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:
> "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
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