#47 Need to associated foreign key (not add)

[Alexander Bibighaus]

For example, we have classes A,B, and C. There are
association A (1) -> B (n) and C(1) -> B(n). I would
like to insert instance of B and connect this instance
to A and C . All classes have primery keys of UID type
and autoincrement.
If I go via class A and change collection in A, how can
I connect new instance to existing B (change refernce
to B in class C). And second, it seems to me that I
have to enter reference key to A (A primary key) in C
instance. But I haven't possibility to enter this key.