Talk:Unique key: Difference between revisions

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Remark

Unique with respect to DBMS is a value which is unique. Unique key is like a primary key but unique key may start from "0".

Such semantics (=0) are by no means implied by unique keys. --Stolze 14:48, 14 February 2007 (UTC)[reply]

As "The values in a unique key columns may ... be NULL"; it is not possible that: "A unique key must uniquely identify all possible rows that exist in a table" because rows that are identified by NULL cannot be uniquely distinguished. 212.136.56.20 12:16, 27 July 2007 (UTC)[reply]

Please delete this article -- it's redundant

Editors,

This article, "Unique Key", is redundant with Candidate Key, Primary Key and Superkey. It has no reason to exist. Please delete it. Jberkus 20:04, 23 September 2006 (UTC)[reply]

Take it to WP:AFD if you feel that strongly about it. --Spartaz 21:47, 23 September 2006 (UTC)[reply]

the primary key page doesn't really explain unique key, if this is removed it would be helpful to move the info there.

I copied the contect from the PK article here because it logically belongs here (PK is just a special unique key). Unless there are some objects, I will make primary key a redirect to this article here. --Stolze 14:48, 14 February 2007 (UTC)[reply]

@@ Line 2: / Line 2: @@
 ==Remark==
 Unique with respect to DBMS is a value which is unique. Unique key is like a primary key but unique key may start from "0".
 :Such semantics (=0) are by no means implied by unique keys. --[[User:Stolze|Stolze]] 14:48, 14 February 2007 (UTC)
+As "The values in a unique key columns may ... be NULL"; it is not possible that: "A unique key must uniquely identify all possible rows that exist in a table" because rows that are identified by NULL cannot be uniquely distinguished. [[User:212.136.56.20|212.136.56.20]] 12:16, 27 July 2007 (UTC)
 == Please delete this article -- it's redundant ==