Re: Data modeling for a multi-company product

On Jan 24, 10:38 am, "dawn" <dawnwolth..._at_gmail.com> wrote:
> One feature of some ERP and other software application systems is the
> ability for the customer site to indicate in the setup which attributes
> are required and which are not related to the various data entry
> "screens." So, customer A might consider birthdate to be a required
> "field" when a user is entering data into the XYZ screen/form while
> customer B does not.
>
> When I was reading about designing for the elimination of NULLs, it
> struck me that I was not sure how to prepare an elegant logical data
> design if the exact same software is to be deployed to multiple
> customer sites with the customer having this option. This means that
> other than "primary keys" (those used to create new or lookup existing
> information) almost all attributes are optional.
>
> How do SQL-based ERP solutions and other software to be deployed to
> multiple companies model the data for this feature? Do any ERP or
> other multi-company software solutions come close to doing this
> "properly" with no nullable attributes? Do they then have a separate
> table for each attribute where it is possible for a site to configure
> it as not being required? Maybe I'm confusing some issues here, so any
> clues would be appreciated.
>
> Thanks. --dawn

In the case of generic software designed to operate with a number of DBMS (SQL) products; in order to allow some customisation of each implementation, nullable attributes are pretty well a certainty. Further, because the SQL standard defines nulls, there is a tendency to use nullable attributes even when an extra table would have been the better option.

Regards, Keith Received on Wed Jan 24 2007 - 23:17:37 CET