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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: <a rel="nofollow" href="http://fd0man.theunixplace.com/";>http://fd0man.theunixplace.com/</a> Jabber: mtrausch at jabber.com
> > Phone: +1-(678)-522-7934 FAX (US Only): 1-866-806-4647
> > =======================================================================
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> >
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--
James Sumners
<a rel="nofollow" href="http://james.roomfullofmirrors.com/";>http://james.roomfullofmirrors.com/</a>
"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
</pre>
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<ul><li><strong>References</strong>:
<ul>
<li><strong><a name="00401" href="msg00401.html">[ale] Getting the next index of a table in mysql</a></strong>
<ul><li><em>From:</em> cfowler at outpostsentinel.com (Chris Fowler)</li></ul></li>
<li><strong><a name="00402" href="msg00402.html">[ale] Getting the next index of a table in mysql</a></strong>
<ul><li><em>From:</em> james.sumners at gmail.com (James Sumners)</li></ul></li>
<li><strong><a name="00403" href="msg00403.html">[ale] Getting the next index of a table in mysql</a></strong>
<ul><li><em>From:</em> fd0man at gmail.com (Michael B. Trausch)</li></ul></li>
<li><strong><a name="00405" href="msg00405.html">[ale] Getting the next index of a table in mysql</a></strong>
<ul><li><em>From:</em> cfowler at outpostsentinel.com (Chris Fowler)</li></ul></li>
<li><strong><a name="00406" href="msg00406.html">[ale] Getting the next index of a table in mysql</a></strong>
<ul><li><em>From:</em> fd0man at gmail.com (Michael B. Trausch)</li></ul></li>
<li><strong><a name="00407" href="msg00407.html">[ale] Getting the next index of a table in mysql</a></strong>
<ul><li><em>From:</em> cfowler at outpostsentinel.com (Chris Fowler)</li></ul></li>
</ul></li></ul>
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