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From:Tim Gustafson Date:February 23 2005 1:42pm
Subject:RE: UNIQUE Key Allowing Duplicate NULL Values
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Martijn,

The problem is that I don't want more than one row in the table that has
a null value in the column.  As you've pointed out in your e-mail,
there's a difference between NULL and BLANK.  It's not that I don't want
NULL values, it's that I don't want MORE THAN ONE.

Tim Gustafson
MEI Technology Consulting, Inc
tjg@stripped
(516) 379-0001 Office
(516) 480-1870 Mobile/Emergencies
(516) 908-4185 Fax
http://www.meitech.com/ 



-----Original Message-----
From: Martijn Tonies [mailto:m.tonies@stripped]
Sent: Wednesday, February 23, 2005 8:37 AM
To: Gustafson, Tim; Paul DuBois; mysql@stripped
Subject: Re: UNIQUE Key Allowing Duplicate NULL Values


Tim,

> Oh well, thanks anyhow.
>
> If I could put in a feature suggestion, it would be a flag that I
could
> set to disallow duplicate nulls.  :)

What for?

NULL is not equal to NULL. Period.

If you don't want NULLs, make the column "not null".

The specification is correct.

With regards,

Martijn Tonies
Database Workbench - developer tool for InterBase, Firebird, MySQL & MS
SQL
Server
Upscene Productions
http://www.upscene.com


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Thread
UNIQUE Key Allowing Duplicate NULL ValuesTim Gustafson22 Feb
  • Re: UNIQUE Key Allowing Duplicate NULL ValuesPaul DuBois22 Feb
RE: UNIQUE Key Allowing Duplicate NULL ValuesTim Gustafson23 Feb
  • RE: UNIQUE Key Allowing Duplicate NULL ValuesPaul DuBois23 Feb
RE: UNIQUE Key Allowing Duplicate NULL ValuesTim Gustafson23 Feb
  • Re: UNIQUE Key Allowing Duplicate NULL ValuesMartijn Tonies23 Feb
RE: UNIQUE Key Allowing Duplicate NULL ValuesTim Gustafson23 Feb
  • Re: UNIQUE Key Allowing Duplicate NULL ValuesMartijn Tonies23 Feb
  • Re: UNIQUE Key Allowing Duplicate NULL ValuesHarald Fuchs23 Feb
Re: UNIQUE Key Allowing Duplicate NULL ValuesMartijn Tonies23 Feb