inventory/backend/config/database.php

<?php
class Database {
    private $host;
    private $db_name;
    private $username;
    private $password;
    public $conn;

    public function __construct() {
        $this->host = getenv('DB_HOST') ?: 'localhost';
        $this->db_name = getenv('DB_NAME') ?: 'inventory_db';
        $this->username = getenv('DB_USER') ?: 'root';
        $this->password = getenv('DB_PASS') ?: '';
    }

    public function getConnection() {
        $this->conn = null;

        try {
            $dsn = "mysql:host=" . $this->host . ";dbname=" . $this->db_name . ";charset=utf8mb4";
            $this->conn = new PDO($dsn, $this->username, $this->password);
            $this->conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            $this->conn->exec("set names utf8");
        } catch(PDOException $exception) {
            error_log("Database connection error: " . $exception->getMessage());
            throw new Exception("Database connection failed");
        }

        return $this->conn;
    }
}
?>