mysql 安装后无法登陆mysql的 shell 那mysql>经验：ERROR 1045 (28000): Access denied for user 'root'@'localhost‘

[root@hzswtb2-mpc ~]# mysql

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

遇到：ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

网上找了非常多的文章还是没有解决我的问题。

1.首先能够确认的是mysql 命令行 sql命令keyword是不区分大写和小写；在mysql 5.1.51版本号；

2.先将正常启动的mysqld stop掉；

3.再以绕过root口令检查的方式 启动 mysqld。

4.查询 user 表，发现user表是空的，insert 一个 root 用户， 关闭mysqld，正常启动mysqld，用root用户，新的password newpass 就能够登录 mysql shell 了

下面是解决经过：

1.先将正常启动的mysqld stop掉

[root@hzswtb2-mpc ~]# service mysqld stop

Stopping mysqld:                                           [  OK  ]

2.用绕过root口令检查的方式 启动 mysql server，而且让其在后台执行。

[root@hzswtb2-mpc ~]# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &

[1] 25513

[root@hzswtb2-mpc ~]# 141215 15:00:16 mysqld_safe Logging to '/var/log/mysqld.log'.

141215 15:00:16 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

3. mysql回车，进入mysql shell，依照前人留下的方法， update user表中的 root 用户的password，结果发现 0 rows affected，再select 细看 user 表是空的；

[root@hzswtb2-mpc ~]# mysql

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 1

Server version: 5.1.51 Source distribution

mysql> UPDATE user SET PASSWORD=PASSWORD('123456') where USER='root';       

Query OK, 0 rows affected (0.00 sec)

Rows matched: 0  Changed: 0  Warnings: 0

mysql>  use mysql

Database changed

mysql> show tables;

+---------------------------+

| Tables_in_mysql           |

+---------------------------+

| columns_priv              |

| db                        |

| event                     |

| func                      |

| general_log               |

| help_category             |

| help_keyword              |

| help_relation             |

| help_topic                |

| host                      |

| ndb_binlog_index          |

| plugin                    |

| proc                      |

| procs_priv                |

| servers                   |

| slow_log                  |

| tables_priv               |

| time_zone                 |

| time_zone_leap_second     |

| time_zone_name            |

| time_zone_transition      |

| time_zone_transition_type |

| user                      |

+---------------------------+

23 rows in set (0.00 sec)

mysql> select * from user;

Empty set (0.00 sec)

4.在user表 insert 一个名称为root的用户。

mysql> insert into user(Host,User,Password,Select_priv,Insert_priv) VALUES('localhost','root',PASSWORD('pass3'),'Y','Y');

Query OK, 1 row affected, 3 warnings (0.00 sec)

5.看到有个root用户了；

mysql> select * from user                

    -> ;

+-----------+------+-------------------------------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+

| Host      | User | Password                                  | Select_priv | Insert_priv | Update_priv | Delete_priv | Create_priv | Drop_priv | Reload_priv | Shutdown_priv | Process_priv | File_priv | Grant_priv | References_priv | Index_priv | Alter_priv
| Show_db_priv | Super_priv | Create_tmp_table_priv | Lock_tables_priv | Execute_priv | Repl_slave_priv | Repl_client_priv | Create_view_priv | Show_view_priv | Create_routine_priv | Alter_routine_priv | Create_user_priv | Event_priv | Trigger_priv | ssl_type
| ssl_cipher | x509_issuer | x509_subject | max_questions | max_updates | max_connections | max_user_connections |

+-----------+------+-------------------------------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+

| localhost | root | *35B5E90BC4F5AE5D02ED515DF6B61141F24EDA02 | Y           | Y           | N           | N           | N           | N         | N           | N             | N            | N         | N          | N               | N          | N         
| N            | N          | N                     | N                | N            | N               | N                | N                | N              | N                   | N                  | N                | N          | N            |         
|            |             |              |             0 |           0 |               0 |                    0 |

+-----------+------+-------------------------------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+

1 row in set (0.00 sec)

6 再更新 root 用户的password，也能返回成功了；

mysql> UPDATE user SET Password = PASSWORD('newpass') WHERE user = 'root';

Query OK, 1 row affected (0.00 sec)

Rows matched: 1  Changed: 1  Warnings: 0

mysql> FLUSH PRIVILEGES;

Query OK, 0 rows affected (0.00 sec)

mysql> exit

7.stop 刚才的 mysql服务，以正常方式又一次启动mysql server。mysql -u root -p  password是newpass

[root@hzswtb2-mpc ~]# service mysqld stop

141215 16:12:24 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended

Stopping mysqld:                                           [  OK  ]

[1]+  Done                    mysqld_safe --user=mysql --skip-grant-tables --skip-networking

[root@hzswtb2-mpc ~]# service mysqld start

Starting mysqld:                                           [  OK  ]

[root@hzswtb2-mpc ~]#

[root@hzswtb2-mpc ~]# mysql

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

[root@hzswtb2-mpc ~]# mysql -u root -p

Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 4

Server version: 5.1.51 Source distribution

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This software comes with ABSOLUTELY NO WARRANTY. This is free software,

and you are welcome to modify and redistribute it under the GPL v2 license

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

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