Question about Primary Key

PK columns cannot be null. But you can get uniqueness by
creating it as a unique constraint or unique index... Bruce

>--Original Message--
>I want to create a Primay Key
>as combination of 3 fields.
>Prod_NO
>Prod_Item
>Prod_cont
>In this case there is a chance that PRod_item
>or Prod_Cont will be blank, can I still create
>these three as Primary Key? If not, what is the
>alternate way to do so?
>Thank you,
>.
>Bruce,
I think what you suggested will work, but do you foresee
any other problems in this? Will everything else
work the same? I haven't used it any times hence
the question.
Thank you,
-M
"Bruce de Freitas" wrote:

> PK columns cannot be null. But you can get uniqueness by
> creating it as a unique constraint or unique index... Bruce
>
>|||It depends...
PK Constraints do not allow NULLs, but UNIQUE constraints allow a single
NULL.
So if your data looked like:
1, NULL, NULL
That would be okay for a UNIQUE Constraint.
Another record of
1, NULL, NULL will violate the constraint however.
HTH
Rick Sawtell
MCT, MCSD, MCDBA
"Me" <Me@.discussions.microsoft.com> wrote in message
news:33CCE845-1F74-4FE3-9570-B79E0D442C20@.microsoft.com...[vbcol=seagreen]
> Bruce,
> I think what you suggested will work, but do you foresee
> any other problems in this? Will everything else
> work the same? I haven't used it any times hence
> the question.
> Thank you,
> -M
> "Bruce de Freitas" wrote:
>