但是,在mongoDB中如何进行以下操作:
create table pruefen
( MatrNr integer references Studenten on delete cascade,
VorlNr integer references Vorlesungen,
PersNr integer references Professoren on delete set null,
Note numeric(2,1) check (Note between 0.7 and 5.0),
primary key (MatrNr, VorlNr));
DBRef并不是外键的替代品,我尝试过但无法达到这个效果。
如果应用程序接管了,它会是什么样子?