Re: Oracle NULL vs '' revisited

On Aug 25, 2:58 am, "Tony Rogerson" <tonyroger..._at_torver.net> wrote:
> > If it CAN change it is NOT a key. That is the definition. Let me give
> > you an example.
>
> That's just Oracle speek in the Oracle environment because your candidate
> key cannot be changed ->http://orafaq.com/node/24.

Tony,

try dropping into comp.database.theory
I doubt you will last long in that forum.

>
> It's not how the real world works which brings us full circle back to the
> original thread - NULL behaviour, I love your comment about a proper design
> having all NOT NULL to get round the weakness in the product; that's just
> not possible in the real world.

Earlier I asked this question:
If I have a user filling out an electronic form and they enter nothing into one of the fields (they TAB right past it), I would load a NULL in the DB. Would you really try loading an empty string?

(a related question: How would you fill out the form on paper?)

The issue of not having a middle name and not having the middle name entered on a form (ie NULL) is a special case. Names are a very special case. The entire name ideally should be entered into one field. What we call Last names are really Surnames. For example in oriental culture it is often the Surname that comes FIRST. And the use of shortened versions (Ed Edward, Eddie) and spelling/pronunciation variations (Eduard, others?) makes names a poor choice for PK and other DB concept discussions.

(but you think you have all this solved by using surrogate keys. enjoy your bliss until the day an update programming error happens and knocks some of your keys out of sync. Hopefully you find out the day it happens and can recover.)

>
> > If you need additional help with the concept please ask.
>
> No need and believe me it wouldn't be you, you appear to have problems with
> understanding database theory, that's the problem teaching syntax day in day
> out.

On the contrary you seem to have the problem with understanding relational DB theory. That's the problem with only coding all day and not getting out to talk (just talk, not argue) to other DB people using other products. You need to learn to not be so dogmatic.

  Ed Received on Sat Aug 25 2007 - 21:30:43 CDT