Ubuntu 系统上安装Mysql 遇到的问题小结

问题一：ERROR 1698 (28000): Access denied for user ‘root’@'localhost 该问题是没有设置登录密码；

1. sudo mysql -u root ;  #进入安全模式设置密码
2. 进入数据库中添加用户，并给予管理员权限
3. sudo /etc/init.d/mysql restart; 重启数据库

问题二：ERROR 1819 (HY000): Your password does not satisfy the current policy requirements

该问题其实与mysql的validate_password_policy的值有关。
查看一下msyql密码相关的几个全局参数：

mysql> select @@validate_password_policy;
+----------------------------+
| @@validate_password_policy |
+----------------------------+
| MEDIUM                     |
+----------------------------+
1 row in set (0.00 sec)

mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+--------+
| Variable_name                        | Value  |
+--------------------------------------+--------+
| validate_password_dictionary_file    |        |
| validate_password_length             | 8      |
| validate_password_mixed_case_count   | 1      |
| validate_password_number_count       | 1      |
| validate_password_policy             | MEDIUM |
| validate_password_special_char_count | 1      |
+--------------------------------------+--------+
6 rows in set (0.08 sec)
通过修改参数就可以了；
set global validate_password_policy=0;

问题三.修改密码的三种方式

1. set password =password("new password");
2. update mysql.user
set password= "new password"  set password= "new password"
where user= "root";
3 grant all privilige  on *.* to root@localhost identified by "1234";