UBuntu Database Error: Access denied for user 'root@localhost' (using password:NO)

 
https://stackoverflow.com/questions/2995054/access-denied-for-user-rootlocalhost-using-passwordno

[root ~]# mysql -u root
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password:NO)

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

sudo mysqld_safe --skip-grant-tables --skip-networking &

1. Stop the service/daemon of mysql running

    [root ~]# service mysql stop   
    mysql stop/waiting

2. Start mysql without any privileges using the following option; This option is used to boot up and do not use the privilege system of MySQL.
    [root ~]# mysqld_safe --skip-grant-tables &

3. enter the mysql command prompt
    [root ~]# mysql -u root
    mysql>

4. Fix the permission setting of the root user ;
    mysql> use mysql;
    Database changed
    mysql> select * from  user;
    Empty set (0.00 sec)
    mysql> truncate table user;
    Query OK, 0 rows affected (0.00 sec)
    mysql> flush privileges;
    Query OK, 0 rows affected (0.01 sec)
    mysql> grant all privileges on *.* to root@localhost identified by 'YourNewPassword' with grant option;
    Query OK, 0 rows affected (0.01 sec)

*if you don`t want any password or rather an empty password
    
    mysql> grant all privileges on *.* to root@localhost identified by '' with grant option;
    Query OK, 0 rows affected (0.01 sec)*
    mysql> flush privileges;
    Query OK, 0 rows affected (0.00 sec)

Confirm the results:
    mysql> select host, user from user;
    +-----------+------+
    | host      | user |
    +-----------+------+
    | localhost | root |
    +-----------+------+
    1 row in set (0.00 sec)

5. Exit the shell and restart mysql in normal mode.
    mysql> quit;
    [root ~]# kill -KILL [PID of mysqld_safe]
    [root ~]# kill -KILL [PID of mysqld]
    [root ~]# service mysql start

6. Now you can successfully login as root user with the password you set
    [root ~]# mysql -u root -pYourNewPassword
     mysql>