MySQL Auto-Increment Issue – Table Shows ID (Auto-Increment) as 0 in All Rows

auto-incrementMySQLphpmyadmin

I am using laravel 5.2 to develop my web application. i recently uploaded the web application from localhost to my hosting account. I also imported MySQL tables from phpmyadmin localhost to my phpmyadmin localhost in my hosting account.

When I opened my phpmyadmin I noticed that in one of my tables, the id (which is set to auto-increment) is not working. It is displaying 0 in all the rows.

When I set the id to auto-increment in phpmyadmin it gives me the following error:

#1075 – Incorrect table definition; there can be only one auto column and it must be defined as a key

Table structure in phpmyadmin

`SHOW CREATE TABLE`

Best Answer

The problem is that you can not create AUTO_INCREMENT without a key so try something like this:

CREATE TABLE `project_application` (
`id` int(11) NOT NULL PRIMARY KEY AUTO_INCREMENT,
`user_id` int(11) NOT NULL,
`project_title` varchar(255) NOT NULL,
`project_id` int(11) NOT NULL,
`team_leader` varchar(255) NOT NULL,
`team_member` text,
`created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE     CURRENT_TIMESTAMP,
`createt_et` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00'
)

Hope this helps

SUGGESTION

If the table has barely 1000 rows, you could manually compress it and force to have MAX(id) each time. Suppose the table looks something like this:

USE mydb
CREATE TABLE x
(
    id INT NOT NULL AUTO_INCREMENT,
    ...
    PRIMARY KEY (id)
);

Try doing OPTIMIZE TABLE manually as follows:

InnoDB or MyISAM tables with no non-unique keys

USE mydb
CREATE TABLE x_new LIKE x;
INSERT INTO x_new SELECT * FROM x ORDER BY id;
ALTER TABLE x RENAME x_old;
ALTER TABLE x_new RENAME x;
DROP TABLE x_old;

MyISAM tables with non-unique keys

USE mydb
CREATE TABLE x_new LIKE x;
ALTER TABLE x_new DISABLE KEYS;
INSERT INTO x_new SELECT * FROM x ORDER BY id;
ALTER TABLE x_new ENABLE KEYS;
ALTER TABLE x RENAME x_old;
ALTER TABLE x_new RENAME x;
DROP TABLE x_old;

This should preserve all id's and assign AUTO_INCREMENT appropriately.

It should work just fine with MySQL Replication.

CAVEAT

If the ids are different for any reason between Master and Slave, blame MySQL (I mean blame Oracle) : http://dev.mysql.com/doc/refman/5.5/en/replication-features-auto-increment.html

If the aforementioned suggestion does not rectify this, there is only one thing left to do and it is guaranteed to work. What is it?

Run this on the Master Only:

mysqldump -uroot -p... --triggers mydb x > mydb_x.sql
mysql -uroot -p... -Dmydb < mydb_x.sql

With a table of 1000 rows, this should

go pretty quickly
replicate and produce an exact copy on the slave
restore auto_increment behavior to Master and Slave

Give it a Try !!!

UPDATE 2013-02-11 19:30 EDT

Let's assume that x and xhistory have identical layouts. Let's also add some columns:

CREATE TABLE x
(
    xid int(10) unsigned NOT NULL AUTO_INCREMENT,
    col1 ... ,
    col2 ... ,
    col3 ... ,
    PRIMARY KEY (xid)
) ENGINE=MyISAM AUTO_INCREMENT=124 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

CREATE TABLE xhistory
(
    xid int(10) unsigned NOT NULL DEFAULT '0',
    col1 ... ,
    col2 ... ,
    col3 ... ,
    PRIMARY KEY (xid)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

Perhaps you could just use the REPLACE command. It mechanically operates as either an INSERT or UPDATE via DELETE and INSERT.

REPLACE INTO xhistory SELECT * FROM x;
TRUNCATE TABLE x;

Previously existing rows get deleted from xhistory and then inserted from x into xhistory. New rows are simply inserted.

How to Reset MySQL Table Auto-Increment to 1 in phpMyAdmin

phpmyadmin

Perhaps you could just select the phpMyAdmin Operations tab:

In phpMyAdmin, click on the table you want to reset or change the AUTO_INCREMENT value
Click on the Operations Tab
In the Table Options box find the auto_increment field.
Enter the new auto_increment starting value
Click on the Go button for the Table Options box.

Since this one of the most frequently asked questions for phpmyadmin, you can learn more about this in this blog : http://trebleclick.blogspot.com/2009/01/mysql-set-auto-increment-in-phpmyadmin.html

Supplemental Info

For an empty table, another way to reset the auto_increment attribute is to run

TRUNCATE TABLE mydb.tablename;

Don't run this if you have data in it. If you want to hose the data, then be my guest.

In phpmyadmin, just click the SQL tab, enter the command, and run it.

For a nonempty table, you may want to adjust the auto_increment attribute to the highest existing id in use in case higher entries were deleted.

First, optimize the table

OPTIMIZE TABLE mydb.mytable;

Next, locate the highest value for the auto_increment column (say it is id)

SELECT MAX(id) maxid FROM mydb.mytable;

Suppose the answer returns 27. Goto the Operations tab and enter 28.