SQL: Update mit Select und IF/CASE in der Bedingung

[Uwe Raabe]

Was spricht denn gegen das hier?

SQL-Code:

(select SUM(B.Brutto) as Summe from BEL B
             where
               (B.Art = 'BLUBB' or B.Art = 'BLA') and
                ((B.Adr IS NOT NULL and B.Adr = ADR.Adr) or
                 (B.Adr IS NULL and B.KDNR = ADR.Adr))