Question: Entities With Common Attributes

From: SQL-er <SQL-er_at_noemail.com>
Date: Wed, 4 Apr 2001 05:22:00 +0100
Message-ID: <9ae7he$pli$1@newsg1.svr.pol.co.uk>

Thanks in advance for any suggestions offered:

All right, I *thought* I understood database modelling and SQL, until the following arose:

What is the "accepted way" of handling something like this ?

A database model for a company sales obviously contains an entity "customer"

But, in this case, there are 2 types of customer - "businesses" and "individuals"
Different attributes are recorded for each type

eg: something like:

Individual-Customer

    Customer-number
    Name
    Phone-no
    Driving-Licence-number

Business-Customer

    Customer-number
    Business-name
    Business-type

    phone-no
    fax-no

So, the customer-number is the only attribute common to both types of customer
But, I don't see how that ought to be handled

I'm probably missing something very obvious here... Could someone give me a hint as to what it is ?

novice SQL-er ( still learning ) Received on Tue Apr 03 2001 - 23:22:00 CDT