centos7.4 mysql8.0.40修改密码

数据库操作不成功，74啦！！

mysql> ALTER USER ‘root’@‘localhost’ IDENTIFIED WITH mysql_native_password BY ‘rootroot’;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '‘rootroot’' at line 1
mysql> ALTER USER ‘root’@‘localhost’ IDENTIFIED WITH mysql_native_password BY ‘Root1234’;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '‘Root1234’' at line 1
mysql> ALTER USER ‘root’@‘localhost’ IDENTIFIED WITH mysql_native_password BY ‘Root123.’;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '‘Root123.’' at line 1
mysql> ALTER USER ‘root’@‘localhost’ IDENTIFIED WITH mysql_native_password BY ‘Root1234.’;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '‘Root1234.’' at line 1
mysql> ALTER USER ‘root’@‘localhost’ IDENTIFIED WITH mysql_native_password BY ‘rooT123.’;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '‘rooT123.’' at line 1
mysql> ALTER USER ‘root’@‘localhost’ IDENTIFIED WITH mysql_native_password BY ‘Root123;’;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '‘Root123' at line 1
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '’' at line 1
mysql> ALTER USER ‘root’@‘localhost’ IDENTIFIED WITH mysql_native_password BY 'Root123.';
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> ALTER USER 'root'@'hdp2' IDENTIFIED WITH mysql_native_password BY 'Root123.';
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> ALTER USER 'root'@'hdp2' IDENTIFIED WITH mysql_native_password BY 'rootA1234;';
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> ALTER USER 'root'@'hdp2' IDENTIFIED WITH mysql_native_password BY 'rootA1234#';
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> set password for root@hdp2 = password('root');
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'password('root')' at line 1
mysql> set password for root@hdp2 = password('rooT123#');
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'password('rooT123#')' at line 1
mysql> use mysql; 
No connection. Trying to reconnect...
Connection id:    9
Current database: *** NONE ***

ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> show databases;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> use mysql
No connection. Trying to reconnect...
Connection id:    10
Current database: *** NONE ***

ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> update user set authentication_string='' where user='root';
ERROR 1046 (3D000): No database selected
mysql> ALTER USER USER() IDENTIFIED BY 'wingkin45';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> set global validate_password_policy=LOW;
ERROR 1193 (HY000): Unknown system variable 'validate_password_policy'
mysql> alter user 'root'@'hdp2' identified by 'Root@123456';
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> use mysql;
No connection. Trying to reconnect...
Connection id:    11
Current database: *** NONE ***

ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> SET SESSION wait_timeout=600;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> set global validate_password.policy=0;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> set global validate_password.length=1;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> set global validate_password_policy=0;
ERROR 1193 (HY000): Unknown system variable 'validate_password_policy'
mysql> set global validate_password_length=1;
ERROR 1193 (HY000): Unknown system variable 'validate_password_length'

改配置文件，重启MySQL

在my.cnf中添加：

[mysqld]
skip-grant-tables

推荐个大佬的文章，能量感爆棚； 

最新 CentOS7 上使用 yum 安装 MySQL8 超详细教程_yum安装mysql8-优快云博客

小编的目的是用MySQL做hive元数据管理用，So. i need one passwrod of the mysql8040 

0、先给你个空空

use mysql;
update user set authentication_string = "" where user = "root";

1、要注解skip-grant-tables

2、要生成自己定义的密码

[mysqld]
#skip-grant-tables

重启原神： 

 systemctl restart mysqld

mysql> use mysql
No connection. Trying to reconnect...
Connection id:    9
Current database: *** NONE ***

ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
（大致意思是：先用ALTER USER给我修改个密码，我有条件长度大于8，有大小写、有特殊符号还有数字）
mysql> ALTER user 'root'@'localhost' IDENTIFIED BY 'root';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
（密码不符合条件）
mysql> ALTER user 'root'@'localhost' IDENTIFIED BY 'Root123@4';
Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges;
（刷新新）

看到authentication_string有值，且是字符串，就证明成功了。

mysql> select plugin,Host,User,authentication_string from user;
+-----------------------+-----------+------------------+------------------------------------------------------------------------+
| plugin                | Host      | User             | authentication_string                                                  |
+-----------------------+-----------+------------------+------------------------------------------------------------------------+
| caching_sha2_password | localhost | mysql.infoschema | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| caching_sha2_password | localhost | mysql.session    | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| caching_sha2_password | localhost | mysql.sys        | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| caching_sha2_password | localhost | root             | $A$005$qd%_zJ.[s.+F7u:xDy/3uKO0R6AT6If/pPFwt4qa2JDCW608JuNobUhPcl. |
+-----------------------+-----------+------------------+------------------------------------------------------------------------+

 疑问：我不注解skip-grant-tables会发生什么？

会报错呀！烧脑ing！

ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement

注解后重启原神，回到"小编"开始操作ING！