Re: Unique Key

Juan Carlos wrote on 27-Jul-99 23:00:06:
>We want to create a xref table for SSN and an Employee ID which will be
>different. The table will just be those two columns. But I have a
>dilemma. If I make SSN the PK, this would allow duplicate Employee
>ID's. If I make it a composite PK, it would be possible to have
>duplicate SSN's but different Employee ID's. Is there a way to make
>the unique and distinct at the same time without triggers? JerryTWP: el
>subject debe ser "Unique Key"

Yes, there is a way:

1. Set the PK to SSN
2. Create an additional unique index on Emp ID

This should solve your problem.

Hope that helps,
Lothar

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