Statt CTE kann man den "x"-Ausdruck auch direkt
Code:
Select Mark from
   (Select Nummer, Num2, Max(VKDAT) MaxVkDat
      from YourTable  
   Where     Nummer = 310000006
       and Num2   = 90080
       and VKDat <= 20190828
    Group By Nummer, Num2
) x
join yourTable y on x.Nummer = y.Nummer
                      and x.Num2 = y.Num2
                      and VKDat  = MaxVkdat
Order By Zeile Desc
fetch first 1 rows only
kodieren: