1. 在Ubuntu上安装完Mysql；
2.运行 $mysql 或者 $mysql -u root 命令均有如下错误信息提示：
Access denied for user 'root'@'localhost' (using password: NO)出现这个错误的根本原因是安装Mysql后没有设置登录密码。
解决办法：
t@servert1 ~]$ /etc/init.d/mysqld stop
Stopping MySQL: [ OK ]
[root@servert1 ~]$ mysqld_safe --skip-grant-tables &
[root@servert1 ~]$ Starting mysqld daemon with databases from
Stopping MySQL: [ OK ]
[root@servert1 ~]$ mysqld_safe --skip-grant-tables &
[root@servert1 ~]$ Starting mysqld daemon with databases from
$sudo service mysql start
[root@servert1 ~]# mysql -u root
[root@servert1 ~]# mysql -u root
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 34
Server version: 5.1.49-1ubuntu8 (Ubuntu)
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>update user set password=PASSWORD("testpass") where User='root';
ERROR 1046 (3D000): No database selected
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| test |
+--------------------+
3 rows in set (0.13 sec)
mysql> use mysql;
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;
+---------------------------+
| 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> update user set password=PASSWORD("testpass") where User='root';
Query OK, 3 rows affected (0.05 sec)
Rows matched: 3 Changed: 3 Warnings: 0
mysql> flush privileges;
Query OK, 0 rows affected (0.04 sec)
mysql> quit
Bye
[root@servert1 ~]# /etc/init.d/mysql restart
bash: /etc/init.d/mysql: No such file or directory
[root@servert1 ~]# /etc/init.d/mysqld restart
STOPPING server from pid file /var/run/mysqld/mysqld.pid
101120 04:17:15 mysqld ended
Stopping MySQL: [ OK ]
Starting MySQL: [ OK ]
[1]+ Done mysqld_safe --skip-grant-tables
[root@servert1 ~]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.0.77 Source distribution
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> quit
Bye
[root@servert1 ~]#