Re: Many to Many Relationship with a Twist

Hi Jim:

    It's the second case. After thinking about it I think I'll probably stick with the multiple intersection tables. And for the reason you mention - I'm not sure the queries would be written properly.

Van

Jim Gregory <JG200024_at_NCR.com> wrote in message news:397898a4$1_at_rpc1284.daytonoh.ncr.com...
> Van
>
> Your following relation is unclear:
>
> " Any NEWS item can be associated with C and/or R and/or B".
>
> If you mean to say " Any NEWS item can be associated with 0 or 1 rows in C
> and/or R and/or B" then you don't have a many to many relationship and you
> don't need an intersection table.
>
> However, if you mean to say " Any NEWS item can be associated with 0, 1,
 or
> more rows in C and/or R and/or B" then you do have a many to many
> relationship between NEWS and the other tables. If this is the case, I
> would probably go the intersection route instead of trying to develop a
 more
> "elegant" solution. "Elegant" in my experience means more complicated and
> fraught with gotchas down the road that aren't immediately obvious. Give
> the developers a break and don't make their jobs any more complicated then
> it needs to be.
> (just my opinion)
>
> HTH
> --
> Jim Gregory
> Principal Consultant for Keane, Inc.
> Currently assigned to NCR
> "Opinions are my own and do not reflect
> those of Keane or my clients"
>
> Van Messner <vmessnerNOvmSPAM_at_discovernet.com.invalid> wrote in message
> news:16160e7a.9245beac_at_usw-ex0106-046.remarq.com...
> >
> > Imagine three tables C, R and B. C has a primary key of CKEY, R
> > is RKEY and B is BKEY.
> >
> > Another table NEWS has a primary key of NEWSKEY.
> >
> > C, R and B can all be associated with zero to many NEWS items.
> > Any NEWS item can be associated with C and/or R and/or B.
> >
> > One model is to put an intersection table between NEWS and C,
> > NEWS and B, and NEWS and R.
> >
> > But when I add more tables at the level of C, R and B then I will
> > need more intersection tables. Is there a more elegant solution?
> > Please be specific about which would be the key and foreign key
> > columns of any alternative solution.
> >
> > Many thanks,
> >
> > Van
> >
> >
> >
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>
Received on Sat Jul 22 2000 - 00:00:00 CDT