insert into Vorlesungen (VorlNr, Titel, gelesenVon) values (4711,'Selber Atmen', 2125)
insert into hoeren select MatrNr, VorlNr from Studenten, Vorlesungen where Titel = 'Selber Atmen'
update vorlesungen set SWS=6 where Titel='Selber Atmen'
delete from hoeren where vorlnr = (select VorlNr from Vorlesungen where Titel = 'Selber Atmen')
delete from Vorlesungen where titel = 'Selber Atmen'