I have 2 types of records: there are many records in the second table that must point to one record in the first table, and each record in the first table must point to only one record in the second. How should i make the associations between the two classes. I am not interested to have in the first table the children set reference, only one at my choice (whichi i have to be able to update independently). Both records have unique independent identifiers.
The simplified case is:

example:
the class1 object should have:
itsId, myPreferedChildOfClass2
second class object shoudl have:
itsId, parentObjectOfClass1
for the second class i think i should use many-to-one for the parentObjectOfClass1, but i am not sure of first class mapping...

regards,