报错信息：Error No. 1251 client does not support authentication protocol requested by server;consider upgrading Mysql client

主要原因

主要是由于mysql8以前的加密规则与mysql8以后的存在差异

解决方法

1. 确认mysql服务已启动

   [root@influxdb252 ~]# systemctl status mysqld
   

   如果没有启动，先启动。否则，跳过启动进入2。

   启动mysql服务：

   [root@influxdb252 ~]# systemctl start mysqld
   [root@influxdb252 ~]# systemctl enable mysqld
   [root@influxdb252 ~]# systemctl status mysqld
   

   确认mysql服务已启动

   

2. 登录mysql -u root -pPassword（第一次登录没有密码，直接按回车过）！

   [root@influxdb252 ~]# mysql -u root -pPassword
   mysql: [Warning] Using a password on the command line interface can be insecure.
   Welcome to the MySQL monitor.  Commands end with ; or \g.
   Your MySQL connection id is 1423
   Server version: 8.0.19 MySQL Community Server - GPLCopyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or its
   affiliates. Other names may be trademarks of their respective
   owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> 
   

3. 查看用户信息

   mysql> select host,user,plugin,authentication_string from mysql.user;
   

   
   $可以发现root那里的密码与其他的不同$

4. 修改用户密码（说明：修改后密码可以与原密码保持一致）

   mysql> ALTER user root IDENTIFIED WITH mysql_native_password BY 'Password';
   

5. 再次查看用户信息，root密码显示正常了

   mysql> select host,user,plugin,authentication_string from mysql.user;
   +-----------+------------------+-----------------------+------------------------------------------------------------------------+
   | host      | user             | plugin                | authentication_string                                                  |
   +-----------+------------------+-----------------------+------------------------------------------------------------------------+
   | %         | larry            | mysql_native_password | *4FE78770B27294B5EF3206556095531B90465771                              |
   | %         | myadmin          | mysql_native_password | *4A0173621A97B6BA2FE81B6CE76DED94B6FE0B3F                              |
   | %         | root             | mysql_native_password | *83A86A028696B5BC755E0BF5FDB1B2D17AD20C1C                              |
   | localhost | mysql.infoschema | caching_sha2_password | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
   | localhost | mysql.session    | caching_sha2_password | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
   | localhost | mysql.sys        | caching_sha2_password | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
   +-----------+------------------+-----------------------+------------------------------------------------------------------------+
   6 rows in set (0.00 sec)
   

重新使用SQLyog连接mysql数据库，连接成功

如果仍然失败，刷新下数据库

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)mysql>