How can I reset the AUTO_INCREMENT
of a field?
I want it to start counting from 1
again.
11
24 Answers
You can reset the counter with:
ALTER TABLE tablename AUTO_INCREMENT = 1
For InnoDB you cannot set the auto_increment
value lower or equal to the highest current index. (quote from ViralPatel):
Note that you cannot reset the counter to a value less than or equal
to any that have already been used. For MyISAM, if the value is less
than or equal to the maximum value currently in the AUTO_INCREMENT
column, the value is reset to the current maximum plus one. For
InnoDB, if the value is less than the current maximum value in the
column, no error occurs and the current sequence value is not changed.
See How can I reset an MySQL AutoIncrement using a MAX value from another table? on how to dynamically get an acceptable value.
4
This can take forever for a filled up table. Be careful with this: stackoverflow.com/questions/2681869/…
– B TBear in mind that MySql will create a new table, with the same structure and new auto_increment value and copy all records from the original table, drop the original and rename the new one. This could have a considerable performance impact (and disk space) on production environments if the table is large.
– Rostol@Rostol Does this problem exist even today (2021 with MySQL 8+)? I see that resetting AUTO_INCREMENT is instantaneous for even large tables. I kind of need the reset feature as I have ON DUPLICATE KEY UPDATE queries that unnecessarily increase the counter every time they are run.
– workwise
SET @num := 0;
UPDATE your_table SET id = @num := (@num+1);
ALTER TABLE your_table AUTO_INCREMENT =1;
I think this will do it
1
Simply like this:
ALTER TABLE tablename AUTO_INCREMENT = value;
Reference: 13.1.9 ALTER TABLE Statement
1
reset
means to set it to the default value … so you can replace “value” by 1– Besnik
There is a very easy way with phpMyAdmin under the “operations” tab. In the table options you can set autoincrement to the number you want.
0
The best solution that worked for me:
ALTER TABLE my_table MODIFY COLUMN ID INT(10) UNSIGNED;
COMMIT;
ALTER TABLE my_table MODIFY COLUMN ID INT(10) UNSIGNED AUTO_INCREMENT;
COMMIT;
It’s fast, works with InnoDB, and I don’t need to know the current maximum value!
This way. the auto increment counter will reset and it will start automatically from the maximum value exists.
0
The highest rated answers to this question all recommend “ALTER yourtable AUTO_INCREMENT= value”. However, this only works when value
in the alter is greater than the current max value of the autoincrement column. According to the MySQL 8 documentation:
You cannot reset the counter to a value less than or equal to the value that is currently in use. For both InnoDB and MyISAM, if the value is less than or equal to the maximum value currently in the AUTO_INCREMENT column, the value is reset to the current maximum AUTO_INCREMENT column value plus one.
In essence, you can only alter AUTO_INCREMENT to increase the value of the autoincrement column, not reset it to 1, as the OP asks in the second part of the question. For options that actually allow you set the AUTO_INCREMENT downward from its current max, take a look at Reorder / reset auto increment primary key.
As of MySQL 5.6 you can use the simple ALTER TABLE with InnoDB:
ALTER TABLE tablename AUTO_INCREMENT = 1;
The documentation are updated to reflect this:
My testing also shows that the table is not copied. The value is simply changed.
There are good options given in How To Reset MySQL Autoincrement Column
Note that ALTER TABLE tablename AUTO_INCREMENT = value;
does not work for InnoDB
1
The link still works, but perhaps summarise here?
You can also use the syntax TRUNCATE
table like this:
TRUNCATE TABLE table_name
Beware! TRUNCATE TABLE your_table
will delete everything in your your_table
.
2
New programmers, be aware that
TRUNCATE
will also delete ALL of your rows in specified table!why delete all ?
ALTER TABLE news_feed DROP id
ALTER TABLE news_feed ADD id BIGINT( 200 ) NOT NULL AUTO_INCREMENT FIRST ,ADD PRIMARY KEY (id)
I used this in some of my scripts. The id field is dropped and then added back with previous settings. All the existent fields within the database table are filled in with the new auto increment values. This should also work with InnoDB.
Note that all the fields within the table will be recounted and will have other ids!!!.
0
It is for an empty table:
ALTER TABLE `table_name` AUTO_INCREMENT = 1;
If you have data, but you want to tidy up it, I recommend to use this:
ALTER TABLE `table_name` DROP `auto_colmn`;
ALTER TABLE `table_name` ADD `auto_colmn` INT( {many you want} ) NOT NULL AUTO_INCREMENT FIRST ,ADD PRIMARY KEY (`auto_colmn`);
0
As of MySQL 5.6 the approach below works faster due to online DDL (note algorithm=inplace
):
alter table tablename auto_increment=1, algorithm=inplace;
1
DDL = data definition language?
Here is my solution, but I will not advise to do this if your column has constraints or is connected as foreign key to other tables as it would have bad effects or will not even work.
First: drop the column
ALTER TABLE tbl_name DROP COLUMN column_id
Second: recreate the column and set it as FIRST if you want it as the first column I assume.
ALTER TABLE tbl_access ADD COLUMN `access_id` int(10) NOT NULL PRIMARY KEY AUTO_INCREMENT FIRST
This works well!
SET @num := 0;
UPDATE your_table SET id = @num := (@num+1);
ALTER TABLE your_table AUTO_INCREMENT =1;
2
An explanation would be in order. E.g., what is the idea/gist? How is it different from other answers? Please respond by editing (changing) your answer, not here in comments (without “Edit:”, “Update:”, or similar – the answer should appear as if it was written today).
