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

From: Cimode <cimode_at_hotmail.com>
Date: 4 Oct 2006 04:48:00 -0700
Message-ID: <1159962480.693094.244840_at_c28g2000cwb.googlegroups.com>


miklesw_at_gmail.com wrote:
> I'm no database expert.. just a student..
>
> I'm using Database Management Systems - Ramakrishnan & Gehrke

> To be honest, there isn't an explicit statement.. but the only example
> for implementing ternary relationships is a create table for the
> relationship..

> My question was whether this is also necessary in the case of a
> relationship with cardinality of 1-1-M..
>
> Just to put you in the picture.. I identified this ternary relationship
> in the conceptual model (before finding the cardinalities)....
>
> When I reviewed the relational schema with someone else.. they pointed
> out.. that my implementation was 2 binary relationships.. and that
> ternary relationships should always be implemented as a seperate
> table....however I am finding it hard to accept this..Especially since
> 2 binary relationships do not capture the concept behind this
> relationship...
I suggest you get the reference that explains relational modeling...The textbook you have been quoting seems to confuse you more than explain relations to you. After all, it is a good thing that you question what you read....Good luck in your learning... Received on Wed Oct 04 2006 - 13:48:00 CEST

Original text of this message