How to connect to different database servers (e.g., MySQL, PostgreSQL) using PDO in PHP?

To connect to different database servers using PDO in PHP, follow these steps:

Make sure PDO extension is enabled in your PHP installation. You can check this by looking for "PDO" in the output of phpinfo() function.
Install the necessary PDO driver for the database server you want to connect to. For example, if you want to connect to MySQL, make sure you have the "pdo_mysql" driver installed. If you want to connect to PostgreSQL, make sure you have the "pdo_pgsql" driver installed. You can install these drivers using package managers or by enabling them in your PHP installation.
Create a new PDO instance with the appropriate connection details. Here's an example for connecting to a MySQL database:

$dsn = 'mysql:host=localhost;dbname=mydatabase;charset=utf8mb4';
$username = 'your_username';
$password = 'your_password';

try {
    $pdo = new PDO($dsn, $username, $password);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo "Connected to MySQL database successfully";
} catch (PDOException $e) {
    echo "Connection failed: " . $e->getMessage();
    exit;
}

Here's an example for connecting to a PostgreSQL database:

$dsn = 'pgsql:host=localhost;port=5432;dbname=mydatabase;user=your_username;password=your_password';

try {
    $pdo = new PDO($dsn);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo "Connected to PostgreSQL database successfully";
} catch (PDOException $e) {
    echo "Connection failed: " . $e->getMessage();
    exit;
}

Note that the connection details such as host, port, database name, username, and password may vary depending on your specific setup.

You can now execute queries and interact with the database using the $pdo object. For example:

$stmt = $pdo->query('SELECT * FROM users');
while ($row = $stmt->fetch()) {
    echo $row['name'] . ', ' . $row['email'] . '<br>';
}

Remember to handle any exceptions that may occur during database operations using try-catch blocks.

That's it! You can now connect to different database servers using PDO in PHP.