mulitiple primary keys in a table

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SQL-Server

how to set multiple primary keys in a table
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Posted 20-Oct-13 18:35pm

King Fisher

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Thanks7872 21-Oct-13 0:44am

What? Multiple Primary key? Can you please elaborate your question?

Sergey Alexandrovich Kryukov 21-Oct-13 1:00am

I think I understand the question, please see my answer.
—SA

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Sergey Alexandrovich Kryukov · Accepted Answer · 2013-10-20T18:53:00

In addition to Solution 1:

It would be very useful for you to learn some basics first, in particular, about unique and primary keys. Please see: http://en.wikipedia.org/wiki/Primary_key[^].

Pay attention for the section: "Differences between Primary Key and Unique Key":

Wikipedia says:
Each table can have at most one primary key.

So, no, you cannot have multiple primary keys. And you don't want it. It would not really make sense. The mere fact that the multiplicity of COLUMN expression in the syntax diagram is 1+ should be enough for you.

—SA

Soumitra Mithu · Accepted Answer · 2013-10-20T18:40:00

Solution 1

you can use composite primary key in your table.
Check this link.

Posted 20-Oct-13 18:40pm

Soumitra Mithu

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Sergey Alexandrovich Kryukov 21-Oct-13 0:59am

This is quite correct, but it does not formally answers the question. And the answer should be "no, a table cannot have multiple primary keys". And only than bring to OP's attention the use of composite keys. Please see my answer and the referenced article.
I voted 4.
—SA