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From:Martijn Tonies Date:March 16 2006 11:23am
Subject:Re: Accountability with MySQL
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> But (in at least some situations) is not appropriate to record that you
know that you don't have a value?
>

Sure it would. It it's needed.

But the answer doesn't have to be a NULL. Remember
the example about recording the fact that a student did
not make a test for whatever reason?

It was then said you could store "null" for the test score.

I then replied that that was a bit backward IMO, cause
you're using the "test scores" table to store that a student
did not take a test, which is wrong, given that each row
in a table should mean exactly the same thing (theory
knocking at the door once again) and that makes a design
more clear.

> I think the words of Donald Rumsfeld are appropriate here:
> "There are known knowns. These are things we know that we know. There are
known unknowns. That is to say, there are things that we know we don't know.
But there are also unknown unknowns. There are things we don't know we don't
know."
>

I think we'll have a hard time storing Donalds "knows" and
"unknowns" in a database... :-)

> At 12:02 pm +0100 16/3/06, Martijn Tonies wrote:
> >Well, the question still is if you should store "unknown" at all ;)
> >
> >Not according to Date: you should store what is known.
> <snip>

Martijn Tonies
Database Workbench - development tool for MySQL, and more!
Upscene Productions
http://www.upscene.com
My thoughts:
http://blog.upscene.com/martijn/
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Thread
Accountability with MySQLBruno B B Magalháes14 Mar
  • Re: Accountability with MySQLMartijn Tonies14 Mar
    • Re: Accountability with MySQLBruno B B Magalháes14 Mar
  • Re: Accountability with MySQLSGreen14 Mar
    • Re: Accountability with MySQLMartijn Tonies14 Mar
    • Re: Accountability with MySQLRhino14 Mar
    • Re: Accountability with MySQLMartijn Tonies14 Mar
    • Re: Accountability with MySQLRhino15 Mar
      • Re: Accountability with MySQLJames Harvard15 Mar
    • Re: Accountability with MySQLMartijn Tonies15 Mar
    • Re: Accountability with MySQLMartijn Tonies15 Mar
    • Re: Accountability with MySQLRhino15 Mar
    • Re: Accountability with MySQLMartijn Tonies15 Mar
      • Re: Accountability with MySQLStephen Cook16 Mar
    • Re: Accountability with MySQLRhino15 Mar
      • Re: Accountability with MySQLJames Harvard16 Mar
    • Re: Accountability with MySQLMartijn Tonies16 Mar
      • Re: Accountability with MySQLMark Leith16 Mar
    • Re: Accountability with MySQLMartijn Tonies16 Mar
      • Re: Accountability with MySQLJames Harvard16 Mar
      • Re: Accountability with MySQLAlec.Cawley16 Mar
        • Re: Accountability with MySQLMartijn Tonies16 Mar
          • Re: Accountability with MySQLAlec.Cawley16 Mar
          • Re: Accountability with MySQLJames Harvard16 Mar
          • RE: Accountability with MySQLGordon16 Mar
            • On MySQL Views (Re: Accountability with MySQL)Martijn Tonies16 Mar
    • Re: Accountability with MySQLMartijn Tonies16 Mar
    • Coalesce (was: Re: Accountability with MySQL)Martijn Tonies16 Mar
    • True Propositions (was Re: Accountability with MySQL)Martijn Tonies16 Mar
  • Re: Accountability with MySQLMartijn Tonies14 Mar
    • Re: Accountability with MySQLSGreen14 Mar
      • Re: Accountability with MySQLMartijn Tonies14 Mar
  • Re: Accountability with MySQLRhino14 Mar
  • Re: Accountability with MySQLRhino14 Mar
Re: Accountability with MySQLBruno B B Magalháes14 Mar
  • Re: Accountability with MySQLRhino15 Mar
Re: Accountability with MySQLMartijn Tonies16 Mar
Re: Accountability with MySQLMartijn Tonies16 Mar