@num should be the last Id number on the table. It will add 1 to this and set the next number of Id on insertion to this @Num+1. Then the auto_increment will be set to add 1 to the next ID every time an insertion occurs. Note that t:= and = do the very same thing.
To update to the latest plus one id:
ALTER TABLE table_name AUTO_INCREMENT =
(SELECT (id+1) id FROM table_name order by id desc limit 1);
Edit:
SET @latestId = SELECT id FROM table_name order by id desc limit 1;
SET @latestIdPlusOne = @latestId + 1;
ALTER TABLE table_name AUTO_INCREMENT = @latestIdPlusOne;
Not tested please test before you run*
1
That is kind of confusing. Can you rephrase?
The auto-increment counter for a table can be (re)set in two ways:
By executing a query, like others already explained:
ALTER TABLE <table_name> AUTO_INCREMENT=<table_id>;
Using Workbench or another visual database design tool. I am going to show in Workbench how it is done – but it shouldn’t be much different in other tools as well. By right clicking over the desired table and choosing
Alter table
from the context menu. On the bottom you can see all the available options for altering a table. ChooseOptions
and you will get this form:
Then just set the desired value in the field Auto increment
as shown in the image. This will basically execute the query shown in the first option.
0
I tried to alter the table and set auto_increment to 1 but it did not work. I resolved to delete the column name I was incrementing, then create a new column with your preferred name and set that new column to increment from the onset.
0
You can simply truncate the table to reset the sequence:
TRUNCATE TABLE TABLE_NAME
0
Try to run this query:
ALTER TABLE tablename AUTO_INCREMENT = value;
Or try this query for the reset auto increment
ALTER TABLE `tablename` CHANGE `id` `id` INT(10) UNSIGNED NOT NULL;
And set auto increment and then run this query:
ALTER TABLE `tablename` CHANGE `id` `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT;
I googled and found this question, but the answer I am really looking for fulfils two criteria:
- using purely MySQL queries
- reset an existing table auto-increment to max(id) + 1
Since I couldn’t find exactly what I want here, I have cobbled the answer from various answers and sharing it here.
Few things to note:
- the table in question is InnoDB
- the table uses the field
id
with type asint
as primary key - the only way to do this purely in MySQL is to use stored procedure
- my images below are using SequelPro as the GUI. You should be able to adapt it based on your preferred MySQL editor
- I have tested this on MySQL Ver 14.14 Distrib 5.5.61, for debian-linux-gnu
Step 1: Create Stored Procedure
create a stored procedure like this:
DELIMITER //
CREATE PROCEDURE reset_autoincrement(IN tablename varchar(200))
BEGIN
SET @get_next_inc = CONCAT('SELECT @next_inc := max(id) + 1 FROM ',tablename,';');
PREPARE stmt FROM @get_next_inc;
EXECUTE stmt;
SELECT @next_inc AS result;
DEALLOCATE PREPARE stmt;
set @alter_statement = concat('ALTER TABLE ', tablename, ' AUTO_INCREMENT = ', @next_inc, ';');
PREPARE stmt FROM @alter_statement;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END //
DELIMITER ;
Then run it.
Before run, it looks like this when you look under Stored Procedures in your database.
When I run, I simply select the stored procedure and press Run Selection
Note: the delimiters part are crucial. Hence if you copy and paste from the top selected answers in this question, they tend not to work for this reason.
After I run, I should see the stored procedure
If you need to change the stored procedure, you need to delete the stored procedure, then select to run again.
Step 2: Call the stored procedure
This time you can simply use normal MySQL queries.
call reset_autoincrement('products');
Originally from my own SQL queries notes in https://simkimsia.com/reset-mysql-autoincrement-to-max-id-plus-1/ and adapted for Stack Overflow.
2
The link is broken: “Not Found. The requested resource was not found on this server.”
Thank you, @PeterMortensen. I have fixed the broken link.
The best way is remove the field with AI and add it again with AI. It works for all tables.
1
What is “AI”? Artificial intelligence? Or something else?
You need to follow the advice from Miles M’s comment and here is some PHP code that fixes the range in MySQL. Also you need to open up the my.ini file (MySQL) and change max_execution_time=60 to max_execution_time=6000; for large databases.
Don’t use “ALTER TABLE tablename AUTO_INCREMENT = 1”. It will delete everything in your database.
$con = mysqli_connect($dbhost, $dbuser, $dbpass, $database);
$res = mysqli_query($con, "select * FROM data WHERE id LIKE id ORDER BY id ASC");
$count = 0;
while ($row = mysqli_fetch_array($res)){
$count++;
mysqli_query($con, "UPDATE data SET id='".$count."' WHERE id='".$row['id']."'");
}
echo 'Done reseting id';
mysqli_close($con);
1
Re “Miles M’s comment”: Do you mean Miles M’s answer?
I suggest you to go to Query Browser and do the following:
Go to schemata and find the table you want to alter.
Right click and select copy create statement.
Open a result tab and paste the create statement their.
Go to the last line of the create statement and look for the Auto_Increment=N,
(Where N is a current number for auto_increment field.)Replace N with 1.
Press Ctrl + Enter.
Auto_increment should reset to one once you enter a new row in the table.
I don’t know what will happen if you try to add a row where an auto_increment field value already exist.
0
You may get a better response on the site for DBAs at dba.stackexchange.com
You’ll probably want to empty the table too:
TRUNCATE TABLE yourTableName;
possible duplicate of MySQL: Reorder/Reset auto increment primary key?
yes, truncate table is best in this case. it also reset auto increment start to 1.
Sometimes you don’t have permission to TRUNCATE as that requires DROP permissions.