in-Klausel in großen Tabellen

[Delphi.Narium]

Also eher sowas?

SQL-Code:

select * from tabelle a where exists (
  select 1 from tabelle b 
  where a.AuftragsNr = b.AuftragsNr
  and b.Fertigdatum between CAST('2018-01-01' AS DATE) and CAST('2018-12-31' AS DATE) 
)