Access denied for user 'root'@'localhost' (using password: NO) for MySQL 8.0+

Question

Initially mysql -u root was working fine.

Then I tried to reset root user password using below command

UPDATE set authentication_string=PASSWORD("password") where User='root';

But when I tried mysql -u root -ppassword it's throwing

access denied for user 'root'@'localhost' (using password: NO)

Answer 1

So to fix above solution do following steps:

1. First search where your mysql scripts exist in your system using which mysql

/usr/local/bin/mysql

2. run cd /usr/local/bin
3. Then look for mysql.server file and execute mysql.server stop

output is:
Shutting down MySQL
. SUCCESS!

4. run killall mysqld mysqld_safe
5. run mysqld_safe --skip-grant-tables &
6. Then try mysql -u root it will work

So next step is to update the root password back to <no-password>

7. run use mysql;
8. run Update user set authentication_string='' where User='root';

NOTE: To update mysql 8.0+ password, always use

ALTER USER 'root'@'localhost' IDENTIFIED BY 'newpassword';