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

Bob Badour wrote:
> miklesw_at_gmail.com wrote:
> > What do you mean by "A pointer that allows to design cardinalities"?
> > I'm not following..
> >
> > Cimode wrote:
> >
> >>You are using an incorrect terminology. You believe a relationship is
> >>a pointer that allows to design cardinalities (it is not). The proper
> >>way for you to deal with the problem you are describing is to do some
> >>serious reading about relational model...Here is the reference...Hope
> >>this helps...
> >>
> >>Introduction to Database Theory by CJ DATE
> >>
> >>
> >>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
>
> Hi Mike,
>
> Cimode is a crank. In general, you can safely ignore him; however, his
> pointer to Chris Date is sound.
>
> I suspect the reason you have not received any better responses is
> nobody really has any idea what you are talking about.
>
> If you have any 1-1 relative cardinality between two relations, you can
> reduce that into a single relation, which would seem to leave you with a
> simple 1-M foreign key reference. However, I am not confident that I
> even know whe

I have no time playing with you Bob, a people's education quality is at stake.

Mike,

Ignore all comments made by Bob concerning my person (been called worse) but listen to his confirming advice about reading the Date's book. Hope this helps.... Received on Wed Oct 04 2006 - 14:56:21 CEST