Comments on: MySQL: Reset Auto Increament Number

By: anhtrue

anhtrue — Sun, 26 Jul 2009 17:53:26 +0000

thanks a lot! it is very helpful. I have the same problem with my database.

By: sandeep

sandeep — Fri, 24 Jul 2009 14:45:10 +0000

SET @var_name = 0;
UPDATE gmid SET ID = (@var_name := @var_name +1);

Wow Bach You Are God Man i have a huge problem 100000 records and in first 500 i had a huge gap like after id30 next record starts from id 167 i run that and voilla my ids are starts again from 1 and all sorted man u make my day thank you genius !!

By: pablo

pablo — Sat, 10 Feb 2007 01:16:04 +0000

“OMW” does that mean “Oh my Woz”? because Wozzie’s kinda like a god… to some.

Seriously though,
ALTER TABLE Tablename AUTO_INCREMENT = 6;
Genius!

Thanks so much.

By: william

william — Fri, 26 Jan 2007 11:10:42 +0000

OMW… you just saved me having to re-enter like 400 records this afternoon. you’re the best Bach

By: Bach

Bach — Tue, 23 Jan 2007 21:46:53 +0000

To Eugene:

To re number the ID instead you can do this magic trick:

SET @var_name = 0;
UPDATE Tablename SET ID = (@var_name := @var_name +1);

You can change @var_name to start from 80, and your ID will be:
81, 82,83, …

then combine it with

ALTER TABLE Tablename AUTO_INCREMENT = 6;

So the next auto_increment will be 6 , and all your ID is 1,2,3,4,5.
Hope this helps.

Thanks.

By: T2_T2

T2_T2 — Wed, 24 May 2006 07:13:08 +0000

If my primary key is Auto increament then what happens when it crosses its upper limit ?
How to find the upper limit ?

By: Eugene

Eugene — Mon, 22 May 2006 23:35:06 +0000

Hey Liew, thanks for that piece of infomation, but i am looking at how to renumber the ID instead.

Example, i have 7 records and i deleted ID 4 and ID 5, so i would like to renumber all the ID and so that the last auto number is 5.

By: Marvin

Marvin — Thu, 02 Feb 2006 20:26:21 +0000

Thanks ALOT! this helped me sooo much !

By: Peter

Peter — Sat, 29 Oct 2005 12:43:17 +0000

Thanks a lot for writing this down and publishing it.

I found you via Google with a search of
mysql auto_increment reset
and it was precisely the piece of information I needed.

@moo_t – why reset primary key?
In my NucleusCMS I would like to publish a new blog (the fourth one). The blogid is visible in the url as index.php?blogid=x.

As I had setup new blogs and deleted them, my supposed blog nr. 4 had blogid=7. It may be a cosmetic change, but from a users point of view (and from mine too) it’s just not logical if blog nr. 4 has id nr. 7

By: Ray

Ray — Mon, 26 Sep 2005 08:19:51 +0000

I have the same problem…

I want to do this because I will run out of records after a few months/years.

By: moo_t

moo_t — Wed, 06 Oct 2004 12:13:14 +0000

Just don’t understand in what circumstances you want to reuse the Primary key.

And for sorting, btree table is good enough for daily usage.

By: tkh

tkh — Sun, 18 Apr 2004 03:56:54 +0000

SQL not a problem to me… thks for ur advice

By: LcF

LcF — Fri, 16 Apr 2004 05:48:42 +0000

if you know SQL then MySQL is not a problem to you.
just sometimes need to refer to its specified commands..

By: tkh

tkh — Fri, 16 Apr 2004 03:56:21 +0000

Havent learn mysql yet. going to start after my final. always take extra subject in every sem, after minus all my assignment + project.. dont have much space for me to learn other knowledge..

By: LcF

LcF — Thu, 15 Apr 2004 08:47:34 +0000

the first condition to use insert_id is you must provide the auto increament value that you want to use.
Do you mean that whenever you insert a new record, the new record will fill in the gap(s)? I have no idea about it yet and I don’t think it is good idea to do so. In what situation you need insert record like this?

Or, do you mean sort the records accordingly? Maybe you can do like this: Get the total number of records. Run a for loop, check the auto increament column value against loop seed. Alter the column value if not match.

By: spoonfork

spoonfork — Thu, 15 Apr 2004 08:21:07 +0000

yeah, but how would you automatically locate the gaps in insert_id if the records are deleted randomly?