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From:Hank Date:May 5 2005 1:17am
Subject:Re: Unique Index on multiple columns that can contain NULL in MySQL
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I think you should review the very recent thread "why NOT NULL in
PRIMARY key??" which might shed some light on your particular issue.

In a nutshell, NULL!=NULL, so the database engine can not detect the
duplicate rows, as is expected.

-Hank

On 5/4/05, Dennis Fogg <dennisfogg@stripped> wrote:
> I'm getting lots of duplicate rows even though I have a
> unique index defined over multiple columns.
Thread
Unique Index on multiple columns that can contain NULL in MySQLDennis Fogg5 May
  • Re: Unique Index on multiple columns that can contain NULL in MySQLHank5 May
  • Re: Unique Index on multiple columns that can contain NULL in MySQLJigal van Hemert5 May
  • Re: Unique Index on multiple columns that can contain NULL in MySQLMartijn Tonies5 May