[FIXED] Problems installing mysql in ubuntu 18.04

Issue

I have installed mysql since upgrading the operating system. But there seems to be a problem with the root password. I have tried to fix this in many ways on the web, so far it has not been successful.

systemctl status mysql.service give:

● mysql.service - MySQL Community Server
   Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Wed 2018-05-02 16:57:24 +07; 13s ago
  Process: 6172 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=217/USER)
Thg 5 02 16:57:24 thiennguyen systemd[1]: mysql.service: Service hold-off time  over, scheduling restart.
Thg 5 02 16:57:24 thiennguyen systemd[1]: mysql.service: Scheduled restart job,  restart counter is at 5.
Thg 5 02 16:57:24 thiennguyen systemd[1]: Stopped MySQL Community Server.
Thg 5 02 16:57:24 thiennguyen systemd[1]: mysql.service: Start request repeated too quickly
Thg 5 02 16:57:24 thiennguyen systemd[1]: mysql.service: Failed with result 'exit-code'.
Thg 5 02 16:57:24 thiennguyen systemd[1]: Failed to start MySQL Community Server

journalctl -xe give: http://codepad.org/6EbGVu2Q

mysql_secure_installation give:

Securing the MySQL server deployment.
Enter password for user root: 
Error: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

mysql -u root -p give:

Enter password: 
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

Especially when I install, mysql does not require setting password for root and i have reinstalled many times. Maybe the problem is old, but I have found many ways on the network but can not solve, so look forward to the help.

Solution

You have to change the old password of MySQL at the time of secure installation. If you don't remember the old password try following way via root privilege:-

Stop the MySQL service.

service mysql stop

Start MySQL without password and permission checks.

mysqld_safe --skip-grant-tables &

Connect to MySQL

mysql -u root mysql

Run following commands to set a new password for root user.

UPDATE user SET password=PASSWORD('NEW_PASSWORD') WHERE user='root';
FLUSH PRIVILEGES;
service mysql restart

Some new version not support above UPDATE query try to use below

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

Answered By - Ganesh