PDO DSN and Connection Options

DSN Options

The Data Source Name (DSN) string encodes connection details. Additional options control persistent connections, timeouts, and character sets.

Example

<?php
// Full MySQL DSN with all options
$dsn = "mysql:host=db.example.com;port=3306;dbname=myapp;charset=utf8mb4";

$options = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
    PDO::ATTR_PERSISTENT         => false, // Avoid persistent connections in web
    PDO::MYSQL_ATTR_INIT_COMMAND => "SET time_zone = '+00:00'",
    PDO::ATTR_TIMEOUT            => 5,     // Connect timeout seconds
];

$pdo = new PDO($dsn, "username", "password", $options);

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Pro Tip

Set the connection timezone to UTC via MYSQL_ATTR_INIT_COMMAND to avoid timezone-related date bugs.

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