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From:Yang Zhang Date:January 25 2010 3:39pm
Subject:Re: auto_increment without primary key in innodb?
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Right, I saw the docs. I'm fine with creating an index on it, but the
only way I've successfully created a table with auto_increment is by
making it a primary key. And I still don't understand why this
requirement is there in the first place.

On Mon, Jan 25, 2010 at 10:32 AM, Tom Worster <fsb@stripped> wrote:
> it's not an innodb thing:
>
> http://dev.mysql.com/doc/refman/5.0/en/create-table.html
>
> "Note
> "There can be only one AUTO_INCREMENT column per table, it must be indexed, and it
> cannot have a DEFAULT value. An AUTO_INCREMENT column works properly only if it contains
> only positive values. Inserting a negative number is regarded as inserting a very large
> positive number. This is done to avoid precision problems when numbers “wrap”
> over from positive to negative and also to ensure that you do not accidentally get an
> AUTO_INCREMENT column that contains 0."
>
> -----Original Message-----
> From: "Yang Zhang" <yanghatespam@stripped>
> Sent: Monday, January 25, 2010 10:21am
> To: mysql@stripped
> Subject: auto_increment without primary key in innodb?
>
> In innodb, is it possible to have an auto_increment field without
> making it a (part of a) primary key? Why is this a requirement? I'm
> getting the following error. Thanks in advance.
>
> ERROR 1075 (42000): Incorrect table definition; there can be only one
> auto column and it must be defined as a key
> --
> Yang Zhang
> http://www.mit.edu/~y_z/
>
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>
>



-- 
Yang Zhang
http://www.mit.edu/~y_z/
Thread
auto_increment without primary key in innodb?Yang Zhang25 Jan
  • RE: auto increment without primary key in innodb?Tom Worster25 Jan
    • Re: auto_increment without primary key in innodb?Yang Zhang25 Jan
      • Re: auto_increment without primary key in innodb?Jaime Crespo Rinc√≥n25 Jan
      • Re: auto_increment without primary key in innodb?Paul DuBois25 Jan
  • Re: auto_increment without primary key in innodb?Yong Lee26 Jan
    • Re: auto_increment without primary key in innodb?Johan De Meersman26 Jan