Re: [PHP-DB] novice on table design

[Tony S. Wu]

actually, no, Shop, Employee, and Customer are not distinct.
in your instance they are the same type of entry.
don't distinguish them by tables, rather use a column to hold some sort 
of an ID for each type.
of course you'll end up with a table with many columns, and many of 
them will be null depending on which type an entry is.
but with this approach, you can easily associate with an address table.

Tony S. Wu
[EMAIL PROTECTED]

On May 14, 2005, at 4:49 AM, tony yau wrote:
Hi Miguel,
    Thanks for the reply.
    the non-customer is actually a Shop, so Employee, Customer and 
Shop are
distinct enough to have their own tables. Now they all have an 
Address, and
the problem is how do I allow multiple addresses for each these 
'people'
(without using
a lookup table)

tony.
"Miguel Guirao" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
The schema of your table is wrong, is you do bnormalize it you will 
find
out
that you need two tables for this approach.
One table for your people and another one for the n addresses of your
people.
If you keep your current schema, you will have as many rows for one 
person
as many addresses for that person you have, and you will be 
duplicating
many
fields. So you must split your tables, one for your people and 
another for
your people's addresses.

-----Original Message-----
From: tony yau [mailto:[EMAIL PROTECTED]
Sent: Viernes, 13 de Mayo de 2005 09:27 a.m.
To: php-db@lists.php.net
Subject: [PHP-DB] novice on table design

Hi all,
I have the following tables
    Employee            Customer            non-Customer
Address
==========    ==========    =============    ==========
    pkey                     pkey                    pkey
pkey
    number                 type                     type
...
    payrate                 grant                    capital
I need to allow the three types of people to have n addresses, so I've
added
a type to distinguish the 3 types of people and their respective pkey 
onto
address table.

    Address
=========
    pkey
    ...
    type    (either Employee, Customer or non-Customer etc)
    fkey    (the pkey of Employee, Customer or non-Customer etc)
I know this design looks awkward but it does have the advantage of 
having
less tables otherwise.
BUT somehow it doesn't feel right. Can someone points me its pros and
cons.
thanks all.
Tony Yau
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