From: Martijn Tonies
Date: March 14 2006 6:28pm
Subject: Re: Accountability with MySQL
List-Archive: http://lists.mysql.com/mysql/195808
Message-Id: <067c01c64795$2695ab80$cd02a8c0@martijnws>
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>Should you have a flag for the status "movement complete" ? I would say
>yes but instead of a simple checkbox, you could store a date value. That
>gives you two pieces of information
>
>a) if the date is null then the movement is not complete.
>b) if the date is NOT null then the movement is complete and you know when
>it finished.

There, Shawn and I disagree :-)

In case of a very simple database, one could use NULL
as a "flag" or "signal". But in general, I would avoid
storing NULLs.

Basics of database design: store what you know.

Given that NULLs basically means the absence of a value
(eg: unknown), you shouldn't be storing NULLs.

Martijn Tonies
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