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

On Mon, Jan 25, 2010 at 18:51, Joseph Thayne <webadmin@thaynefam.org> 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@gmail.com> > <parham90@gmail.com> 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 :) > > > > -- Mailed by: UnReAl4U - unreal4u ICQ #: 54472056 www1: http://www.chw.net/ www2: http://unreal4u.com/