QGIS » QGIS Application

I'm just trying to use QGIS as another GIS platform for our product suite (in addition to ArcGIS, AutoCAD Map, GeoMedia, ...).
We use MSSQL and Oracle as DBMS backend, and I have problems with MSSQL.

I would like to use a SELECT statement as data source. This seems to be possible with postgres, but it's not possible with MSSQL, because the "table=dbo.tablename"-part of the data source must have this exact format. In postgres it's possible to use "table=(SELECT ... FROM xyz)". I don't know if this is a bug or if I should create a feature request ;-)
For now it's ok to use a view instead of a SELECT statement as data source, and this works in principle ("table=dbo.viewname").

In this case I have to set "key=primarykeycolumn" in the data source, so that each row is identifiable.
Our primary key-columns are of type "char", and this does not work for the MSSQL (but it does for Oracle).
SQL Profiler told me, that "int" seems to be the required type for the key columns, because every SQL statement contains a "0" as primary key value.

I've also noticed that "STIntersects()" is used to query the currently visible elements - I think you should consider using "Filter()" to get (much) better performance.

Markus