Re: Mapping one to many - Mailing list pgsql-novice

From Nabil
Subject Re: Mapping one to many
Date
Msg-id 155D2E10-52EE-4DB8-B439-F0F05F0F263D@kramer-smilko.com
Whole thread Raw
In response to Re: Mapping one to many  (Richard Broersma Jr <rabroersma@yahoo.com>)
Responses Re: Mapping one to many
Re: Mapping one to many
List pgsql-novice
I am not saying that this solution doesn't work or even that is a
"bad" one but what I'm saying is that there is obviously a better
solution. Also there are better forms, other than row/column, in
which to module data but there any Databases that support them. If
you'll notice from my second message I was asking why that is so is
so and to please enlighten me to the magic of RMDBs. I feel as if
there is something about RMDBs that will explain alot but is just
beyond my reach and I what to know what it is.


On Jun 13, 2007, at 2:05 PM, Richard Broersma Jr wrote:

>
> --- Nabil <Nabil@kramer-smilko.com> wrote:
>
>> Ahh but groups dont know about there members. It it was implemented
>> the way that it has been suggested to me (a table for each users,
>> groups and mapping user to groups) you would end up with a many to
>> many relationship. The way I wanted to do it was just map user to
>> groups without mapping groups to users. In other words map one user
>> to many groups, the groups know nothing about the users.
>
> What will you do when you have that you have to add more groups and
> delete other groups?  Are you
> going to redefine the dimementions of your array and the assignment
> of your array indexes as
> records are added and deleted to your groups table?
>
> A "many to many" table is really a relationship between two or more
> entity tables.  The groups
> table would know nothing about members and members would know
> nothing about groups.  They way to
> determine the relationship between members and groups is to query
> across the relationship table.
>
> This is a time test any univerally accepted model for (Relational)
> database systems.
>
> Regards,
> Richard Broersma Jr.
>
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