At 9:16 AM -0800 1999-12-11, J C Lawrence wrote:
>Given an auto_increment column, can I trust it to do the right thing
>and roll back to 0 when the max value of the typ is exceeded? What
>happens if 0 is occupied? Does it then find the next available free
No. You should use a type that is large enough to hold the largest
value you expect to have. If the sequence reaches the largest value,
the next attempt to generate a sequence value results in an error.
>Consider the case of an auto_increment unsigned bigint. What
>happens if the last value assigned was 0xFFFFFFFFFFFFFFFF and you
>add a new row? What value does it get? What if there is a row with
>value 0, and value N (say 5) is unassigned?
You cannot have a row with value 0 in an auto-increment column.
Assigning 0 is like assigning NULL - MySQL generates a sequence number
and assigns that instead.
Paul DuBois, paul@stripped