How to add the candidate key?

Hello
can you explain to me what is candidate key?

Suppose I created the table

SQL > create table t3
(a number;
b the number,
c number);
Table created.

Now how to add candidate key?

Now how to add candidate key?

Maybe

alter table t3 add candidate_key number;

(Sorry, couldn't resist.)

Concerning
Peter
http://en.Wikipedia.org/wiki/Candidate_key

Published by: Peter on December 10, 2009 02:12
-You wonder how this was considered "correct".

Tags: Database

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