (in DB2 I'll only type 
> "select * from road_vector_in_grass"). Attributes for these roads should also 
> be returned.
> 
> I don't want to:
> - use DB2 UDB as another possibility for grass to store data
> - access raster data, because of the time limit I only want to have a look on 
> vector data
> 
> Thank you,
> 
> Andreas
>