The server requested authentication method unknown to the client

SQLSTATE[HY000] [2054] The server requested authentication method unknown to the client.

In MySQL 8.0+, the default authentication plugin has changed from
‘mysql_native_password‘ to ‘caching_sha2_password‘, and the
‘root‘@‘localhost‘ administrative account uses the
‘caching_sha2_password‘ authentication plugin by default. If you prefer
that the root account use the previous default authentication plugin
‘mysql_native_password‘.

The PDO_MySQL and ext/mysqli extensions of PHP do not support
caching_sha2_password. In addition, when PHP MySQL extensions used with
PHP versions before 7.1.16 and PHP 7.2 before 7.2.4, they fail to
connect with default_authentication_plugin=caching_sha2_password even if
caching_sha2_password is not used. However the X DevAPI PHP extension
(mysql_xdevapi) supports it.

To restore MySQL pre-8.0 compatibility, you can reconfigure the server
to revert to the previous default authentication plugin
mysql_native_password like:

1. [mysqld]
2. default_authentication_plugin=mysql_native_password

复制代码

Restart
the MySQL database, the problem should be solved, otherwise you may
need to reinitialize the MySQL installation data and reinstall it.

You can connect to the MySQL database using mysql commandline utility,
and then create a new user with the older mysql_native_password plugin
with SQL.

1. mysql -uroot -p

1. CREATE USER ‘WUXIANCHENG‘ IDENTIFIED WITH ‘mysql_native_password‘ BY ‘YOUR_PASSWORD_IN_TRANSPARENT_TEXT‘;
2. GRANT ALL PRIVILEGES ON *.* TO ‘WUXIANCHENG‘@‘%‘;

Now
you can connect to the MySQL database in PHP using the newly created
account. You can also change existing users‘ authentication plugin after
connecting to the MySQL database with the new account.

1. use mysql;
2. UPDATE `user` SET `Host`=‘%‘ WHERE `User`=‘root‘;
3. ALTER USER ‘root‘ IDENTIFIED WITH ‘mysql_native_password‘ BY ‘YOUR_PASSWORD_IN_TRANSPARENT_TEXT‘;

If
the default root user was restricted to localhost, the ALTER USER
statment will fail with message like "ERROR 1396 (HY000): Operation
ALTER USER failed for ‘root‘@‘%‘", so you have to change Host from
localhost to % first.

Dont‘ forget to replace YOUR_PASSWORD_IN_TRANSPARENT_TEXT with your own password!

原文地址：https://www.cnblogs.com/jdcai/p/9202584.html