ubuntu14.10下解决"ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)"

1. 问题描述

ubuntu下mysql数据库的安装请看：http://blog.csdn.net/cryhelyxx/article/details/23551605

修改mysql数据库用户root的密码请看：http://blog.csdn.net/cryhelyxx/article/details/39475433

好了， 了解了上面两篇文章后， 我们假设你已在ubuntu下成功安装上了mysql数据库。

启动ubuntu14.10系统后， ctrl ＋ alt ＋ t打开终端

首先进入mysql的安装目录下启动mysql服务：

xx@ubuntu:~$ cd /usr/local/mysql/xx@ubuntu:/usr/local/mysql$ sudo ./support-files/mysql.server startStarting MySQL.. * xx@ubuntu:/usr/local/mysql$ 

启动mysql服务后， 接着我们进入mysql的shell， 即进入mysql的控制台，

xx@ubuntu:/usr/local/mysql$ mysql -u root mysqlERROR 1045 (28000): Access denied for user 'xx'@'localhost' (using password: NO)xx@ubuntu:/usr/local/mysql$

发现出现拒绝访问“ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)”信息。

回到上面， 我们在刚刚安装完mysql数据库是未对mysql中的root用户进行密码设置的。下面我们通过修改mysql中的root用户密码进行解决问题。

2. 解决方法

我们先把mysql的服务停止下来

xx@ubuntu:/usr/local/mysql$ sudo ./support-files/mysql.server stopShutting down MySQL.. * xx@ubuntu:/usr/local/mysql$ 

mysql服务停止后， 执行以下命令， 这里我们sudo -s切换到root管理员下执行命令,如下

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

root@ubuntu:/usr/local/mysql# cd bin/root@ubuntu:/usr/local/mysql/bin# ./mysqld_safe --user=mysql --skip-grant-tables --skip-networking&[1] 5810root@ubuntu:/usr/local/mysql/bin# 150104 19:01:43 mysqld_safe Logging to '/usr/local/mysql/data/ubuntu.err'.150104 19:01:43 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data150104 19:15:35 mysqld_safe mysqld from pid file /usr/local/mysql/data/ubuntu.pid ended

当出现上面的信息时， 我们再ctrl + alt + t打开另一个终端窗口， 键入mysql -u root mysql进入mysql的shell下， 并可以修改mysql里root用户的密码

如下：

xx@ubuntu:~$ mysql -u root mysqlReading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -AWelcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 1Server version: 5.7.5-m15 MySQL Community Server (GPL)Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> UPDATE user SET Password=PASSWORD('123456') whereUSER='root';ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'whereUSER='root'' at line 1mysql> use mysql;Database changedmysql> UPDATE user SET password=PASSWORD('123456') WHERE user='root';Query OK, 1 row affected (0.22 sec)Rows matched: 1  Changed: 1  Warnings: 0mysql> FLUSH PRIVILEGES;Query OK, 0 rows affected (0.03 sec)mysql> exitByexx@ubuntu:~$ mysql -uroot -p123456mysql: [Warning] Using a password on the command line interface can be insecure.Welcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 2Server version: 5.7.5-m15Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> quitByexx@ubuntu:~$ 

mysql>use mysql;mysql>UPDATE user SET password=PASSWORD('newpassword') WHERE user='root';mysql>FLUSH PRIVILEGES;

即上面三个命令就可完成mysql里root用户的密码修改。

3. 再次以新密码进入mysql的shell

如果mysql未启动， 请先启动mysql服务， 再来执行命令

启动mysql服务如下：

xx@ubuntu:~$ cd /usr/local/mysql/xx@ubuntu:/usr/local/mysql$ sudo ./support-files/mysql.server startStarting MySQL.. * xx@ubuntu:/usr/local/mysql$

$ mysql -uroot -p123456

xx@ubuntu:~$ mysql -uroot -p123456mysql: [Warning] Using a password on the command line interface can be insecure.Welcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 2Server version: 5.7.5-m15 MySQL Community Server (GPL)Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> quitByexx@ubuntu:~$ mysql -uroot -p123456mysql: [Warning] Using a password on the command line interface can be insecure.Welcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 3Server version: 5.7.5-m15 MySQL Community Server (GPL)Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> 

上面提示密码显示不安全信息， 我们也可以键入

$ mysql -uroot -p

然后再接入mysql用户root的新密码进行登录shell即可， 如下：

xx@ubuntu:~$ mysql -uroot -pEnter password: Welcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 4Server version: 5.7.5-m15 MySQL Community Server (GPL)Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> 

OK, Enjoy it!!!