Does MySQL allow two primary keys on one table?

Posted by Bharanikumar on Stack Overflow See other posts from Stack Overflow or by Bharanikumar
Published on 2010-05-18T02:42:05Z Indexed on 2010/05/18 4:10 UTC
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sql

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mysql

CREATE TABLE Orders
-> (
->    ID SMALLINT UNSIGNED NOT NULL,
->    ModelID SMALLINT UNSIGNED NOT NULL,
->    Descrip VARCHAR(40),
->    PRIMARY KEY (ID, ModelID)
-> );

Basically, this appears to me to be creating two primary key on one table. Is that correct?

I thought that we could create a number of unique keys in one table, but only one primary key.

How is it that my system is allowing the creation of multiple primary keys?

Please advise: what are the rules governing this?

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