Error on creating connection to PDO in PHP

Question

Today, I removed and reinstalled the latest version of lampp in order to move to php 5.30, and suddenly a very simple app is failing to connect to the mysql database. I'm using PDO to connect, and receiving the following error:

Warning: PDO::__construct() [pdo.--construct]: [2002] Invalid argument (trying to connect 
via unix://) in /home/raistlin/www/todoapp/home.php on line 9

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY000] [2002]
Invalid argument' in /home/raistlin/www/todoapp/home.php:9 Stack trace: #0
/home/raistlin/www/todoapp/home.php(9): PDO->__construct('mysql:host=loca...', 'USER', 
'PASSWORD') #1 {main} thrown in /home/raistlin/www/todoapp/home.php on line 9

I am not catching the error at the moment, for the sake of debugging it.

The following code is enough to replicate the issue on my system:

<?php
$DBACCESS = array(
    "connstring"=>"mysql:host=localhost;dbname=todoapp",
    "host"=>"localhost",
    "user"=>"user",
    "password"=>"password",
    "todoapp"=>"todoapp"
    );

    echo implode('<br \>',$DBACCESS);

    $dbh = new PDO($DBACCESS['connstring'],$DBACCESS['user'],$DBACCESS['password']);

    $dbh = null;
?>

Looking online, I've found one or two other people with the same issue, but none of them have received a response, much less a working one. Does anyone know what is happening? Is there something I missed in the configuration? What do I need to do to fix it?

Answer 1

Usually means that you need to specify TCP/IP (1), or tell MySQL where your Unix socket is (2):

1. "mysql:host=127.0.0.1" or "mysql:host=localhost;port=3306"
2. "mysql:unix_socket=/var/run/mysqld/mysqld.sock"

Answer 2

You can also use 127.0.0.1, rather than specifying "localhost", in your db connection string to avoid this issue altogether.

Answer 3

You might want to modify php.ini so PDO can find mysql.sock by specifying the pdo_mysql.default_socket = /opt/lampp/var/mysql/mysql.sock (in the case of xampp). Don't forget to restart Apache after changing php.ini.

(Sorry, this seems to be a repeated solution).

Answer 4

I'm using MAMP 2.0.1 and Symfony 1.4 with Doctrine for this project.

Third option worked for me with a small modification: in /config/databases.yml

dsn: 'mysql:unix_socket=/Applications/MAMP/tmp/mysql/mysql.sock;dbname=MY_DB_NAME;'

Answer 5

The most common cause of an error like this would be that MySQL isn’t running.