Re: Unique Index on multiple columns that can contain NULL in MySQL

[Hank]

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.