Why Does My PHP Application Get a 'Authentication Method Unknown to Client' Error When Connecting to MySQL 8.0 ?

PHP with MySQL 8.0 Connection Error: Authentication Method Unknown to Client

Problem Description

When establishing a connection between PHP and a MySQL 8.0 database, an error occurs: "The server requested authentication method unknown to the client." This error can indicate issues with the authentication plugin assigned to the database.

Answer

The default authentication plugin in MySQL 8 is 'auth_socket,' which requires the connecting client to use socket-based authentication. However, PHP applications typically prefer password-based authentication. To resolve this issue:

1. Log in as root to MySQL: Connect to your MySQL server as the root user using your preferred method (e.g., MySQL Workbench or command prompt).
2. Change the authentication plugin: Execute the following SQL command:

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password
BY 'password';

Be sure to replace 'password' with the desired root password. If your application logs in using a different user, replace 'root' with the appropriate username in the command.

This command alters the authentication plugin for the 'root' user (or the specified user) to 'mysql_native_password,' which supports password-based authentication.

3. Restart MySQL: Once the command is executed, restart MySQL to apply the changes. The specific method varies depending on your operating system and installation method.
4. Verify connection: Retry connecting to MySQL using your PHP application. The error should no longer occur.

Additional information can be found at Digital Ocean's documentation on [Installing MySQL](https://www.digitalocean.com/community/tutorials/how-to-install-mysql-on-ubuntu-20-04).

The above is the detailed content of Why Does My PHP Application Get a 'Authentication Method Unknown to Client' Error When Connecting to MySQL 8.0 ?. For more information, please follow other related articles on the PHP Chinese website!