Just like I thought, session_id is a varchar. Varchars alphabetize like this:
0
1
10
11
2
3
4
5
6
7
8
9
So 9 is the max, which isn't what you want. Make session_id a number, or make sure you always zero-pad it, or initialize it to "aaaaaaaaaa", or something.

Update: Don't know if it's possible two copies of this script could run at the same time, but you might have a problem with two different sessions creating the same new session id at once. Might be better for you to do something like: 

insert into sessions (session_id, session_date)
select max(session_id)+1, ?
from sessions

[download]
... or anything else that does proper locking.

In reply to Re: yesterday I posted this and you all aksed for more info so ........ by no_slogan
in thread SQL unique IDs and Sessions (was: yesterday I posted this and you all aksed for more info so ........) by esolm

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