Really closing database connections

[SymbolicFrank]

This one works

1. Use a dedicated, native connection and don't use any high-level functions of the connection (or transaction) you extracted it from.
2. Try all transactions until they succeed, or a fatal error is returned.
3. Read the statusses until nil;
4. Don't forget to collect the error message.

And, finally: format the fields correctly (I had a comma as decimal separator in my floats).