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

Php Problem Overview

I'm trying to connect to a MySQL database from Symfony 3 application. But when trying to create MySQL schema from a Symfony console command I get this error: PDO::__construct(): Server sent charset (255) unknown to the client. Please, report to the developers

Both PHP and MySQL are running in Docker containers.

MySQL version: 8.0.1

PHP version: 7.1.3

Driver: pdo_mysql

charset: UTF8

dsn: "mysql:host=mysql;dbname=database;charset=UTF8;"

Any ideas?

Php Solutions

Solution 1 - Php

MySQL 8 changed the default charset to utf8mb4. But some clients don't know this charset. Hence when the server reports its default charset to the client, and the client doesn't know what the server means, it throws this error.

That bug is against the MySQL Connector/C++ so it's affecting more than just PHP.

Okay—I got it to work by changing the character set to utf8, to be compatible with non-upgraded clients. I added this to /etc/my.cnf and restarted mysqld:

[client]
default-character-set=utf8

[mysql]
default-character-set=utf8


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

I found these settings in an answer from 2010: https://stackoverflow.com/questions/3513773/change-mysql-default-character-set-to-utf-8-in-my-cnf

Solution 2 - Php

The accepted answer saved me (thanks, Bill!!!), but I ran into another related issue, just wanted to provide some details on my experience -

After upgrading to MySQL 8.0.11, I experienced the same problem as the OP when using PHP's mysqli_connect() function. In my MySQL directory (in my case, usr/local/mysql), I created the my.cnf file, added the content in the accepted answer, then restarted the MySQL server. However, this produced a new error:

mysqli_connect(): The server requested authentication method unknown to the client [caching_sha2_password]

I added the line default_authentication_plugin = mysql_native_password, so my.cnf now looked like:

[client]
default-character-set=utf8

[mysql]
default-character-set=utf8

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

and I was good to go!

For additional reference: https://github.com/laradock/laradock/issues/1392

Solution 3 - Php

My case was that I was using RDS (MySQL db verion 8) of AWS and was connecting my application through EC2 (my php code 5.6 was in EC2).

Here in this case since it is RDS there is no my.cnf the parameters are maintained by PARAMETER Group of AWS. Refer: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithParamGroups.html

So what I did was:

Created a new Parameter group and then edited them.
Searched all character-set parameters. These are blank by default. edit them individually and select utf8 from drop down list.

character_set_client, character_set_connection, character_set_database, character_set_server

SAVE

And then most important, Rebooted RDS instance.

This has solved my problem and connection from php5.6 to mysql 8.x was working great.

Please view this image for better understanding.

enter image description here

Solution 4 - Php

Works for me >

the environment:

localhost
Windows 10
PHP 5.6.31
MYSQL 8

set:

default-character-set=utf8

on:

> c:\programdata\mysql\mysql server 8.0\my.ini

Not works on> C:\Program Files\MySQL\MySQL Server 5.5\my.ini

Tools that helps:

C:\Program Files\MySQL\MySQL Server 8.0\bin>mysql -u root -p

mysql> show variables like 'char%';

mysql> show variables like 'collation%';

\m/

Solution 5 - Php

I had this problem also. The issue was because I was running an old version of PHP (5.6) and once I upgraded to PHP 7.4 the errors went away.

This was on Amazon Linux 2 for me and the command to upgrade was:

amazon-linux-extras install php7.4

Other flavors of *nix might have it in their repositories otherwise if you're on a flavor of Linux then Remi might have it for you here: https://rpms.remirepo.net/

Solution 6 - Php

I was facing the same issue so I had reinstalled MySQL 8 with different Authentication Method "Use Legacy Authentication Method (Retain MySQL 5.x compatibility)" and it worked properly.

I recommend, Choose Second Method of Authentication while installing.

Solution 7 - Php

I had a very similar issue to this when testing a restored backup of a mysql and associated php system. No matter what configuration settings I added on mysql it was not making any difference. After troubleshooting the issue for some time I noticed in the mysql logs that the mysql config files were being largely ignored by mysql. The reason was due to the file permissions being too open which was due to the fact my zip backup and restore process was losing all file permissions. I modified my backup and restore scripts to use tar instead and then everything worked as it should.

In summary, check the file permissions on your mysql config files are correct. Hope this helps someone.

Solution 8 - Php

find section [MySQLi] in your php.ini and add line mysqli.default_charset = "UTF-8". Similar changes my require for section [Pdo_mysql] and [mysqlnd].

Issue seems to be specifically with MySQL version 8.0, and above solution found working with PHP Version 7.2, and solution didn't work with PHP 7.0

Solution 9 - Php

In My Aws Windows I Solved it and steps are

Open "C:\ProgramData\MySQL\MySQL Server 8.0"
Open My.ini
Find "[mysql]"
After "no-beep=" Brake Line and insert "default-character-set=utf8"
Find "[mysqld]"
Insert "collation-server = utf8_unicode_ci"
Insert "character-set-server = utf8"

example

...
# socket=MYSQL

port=3306

[mysql]
no-beep=
default-character-set=utf8
# default-character-set=

# SERVER SECTION
# ----------------------------------------------------------------------
# 
# The following options will be read by the MySQL Server. Make sure that
# you have installed the server correctly (see above) so it reads this 
# file.=
# 
# server_type=2
[mysqld]

collation-server = utf8_unicode_ci
character-set-server = utf8
# The next three options are mutually exclusive to SERVER_PORT below.
# skip-networking=
# enable-named-pipe=
# shared-memory=
...

Solution 10 - Php

I solved this problem by adding following code into my /etc/my.cnf file -

[client]
default-character-set=utf8

[mysql]
default-character-set=utf8


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

After saving that,I went into my system settings and stopped MYSQL server and started again, and it worked.

Solution 11 - Php

I had the same issue to connect to local system.

I checked in the services list (Run->Services.msc->Enter) wampmysqld64 was stopped.

Restarted it. and was able to login.

Content Type	Original Author	Original Content on Stackoverflow
Question	Napas	View Question on Stackoverflow
Solution 1 - Php	Bill Karwin	View Answer on Stackoverflow
Solution 2 - Php	skwidbreth	View Answer on Stackoverflow
Solution 3 - Php	Qayed	View Answer on Stackoverflow
Solution 4 - Php	reyqueson	View Answer on Stackoverflow
Solution 5 - Php	jbrahy	View Answer on Stackoverflow
Solution 6 - Php	npsingh	View Answer on Stackoverflow
Solution 7 - Php	CPP	View Answer on Stackoverflow
Solution 8 - Php	user7154703	View Answer on Stackoverflow
Solution 9 - Php	MRRaja	View Answer on Stackoverflow
Solution 10 - Php	hardik chugh	View Answer on Stackoverflow
Solution 11 - Php	Shashikant Pandit	View Answer on Stackoverflow