给了我提醒，是不是mysql8.0以上的版本密码策略和更改语法不对了。
重新操作一遍：
#vim /etc/my.cnf
【mysql】
添加skip-grant-table
#systemctl stop mysqld.service
#systemctl start mysqld.service
#mysql –u root
[敲回车进入]
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> alter user 'root'@'localhost'IDENTIFIED BY 'MyNewPass';
ERROR 1819 (HY000): Your password does notsatisfy the current policy requirements
mysql> alter user 'root'@'localhost'IDENTIFIED BY 'MyNewPass@123';
ERROR 1396 (HY000): Operation ALTER USERfailed for 'root'@'localhost'
mysql> alter user'root'@'%' IDENTIFIED BY 'MyNewPass@123';
【mysql8.0以上密码策略限制必须要大小写加数字特殊符号，我之前用mysqladmin,set,update，参考修改root密码的前人：http://www.cnblogs.com/liufei88866/p/5619215.html】
Query OK, 0 rows affected (0.05 sec)
退出，把Skip-grant-table语句删除，重新启动数据库
[root@localhost ~]# vim /etc/my.cnf【删除省略】
[root@localhost ~]# systemctl stopmysqld.service
[root@localhost ~]# systemctl startmysqld.service
[root@localhost ~]# mysql -uroot –p
mysql> CREATE USER dbadmin@localhost
-> IDENTIFIED BY 'pwd123';
ERROR 1819 (HY000): Your password does notsatisfy the current policy requirements
mysql> CREATE USER dbadmin@localhost
-> IDENTIFIED BY 'Pwd123';
ERROR 1819 (HY000): Your password does notsatisfy the current policy requirements
mysql> CREATE USER dbadmin@localhost
-> IDENTIFIED BY 'Pwd@123';
ERROR 1819 (HY000): Your password does notsatisfy the current policy requirements
mysql> CREATE USER dbadmin@localhost
-> IDENTIFIED BY 'MyNewPass@123';
Query OK, 0 rows affected (0.10 sec)
【可以正常创建用户，密码安全性还是要求着设置复杂度要高一些】
第二使用SQL工具进行远程连接，这里使用SQLyog进行远程连接。
一般来说，直接用ROOT用户的账号密码去连接是不行，即时密码正确。
MYSQL 8.0内新增加mysql_native_password函数，通过更改这个函数密码来进行远程连接。
2.1 第一可以更改ROOT用户的native_password密码
mysql> ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY'MyPass@123';
Query OK, 0 rows affected (0.15 sec)
2.2 第二可以用Root用户登录新增加用户，进行授权再远程连接。
mysql> CREATE USER 'super'@'%'IDENTIFIED BY 'MyPass@123';
Query OK, 0 rows affected (0.10 sec)
Query OK, 0 rows affe mysql> GRANT ALLON *.* TO 'super'@'%' WITH GRANT OPTION;
Query OK, 0 rows affected (0.10 sec)
mysql> Flush privileges;
Query OK, 0 rows affected (0.00 sec)cted(0.01 sec)
mysql> ALTER USER 'super'@'%' IDENTIFIEDWITH mysql_native_password BY 'MyPass@123';
Query OK, 0 rows affected (0.10 sec)
注意：更改了mysql_native_passwd密码，等同更改用户原始密码。MYSQL 8.0 内以mysql-native_passwd为主，从Shell界面登录需要注意了。
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版权声明：本文为CSDN博主「奥斯维克鸡腿学徒」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/yi247630676/article/details/80352655