在我的例子中，当有一个错误的引用时，错误就出现了:

GRANT所有database_name。* ' user1 ' @'8.10.12.2';(用户名周围的单引号错误)

vs

GRANT所有database_name。* 'user1'@'8.10.12.2';(正确)

我有同样的问题，答案就在你面前，记得当你在安装mysql的时候运行脚本

sudo mysql_secure_installation

您可以在某个地方选择想要的密码类型

密码验证策略有三种级别:

LOW长度>= 8 中等长度>= 8，数字，混合大小写，特殊字符 STRONG长度>= 8，数字，混合大小写，特殊字符和字典文件

请输入0 = LOW, 1 = MEDIUM, 2 = STRONG:

你必须给相同的策略设置密码

下面是一些密码示例: 对于类型0:abcdabcd 类型1:abcd1234 类型2:ancd@1234

步骤1:检查默认的身份验证插件

SHOW VARIABLES LIKE 'default_authentication_plugin';

步骤2:veryfing您的密码验证要求

SHOW VARIABLES LIKE 'validate_password%';

步骤3:使用正确的密码要求设置用户

CREATE USER '<your_user>'@'localhost' IDENTIFIED WITH '<your_default_auth_plugin>' BY 'password';

对于MySQL 8，你可以使用下面的脚本:

SET GLOBAL validate_password.LENGTH = 4;
SET GLOBAL validate_password.policy = 0;
SET GLOBAL validate_password.mixed_case_count = 0;
SET GLOBAL validate_password.number_count = 0;
SET GLOBAL validate_password.special_char_count = 0;
SET GLOBAL validate_password.check_user_name = 0;
ALTER USER 'user'@'localhost' IDENTIFIED BY 'pass';
FLUSH PRIVILEGES;

this information is important to all answers above : When you restart mysql server all policy config will be RESET and will be LOST, so to make your policy configuration PERSISTENT, you should follow these instructions: (tested on ubuntu server version 20.10)

用mysql应用这些变化后，洪阮回答 Sudo nano /etc/mysql/mysql.conf.d/mysqld.cnf 加上最后一行:

[mysqld]
#
# * Basic Settings
#
..
..
..
validate_password.policy = LOW   # <== this line
..
..
# IMPORTANT notes: 
# - you can add more policy commands each by your needs.
# - notice the "." before "policy" , in some mysql versions is "_" , so be aware of that.

保存文件并重新启动mysql server: sudo service mysql restart 连接并检查配置的持久性: Sudo mysql -u your_username -p 显示像"validate_pass%"这样的变量; 结果应该是这样的:

+--------------------------------------+-------+
| Variable_name                        | Value |
+--------------------------------------+-------+
| validate_password.check_user_name    | ON    |
| validate_password.dictionary_file    |       |
| validate_password.length             | 6     |
| validate_password.mixed_case_count   | 1     |
| validate_password.number_count       | 0     |
| validate_password.policy             | LOW   |
| validate_password.special_char_count | 1     |
+--------------------------------------+-------+

我希望这能帮助到人们。

编辑:感谢@ahmednawazbutt:不要忘记FLUSH特权;

您必须将MySQL密码策略更改为LOW。

以root用户登录

mysql -u root -p

改变政策

SET GLOBAL validate_password_policy=LOW;

or

SET GLOBAL validate_password_policy=0;

exit

exit

重启MySQL服务

sudo service mysql restart

请将MySQL密码策略修改为Low = 0 / Medium = 1 / High = 2。

SET GLOBAL validate_password_policy=0;
SET GLOBAL validate_password_policy=1;    
SET GLOBAL validate_password_policy=2;