Re: Transforming 1-1-M Ternary Relationships into Logical

miklesw_at_gmail.com wrote:
> What do you mean by "A pointer that allows to design cardinalities"?
> I'm not following..
Relationships should not be defined primarily according to the concept of cardinality. Definition of relationships is basically defined by domain implementation and restriction and numerous other relational algebric principles defined by Codd, Date and other knowledgeable audiences.

Another way to put it is that you do not seem to be using the term *relationship* as it is defined by knowledgeable audiences about relational model. But I am curious: which textbook tells you, word for word, that *a ternary relationship, meaning 3 attributes are necessarily implemented as a FK for all relations* ..Could you provide reference?

miklesw_at_gmail.com wrote:
> Most text books state that Ternary relationships are implemented as a
> table with FKs for all the relations.. i was wondering how are 1-1-M
> relationships implemented..
>
> It seems pointless to me... In 1-M binary relationships.. the FK is
> placed on the M end...
> In this case it would make sense to put 2 FKs in the Many end..
>
> What is the proper way of implementing this?
>
> Tnx,
>
> Mike
Received on Wed Oct 04 2006 - 12:51:21 CEST