Why Does My Symfony 3 App Get a 'PDO::__construct(): Server sent charset (255) unknown to the client' Error When Connecting to MySQL?

PDO::__construct() Error: Server Charset Unknown to Client

When attempting to establish a MySQL database connection from a Symfony 3 application, you may encounter the following error:

PDO::__construct(): Server sent charset (255) unknown to the client. Please, report to the developers

Problem:

This error arises because the MySQL server is transmitting a character set (255), which is unrecognized by the client. The issue stems from a recent change in MySQL 8, where the default character set was modified to utf8mb4. However, certain clients, including the one utilized by PDO, are unaware of this change, resulting in the error.

Solution:

To resolve this issue, you have two options:

1. Upgrade Your Client: The most effective solution is to upgrade your PDO client to the latest version, which supports the updated character set.
2. Modify Server Character Set: If you cannot upgrade the client, you can change the character set of the MySQL server to utf8, which is compatible with older clients. To do this, add the following settings to /etc/my.cnf and restart MySQL:

[client]
default-character-set=utf8

[mysql]
default-character-set=utf8


[mysqld]
collation-server = utf8_unicode_ci
character-set-server = utf8

By enabling the utf8 character set on the server, you can make it compatible with clients that do not support utf8mb4. This will resolve the charset mismatch error and allow you to establish a successful connection to the MySQL database.

The above is the detailed content of Why Does My Symfony 3 App Get a 'PDO::__construct(): Server sent charset (255) unknown to the client' Error When Connecting to MySQL?. For more information, please follow other related articles on the PHP Chinese website!