[ale] Getting the next index of a table in mysql

[James Sumners]

"SELECT LAST_INSERT_ID();"

Scroll down until you find it (stupid site doesn't have anchors) --
http://dev.mysql.com/doc/mysql/en/information-functions.html

On 6/9/05, Chris Fowler <cfowler at outpostsentinel.com> wrote:
> I'm going to control deletion.  Once a row is inserted it can not be
> changed.
> 
> There is a problem if the user does do the following in an empty DB.
> 
> insert into sensor_533 values (533, now());
> 
> Now max will retrieve the 533 as the max with only one row in the DB.
> 
> > Checking the new Row ID after an insert is the only real way to go
> about it.
> 
> This might be the best way but how do I do this?  "select serial_no from
> table_533 where ....."
> 
> The table is very simple for now.
> 
>  CREATE TABLE sensor_533 (
>   serial_no INTEGER(9) NOT NULL AUTO_INCREMENT,
>   issued DATETIME NOT NULL,
>   PRIMARY KEY(serial_no),
> );
> 
> CREATE TABLE device (
>   device_id INTEGER(11) NOT NULL AUTO_INCREMENT,
>   name VARCHAR(20) NULL,
>   table_name VARCHAR(20) NULL,
>   PRIMARY KEY(device_id),
> );
> 
> insert into device values (0, "533", "sensor_533");
> 
> Evan that method has the same problem as select max(...)  In the MySQL
> documents it stated that the auto_increment value was stored in memory
> at startup and the program simply does a select max(...) to get the
> correct value.
> 
> 
> 
> On Thu, 2005-06-09 at 09:05 -0400, Michael B. Trausch wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: RIPEMD160
> >
> > Chris Fowler wrote:
> > >
> > > I've attached a perl program where I hacked out a way to get the next
> > > logical entry.  This program does not do the insert yet.
> > >
> >
> > Just note that if entries are added and deleted and so forth, that this
> > will not be accurate.  The program is selecting the highest current
> > serial number, when in fact, I could add 500 rows, and then delete them
> > all.  The max serial would then be (next_incremented_serial-501), and
> > then you'd be out of sync with the DB.  In addition, when you next
> > INSERT using a non-explicit ID count, you'll be out of sync.
> >
> >       - Mike
> >
> > - --
> > Michael B. Trausch                                     fd0man at gmail.com
> > Web: http://fd0man.theunixplace.com/        Jabber: mtrausch at jabber.com
> > Phone: +1-(678)-522-7934                  FAX (US Only): 1-866-806-4647
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-- 
James Sumners
http://james.roomfullofmirrors.com/

"All governments suffer a recurring problem: Power attracts
pathological personalities. It is not that power corrupts but that it
is magnetic to the corruptible. Such people have a tendency to become
drunk on violence, a condition to which they are quickly addicted."

Missionaria Protectiva, Text QIV (decto)
CH:D 59