[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)

網上找了非常多的文章還是沒有解決我的問題；

1.首先能夠確認的是mysql 命令行 sql命令關鍵字是不區分大寫和小寫。在mysql 5.1.51版本號；

2.先將正常啟動的mysqld stop掉。

3.再以繞過root口令檢查的方式?啟動 mysqld；

4.查詢 user 表，發現user表是空的。insert 一個 root 用戶， 關閉mysqld，正常啟動mysqld，用root用戶，新的密碼 newpass 就能夠登錄 mysql shell 了

?

下面是解決經過：

1.先將正常啟動的mysqld stop掉

[root@hzswtb2-mpc ~]# service mysqld stop
Stopping mysqld:?????????????????????????????????????????? [? OK? ]

2.用繞過root口令檢查的方式?啟動 mysql server，而且讓其在後臺執行；

[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回車。進入mysql shell。依照前人留下的方法， update user表中的 root 用戶的密碼。結果發現 0 rows affected。再select 細看 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 一個名稱為root的用戶。?

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.看到有個root用戶了；

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 用戶的密碼。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 剛才的 mysql服務，以正常方式又一次啟動mysql server，mysql -u root -p? 密碼是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

Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
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.

mysql>

?

mysql 安裝完畢後登陸不了mysql的 shell 即mysql>遇到：ERROR 1045 (28000): Access denied for user 'root'@'localhost‘