How to change the mysql root password

问题:

I have installed MySQL server 5 on redhat linux. I can't login as root so I can't change the root password.

mysql -u root -p  
Enter password:  <blank>
ERROR 1045 (28000): Access denied for user 'root'@'localhost'
(using password: NO)

When I try to set one like this:

mysqladmin -u root password 'newpass'

I get an error:

mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' 
(using password: NO)'

As if there is a root password set.

I have also tried resetting the password using (described here)

/sbin/service mysqld start --skip-grant-tables

And then making:

mysql> UPDATE mysql.user SET Password=PASSWORD('newpass')     
->  WHERE User='root';  
ERROR 1142 (42000): UPDATE command denied to user ''@'localhost' for table 'user'

I even uninstalled mysql-server (using yum) and then reinstalled it but that did not help.

How do I force reset the root password?

回答1:

One option is to save UPDATE mysql.user SET Password=PASSWORD('newpass') WHERE User='root'; into a file and then manually start mysqld with --init-file=FILENAME. Once the server starts, it should reset your password, and then you should be able to log in. After this, you should shut down the server and start it normally.

回答2:

The root user password is an empty string by default.

And (using password: NO) says that there is no password.

Do you try to login from another system? I imagine you can only login as root user locally.

回答3:

I removed the MySQL installation and deleted the data files, and then reinstalled it.

Then I was able to set the root password. Once you set the root password to something. mysqladmin won't let you reset it if you don't know it.

To reset it, you've got to have ownership over how mysqld is executed, and feed it an init file to change the root password: https://dev.mysql.com/doc/refman/5.0/en/resetting-permissions.html

回答4:

Remove the -p from your command. -p forces the prompt for password.

Use : mysql -u root

This will resolve your problem.

回答5:

Try do this:

mysql -u root

and then:

mysql> UPDATE mysql.user SET Password=PASSWORD('MyNewPass')
    ->                   WHERE User='root'; 

mysql> FLUSH PRIVILEGES;

Worked fine for me!

回答6:

This helped me on Windows with MySQL Server 5.6. Make sure you change the mysqld path to point to where you have installed MySql Server, for me it was "C:\Program Files\mysql\MySQL Server 5.6\bin\mysqld.exe":

1. Log on to your system as Administrator.

2. Stop the MySQL server if it is running. For a server that is running as a Windows service, go to the Services manager: From the Start menu, select Control Panel, then Administrative Tools, then Services. Find the MySQL service in the list and stop it.

   If your server is not running as a service, you may need to use the Task Manager to force it to stop.

3. Create a text file containing the following statements. Replace the password with the password that you want to use.

   UPDATE mysql.user SET Password=PASSWORD('MyNewPass') WHERE User='root';
   FLUSH PRIVILEGES;
   

   Write the UPDATE and FLUSH statements each on a single line. The UPDATE statement resets the password for all root accounts, and the FLUSH statement tells the server to reload the grant tables into memory so that it notices the password change.

4. Save the file. For this example, the file will be named C:\mysql-init.txt.

5. Open a console window to get to the command prompt: From the Start menu, select Run, then enter cmd as the command to be run.

6. Start the MySQL server with the special --init-file option (notice that the backslash in the option value is doubled):

   C:\> C:\mysql\bin\mysqld --init-file=C:\\mysql-init.txt
   

   If you installed MySQL to a location other than C:\mysql, adjust the command accordingly.

   The server executes the contents of the file named by the --init-file option at startup, changing each root account password.

   You can also add the --console option to the command if you want server output to appear in the console window rather than in a log file.

   If you installed MySQL using the MySQL Installation Wizard, you may need to specify a --defaults-file option:

   C:\> "C:\Program Files\MySQL\MySQL Server 5.5\bin\mysqld.exe"
        --defaults-file="C:\\Program Files\\MySQL\\MySQL Server 5.5\\my.ini"
        --init-file=C:\\mysql-init.txt
   

   The appropriate --defaults-file setting can be found using the Services Manager: From the Start menu, select Control Panel, then Administrative Tools, then Services. Find the MySQL service in the list, right-click it, and choose the Properties option. The Path to executable field contains the --defaults-file setting.

7. After the server has started successfully, delete C:\mysql-init.txt.

http://docs.oracle.com/cd/E17952_01/refman-5.5-en/resetting-permissions.html

回答7:

Probably a bit late here , but here is what I did :

create file resetpass.sh which has :

UPDATE mysql.user SET Password=PASSWORD('newpassword') WHERE User='root';

# mysqld_safe --init-file=resetpass.sh

# service mysqld start --skip-grant-tables

# mysql -u root -p

Enter pass

mysql >  change root pass ; flush privs; 

quit

# restart mysql service 

The MySQL version I was using was 5.1.73 under centos6

回答8:

A little late to the game, but I had the same issue on a raspberry pi install and found out that it needs elevation. Adding a sudo to the front of the password change allowed it to work.

sudo mysqladmin -u root password 'newpass'

followed by an elevated sql access

sudo mysql -u root -p  

If either are not run as sudo, it will fail.

回答9:

According to the docs, in MySQL 5.7 the temp password gets put in /var/log/mysqld, but this is evidently not the case in 5.6.

With MySQL version 5.6 installed on RHEL 6.7, I finally found the temporary root password set during install was placed in the file /root/.mysql_secret.