Re: MySQL ID -- what happens when you run out of range?

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On Mon, Jan 25, 2010 at 18:51, Joseph Thayne <webadmin@xxxxxxxxxxxxx> wrote:

>  That is incorrect.  What will happen is as follows:
>
> 1.  The value will be incremented by 1 causing the value to be greater than
> the maximum integer allowed.
> 2.  MySQL will see this as a problem and "truncate" it to the closest
> value.
> 3.  MySQL will then try and insert the new row with the updated id.
> 4.  MySQL will find that the id already exists, and will return a duplicate
> ID error.
>
> If you want to verify what occurs, create a table with a tinyint value for
> the id and autoincrement it.
>
>
you're absolutely right ! sorry, my bad xD
MySQL does indeed truncate the value to the closest one... I had that
problem once xD (field was tinyint, but signed, which means max value for
that row was 127 instead of 255 which was what I needed, when I tried to
insert any value above 127 it was automaticly truncated to 127).




> It is correct also, that you cannot use negative numbers for the
> autoincrement field.
>
>
> Camilo Sperberg wrote:
>
> On Mon, Jan 25, 2010 at 17:15, Parham Doustdar <parham90@xxxxxxxxx> <parham90@xxxxxxxxx> wrote:
>
>
>
>  Hello there,
> A friend called me today and was wondering what happens if the ID colomn of
> an MYSQL database, set to autoinc reaches the int limit. Will it return and
> begin choosing the ID's that have been deleted, or... what?
> Thanks!
>
>
>
>
>
>  from what I know, MySQL will convert that number into a negative number,
> which would be invalid for an auto-increment field (auto-increment ==
> unsigned). That would raise an error ;)
>
> Greetings :)
>
>
>
>


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