What are some alternative database management systems that can be used with PHP besides MySQL?

While MySQL is a popular choice for database management with PHP, there are several alternative database management systems that can be used. Some of these alternatives include PostgreSQL, SQLite, Microsoft SQL Server, and Oracle. These systems offer different features and capabilities that may better suit the needs of a particular project.

// Example of connecting to a PostgreSQL database in PHP
$host = 'localhost';
$database = 'dbname';
$user = 'username';
$password = 'password';

$pdo = new PDO("pgsql:host=$host;dbname=$database", $user, $password);