[OFF TOPIC] Re: mysqldb simple question (find unique number)

[Bob Kline]

On Thu, 26 Apr 2001, Brian Langenberger wrote:

> : Of course, you will realise that problems might arise should any two users
> : concurrently try to use any such routine, since NySQL (as far as I remember)
> : does not support transactions.
> 
> It might be better to simply use MySQL's "auto_increment" tag for
> the key column.  That way, one can simply use "0" as the ID number
> and MySQL will automatically generate a new, unique ID.
> 
> Of course, if you need to return that same ID again for other 
> purposes, you'll need the max() function along with some table 
> locking before and aftwarwards (to keep the process atomic).  

This is really in the wrong mailing list [1] for this discussion, but I
believe MySQL supports what is needed here without the need for table
locking.  Take a look at the documentation [2] for the LAST_INSERT_ID()
function, which returns the last automatically generated value that was
inserted into an AUTO_INCREMENT column on a per-connection basis.

[1] http://www.mysql.com/documentation/lists.html
[2] http://www.mysql.com/documentation/mysql/bychapter/manual_Reference.html#Miscellaneous_functions

-- 
Bob Kline
mailto:bkline at rksystems.com
http://www.rksystems.com