How to change my MySQL root password back to empty?

Solution 1:

To change the root password to newpassword:

 mysqladmin -u root -p'oldpassword' password 'newpassword'

To change it so root doesn't require a password:

 mysqladmin -u root -p'oldpassword' password ''

Note: I think it matters that there isn't a space between the -p and 'oldpassword' but I may be wrong about that

Solution 2:

Rather than removing the password (which may have unpleasant consequences in the future if you happen to expose that server to the wilds), put the current password (and your username) into ~/.my.cnf (or presumably some equivalent location in Windows) that looks like this:

[client]
user = root
password = s3kr1t

This gives MySQL the awesome ability to autologin using the credentials provided, without leaving you wide open for unpleasantness in the future.

Solution 3:

1. Stop mysqld and restart it with the --skip-grant-tables option.
2. Connect to it using just mysql.
3. Change the root password:

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

FLUSH PRIVILEGES;

For reference: the official mysql docs.

Solution 4:

Note that starting with MySQL 5.7, the validate_password plugin is active by default, and prevents you from using an empty password.

You need to disable this plugin to allow for an empty password:

UNINSTALL PLUGIN validate_password;
SET PASSWORD FOR root@localhost = PASSWORD('');

Be careful that unless you don't care about security, you should follow @womble's advice and use a password, along with a .my.cnf file for convenience.

Check my article Removing the MySQL root password on this topic!

Solution 5:

In newer versions

UPDATE mysql.user SET authentication_string=PASSWORD('MyNewPass') WHERE User='root'

and this will remove password

UPDATE mysql.user SET authentication_string=PASSWORD('') WHERE User='root'