Access denied for user 'root'@'localhost' even password is correct

Error : SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket

Step 1 : For backup = cp -rfv /var/lib/mysql /var/lib/mysql$(date +%s)

Step 2 : sudo /etc/init.d/mysql stop

Step 3 : sudo mysqld_safe --skip-grant-tables & (If process will not complete after 5 minuts keep this window open and open another terminal window)

Step 4 :  mysql -u root -p 

Step 5 : FLUSH PRIVILEGES;

Step 6 : UPDATE user SET Grant_priv = 1, Super_priv = 1 WHERE user = 'root'

Step 7 : update user set password=PASSWORD("Franki3r0s3") where User='root';

Step 8 : GRANT ALL PRIVILEGES ON . TO 'root'@'localhost' IDENTIFIED BY 'anki8f0s3';

Additional commands : 

1. mysql# show users;
2. mysql# SELECT User FROM mysql.user;
3. ps -e | grep mysqld
4. kill -kill 16300
5. ps -x

How to reset MySQL / phpmyadmin root password on Ubuntu 18.04 Linux

1. The simplest approach to reset MySQL database root password is to execute mysql_secure_installation program and when prompted entering your new root MySQL password:

sudo mysql_secure_installation

New password:
Re-enter new password:

2. Let's stop the currently running MySQL database:

sudo service mysql stop

3. create a /var/run/mysqld directory to be used by MySQL process to store and access socket file:

sudo mkdir -p /var/run/mysqld
sudo chown mysql:mysql /var/run/mysqld 

4. Start manually MySQL with the following linux commands :

sudo /usr/sbin/mysqld --skip-grant-tables --skip-networking &

5. Confirm that the process is running as expected: 

jobs

6. Access MySQL database without password 

mysql -u root

7. First flush privileges MySQL session

mysql> FLUSH PRIVILEGES;

8. The following commands will reset MySQL root password to "root" 

mysql> USE mysql;
mysql> UPDATE user SET authentication_string=PASSWORD("root") WHERE User='root';
mysql> UPDATE user SET plugin="mysql_native_password" WHERE User='root';

9. Exit MySQL session: 

mysql> exit

10. Terminate current mysqld process 

sudo pkill mysqld

11. Start MYSQL database:

sudo service mysql start

12. If all went well you should now be able to login to your MySQL database with a root password: 

mysql -u root --password=root
mysql> exit