[dba-SQLServer] NULLs

Asger,  I do see your point, I guess I'm playing more devil's advocate here
since I DO user Nulls in my designs.  In the business world, generally where
the business is so large that they need to keep track of everyone in a
database to know who works for who and what their titles are, I typically
see a position created, and then it filled by the boss' son/nephew/etc, etc.
etc.


-Francisco
http://sqlthis.blogspot.com | Tsql and More...


On Mon, Mar 16, 2009 at 8:32 AM, Asger Blond <ab-mi at post3.tele.dk> wrote:

> OK, I see.
> Regarding the example: Ever heard of nepotism? The HR manager is asked to
> register the boss' son as a new employee not deciding for the moment which
> department should have the honour.
> And of course: Normally a FK constraint should not allow NULLs. But the
> fact
> that you have to explicitly prevent this using a NOT NULL constraint makes
> room for exceptions.
>
> Asger
> -----Oprindelig meddelelse-----
> Fra: dba-sqlserver-bounces at databaseadvisors.com
> [mailto:dba-sqlserver-bounces at databaseadvisors.com] På vegne af Francisco
> Tapia
> Sendt: 16. marts 2009 15:59
> Til: Discussion concerning MS SQL Server
> Emne: Re: [dba-SQLServer] NULLs
>
> I was simply giving an example of  how such a join might look.  Also, I
> thought it would be odd for a company to hire an employee w/o already
> having
> a position to fill, generally I've never seen this to be true, but possibly
> does happen, just haven't ran into it myself.
> --
> -Francisco
> http://sqlthis.blogspot.com | Tsql and More...
>
>
> On Mon, Mar 16, 2009 at 7:55 AM, Asger Blond <ab-mi at post3.tele.dk> wrote:
>
> > > Logically the join between the employee and the dept can
> > > be a many to many which would allow you to have an unassigned employee
> >
> > Don't know if I get your point here. Are you implying that an unassigned
> > employee can't exist in a one to many relationship with referential
> > integrity? If so you are not right: a FK constraint doesn't forbid NULLs
> in
> > the FK column.
> >
> > Asger
> >
>
>