MySQL学习2_CentOS下安装MySQL遇到问题：Access denied for user 'root'@'localhost'

问题描述：

[root@Master hadoop]# mysqladmin -u root password 'root'

mysqladmin: connect to server at 'localhost' failed

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

问题原因：

在前面已经为root账号设定了一个密码，再次设置就失败，可以进行下面的操作后，继续往下进行。

具体指令：

/etc/init.d/mysqld stop

mysqld_safe --user=mysql --skip-grant-tables --skip-networking & 

mysql -u root mysql

UPDATE user SET Password=PASSWORD('root') where USER='root';

FLUSH PRIVILEGES;

quit

/etc/init.d/mysqld restart

mysql -u root -p

描述：

[root@Master hadoop]# /etc/init.d/mysqld stop
Stopping mysqld:                                           [  OK  ]
[root@Master hadoop]# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
[1] 9748
[root@Master hadoop]# 150917 19:39:25 mysqld_safe Logging to '/var/log/mysqld.log'.
150917 19:39:25 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
mysql -u root mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A


Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.1.73 Source distribution


Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.


Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.


Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.


mysql> UPDATE user SET Password=PASSWORD('root') where USER='root';
Query OK, 0 rows affected (0.00 sec)
Rows matched: 3  Changed: 0  Warnings: 0


mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)


mysql> quit
Bye
[root@Master hadoop]# /etc/init.d/mysqld restart
150917 19:41:01 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
Stopping mysqld:                                           [  OK  ]
Starting mysqld:                                           [  OK  ]
[1]+  Done                    mysqld_safe --user=mysql --skip-grant-tables --skip-networking
[root@Master hadoop]# mysql -u root -p
Enter password:       
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.1.73 Source distribution


Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.


Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.


Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.


mysql> exit
Bye