Geht es, wenn Du eine Klammer drum rum machst?
SQL-Code:
SELECT a.id, a.color,a.archiv, RTRIM(a.name) + '', '' + RTRIM(a.first_name) as wholename FROM contacts as a
WHERE (a.archiv=0) AND (a.id NOT IN (SELECT b.contact_id FROM projects_to_contacts as b WHERE b.project_id=103)) ORDER BY a.nam