I want to clarify what's my problem with the "untyped" NULL values.
I have to build SQL queries dynamically. Basically it's something like merging different queries (or query parts) into a bigger query.
I don't know the data types of the "source" columns und I have to add NULL columns to the resulting query.
This combination is causing the trouble, and for me there's no way to work around this issue in another way.
Hope that helps.
Markus