mysql忘记密码解决方法

[root@cacti mysql]# mysqld_safe --skip-grant-tables& //启动mysql时不启动grant-tables，授权表，当忘记密码时候非常有用
Starting mysqld daemon with databases from /var/lib/mysql

[root@cacti ~]# mysql -uroot //现在直接不需要密码直接进入 mysql数据库
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.0.95 Source distribution

Copyright (c) 2000, 2011, 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> use mysql; //进入mysql数据库
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed

mysql> show tables;//查看当前所有表
+---------------------------+
| Tables_in_mysql           |
+---------------------------+
| columns_priv              | 
| db                        | 
| func                      | 
| help_category             | 
| help_keyword              | 
| help_relation             | 
| help_topic                | 
| host                      | 
| proc                      | 
| procs_priv                | 
| tables_priv               | 
| time_zone                 | 
| time_zone_leap_second     | 
| time_zone_name            | 
| time_zone_transition      | 
| time_zone_transition_type | 
| user                      | 
+---------------------------+
17 rows in set (0.00 sec)

mysql> select *from user; //查看user表中的所有内容
+-----------+------+------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+
| 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 | ssl_type | ssl_cipher | x509_issuer | x509_subject | max_questions | max_updates | max_connections | max_user_connections |
+-----------+------+------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+
| localhost | root | 565491d704013245 | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                |          |            |             |              |             0 |           0 |               0 |                    0 | 
| cacti     | root |                  | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                |          |            |             |              |             0 |           0 |               0 |                    0 | 
| 127.0.0.1 | root |                  | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                |          |            |             |              |             0 |           0 |               0 |                    0 | 
| localhost |      |                  | 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 | 
| cacti     |      |                  | 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 | 
+-----------+------+------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+
5 rows in set (0.00 sec)

mysql> update user set password="565491d704013245" where user="root"; //更新root连接mysql数据库密码为123456.
Query OK, 3 rows affected (0.00 sec)
Rows matched: 3  Changed: 3  Warnings: 0

mysql> flush privileges; //刷新MySQL的系统权限相关表,否则会出现拒绝访问,或者重新启动mysql服务

mysql> select *from user;//再次查看user表中的内容如下
+-----------+------+------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+
| 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 | ssl_type | ssl_cipher | x509_issuer | x509_subject | max_questions | max_updates | max_connections | max_user_connections |
+-----------+------+------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+
| localhost | root | 565491d704013245 | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                |          |            |             |              |             0 |           0 |               0 |                    0 | 
| cacti     | root | 565491d704013245 | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                |          |            |             |              |             0 |           0 |               0 |                    0 | 
| 127.0.0.1 | root | 565491d704013245 | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                |          |            |             |              |             0 |           0 |               0 |                    0 | 
| localhost |      |                  | 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 | 
| cacti     |      |                  | 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 | 
+-----------+------+------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+
5 rows in set (0.00 sec)

mysql> delete from user where host="cacti"; //删除多余的连接用户
Query OK, 2 rows affected (0.00 sec)

mysql> select *from user; //再次查询user表
+-----------+------+------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+
| 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 | ssl_type | ssl_cipher | x509_issuer | x509_subject | max_questions | max_updates | max_connections | max_user_connections |
+-----------+------+------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+
| localhost | root | 565491d704013245 | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                |          |            |             |              |             0 |           0 |               0 |                    0 | 
| 127.0.0.1 | root | 565491d704013245 | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                |          |            |             |              |             0 |           0 |               0 |                    0 | 
| localhost |      |                  | 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 | 
+-----------+------+------------------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+----------+------------+-------------+--------------+---------------+-------------+-----------------+----------------------+
3 rows in set (0.00 sec)